Data transmission method and device, equipment and storage medium

Abstract

The invention relates to a data transmission method and device, equipment and a storage medium. According to the invention, the point-to-point interface between the CU and the DU in the same base station is changed into the service interface for interaction, and the DUs in different base stations are registered in the same network element, so that the CU of the first base station can directly perform signaling interaction with the DU of the second base station, and the CU of the second base station does not need to participate in unvarnished transmission or forwarding. In addition, signaling interaction between the DU of the first base station and the DU of the second base station can be realized through the CU of the first base station, and the CU of the second base station does not need to participate in transparent transmission or forwarding. Besides, different DUs in the same base station also interact through service interfaces, so that the different DUs in the same base station can directly communicate with one another, and the CU in the base station does not need to participate in forwarding or unvarnished transmission. Therefore, the signaling interaction overhead is reduced, and the data transmission time delay is reduced.

Description

Technical Field

[0001] The present disclosure relates to the field of information technology, and in particular to a data transmission method, device, equipment and storage medium. Background Art

[0002] At present, a base station with a distributed architecture consists of a concentrated unit (CU) and multiple distribution units (DU). The CU in the same base station can communicate with any DU in the base station.

[0003] However, the communication process between CU and DU of different base stations, the communication process between DU and DU of different base stations, and the communication process between DUs in the same base station are relatively complicated, resulting in large signaling interaction overhead and large data transmission delay. Summary of the invention

[0004] In a first aspect, an embodiment of the present disclosure provides a data transmission method, which is applicable to a first base station, wherein the first base station includes a first centralized unit and multiple first distributed units, wherein the first centralized unit interacts with the first distributed unit through a service-oriented interface, and different first distributed units interact with each other through a service-oriented interface, and the method includes:

[0005] The first centralized unit acquires identification information of a second distributed unit included in the second base station from the registration information, and the plurality of first distributed units and the second distributed unit are registered in the same network element;

[0006] The first centralized unit sends request information to the second distributed unit according to the identification information;

[0007] The first centralized unit receives the response information sent by the second distributed unit.

[0008] Optionally, the plurality of first distribution units and the second distribution unit are registered in the first centralized unit; and / or

[0009] The plurality of first distribution units and the second distribution unit are registered in a second centralization unit included in the second base station.

[0010] Optionally, the plurality of first distribution units and the second distribution unit are registered in a logical entity.

[0011] Optionally, the first centralized unit, the multiple first distributed units, the second centralized unit included in the second base station, and the second distributed unit are registered in a logical entity.

[0012] Optionally, the registration information includes a registration identifier, a service name, and a base station identifier;

[0013] The registration identification of the first distribution unit includes identification information of the first distribution unit and identification information of the first base station or identification information of the access network to which the first distribution unit belongs;

[0014] The registration identification of the second distribution unit includes identification information of the second distribution unit and identification information of the second base station or identification information of the access network to which the second distribution unit belongs;

[0015] The registration identification of the first centralized unit includes identification information of the first centralized unit and identification information of the first base station or identification information of the access network to which the first centralized unit belongs;

[0016] The registration identification of the second centralized unit includes identification information of the second centralized unit and identification information of the second base station or identification information of the access network to which the second centralized unit belongs.

[0017] Optionally, the first centralized unit sends request information to the second distributed unit according to the identification information, including:

[0018] The first centralized unit receives the request information sent by the first distributed unit;

[0019] The first centralized unit sends the request information to the second distributed unit according to the identification information.

[0020] Optionally, the first centralized unit sends request information to the second distributed unit according to the identification information, including:

[0021] In a process where the terminal device switches from the second base station to the first base station, the first centralized unit sends a terminal context release request to the second distributed unit according to the identification information;

[0022] The first centralized unit receives the response information sent by the second distributed unit, including:

[0023] After the second centralized unit in the second base station completes the bearer context release process, the first centralized unit receives a terminal context release response sent by the second distributed unit.

[0024] Optionally, the method further includes:

[0025] Any two first distribution units among the multiple first distribution units transmit data through the service-based interface.

[0026] Optionally, the any two first distribution units include a source distribution unit and a target distribution unit;

[0027] The data transmission between any two first distribution units through the service-oriented interface includes:

[0028] In the process of the terminal device switching from the source distribution unit to the target distribution unit, the target distribution unit sends a downlink message transmission request to the source distribution unit through the service interface, and the downlink message transmission request includes radio resource control reconfiguration information;

[0029] The target distribution unit receives the uplink message transmission response sent by the source distribution unit through the service-oriented interface.

[0030] Optionally, the target distribution unit is a target distribution unit selected by the terminal device from a plurality of candidate distribution units.

[0031] In a second aspect, an embodiment of the present disclosure provides a data transmission method, which is applicable to a second base station, wherein the second base station includes a second centralized unit and a plurality of second distributed units, wherein the second centralized unit interacts with the second distributed unit through a service-oriented interface, and different second distributed units interact with each other through a service-oriented interface, and the method includes:

[0032] The second distribution unit receives the request information sent by the first centralized unit included in the first base station, and the first centralized unit is used to obtain the identification information of the second distribution unit from the registration information, and send the request information to the second distribution unit according to the identification information;

[0033] The second distributed unit sends response information to the first centralized unit.

[0034] Optionally, the second distribution unit receives request information sent by the first centralized unit included in the first base station, including:

[0035] In a process where the terminal device switches from the second base station to the first base station, the second distribution unit receives a terminal context release request sent by a first centralized unit included in the first base station;

[0036] The second distribution unit sends response information to the first centralized unit, including:

[0037] After the second centralized unit completes the bearer context release process, the second distributed unit sends a terminal context release response to the first centralized unit.

[0038] In a third aspect, an embodiment of the present disclosure provides a data transmission device, where the data transmission device is configured at a first base station, and the data transmission device includes:

[0039] An acquisition module, configured to acquire identification information of a second distribution unit included in the second base station from registration information, wherein a plurality of first distribution units included in the first base station and the second distribution unit are registered in the same network element;

[0040] A sending module, configured to send request information to the second distribution unit according to the identification information;

[0041] The receiving module is used to receive the response information sent by the second distribution unit.

[0042] In a fourth aspect, an embodiment of the present disclosure provides a data transmission device, which is configured at a second base station, and includes:

[0043] A receiving module, configured to receive request information sent by a first centralized unit included in a first base station, the first centralized unit being configured to obtain identification information of a second distributed unit included in the second base station from registration information, and to send the request information to the second distributed unit according to the identification information;

[0044] The sending module is used to send response information to the first centralized unit.

[0045] In a fifth aspect, an embodiment of the present disclosure provides a first base station, including a memory, a transceiver, and a processor:

[0046] A memory for storing a computer program; a transceiver for transmitting and receiving data under the control of the processor; and a processor for reading the computer program in the memory and performing the following operations:

[0047] Acquire identification information of a second distribution unit included in the second base station from the registration information, where the plurality of first distribution units and the second distribution unit are registered in the same network element;

[0048] Sending request information to the second distribution unit according to the identification information;

[0049] Receive response information sent by the second distribution unit.

[0050] Optionally, the plurality of first distribution units and the second distribution unit are registered in the first centralized unit; and / or

[0051] The plurality of first distribution units and the second distribution unit are registered in a second centralization unit included in the second base station.

[0052] Optionally, the plurality of first distribution units and the second distribution unit are registered in a logical entity.

[0053] Optionally, the first centralized unit, the multiple first distributed units, the second centralized unit included in the second base station, and the second distributed unit are registered in a logical entity.

[0054] Optionally, the registration information includes a registration identifier, a service name, and a base station identifier;

[0055] The registration identification of the first distribution unit includes identification information of the first distribution unit and identification information of the first base station or identification information of the access network to which the first distribution unit belongs;

[0056] The registration identification of the second distribution unit includes identification information of the second distribution unit and identification information of the second base station or identification information of the access network to which the second distribution unit belongs;

[0057] The registration identification of the first centralized unit includes identification information of the first centralized unit and identification information of the first base station or identification information of the access network to which the first centralized unit belongs;

[0058] The registration identification of the second centralized unit includes identification information of the second centralized unit and identification information of the second base station or identification information of the access network to which the second centralized unit belongs.

[0059] Optionally, when the processor sends the request information to the second distribution unit according to the identification information, it is specifically configured to:

[0060] receiving request information sent by the first distribution unit;

[0061] The request information is sent to the second distribution unit according to the identification information.

[0062] Optionally, when the processor sends the request information to the second distribution unit according to the identification information, it is specifically configured to:

[0063] During the process of the terminal device switching from the second base station to the first base station, sending a terminal context release request to the second distribution unit according to the identification information;

[0064] When the processor receives the response information sent by the second distribution unit, it is specifically used to:

[0065] After the second centralized unit in the second base station completes the bearer context release process, it receives a terminal context release response sent by the second distributed unit.

[0066] Optionally, any two first distribution units among the multiple first distribution units are used to transmit data through a service-based interface.

[0067] Optionally, the any two first distribution units include a source distribution unit and a target distribution unit;

[0068] In the process of the terminal device switching from the source distribution unit to the target distribution unit, the target distribution unit is used to send a downlink message transmission request to the source distribution unit through the service interface, and the downlink message transmission request includes radio resource control reconfiguration information;

[0069] The target distribution unit is used to receive the uplink message transmission response sent by the source distribution unit through the service-oriented interface.

[0070] In a sixth aspect, an embodiment of the present disclosure provides a second base station, including a memory, a transceiver, and a processor:

[0071] A memory for storing a computer program; a transceiver for transmitting and receiving data under the control of the processor; and a processor for reading the computer program in the memory and performing the following operations:

[0072] receiving request information sent by a first centralized unit included in the first base station, wherein the first centralized unit is used to obtain identification information of the second distributed unit from registration information, and send the request information to the second distributed unit according to the identification information;

[0073] Send response information to the first centralized unit.

[0074] Optionally, when the processor receives request information sent by the first centralized unit included in the first base station, it is specifically configured to:

[0075] In the process of the terminal device switching from the second base station to the first base station, receiving a terminal context release request sent by a first centralized unit included in the first base station;

[0076] When the processor sends the response information to the first centralized unit, it is specifically used to:

[0077] After the second centralized unit completes the bearer context release process, a terminal context release response is sent to the first centralized unit.

[0078] In a seventh aspect, an embodiment of the present disclosure provides a processor-readable storage medium, which stores a program for causing the processor to execute the method of the first aspect.

[0079] In an eighth aspect, an embodiment of the present disclosure provides a processor-readable storage medium, which stores a program for causing the processor to execute the method as in the second aspect.

[0080] The data transmission method, apparatus, device and storage medium provided by the embodiments of the present disclosure change the point-to-point interface between the CU and the DU in the same base station to a service-oriented interface for interaction, and register the DUs in different base stations in the same network element, so that the CU of the first base station can directly interact with the DU of the second base station for signaling, thereby eliminating the need for the CU of the second base station to participate in transparent transmission or forwarding. In addition, since the CU of the first base station can transparently transmit or forward signaling for the DU of the first base station, the signaling interaction between the DU of the first base station and the DU of the second base station can be achieved through the CU of the first base station, and the CU of the second base station does not need to participate in transparent transmission or forwarding. In addition, since different DUs in the same base station also interact through a service-oriented interface, different DUs in the same base station can communicate directly without the need for the CU in the base station to participate in forwarding or transparent transmission. This simplifies the communication process between the CU and DU of different base stations, the communication process between DUs and DUs of different base stations, and the communication process between DUs in the same base station, reduces the signaling interaction overhead, and thus reduces the data transmission delay. BRIEF DESCRIPTION OF THE DRAWINGS

[0081] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present disclosure and, together with the description, serve to explain the principles of the present disclosure.

[0082] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

[0083] Figure 1 A network structure diagram of the prior art;

[0084] Figure 2 A signaling diagram of a switching process of a terminal device between different base stations in the prior art;

[0085] Figure 3 A signaling diagram of a switching process of a terminal device between different DUs under the same base station in the prior art;

[0086] Figure 4 A signaling diagram of a switching process of a terminal device between different DUs under the same base station in the prior art;

[0087] Figure 5 A schematic diagram of the architecture of a communication system applicable to the data transmission method provided in an embodiment of the present application;

[0088] Figure 6 A flow chart of a data transmission method provided by an embodiment of the present disclosure;

[0089] Figure 7 A schematic diagram of a first base station and a second base station provided in an embodiment of the present disclosure;

[0090] Figure 8 A registration schematic diagram provided for an embodiment of the present disclosure;

[0091] Fig. 9 A registration schematic diagram provided for an embodiment of the present disclosure;

[0092] Fig.10 A registration schematic diagram provided for an embodiment of the present disclosure;

[0093] Fig.11 A signaling diagram of a DU registration process with a CU provided in an embodiment of the present disclosure;

[0094] Fig.12 A signaling diagram for DU to CU update provided in an embodiment of the present disclosure;

[0095] Fig.13 A signaling diagram for DU to deregister with CU provided in an embodiment of the present disclosure;

[0096] Fig.14 A signaling diagram for a CU and a DU to register, update or deregister with the same logical entity provided in an embodiment of the present disclosure;

[0097] Fig.15 A signaling diagram of a switching process between different base stations of a terminal device provided in an embodiment of the present disclosure;

[0098] Fig.16 A signaling diagram of a switching process between different DUs of a terminal device under the same base station provided in an embodiment of the present disclosure;

[0099] Fig.17 A signaling diagram of a switching process between different DUs of a terminal device under the same base station provided in an embodiment of the present disclosure;

[0100] Fig.18 A flow chart of a data transmission method provided by another embodiment of the present disclosure;

[0101] Fig.19 A schematic diagram of a data transmission method provided in this embodiment;

[0102] Fig. 20 A schematic diagram of the structure of a data transmission device provided in an embodiment of the present disclosure;

[0103] Fig.21 A schematic diagram of the structure of a data transmission device provided in an embodiment of the present disclosure;

[0104] Fig. 22A schematic diagram of the structure of a first base station provided in an embodiment of the present disclosure;

[0105] Fig.23 A schematic diagram of the structure of a second base station provided in an embodiment of the present disclosure. DETAILED DESCRIPTION

[0106] In the embodiments of the present invention, the term "and / or" describes the association relationship of associated objects, indicating that three relationships may exist. For example, A and / or B may represent three situations: A exists alone, A and B exist at the same time, and B exists alone. The character " / " generally indicates that the associated objects before and after are in an "or" relationship.

[0107] In the embodiments of the present application, the term "plurality" refers to two or more than two, and other quantifiers are similar.

[0108] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0109] Current communication systems include, but are not limited to, long term evolution (LTE) systems, LTE frequency division duplex (FDD) systems, LTE time division duplex (TDD) systems, long term evolution advanced (LTE-A) systems, universal mobile telecommunication systems (UMTS), worldwide interoperability for microwave access (WiMAX) systems, 5G new radio (NR) systems and their evolved communication systems, etc. These various systems may include terminal equipment and network equipment. The system may also include a core network part, such as an evolved packet system (EPS), a 5G system (5GS), etc.

[0110] Among them, the terminal device can be a device that provides voice and / or data connectivity to the user, a handheld device with wireless connection function, or other processing equipment connected to a wireless modem. In different systems, the name of the terminal device may also be different. For example, in the 5G system, the terminal device can be called User Equipment (UE). The wireless terminal device can be a USB storage device, other personal computer memory devices and dongles, and can also communicate with one or more core networks (CN) via a radio access network (RAN). The wireless terminal device can be a mobile terminal device, such as a mobile phone (or "cellular" phone) and a computer with a mobile terminal device. For example, it can be a portable, pocket-sized, handheld, computer-built-in or vehicle-mounted mobile device, which exchanges language and / or data with the radio access network. For example, Personal Communication Service (PCS) phones, cordless phones, Session Initiated Protocol (SIP) phones, Wireless Local Loop (WLL) stations, Personal Digital Assistants (PDA), personal computers, tablet computers, Machine-type Communication (MTC) terminal devices, etc. Wireless terminal devices may also be referred to as systems, subscriber units, subscriber stations, mobile stations, mobile stations, remote stations, access points, remote terminal devices, access terminal devices, user terminal devices, user agents, user devices, and wireless access points and routers / modems that meet the limitations of this definition, which are not limited in the embodiments of the present application.

[0111] The network device may be a base station, which may include multiple cells providing services to the terminal. Depending on the specific application scenario, the base station may also be referred to as an access point, or may be a device in the access network that communicates with the wireless terminal device through one or more sectors on the air interface, or other names. The network device may be used to interchange received air frames with Internet Protocol (IP) packets, as a router between the wireless terminal device and the rest of the access network, wherein the rest of the access network may include an Internet Protocol (IP) communication network. The network device may also coordinate the attribute management of the air interface. For example, the network device involved in the embodiment of the present application may be an evolutionary network device (evolutional Node B, eNB or e-NodeB) in a long term evolution (LTE) system, a 5G base station (gNB) in a 5G network architecture (next generation system), etc., or a home evolved Node B (HeNB), a relay node, a home base station (femto), a pico base station (pico), a network test device, etc., which is not limited in the embodiment of the present application.

[0112] In some network structures, the network device may include a centralized unit (CU) node and a distributed unit (DU) node, and the centralized unit and the distributed unit may also be arranged geographically separately. Among them, a network device may include a CU and multiple DUs. CU and DU can be understood as the division of network devices from the perspective of logical functions. Among them, CU and DU can be physically separated or deployed together, and the embodiment of the present application does not specifically limit this. The CU and DU can be connected through an interface, such as an F1 interface. CU and DU can be divided according to the protocol layer of the wireless network. For example, the functions of the Radio Resource Control (RRC) layer, the Service Data Adaptation Protocol (SDAP) layer, and the Packet Data Convergence Protocol (PDCP) layer are set in the CU, while the functions of the Radio Link Control (RLC) layer, the Media Access Control (MAC) layer, the physical (PHY) layer, etc. are set in the DU. It can be understood that the division of CU and DU processing functions according to this protocol layer is only an example, and they can also be divided in other ways. The embodiments of the present application do not make specific limitations on this.

[0113] Specifically, multiple network devices may constitute a radio access network (RAN). Figure 1 As shown, multiple gNBs constitute the Next Generation Radio Access Network (NG-RAN), and gNBs are interconnected through the Xn interface. gNBs can support frequency division duplexing (FDD) mode, time division duplexing (TDD) mode, or dual-mode operation. The interface between NG-RAN and the 5G Core Network (5GC) is the NG interface. A gNB can consist of a gNB-CU and one or more gNB-DUs. A gNB-CU and a gNB-DU are connected through the F1 interface. A gNB-DU is only connected to one gNB-CU.

[0114] In summary, the current NG-RAN is composed of gNB, which includes one CU and multiple DUs. One CU can be connected to multiple DUs, and one DU can only be connected to one CU. There is no connection or direct communication interface between DUs. Therefore, different DUs of a gNB need to communicate through the transparent transmission of the CU. In addition, if the CU of a gNB needs to communicate with the DU of another gNB, the communication process requires the CU of another gNB to perform transparent transmission. If the DU of a gNB needs to communicate with the DU of another gNB, the communication process requires the CUs of both gNBs to participate in the transparent transmission at the same time. As a result, the communication process between CUs and DUs of different base stations, the communication process between DUs of different base stations, and the communication process between DUs in the same base station are more complicated, resulting in large signaling interaction overhead and large data transmission delay.

[0115] In addition, the CU includes a CU control plane (CU Control Plane, CU-CP) and a CU user plane (CU User Plane, CU-UP). Among them, a CU includes a CU-CP and one or more CU-UPs. CU-CP and CU-UP can be understood as a division of CU from the perspective of logical functions. CU-CP and CU-UP can be divided according to the protocol layer of the wireless network. For example, the control plane in the RRC layer and the PDCP layer is set in the CU-CP, and the user plane in the PDCP layer is set in the CU-UP. In addition, the function of the SDAP layer may also be set in the CU-UP. The CU-CP and CU-UP can be connected through an interface, for example, it can be an E1 interface. The CU-CP and DU can be connected through the control plane interface (F1-C) of F1, and the CU-UP and DU can be connected through the user plane interface (F1-U) of F1.

[0116] It can be understood that the process of switching of the terminal device between different base stations and the process of switching of the terminal device between different DUs under the same base station will respectively involve the communication process between the CU and DU of different base stations and the communication process between DUs of different base stations. The following introduces the communication process between the CU and DU of different base stations and the communication process between DUs of different base stations in combination with the process of switching of the terminal device between different base stations and the process of switching of the terminal device between different DUs under the same base station.

[0117] Figure 2 The figure shows the signaling diagram of the terminal equipment switching process between different base stations. Figure 2 As shown, the process specifically includes the following steps:

[0118] Step 1. The source gNB-CU-CP sends a handover request to the target gNB-CU-CP.

[0119] In case of conditional handover, the target gNB is considered as a candidate gNB, which is accessed by the UE only when the conditional handover (CHO) is met.

[0120] Step 2. The target gNB-CU-CP sends a bearer context establishment request to the target gNB-CU-UP.

[0121] Step 3. The target gNB-CU-UP sends a Bearer Context Setup Response to the target gNB-CU-CP.

[0122] Step 4. The target gNB-DU and target gNB-CU-CP perform the F1 UE context establishment procedure.

[0123] Step 5. The target gNB-CU-CP sends a Handover Request Confirm message to the source gNB-CU-CP.

[0124] For example, the target gNB-CU-CP responds to the source gNB-CU-CP with a Handover Request Ack message.

[0125] Step 6. The source gNB-DU and source gNB-CU-CP perform the F1 UE Context Modification procedure.

[0126] The F1 UE context modification procedure is used to send a handover command to the UE and instruct it to stop the data transmission of the UE.

[0127] Step 7. The source gNB-CU-CP sends a bearer context modification request to the source gNB-CU-UP.

[0128] Step 8. The source gNB-CU-UP sends a Bearer Context Modification Response to the source gNB-CU-CP.

[0129] Specifically, steps 7 and 8 are used to perform a bearer context modification procedure, which is initiated by the source gNB-CU-CP to enable the source gNB-CU-CP to retrieve the Packet Data Convergence Protocol (PDCP) uplink (UL) or downlink (DL) status and exchange data forwarding information for the bearer.

[0130] Step 9. The source gNB-CU-CP sends a Sequence Number STATUS TRANSFER (SN STATUS TRANSFER) or an EARLY STATUS TRANSFER message to the target gNB-CU-CP.

[0131] Step 10. The target gNB-CU-CP sends a bearer context modification request to the target gNB-CU-UP.

[0132] Step 11. The target gNB-CU-UP sends a Bearer Context Modification Response to the target gNB-CU-CP.

[0133] Specifically, steps 10 and 11 are used to perform the bearer context modification procedure. If the PDCP state does not need to be retained (e.g., fully configured), the target gNB-CU-CP does not transmit the PDCP UL / DL status carried by the SN STATUS TRANSFER message to the target gNB-CU-UP. In the case of Dual Active Protocol Stack (DAPS) handover or conditional handover, the COUNT related information carried by the EARLY STATUS TRANSFER message is provided to the target gNB-CU-UP.

[0134] Step 12. Perform data forwarding from the source gNB-CU-UP to the target gNB-CU-UP.

[0135] Step 12a. The target gNB-CU-CP sends a handover success message to the source gNB-CU-CP.

[0136] In case of DAPS handover or conditional handover, the target gNB-CU-CP sends a handover success message to the source gNB-CU-CP to inform the UE that it has successfully accessed the target cell.

[0137] Step 12b. The source gNB-DU and source gNB-CU-CP perform the F1 UE context modification procedure.

[0138] In case of DAPS handover or conditional handover, the F1 UE context modification procedure is performed to instruct to stop the data transmission of the UE.

[0139] Step 12c. The source gNB-CU-CP sends a bearer context modification request to the source gNB-CU-UP.

[0140] Step 12d. The source gNB-CU-UP sends a Bearer Context Modification Response to the source gNB-CU-CP.

[0141] Specifically, steps 12c and 12d are used to perform a bearer context modification procedure to instruct the source gNB-CU-UP to stop data packet transmission and also retrieve the PDCP UL / DL status in case of DAPS switching or conditional switching.

[0142] Step 12e. The source gNB-CU-CP sends a sequence number state transfer message to the target gNB-CU-CP.

[0143] In case of DAPS handover or conditional handover, the source gNB-CU-CP sends an SNSTATUS TRANSFER message to the target gNB-CU-CP.

[0144] Step 12f. The target gNB-CU-CP sends a bearer context modification request to the target gNB-CU-UP.

[0145] Step 12g. The target gNB-CU-UP sends a bearer context modification response to the target gNB-CU-CP.

[0146] Specifically, step 12f and step 12g are used to perform the bearer context modification process to provide the PDCP UL / DL status to the target gNB-CU-UP only when the PDCP status needs to be retained in the case of DAPS switching or conditional switching.

[0147] Step 13. The target gNB-CU-CP and AMF / User Plane Function (UPF) perform the path switching procedure.

[0148] Step 14.AMF / UPF sends an end marker packet to the source gNB-CU-UP.

[0149] Step 15. AMF / UPF and target gNB-CU-UP establish a new path.

[0150] Specifically, steps 13 to 15 are used to perform a path switching process to update DL transport network layer (TNL) address information of the user plane (NG-U) to the core network.

[0151] Step 16. The target gNB-CU-CP sends a UE context release message to the source gNB-CU-CP.

[0152] Step 17. The source gNB-CU-CP sends a bearer context release command to the source gNB-CU-UP.

[0153] Step 18a. The source gNB-CU-CP sends an F1 UE Context Release Command to the source gNB-DU.

[0154] Step 18b. The source gNB-DU sends F1 UE context release complete to the source gNB-CU-CP.

[0155] Specifically, in step 18a and step 18b, the source gNB-DU and the source gNB-CU-CP perform the F1 UE context release procedure. For example, the source gNB-DU and the source gNB-CU-CP perform the F1 UE context release procedure to release the UE context in the source gNB-DU.

[0156] Step 19. The source gNB-CU-UP sends a bearer context release complete message to the source gNB-CU-CP.

[0157] Step 20. The source gNB-CU-CP sends a UE context release complete message to the target gNB-CU-CP.

[0158] Through Figure 2 From the process shown, it can be seen that the CU in the target gNB cannot communicate directly with the DU in the source gNB, and the CU in the source gNB needs to perform transparent transmission or forwarding.

[0159] Figure 3 The figure shows the signaling diagram of the switching process of the terminal device between different DUs under the same base station, and the target DU is predetermined. Figure 3 As shown, the source gNB-DU, target gNB-DU and gNB-CU belong to the same base station, and the source gNB-DU and target gNB-DU are different DUs in the base station. The process includes the following steps:

[0160] Step 1. The UE sends a measurement report to the source gNB-DU.

[0161] Step 2. The source gNB-DU sends an uplink RRC message transmission (carrying a measurement report) to the gNB-CU.

[0162] For example, the source gNB-DU sends an uplink Radio Resource Control (RRC) message transmission message to the gNB-CU to convey the received measurement report.

[0163] Step 2a. The gNB-CU sends a UE Context Modification Request to the source gNB-DU.

[0164] For example, the gNB-CU sends a UE Context Modification Request to the source gNB-DU to query the latest configuration.

[0165] Step 2b. The source gNB-DU sends a UE Context Modification Response to the gNB-CU.

[0166] For example, the source gNB-DU responds with a UE CONTEXT MODIFICATION RESPONSE message containing complete configuration information.

[0167] Step 3. The gNB-CU sends a UE Context Establishment Request to the target gNB-DU.

[0168] For example, the gNB-CU sends a UE Context Setup Request message to the target gNB-DU to create a UE context and set up one or more data bearers. The UE Context Setup Request message includes Handover Preparation Information. In the case of NG-RAN sharing, the gNB-CU includes the Public Land Mobile Network Identity (PLMNID).

[0169] Step 4. The target gNB-DU sends a UE Context Setup Response to the gNB-CU.

[0170] Step 5. The gNB-CU sends a UE Context Modification Request (carrying RRC Reconfiguration) to the source gNB-DU.

[0171] For example, the gNB-CU sends a UE CONTEXT MODIFICATION REQUEST message to the source gNB-DU, which includes the generated RRC RECONFIGURATION message and instructs to stop the data transmission of the UE. The source gNB-DU also sends a DOWNLINK DATA TRANSFER STATUS frame to inform the gNB-CU that the downlink data was not successfully transmitted to the UE.

[0172] Step 6. The source gNB-DU sends the RRC reconfiguration to the UE.

[0173] Step 7. The source gNB-DU sends a UE Context Setup Response to the gNB-CU.

[0174] Step 8. The UE and the target gNB-DU perform the random access procedure.

[0175] Step 9. The UE sends RRC Reconfiguration Complete to the target gNB-DU.

[0176] Step 10. The target gNB-DU sends an uplink RRC message transmission to the gNB-CU (RRC reconfiguration is completed).

[0177] For example, the target gNB-DU sends an Uplink RRC Message Transfer message to the gNB-CU to convey the received RRC Reconfiguration Complete message. Downlink data packets are sent to the UE. In addition, uplink data packets are sent from the UE and forwarded to the gNB-CU via the target gNB-DU.

[0178] Step 11. The gNB-CU sends a UE Context Release Command to the source gNB-DU.

[0179] Step 12. The source gNB-DU sends UE Context Release Complete to the gNB-CU.

[0180] pass Figure 3It can be seen that different DUs in the same base station cannot communicate directly, and need to be transparently transmitted or forwarded through the CU in the base station.

[0181] Figure 4 The figure shows a signaling diagram of the switching process between different DUs under the same base station by a terminal device. There are multiple candidate DUs. The source DU sends information of multiple candidate DUs to the terminal device, and the terminal device determines the target DU from the multiple candidate DUs. Figure 4 As shown, the source gNB-DU, candidate gNB-DU and gNB-CU belong to the same base station, and the source gNB-DU and candidate gNB-DU are different DUs in the base station. The process includes the following steps:

[0182] Step 1. The UE sends a measurement report to the source gNB-DU.

[0183] Step 2. The source gNB-DU sends an uplink RRC message transmission (carrying a measurement report) to the gNB-CU.

[0184] Step 3. The gNB-CU sends a UE context establishment request to the candidate gNB-DU.

[0185] For example, the gNB-CU sends a UE Context Setup Request message to the candidate gNB-DU to create a UE context and establish one or more data bearers. The UE Context Setup Request message is sent for each candidate cell and includes handover preparation information (conditional handover) or cell group configuration information (conditional primary secondary cell (PSCell) change).

[0186] Step 4. The candidate gNB-DU sends a UE Context Setup Response to the gNB-CU.

[0187] For example, the candidate gNB-DU responds to the gNB-CU with a UE Context Setup Response message including the target cell ID requested from the gNB-CU. A response message is sent for each requested candidate cell.

[0188] Step 5. The gNB-CU sends an uplink RRC message transmission (carrying RRC reconfiguration) to the source gNB-DU.

[0189] For example, the gNB-CU sends an uplink RRC message transfer message to the source gNB-DU, which includes the generated RRC reconfiguration message.

[0190] Step 6. The source gNB-DU sends the RRC reconfiguration to the UE.

[0191] For example, the source gNB-DU sends the generated RRC reconfiguration information to the UE.

[0192] Step 7. The UE sends RRC Reconfiguration Complete to the source gNB-DU.

[0193] Step 8. The source gNB-DU sends an uplink RRC message transmission to the gNB-CU (RRC reconfiguration is complete).

[0194] For example, in steps 7 and 8, the UE responds to the source gNB-DU with an RRC Reconfiguration Complete message, for which the source gNB-DU forwards the message to the gNB-CU via an uplink RRC message transport.

[0195] Step 9. The execution conditions that trigger the initiation of conditional handover or conditional PSCell change are met.

[0196] Step 10. The UE and the candidate gNB-DU perform a random access procedure.

[0197] For example, a random access procedure is performed at the candidate gNB-DU, and if successful, the candidate gNB-DU becomes the target gNB-DU. The target gNB-DU sends a downlink data transfer status frame to notify the gNB-CU. The target gNB DU also sends an access success message to notify the gNB-CU which cell the UE has successfully accessed.

[0198] Step 11. The UE sends RRC Reconfiguration Complete to the candidate gNB-DU.

[0199] Step 12. The candidate gNB-DU sends an uplink RRC message transmission (carrying RRC reconfiguration completion) to the gNB-CU.

[0200] Step 13. The gNB-CU sends a UE Context Modification Request to the source gNB-DU.

[0201] For example, the gNB-CU sends a UE CONTEXT MODIFY REQUEST message to the source gNB-DU and instructs to stop the data transmission of the UE. The source gNB-DU also sends a downlink data delivery status frame to notify the gNB-CU of the downlink data that was not successfully sent to the UE. The downlink data is sent from the gNB-CU to the target gNB-DU, and the downlink data may include the PDCP protocol data unit (PDU) that was not successfully sent in the source gNB-DU.

[0202] Step 14. The source gNB-DU sends a UE Context Modification Response to the gNB-CU.

[0203] Step 15. The gNB-CU sends a UE Context Release Command to the source gNB-DU.

[0204] Step 16. The source gNB-DU sends UE Context Release Complete to the gNB-CU.

[0205] pass Figure 4 It can be seen that different DUs in the same base station cannot communicate directly, and need to be transparently transmitted or forwarded through the CU in the base station.

[0206] In response to the above problems, an embodiment of the present application provides a data transmission method and device to simplify the communication process between CU and DU of different base stations, the communication process between DU and DU of different base stations, and the communication process between DUs in the same base station, reduce signaling interaction overhead, and reduce data transmission delay.

[0207] Among them, the method and the device are based on the same application concept. Since the method and the device solve the problem in a similar principle, the implementation of the device and the method can refer to each other, and the repeated parts will not be repeated.

[0208] Specifically, the data transmission method provided in the embodiments of the present application can be applicable to the various communication systems mentioned above.

[0209] Figure 5 The schematic diagram of the architecture of the communication system applicable to the data transmission method provided in the embodiment of the present application is shown in FIG. 1 , and the communication system may include an access network device 51, a terminal device 50 communicating with the access network device 51, and a core network device 52 communicating with the access network device 51. The number of the terminal device 50, the access network device 51, and the core network device 52 may be one or more. Figure 5 Only one terminal device 50 , two access network devices 51 and one core network device 52 are shown. Figure 5 This is only an illustrative description and does not constitute a limitation on the applicable scenarios of the data transmission method in the embodiment of the present application.

[0210] The terminal device 50, also known as User Equipment (UE), Mobile Station (MS), Mobile Terminal (MT), etc., is a device that provides voice / data connectivity to users, such as a handheld device or vehicle-mounted device with wireless connection function. The terminal device can specifically be: a mobile phone, a tablet computer, a laptop computer, a PDA, a mobile Internet device (MID), a wearable device, a virtual reality (VR) device, an augmented reality (AR) device, a wireless terminal in industrial control (Industrial Control), a wireless terminal in self-driving (Self Driving), a wireless terminal in remote medical surgery (Remote Medical Surgery), a wireless terminal in smart grid (Smart Grid), a wireless terminal in transportation safety (Transportation Safety), a wireless terminal in smart city (Smart City), or a wireless terminal in smart home (Smart Home), a terminal device in a 5G communication network or a communication network after 5G, etc., which is not limited in the embodiments of the present application.

[0211] Among them, the core network device 52 is a device deployed in the core network to provide services for the terminal device 50. In systems using different wireless access technologies, the names of core network devices with similar wireless communication functions may be different. For example, when the data transmission method provided in the embodiment of the present application is applied to a 5G system, the core network device may be, for example, but not limited to, an access and mobility management function (Access and Mobility Management Function, AMF) or a network data analysis function (Network Data Analytics Function, NWDAF). Among them, AMF has the functions of mobility management, registration management, connection management, legal interception, support for transmission of session management (Session Management, SM) information between the terminal device 50 and the session management function (Session Management Function, SMF), access authentication and access authorization. NWDAF can collect data from various network functions (Network Function, NF), application functions (Application Function, AF), operation management and maintenance (Operation Administration and Maintenance, OAM), and perform network function analysis and prediction. For the convenience of description only, in the embodiment of the present application, the above-mentioned devices that can provide services for the terminal device 50 are collectively referred to as core network devices. The interface between the core network equipment and the access network equipment is an NG interface.

[0212] The access network device 51 is a device in a wireless communication network, such as a radio access network (RAN) node that connects the terminal device 50 to the wireless communication network. At present, some examples of RAN nodes are: Next Generation Node B (gNB), Next Generation Evolutional Node B (ng-eNB) connected to the next generation core network, Transmission Reception Point (TRP), evolved Node B (eNB), Radio Network Controller (RNC), Node B (NB), Base Station Controller (BSC), Base Transceiver Station (BTS), home base station (e.g., home evolved Node B, or homeNode B, HNB), Base Band Unit (BBU), or Wireless Fidelity (Wifi) Access Point (AP), etc.

[0213] Understandably, the above Figure 5 The communication system shown is only for the purpose of more clearly illustrating the technical solution of the embodiment of the present application, and does not constitute a limitation on the technical solution provided by the embodiment of the present application. For example, the communication system may also include other devices, such as a network control device ( Figure 5 (not shown). The network control device may be an operation administration and maintenance (OAM) system, which may also be referred to as a network management system. The network control device may manage the access network devices and core network devices.

[0214] The communication system and business scenarios described in the embodiments of the present application are intended to more clearly illustrate the technical solutions of the embodiments of the present application, and do not constitute a limitation on the technical solutions provided in the embodiments of the present application. It is known to those skilled in the art that with the evolution of network architecture and the emergence of new business scenarios, the technical solutions provided in the embodiments of the present application are also applicable to similar technical problems.

[0215] The data transmission method provided in the embodiment of the present application is described in detail below.

[0216] Figure 6Flowchart of a data transmission method provided by an embodiment of the present disclosure. The method may be performed by a first base station, which may be as follows Figure 5 One of the two access network devices shown. Figure 5 The other access network device among the two access network devices shown is denoted as a second base station. The first base station includes one CU and multiple DUs, the CU in the first base station is denoted as a first CU, the DU in the first base station is denoted as a first DU, the first CU and each first DU interact with each other through a service-based interface, and different first DUs interact with each other through a service-based interface. The second base station includes one CU and multiple DUs, the CU in the second base station is denoted as a second CU, the DU in the second base station is denoted as a second DU, the second CU and each second DU interact with each other through a service-based interface, and different second DUs interact with each other through a service-based interface. Figure 7 As shown, the first base station is base station 71, the second base station is base station 72, CU 711 is recorded as the first CU, DU 712 and DU 713 are recorded as the first DU, CU 721 is recorded as the second CU, DU 722 and DU 723 are recorded as the second DU, respectively. Figure 7 In the schematic diagram shown, the CU and DU in the same base station interact through a service-based interface, and different DUs in the same base station also interact through a service-based interface. Figure 6 As shown, the specific steps of this method are as follows:

[0217] S601. The first centralized unit obtains identification information of a second distributed unit included in a second base station from registration information, wherein the plurality of first distributed units and the second distributed unit are registered in the same network element.

[0218] In this embodiment, multiple first distribution units in the first base station and a second distribution unit in the second base station are registered in the same network element. Specifically, multiple first distribution units in the first base station can be registered in the same network element, or multiple first distribution units in the first base station can be registered in the same network element.

[0219] For example Figure 7 As shown, DU 712, DU 713 and DU 722 are registered in the same network element, or DU 712, DU 713 and DU 723 are registered in the same network element, or DU 712, DU 713, DU 722 and DU 723 are registered in the same network element. The network element can record the registration information of each DU. Assuming that CU 711 needs to communicate with DU 722, at this time, CU 711 can obtain the registration information from the network element and obtain the identification information of DU 722, such as ID, from the registration information.

[0220] S602: The first centralized unit sends request information to the second distributed unit according to the identification information.

[0221] For example, CU 711 may send a request message to DU 722 according to the ID of DU 722 . The request message may be generated by CU 711 ; or may be generated by DU 712 or DU 713 in base station 71 and forwarded or transparently transmitted by CU 711 .

[0222] S603: The first centralized unit receives response information sent by the second distributed unit.

[0223] After receiving the request information, DU 722 may generate response information according to the request information and send the response information to CU 711. The response information may be response information from DU 722 to CU 711, or may be response information from DU 722 to DU 712 or DU 713 and forwarded or transparently transmitted by CU 711.

[0224] The disclosed embodiment of the present invention exchanges the point-to-point interface between the CU and DU in the same base station by changing it to a service-based interface, and registers the DUs in different base stations in the same network element, so that the CU of the first base station can directly exchange signals with the DU of the second base station, thereby eliminating the need for the CU of the second base station to participate in transparent transmission or forwarding. In addition, since the CU of the first base station can transparently transmit or forward signaling for the DU of the first base station, the signaling interaction between the DU of the first base station and the DU of the second base station can be achieved through the CU of the first base station, and the CU of the second base station does not need to participate in transparent transmission or forwarding. In addition, since different DUs in the same base station also interact through a service-based interface, different DUs in the same base station can communicate directly without the need for the CU in the base station to participate in forwarding or transparent transmission. This simplifies the communication process between CUs and DUs of different base stations, the communication process between DUs and DUs of different base stations, and the communication process between DUs in the same base station, reduces the signaling interaction overhead, and thus reduces the data transmission delay.

[0225] In addition, since the CU and DU in the same base station interact through a point-to-point interface in the prior art, a CU can only interact with one DU at a time. However, the embodiment of the present application changes the point-to-point interface between the CU and DU in the same base station to a service-based interface for interaction, so that a CU in the same base station can interact with multiple DUs at the same time, so that the CU can use a parallel method for signaling transmission, further reducing and improving the data transmission efficiency.

[0226] In the above embodiment, the first centralized unit sends request information to the second distributed unit according to the identification information, including: the first centralized unit receives the request information sent by the first distributed unit; the first centralized unit sends the request information to the second distributed unit according to the identification information.

[0227] For example Figure 7 As shown, the CU and DU in the same base station interact through a service-based interface. For example, CU 711 and DU 712 interact through a service-based interface, and CU 711 and DU 713 interact through a service-based interface. Therefore, CU 711 can receive the request information sent by DU 712 or DU 713. Further, CU 711 can query the registration information in the manner shown in the above embodiment, and obtain the identification information of DU 722 or DU 723 from the registration information, and send the request information to DU 722 or DU 723 according to the identification information of DU722 or DU 723, thereby realizing the communication between DUs under different base stations. In other words, the communication between DUs under different base stations only requires the CU of one base station to participate in transparent transmission or forwarding, and does not require the CUs of two base stations to participate in transparent transmission or forwarding at the same time, thereby reducing the signaling interaction overhead and reducing the data transmission delay.

[0228] With respect to the registration of multiple first distributed units in the first base station and the second distributed unit in the second base station in the same network element as shown in the above embodiment, there may be the following implementation methods.

[0229] In a first possible implementation manner, the plurality of first distribution units and the second distribution unit are registered in the first centralized unit.

[0230] For example Figure 7 As shown, multiple DUs in base station 71 and multiple DUs in base station 72 can be registered in the CU of base station 71, that is, DU 712, DU 713, DU 722 and DU 723 are registered in CU 711.

[0231] In a second possible implementation manner, the plurality of first distribution units and the second distribution unit are registered in a second centralized unit included in the second base station.

[0232] For example Figure 7 As shown, multiple DUs in base station 71 and multiple DUs in base station 72 can be registered in the CU of base station 72, that is, DU 712, DU 713, DU 722 and DU 723 are registered in CU 721.

[0233] It is understandable that the first and second implementable modes as described above can exist simultaneously or separately. That is to say, when they exist simultaneously, multiple DUs in base station 71 need to be registered not only in CU 711 but also in CU 721. Multiple DUs in base station 72 need to be registered not only in CU 721 but also in CU 711.

[0234] In a third possible implementation manner, the plurality of first distribution units and the second distribution unit are registered in a logical entity.

[0235] For example Figure 7 As shown, DU 712 and DU 713 in base station 71, and DU 722 and DU 723 in base station 72 are registered in the same logical entity. For example, the logical entity is a registration function (RF).

[0236] In a fourth possible implementation manner, the first centralized unit, the plurality of first distributed units, the second centralized unit included in the second base station, and the second distributed unit are registered in a logical entity.

[0237] For example Figure 7 As shown, CU 711, DU 712, DU 713 in base station 71, and CU 721, DU 722, and DU 723 in base station 72 are registered in the same logical entity. For example, the logical entity is a registration function (RF).

[0238] Optionally, the registration information includes a registration identifier, a service name, and a base station identifier; the registration identifier of the first distribution unit includes the identifier information of the first distribution unit, and the identifier information of the first base station or the identifier information of the access network to which the first distribution unit belongs; the registration identifier of the second distribution unit includes the identifier information of the second distribution unit, and the identifier information of the second base station or the identifier information of the access network to which the second distribution unit belongs; the registration identifier of the first centralized unit includes the identifier information of the first centralized unit, and the identifier information of the first base station or the identifier information of the access network to which the first centralized unit belongs; the registration identifier of the second centralized unit includes the identifier information of the second centralized unit, and the identifier information of the second base station or the identifier information of the access network to which the second centralized unit belongs.

[0239] For example, Figure 7Taking the registration of CU 711, DU 712, DU 713, CU 721, DU 722 and DU 723 in the same logical entity as shown, no matter it is a CU or DU in base station 71 or a CU or DU in base station 72, after registration, the logical entity will record the corresponding registration information. Specifically, each CU or each DU corresponds to a piece of registration information, and each piece of registration information may include a registration identifier, a service name, and a base station identifier. Among them, the registration identifier may include the identification information of the CU or DU itself, and the identification information of the base station or access network to which the CU or DU belongs. The service name includes the service name supported by the CU or DU. The base station identifier may be the identification information of the base station or access network to which the CU or DU belongs.

[0240] For example, the registration identifier of DU 712 includes the ID of DU 712 itself, and the ID of the base station 71 to which DU 712 belongs or the ID of the RAN to which DU 712 belongs. The registration identifier of DU 713 is similar to the registration identifier of DU 712, and will not be repeated here. The registration identifier of DU 722 includes the ID of DU 722 itself, and the ID of the base station 72 to which DU 722 belongs or the ID of the RAN to which DU 722 belongs. The registration identifier of DU 723 is similar to the registration identifier of DU 722, and will not be repeated here. The registration identifier of CU 711 includes the ID of CU 711 itself, and the ID of the base station 71 to which CU 711 belongs or the ID of the RAN to which CU 711 belongs. The registration identifier of CU 721 includes the ID of CU 721 itself, and the ID of the base station 72 to which CU 721 belongs or the ID of the RAN to which CU 721 belongs.

[0241] In this embodiment, the CU and DU in the same base station interact in a service-oriented manner, and the CU can interact with multiple DUs in parallel through a service-oriented interface. DUs of multiple RANs can register information with CUs of multiple base stations, or DUs and CUs can register with the same logical entity or service respectively, thereby forming a many-to-many topology structure in which one CU can serve multiple DUs, and one DU can also serve multiple CUs. CUs and DUs transmit signaling through a service-oriented interface. In addition, different DUs in the same base station interact with each other using a service-oriented interface, and CUs of different base stations can also interact with each other using a service-oriented interface. Among them, when a DU registers with a CU, the registration identifier ID of the DU = RAN ID + DU ID, RAN ID indicates the ID of the RAN to which the DU belongs, and DU ID indicates the ID of the DU itself. When a DU registers with a CU, the registration identifier that can mark the DU is available. When a DU initiates deregistration with a CU, the registration identifier that can mark the DU is not available. CU is responsible for the generation or management of each DU's ID, or CU is responsible for its own ID generation, registers with RF, and is managed by RF. The registration ID of CU during registration = RAN ID + CU ID, where RAN ID indicates the ID of the RAN to which the CU belongs, and CU ID indicates the ID of the CU itself. When a DU needs to communicate and interact with other DUs, it can query the registration ID of the DU it wants to interact with from the CU it is registered with. CUs exchange information about the DUs they manage through service-based interfaces.

[0242] like Figure 8 As shown, DU1 and DU2 register with CU1 and CU2 respectively, CUs communicate with each other through the service-based interface Ncu, CUs and DUs communicate with each other through the service-based interface Ncd, and DUs communicate with each other through the service-based interface Ndu.

[0243] like Fig. 9 As shown, CU1, CU2, DU1 and DU2 register with RF (registration function) respectively, CU and CU communicate through the service interface Ncu, CU and DU communicate through the service interface Ncd, DU and DU communicate through the service interface Ndu, and CU and DU communicate with RF through the service interface Nrf.

[0244] The following describes the process of DU registering, updating, and deregistering with CU.

[0245] like Fig.10As shown, in addition to registering with the CU of gNB1, DU1, DU2, and DU3 of gNB1 also need to register with the CU of gNB2; similarly, in addition to registering with the CU of gNB2, DU1, DU2, and DU3 of gNB2 also need to register with the CU of gNB1. When multiple gNBs are involved, the registration method is the same. Specifically, when any DU initiates registration information to any CU, the registration information includes the registration identifier, service name, and base station identifier of the DU. For example, DU1 of gNB1 registers with the CU of gNB1, and the corresponding registration information includes the registration identifier of DU1 (e.g., RAN ID+DU1 ID), service name (e.g., the name of the services provided by the service, the name of the supported DU services), and base station identifier (e.g., RAN ID). Among them, RAN ID is the ID of the RAN to which DU1 belongs.

[0246] Fig.11 The signaling diagram of the DU registration process to the CU is shown, and the process includes the following steps:

[0247] S111. DU sends a registration request to CU.

[0248] In this embodiment, DU represents Fig.10 DU1, DU2, DU3 of gNB1, and any DU of DU1, DU2, DU3 of gNB2. CU represents Fig.10 The CU of gNB1 or the CU of gNB2 is shown.

[0249] For example, when the DU starts working for the first time, the DU sends a registration request to the CU. The registration request may carry the DU's configuration file, which may include the DU type, the DU's identifier such as an instance ID, the name of the supported DU service, the ID of the RAN to which the DU belongs, and so on.

[0250] S112.CU stores configuration files.

[0251] For example, after receiving the registration request, the CU may store the configuration file and mark the DU service as available.

[0252] S113. CU sends a registration response to DU.

[0253] For example, when the CU accepts the registration of the DU, the CU may send a registration response to the DU to inform the DU that it has accepted the registration of the DU.

[0254] Fig.12 The figure shows the signaling diagram of DU updating CU. The process includes the following steps:

[0255] S121. DU sends an update request to CU.

[0256] In this embodiment, DU represents Fig.10 DU1, DU2, DU3 of gNB1, and any DU of DU1, DU2, DU3 of gNB2. CU represents Fig.10 The CU of gNB1 or the CU of gNB2 is shown.

[0257] For example, when the configuration file of the DU is updated, the DU sends an update request to the CU. The update request may carry the instance ID of the DU and the part of the configuration file that needs to be updated. The instance ID format when the DU is registered is RAN ID+DU ID.

[0258] S122.CU updates the configuration file.

[0259] For example, after receiving the update request, the CU updates the configuration file of the DU, including the instance ID of the DU and the part of the configuration file that needs to be updated.

[0260] S123. CU sends an update response to DU.

[0261] For example, after the CU accepts and confirms the update of the DU, the CU may send an update response to the DU to inform the DU that it has accepted the update of the DU.

[0262] Fig.13 The figure shows the signaling diagram of DU registering with CU. The process includes the following steps:

[0263] S131. DU sends a deregistration request to CU.

[0264] In this embodiment, DU represents Fig.10 DU1, DU2, DU3 of gNB1, and any DU of DU1, DU2, DU3 of gNB2. CU represents Fig.10 The CU of gNB1 or the CU of gNB2 is shown.

[0265] For example, when a DU cancels its registration under a CU, the DU sends a deregistration request to the CU.

[0266] S132.CU marks DU as unavailable.

[0267] For example, when the CU receives a deregistration request, it may delete the configuration file of the DU according to the DU management policy.

[0268] S133. CU sends a deregistration response to DU.

[0269] For example, after the CU accepts and confirms the deregistration of the DU, the CU may send a deregistration response to the DU to inform the DU that it has accepted the deregistration of the DU.

[0270] Fig.14 The signaling diagram shown is for CU and DU to register, update or deregister with the same logical entity. The process includes the following steps:

[0271] S141. CU, DU sends a registration, update or deregistration request to RF.

[0272] In this embodiment, DU represents Fig.10 DU1, DU2, DU3 of gNB1, and any DU of DU1, DU2, DU3 of gNB2. CU represents Fig.10 The CU of gNB1 or the CU of gNB2 is shown.

[0273] For example, when the DU starts working for the first time, the DU sends a registration request to the RF, and the registration request may carry a configuration file of the DU, and the configuration file may include the DU type, the DU identifier such as the instance ID, the name of the supported DU service, the ID of the RAN to which the DU belongs, etc. When the CU starts working for the first time, the CU sends a registration request to the RF, and the registration request may carry a configuration file of the CU, and the configuration file may include the CU type, the CU identifier such as the instance ID, the name of the supported CU service, the ID of the RAN to which the CU belongs, etc. It can be understood that the DU sending the registration request to the RF and the CU sending the registration request to the RF are independent processes.

[0274] For example, when the configuration file of DU is updated, DU sends an update request to RF, which may carry the instance ID of DU and the part of the configuration file that needs to be updated, wherein the instance ID format when DU is registered is RAN ID+DU ID. When the configuration file of CU is updated, CU sends an update request to RF, which may carry the instance ID of CU and the part of the configuration file that needs to be updated, wherein the instance ID format when CU is registered is RAN ID+CU ID. It can be understood that the update request sent by DU to RF and the update request sent by CU to RF are independent processes.

[0275] For example, when the DU cancels its registration under the RF, the DU sends a deregistration request to the RF. When the CU cancels its registration under the RF, the CU sends a deregistration request to the RF. It can be understood that the DU sending the deregistration request to the RF and the CU sending the deregistration request to the RF are independent processes.

[0276] S142.RF stores, updates or deletes the configuration file.

[0277] For example, after the RF receives a registration request, the corresponding configuration file may be stored. After the RF receives an update request, the corresponding configuration file may be updated. When the RF receives a deregistration request, the corresponding configuration file may be deleted.

[0278] S143. RF sends a registration, update or deregistration response to CU and DU.

[0279] For example, when the RF accepts registration, a registration response is fed back to the corresponding CU or DU. After the CU accepts and confirms the update, an update response is fed back to the corresponding CU or DU. After the CU accepts and confirms the deregistration, a deregistration response is fed back to the corresponding CU or DU.

[0280] Since the process of terminal equipment switching between different base stations and the process of terminal equipment switching between different DUs under the same base station will involve the communication process between CU and DU of different base stations and the communication process between DU and DU of different base stations respectively, the data transmission method provided in the embodiment of the present application can effectively reduce the signaling interaction overhead of the communication process between CU and DU of different base stations and between DU and DU of different base stations, and reduce the data transmission delay. Therefore, the process of terminal equipment switching between different base stations and the process of terminal equipment switching between different DUs under the same base station are introduced in combination with specific embodiments below, thereby showing the fast and easy communication process between CU and DU of different base stations and the fast and easy communication process between DU and DU of different base stations.

[0281] Fig.15 The figure shows the signaling diagram of the terminal equipment switching process between different base stations. Fig.15 As shown, the process specifically includes the following steps:

[0282] Step 1. The source gNB-CU-CP sends a handover request to the target gNB-CU-CP.

[0283] In case of conditional handover, the target gNB is considered as a candidate gNB, which is accessed by the UE only when the conditional handover (CHO) is met.

[0284] Step 2. The target gNB-CU-CP sends a bearer context establishment request to the target gNB-CU-UP.

[0285] Step 3. The target gNB-CU-UP sends a Bearer Context Setup Response to the target gNB-CU-CP.

[0286] Step 4. The target gNB-DU and target gNB-CU-CP perform the F1 UE context establishment procedure.

[0287] Step 5. The target gNB-CU-CP sends a Handover Request Confirm message to the source gNB-CU-CP.

[0288] For example, the target gNB-CU-CP responds to the source gNB-CU-CP with a Handover Request Ack message.

[0289] Step 6. The source gNB-DU and source gNB-CU-CP perform the F1 UE Context Modification procedure.

[0290] The F1 UE context modification procedure is used to send a handover command to the UE and instruct it to stop the data transmission of the UE.

[0291] Step 7. The source gNB-CU-CP sends a bearer context modification request to the source gNB-CU-UP.

[0292] Step 8. The source gNB-CU-UP sends a Bearer Context Modification Response to the source gNB-CU-CP.

[0293] Specifically, steps 7 and 8 are used to perform a bearer context modification procedure, which is initiated by the source gNB-CU-CP to enable the source gNB-CU-CP to retrieve the Packet Data Convergence Protocol (PDCP) uplink (UL) or downlink (DL) status and exchange data forwarding information for the bearer.

[0294] Step 9. The source gNB-CU-CP sends a SN STATUS TRANSFER or EARLY STATUS TRANSFER message to the target gNB-CU-CP.

[0295] Step 10. The target gNB-CU-CP sends a bearer context modification request to the target gNB-CU-UP.

[0296] Step 11. The target gNB-CU-UP sends a Bearer Context Modification Response to the target gNB-CU-CP.

[0297] Specifically, steps 10 and 11 are used to perform the bearer context modification procedure. If the PDCP state does not need to be retained (e.g., fully configured), the target gNB-CU-CP does not transmit the PDCP UL / DL status carried by the SN STATUS TRANSFER message to the target gNB-CU-UP. In the case of Dual Active Protocol Stack (DAPS) handover or conditional handover, the COUNT related information carried by the EARLY STATUS TRANSFER message is provided to the target gNB-CU-UP.

[0298] Step 12. Perform data forwarding from the source gNB-CU-UP to the target gNB-CU-UP.

[0299] Step 12a. The target gNB-CU-CP sends a handover success message to the source gNB-CU-CP.

[0300] In case of DAPS handover or conditional handover, the target gNB-CU-CP sends a handover success message to the source gNB-CU-CP to inform the UE that it has successfully accessed the target cell.

[0301] Step 12b. The source gNB-DU and source gNB-CU-CP perform the F1 UE context modification procedure.

[0302] In case of DAPS handover or conditional handover, the F1 UE context modification procedure is performed to instruct to stop the data transmission of the UE.

[0303] Step 12c. The source gNB-CU-CP sends a bearer context modification request to the source gNB-CU-UP.

[0304] Step 12d. The source gNB-CU-UP sends a Bearer Context Modification Response to the source gNB-CU-CP.

[0305] Specifically, steps 12c and 12d are used to perform a bearer context modification procedure to instruct the source gNB-CU-UP to stop data packet transmission and also retrieve the PDCP UL / DL status in case of DAPS switching or conditional switching.

[0306] Step 12e. The source gNB-CU-CP sends a sequence number state transfer message to the target gNB-CU-CP.

[0307] In case of DAPS handover or conditional handover, the source gNB-CU-CP sends an SNSTATUS TRANSFER message to the target gNB-CU-CP.

[0308] Step 12f. The target gNB-CU-CP sends a bearer context modification request to the target gNB-CU-UP.

[0309] Step 12g. The target gNB-CU-UP sends a bearer context modification response to the target gNB-CU-CP.

[0310] Specifically, step 12f and step 12g are used to perform the bearer context modification process to provide the PDCP UL / DL status to the target gNB-CU-UP only when the PDCP status needs to be retained in the case of DAPS switching or conditional switching.

[0311] Step 13. The target gNB-CU-CP and AMF / User Plane Function (UPF) perform the path switching procedure.

[0312] Step 14.AMF / UPF sends an end marker packet to the source gNB-CU-UP.

[0313] Step 15. AMF / UPF and target gNB-CU-UP establish a new path.

[0314] Specifically, steps 13 to 15 are used to perform a path switching process to update DL transport network layer (TNL) address information of the user plane (NG-U) to the core network.

[0315] Step 16. The target gNB-CU-CP sends a UE Context Release Request to the source gNB-DU.

[0316] Step 17. The source gNB-CU-UP and source gNB-CU-CP perform the bearer context release procedure.

[0317] Step 18. The source gNB-DU sends a UE Context Release Response to the target gNB-CU-CP.

[0318] Specifically, Fig.15 Step 16 shown is equivalent to Figure 2 Steps 16 and 18a in Figure 2 In , the CU of the target gNB cannot communicate directly with the DU of the source gNB, but needs to be forwarded or transparently transmitted by the CU of the source gNB. Fig.15 In this case, the CU of the target gNB can directly communicate with the DU of the source gNB without the need for forwarding or transparent transmission by the CU of the source gNB.

[0319] in addition, Fig.15 Step 17 shown is equivalent to Figure 2 Follow steps 17 and 19 in the . Fig.15 Step 18 shown is equivalent to Figure 2 Similarly, in step 18b and step 20 of Figure 2 In , the DU of the source gNB cannot communicate directly with the CU of the target gNB, but needs to be forwarded or transparently transmitted by the CU of the source gNB. Fig.15 In this case, the DU of the source gNB can directly communicate with the CU of the target gNB without the need for forwarding or transparent transmission by the CU of the source gNB. This can save signaling interaction overhead and reduce data transmission latency.

[0320] Fig.16It is a signaling diagram of the switching process of the terminal device between different DUs under the same base station, and the target DU is predetermined. Fig.16 As shown, the source gNB-DU, target gNB-DU and gNB-CU belong to the same base station, and the source gNB-DU and target gNB-DU are different DUs in the base station. The process includes the following steps:

[0321] Step 1. The UE sends a measurement report to the source gNB-DU.

[0322] Step 2. The source gNB-DU sends an uplink RRC message transmission (carrying a measurement report) to the gNB-CU.

[0323] For example, the source gNB-DU sends an uplink Radio Resource Control (RRC) message transmission message to the gNB-CU to convey the received measurement report.

[0324] Step 2a. The gNB-CU sends a UE Context Modification Request to the source gNB-DU.

[0325] For example, the gNB-CU sends a UE Context Modification Request to the source gNB-DU to query the latest configuration.

[0326] Step 2b. The source gNB-DU sends a UE Context Modification Response to the gNB-CU.

[0327] For example, the source gNB-DU responds with a UE CONTEXT MODIFICATION RESPONSE message containing complete configuration information.

[0328] Step 3. The gNB-CU sends a UE Context Establishment Request to the target gNB-DU.

[0329] For example, the gNB-CU sends a UE Context Setup Request message to the target gNB-DU to create a UE context and set up one or more data bearers. The UE Context Setup Request message includes Handover Preparation Information. In the case of NG-RAN sharing, the gNB-CU includes the Public Land Mobile Network Identity (PLMNID).

[0330] Step 4. The target gNB-DU sends a UE Context Setup Response to the gNB-CU.

[0331] Step 5. The target gNB-DU sends a downlink message transmission request (carrying RRC reconfiguration) to the source gNB-DU.

[0332] Specifically, the RRC reconfiguration information may be relevant information of the target gNB-DU.

[0333] Step 6. The source gNB-DU sends the RRC reconfiguration to the UE.

[0334] Step 7. The source gNB-DU sends an uplink message transmission response to the target gNB-DU, indicating that the RRC reconfiguration is complete.

[0335] Step 8. The UE and the target gNB-DU perform the random access procedure.

[0336] Step 9. The UE sends RRC Reconfiguration Complete to the target gNB-DU.

[0337] Step 10. The target gNB-DU sends an uplink RRC message transmission to the gNB-CU (RRC reconfiguration is completed).

[0338] For example, the target gNB-DU sends an Uplink RRC Message Transfer message to the gNB-CU to convey the received RRC Reconfiguration Complete message. Downlink data packets are sent to the UE. In addition, uplink data packets are sent from the UE and forwarded to the gNB-CU via the target gNB-DU.

[0339] Step 11. The gNB-CU sends a UE Context Release Command to the source gNB-DU.

[0340] Step 12. The source gNB-DU sends UE Context Release Complete to the gNB-CU.

[0341] In this embodiment, Fig.16 and Figure 3 The difference is that Fig.16 Step 5 and Figure 3 Step 5 in is different, and Fig.16 Step 7 and Figure 3 Specifically, in Fig.16 In steps 5 and 7 of the above, the target gNB-DU and the source gNB-DU can communicate directly through the service-oriented interface without the need for forwarding or transparent transmission by the gNB-CU. Figure 3 In step 5 and step 7, the target gNB-DU and the source gNB-DU cannot communicate directly. Therefore, the method shown in this embodiment can reduce the signaling interaction overhead between different DUs in the same base station and reduce the data transmission delay.

[0342] Fig.17 It is a signaling diagram of the switching process between different DUs under the same base station of a terminal device. There are multiple candidate DUs. The source DU sends the information of multiple candidate DUs to the terminal device, and the terminal device determines the target DU from the multiple candidate DUs. Fig.17 As shown, the source gNB-DU, candidate gNB-DU and gNB-CU belong to the same base station, and the source gNB-DU and candidate gNB-DU are different DUs in the base station. The process includes the following steps:

[0343] Step 1. The UE sends a measurement report to the source gNB-DU.

[0344] Step 2. The source gNB-DU sends an uplink RRC message transmission (carrying a measurement report) to the gNB-CU.

[0345] Step 3. The gNB-CU sends a UE context establishment request to the candidate gNB-DU.

[0346] For example, the gNB-CU sends a UE Context Setup Request message to the candidate gNB-DU to create a UE context and establish one or more data bearers. The UE Context Setup Request message is sent for each candidate cell and includes handover preparation information (conditional handover) or cell group configuration information (conditional primary secondary cell (PSCell) change).

[0347] Step 4. The candidate gNB-DU sends a UE Context Setup Response to the gNB-CU.

[0348] For example, the candidate gNB-DU responds to the gNB-CU with a UE Context Setup Response message including the target cell ID requested from the gNB-CU. A response message is sent for each requested candidate cell.

[0349] Step 5. The candidate gNB-DU sends a downlink message transmission request (carrying RRC reconfiguration) to the source gNB-DU.

[0350] Specifically, the RRC reconfiguration information may be relevant information of the candidate gNB-DU.

[0351] Step 6. The source gNB-DU sends the RRC reconfiguration to the UE.

[0352] For example, the source gNB-DU sends the generated RRC reconfiguration information to the UE.

[0353] Step 7. The UE sends RRC Reconfiguration Complete to the source gNB-DU.

[0354] Step 8. The source gNB-DU sends an uplink message transmission response to the candidate gNB-DU, indicating that the RRC reconfiguration is complete.

[0355] Step 9. The execution conditions that trigger the initiation of conditional handover or conditional PSCell change are met.

[0356] Step 10. The UE and the candidate gNB-DU perform a random access procedure.

[0357] For example, a random access procedure is performed at the candidate gNB-DU, and if successful, the candidate gNB-DU becomes the target gNB-DU. The target gNB-DU sends a downlink data transfer status frame to notify the gNB-CU. The target gNB DU also sends an access success message to notify the gNB-CU which cell the UE has successfully accessed.

[0358] Step 11. The UE sends RRC Reconfiguration Complete to the candidate gNB-DU.

[0359] Step 12. The candidate gNB-DU sends an uplink RRC message transmission (carrying RRC reconfiguration completion) to the gNB-CU.

[0360] Step 13. The gNB-CU sends a UE Context Modification Request to the source gNB-DU.

[0361] For example, the gNB-CU sends a UE CONTEXT MODIFY REQUEST message to the source gNB-DU and instructs to stop the data transmission of the UE. The source gNB-DU also sends a downlink data delivery status frame to notify the gNB-CU of the downlink data that was not successfully sent to the UE. The downlink data is sent from the gNB-CU to the target gNB-DU, and the downlink data may include the PDCP protocol data unit (PDU) that was not successfully sent in the source gNB-DU.

[0362] Step 14. The source gNB-DU sends a UE Context Modification Response to the gNB-CU.

[0363] Step 15. The gNB-CU sends a UE Context Release Command to the source gNB-DU.

[0364] Step 16. The source gNB-DU sends UE Context Release Complete to the gNB-CU.

[0365] In this embodiment, Fig.17 and Figure 4 The difference is that Fig.17 Step 5 and Figure 4 Step 5 in is different, and Fig.17 Step 8 and Figure 4 Specifically, in Fig.17 In steps 5 and 8 of , the candidate gNB-DU and the source gNB-DU can communicate directly through the service-oriented interface without the need for forwarding or transparent transmission by the gNB-CU. Figure 4In step 5 and step 8 of the embodiment, the candidate gNB-DU and the source gNB-DU cannot communicate directly. Therefore, the method shown in this embodiment can reduce the signaling interaction overhead between different DUs in the same base station and reduce the data transmission delay.

[0366] Optionally, the first centralized unit sends request information to the second distributed unit according to the identification information, including: in the process of the terminal device switching from the second base station to the first base station, the first centralized unit sends a terminal context release request to the second distributed unit according to the identification information; the first centralized unit receives response information sent by the second distributed unit, including: after the second centralized unit in the second base station completes the bearer context release process, the first centralized unit receives the terminal context release response sent by the second distributed unit.

[0367] Specifically, in Fig.15 The terminal device shown in the figure is switching process between different base stations, for example, in the process of switching from the source gNB to the target gNB, where the source gNB is recorded as the second base station and the target gNB is recorded as the first base station. The target gNB-CU is recorded as the first centralized unit, the first centralized unit includes the target gNB-CU-CP, the source gNB-DU is recorded as the second distributed unit, the source gNB-CU is recorded as the second centralized unit, and the second centralized unit includes the source gNB-CU-CP and the source gNB-CU-UP. The target gNB-CU-CP can query the registration information of the source gNB-DU and obtain the identification information of the source gNB-DU from the registration information, and further send a terminal context release request to the source gNB-DU according to the identification information, for example, as shown in step 16. After the source gNB-CU-UP and the source gNB-CU-CP complete the bearer context release process (as shown in step 17), the source gNB-DU directly sends a terminal context release response to the target gNB-CU-CP, as shown in step 18.

[0368] Optionally, the method further includes: any two first distribution units among the multiple first distribution units transmit data through a service-based interface.

[0369] For example Fig.16 Steps 5 and 7 shown, and Fig.17 In step 5 and step 8 shown in the figure, different DUs under the same base station can directly transmit data through the service-oriented interface. Fig.16 The source gNB-DU and target gNB-DU shown are any two first distributed units in the same base station, Fig.17 The source gNB-DU and candidate gNB-DU shown are any two first distributed units within the same base station.

[0370] Optionally, the any two first distribution units include a source distribution unit and a target distribution unit; the any two first distribution units perform data transmission through a service-based interface, including: in the process of the terminal device switching from the source distribution unit to the target distribution unit, the target distribution unit sends a downlink message transmission request to the source distribution unit through the service-based interface, and the downlink message transmission request includes wireless resource control reconfiguration information; the target distribution unit receives an uplink message transmission response sent by the source distribution unit through the service-based interface.

[0371] For example Fig.16 As shown, the source gNB-DU is recorded as the source distribution unit, and the target gNB-DU is recorded as the target distribution unit. In the process of the terminal device switching from the source gNB-DU to the target gNB-DU, the target gNB-DU sends a downlink message transmission request to the source gNB-DU through the service-oriented interface, and the downlink message transmission request includes the radio resource control reconfiguration information, as shown in step 5. Further, the source gNB-DU sends an uplink message transmission response to the target gNB-DU through the service-oriented interface, that is, the target gNB-DU receives the uplink message transmission response sent by the source gNB-DU through the service-oriented interface, as shown in step 7.

[0372] Optionally, the target distribution unit is a target distribution unit selected by the terminal device from a plurality of candidate distribution units.

[0373] For example Fig.17 The candidate gNB-DU shown is a target distribution unit selected by the terminal device from multiple candidate distribution units. In the process of the terminal device switching from the source gNB-DU to the candidate gNB-DU, the candidate gNB-DU sends a downlink message transmission request to the source gNB-DU through the service-oriented interface, and the downlink message transmission request includes radio resource control reconfiguration information, as shown in step 5. Further, the source gNB-DU sends an uplink message transmission response to the candidate gNB-DU through the service-oriented interface, that is, the candidate gNB-DU receives the uplink message transmission response sent by the source gNB-DU through the service-oriented interface, as shown in step 8.

[0374] Fig.18 A flow chart of a data transmission method provided by another embodiment of the present disclosure. The method is executed by a second base station, the second base station includes a second centralized unit and multiple second distributed units, the second centralized unit and the second distributed unit interact with each other through a service-based interface, and different second distributed units interact with each other through a service-based interface. Figure 7As shown, the first base station is base station 71, the second base station is base station 72, CU 711 is recorded as the first CU, DU 712 and DU 713 are recorded as the first DU respectively. CU 721 is recorded as the second CU, DU 722 and DU 723 are recorded as the second DU respectively. The CU and DU in the same base station interact through the service interface, and different DUs in the same base station also interact through the service interface. In this embodiment, the specific steps of the method are as follows:

[0375] S1801. The second distributed unit receives request information sent by a first centralized unit included in a first base station. The first centralized unit is used to obtain identification information of the second distributed unit from registration information, and send the request information to the second distributed unit according to the identification information.

[0376] In this embodiment, multiple first distribution units in the first base station and a second distribution unit in the second base station are registered in the same network element. Specifically, multiple first distribution units in the first base station can be registered in the same network element, or multiple first distribution units in the first base station can be registered in the same network element.

[0377] For example Figure 7 As shown, DU 712, DU 713, DU 722 and DU 723 are registered in the same network element. The network element can record the registration information of each DU. Assume that CU 711 needs to communicate with DU 722. At this time, CU 711 can obtain the registration information from the network element and obtain the identification information of DU 722, such as ID, from the registration information. Further, CU 711 can send a request message to DU 722 based on the ID of DU 722. The request message can be generated by CU 711; or it can be generated by DU 712 or DU 713 in base station 71 and forwarded or transparently transmitted by CU 711. Accordingly, DU 722 receives the request message sent by CU711.

[0378] S1802. The second distributed unit sends response information to the first centralized unit.

[0379] After receiving the request information, DU 722 may generate response information according to the request information and send the response information to CU 711. The response information may be response information from DU 722 to CU 711, or may be response information from DU 722 to DU 712 or DU 713 and forwarded or transparently transmitted by CU 711.

[0380] This embodiment changes the point-to-point interface between the CU and DU in the same base station into a service-based interface for interaction, and registers the DUs in different base stations in the same network element, so that the CU of the first base station can directly interact with the DU of the second base station for signaling, thereby eliminating the need for the CU of the second base station to participate in transparent transmission or forwarding. In addition, since the CU of the first base station can transparently transmit or forward signaling for the DU of the first base station, the signaling interaction between the DU of the first base station and the DU of the second base station can be achieved through the CU of the first base station, and the CU of the second base station does not need to participate in transparent transmission or forwarding. In addition, since different DUs in the same base station also interact through a service-based interface, different DUs in the same base station can communicate directly without the need for the CU in the base station to participate in forwarding or transparent transmission. This simplifies the communication process between CUs and DUs of different base stations, the communication process between DUs and DUs of different base stations, and the communication process between DUs in the same base station, reduces the signaling interaction overhead, and thus reduces the data transmission delay.

[0381] Optionally, the second distributed unit receives request information sent by the first centralized unit included in the first base station, including: during the process of the terminal device switching from the second base station to the first base station, the second distributed unit receives a terminal context release request sent by the first centralized unit included in the first base station; the second distributed unit sends response information to the first centralized unit, including: after the second centralized unit completes the bearer context release process, the second distributed unit sends a terminal context release response to the first centralized unit.

[0382] exist Fig.15 The terminal device shown in the figure is switching process between different base stations, for example, in the process of switching from the source gNB to the target gNB, where the source gNB is recorded as the second base station and the target gNB is recorded as the first base station. The target gNB-CU is recorded as the first centralized unit, the first centralized unit includes the target gNB-CU-CP, the source gNB-DU is recorded as the second distributed unit, the source gNB-CU is recorded as the second centralized unit, and the second centralized unit includes the source gNB-CU-CP and the source gNB-CU-UP. The target gNB-CU-CP can query the registration information of the source gNB-DU and obtain the identification information of the source gNB-DU from the registration information. Further, according to the identification information, a terminal context release request is sent to the source gNB-DU, and the source gNB-DU receives the terminal context release request sent by the target gNB-CU-CP, for example, as shown in step 16. After the source gNB-CU-UP and the source gNB-CU-CP complete the bearer context release process (as shown in step 17), the source gNB-DU directly sends a terminal context release response to the target gNB-CU-CP, as shown in step 18.

[0383] Fig.19A schematic diagram of the data transmission method provided in this embodiment. For example, IAB-donor1-CU1 represents the CU of base station 1, and IAB-donor2-CU2 represents the CU of base station 2. IAB-donor1-DU1 represents the DU of base station 1, and IAB-donor2-DU2 represents the DU of base station 2. Assuming that the UE switches from being connected to IAB-donor1-DU1 to being connected to IAB-donor2-DU2, that is, switching from path 1 to path 2, when the data transmission method shown in this embodiment is not adopted, IAB-donor1-CU1 is responsible for sending control instructions and address allocation to IAB-donor2-CU2. At the same time, IAB-donor2-CU2 also needs to send relevant information to IAB-donor2-DU2 to complete the data routing from IAB-donor1-DU1 to IAB-donor2-DU2. After adopting the data transmission method shown in this embodiment, IAB-donor1-CU1 can directly control IAB-donor2-DU2, and directly send signaling and address allocation to IAB-donor2-DU2, so as to quickly establish a data connection. Fig.19 It can be explained that when the CU of base station 1 needs to communicate with the DU of base station 2, the CU of base station 1 and the DU of base station 2 can communicate directly without the need for the CU of base station 2 to participate in the communication process, thereby reducing signaling overhead and reducing data transmission delay.

[0384] Fig. 20 The structure diagram of the data transmission device provided in the embodiment of the present disclosure. The data transmission device provided in the embodiment of the present disclosure can execute the processing flow provided in the data transmission method embodiment. The data transmission device can be set in the first base station, or the data transmission device can be a component or assembly in the first base station, or the data transmission device can be the first base station. Fig. 20 As shown, the data transmission device 200 includes:

[0385] The acquisition module 201 is configured to acquire identification information of a second distribution unit included in a second base station from registration information, wherein a plurality of first distribution units included in the first base station and the second distribution unit are registered in the same network element;

[0386] A sending module 202, configured to send request information to the second distribution unit according to the identification information;

[0387] The receiving module 203 is configured to receive the response information sent by the second distribution unit.

[0388] Optionally, the plurality of first distribution units and the second distribution unit are registered in the first centralized unit; and / or

[0389] The plurality of first distribution units and the second distribution unit are registered in a second centralization unit included in the second base station.

[0390] Optionally, the plurality of first distribution units and the second distribution unit are registered in a logical entity.

[0391] Optionally, the first centralized unit, the multiple first distributed units, the second centralized unit included in the second base station, and the second distributed unit are registered in a logical entity.

[0392] Optionally, the registration information includes a registration identifier, a service name, and a base station identifier;

[0393] The registration identification of the first distribution unit includes identification information of the first distribution unit and identification information of the first base station or identification information of the access network to which the first distribution unit belongs;

[0394] The registration identification of the second distribution unit includes identification information of the second distribution unit and identification information of the second base station or identification information of the access network to which the second distribution unit belongs;

[0395] The registration identification of the first centralized unit includes identification information of the first centralized unit and identification information of the first base station or identification information of the access network to which the first centralized unit belongs;

[0396] The registration identification of the second centralized unit includes identification information of the second centralized unit and identification information of the second base station or identification information of the access network to which the second centralized unit belongs.

[0397] Optionally, the receiving module 203 is further used to: receive request information sent by the first distribution unit; when the sending module 202 sends request information to the second distribution unit according to the identification information, it is specifically used to: send the request information from the first distribution unit to the second distribution unit according to the identification information.

[0398] Optionally, when the sending module 202 sends a request message to the second distribution unit according to the identification information, it is specifically used to: during the process of the terminal device switching from the second base station to the first base station, send a terminal context release request to the second distribution unit according to the identification information; when the receiving module 203 receives the response message sent by the second distribution unit, it is specifically used to: after the second centralized unit in the second base station completes the bearer context release process, receive the terminal context release response sent by the second distribution unit.

[0399] Optionally, any two first distribution units among the multiple first distribution units transmit data through a service-based interface.

[0400] Optionally, the any two first distribution units include a source distribution unit and a target distribution unit; in the process of the terminal device switching from the source distribution unit to the target distribution unit, the target distribution unit is used to send a downlink message transmission request to the source distribution unit through the service interface, and the downlink message transmission request includes wireless resource control reconfiguration information; the target distribution unit is used to receive an uplink message transmission response sent by the source distribution unit through the service interface.

[0401] Optionally, the target distribution unit is a target distribution unit selected by the terminal device from a plurality of candidate distribution units.

[0402] Fig. 20 The data transmission device of the illustrated embodiment can be used to execute the technical solution of the above-mentioned terminal device side method embodiment, and its implementation principle and technical effects are similar, which will not be repeated here.

[0403] Fig.21 The structure diagram of the data transmission device provided in the embodiment of the present disclosure. The data transmission device provided in the embodiment of the present disclosure can execute the processing flow provided in the data transmission method embodiment. The data transmission device can be set in the second base station, or the data transmission device can be a component or assembly in the second base station, or the data transmission device can be the second base station. Fig.21 As shown, the data transmission device 210 includes:

[0404] The receiving module 211 is used to receive the request information sent by the first centralized unit included in the first base station, and the first centralized unit is used to obtain the identification information of the second distributed unit included in the second base station from the registration information, and send the request information to the second distributed unit according to the identification information;

[0405] The sending module 212 is configured to send response information to the first centralized unit.

[0406] Optionally, the receiving module 211 is specifically used to: receive a terminal context release request sent by a first centralized unit included in the first base station during the process of the terminal device switching from the second base station to the first base station; the sending module 212 is specifically used to: send a terminal context release response to the first centralized unit after the second centralized unit completes the bearer context release process.

[0407] Fig.21 The data transmission device of the illustrated embodiment can be used to execute the technical solution of the above-mentioned base station side method embodiment. Its implementation principle and technical effects are similar and will not be repeated here.

[0408] It should be noted that the division of units in the embodiments of the present application is schematic and is only a logical function division. There may be other division methods in actual implementation. In addition, each functional unit in each embodiment of the present application may be integrated into a processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit. The above-mentioned integrated unit may be implemented in the form of hardware or in the form of software functional units.

[0409] If the integrated unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a processor-readable storage medium. Based on this understanding, the technical solution of the present application, or the part that contributes to the prior art, or all or part of the technical solution can be embodied in the form of a software product, which is stored in a storage medium and includes several instructions for a computer device (which can be a personal computer, a server, or a network device, etc.) or a processor to perform all or part of the steps of the various embodiments of the present application.

[0410] It should be noted here that the above-mentioned device provided in the embodiment of the present invention can implement all the method steps implemented in the above-mentioned method embodiment, and can achieve the same technical effect. The parts and beneficial effects that are the same as the method embodiment in this embodiment will not be described in detail here.

[0411] The present disclosure also provides a first base station, such as Fig. 22 As shown, the first base station includes a processor 220, a transceiver 221, and a memory 222. The memory 222 stores a computer program, and the computer program is configured to enable the processor 222 to execute the above method steps on the first base station side.

[0412] The transceiver 221 is used to receive and send data under the control of the processor 220 .

[0413] Among them, Fig. 22In the embodiment, the bus architecture may include any number of interconnected buses and bridges, specifically linking together various circuits of one or more processors represented by a processor and a memory represented by a memory. The bus architecture may also link together various other circuits such as peripherals, voltage regulators, and power management circuits, which are well known in the art and are therefore not further described herein. The bus interface provides an interface. The transceiver 221 may be a plurality of components, namely, a transmitter and a receiver, providing a unit for communicating with various other devices on a transmission medium, which transmission medium may include a wireless channel, a wired channel, an optical cable, and the like. The processor is responsible for managing the bus architecture and general processing, and the memory 222 may store data used by the processor 220 when performing operations.

[0414] The processor 220 may be a central processing unit (CPU), an application specific integrated circuit (ASIC), a field programmable gate array (FPGA) or a complex programmable logic device (CPLD). The processor may also adopt a multi-core architecture.

[0415] It should be noted here that the above-mentioned device provided in the embodiment of the present invention can implement all the method steps implemented in the above-mentioned method embodiment, and can achieve the same technical effect. The parts and beneficial effects that are the same as the method embodiment in this embodiment will not be described in detail here.

[0416] In addition, the embodiment of the present disclosure further provides a second base station, such as Fig.23 As shown, the second base station includes a processor 230, a transceiver 231, and a memory 232. The memory 232 stores a computer program, and the computer program is configured to enable the processor 232 to execute the above method steps on the second base station side.

[0417] The transceiver 231 is used to receive and send data under the control of the processor 230 .

[0418] Among them, Fig.23In the embodiment, the bus architecture may include any number of interconnected buses and bridges, specifically linking together various circuits of one or more processors represented by a processor and a memory represented by a memory. The bus architecture may also link together various other circuits such as peripherals, voltage regulators, and power management circuits, which are well known in the art and are therefore not further described herein. The bus interface provides an interface. The transceiver 231 may be a plurality of components, namely, a transmitter and a receiver, providing a unit for communicating with various other devices on a transmission medium, which transmission medium may include a wireless channel, a wired channel, an optical cable, and the like. The processor is responsible for managing the bus architecture and general processing, and the memory 232 may store data used by the processor 230 when performing operations.

[0419] The processor 230 may be a central processing unit (CPU), an application specific integrated circuit (ASIC), a field programmable gate array (FPGA) or a complex programmable logic device (CPLD). The processor may also adopt a multi-core architecture.

[0420] It should be noted here that the above-mentioned device provided in the embodiment of the present invention can implement all the method steps implemented in the above-mentioned method embodiment, and can achieve the same technical effect. The parts and beneficial effects that are the same as the method embodiment in this embodiment will not be described in detail here.

[0421] In addition, an embodiment of the present disclosure further provides a processor-readable storage medium, which stores a program, and the program is used to enable the processor to execute the data transmission method executed by the first base station in the above embodiment.

[0422] In addition, an embodiment of the present disclosure further provides a processor-readable storage medium, which stores a program, and the program is used to enable the processor to execute the data transmission method executed by the second base station in the above embodiment.

[0423] The processor-readable storage medium can be any available medium or data storage device that can be accessed by the processor, including but not limited to magnetic storage (such as floppy disks, hard disks, magnetic tapes, magneto-optical disks (MO), etc.), optical storage (such as CD, DVD, BD, HVD, etc.), and semiconductor storage (such as ROM, EPROM, EEPROM, non-volatile memory (NANDFLASH), solid-state drive (SSD)), etc.

[0424] Those skilled in the art will appreciate that the embodiments of the present application may be provided as methods, systems, or computer program products. Therefore, the present application may adopt the form of a complete hardware embodiment, a complete software embodiment, or an embodiment in combination with software and hardware. Moreover, the present application may adopt the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage and optical storage, etc.) that contain computer-usable program code.

[0425] The present application is described with reference to the flowcharts and / or block diagrams of the methods, devices (systems), and computer program products according to the embodiments of the present application. It should be understood that each process and / or box in the flowchart and / or block diagram, as well as the combination of the processes and / or boxes in the flowchart and / or block diagram, can be implemented by computer executable instructions. These computer executable instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0426] These processor executable instructions may also be stored in a processor readable memory that can direct a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the processor readable memory produce an article of manufacture including an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0427] Obviously, those skilled in the art can make various changes and modifications to the present application without departing from the spirit and scope of the present application. Thus, if these modifications and variations of the present application fall within the scope of the claims of the present application and their equivalents, the present application is also intended to include these modifications and variations.

Claims

1. A data transmission method, characterized in that: The method is applicable to a first base station, the first base station includes a first centralized unit and a plurality of first distributed units, the first centralized unit and the first distributed units interact with each other through a service-oriented interface, and different first distributed units interact with each other through a service-oriented interface, and the method includes: The first centralized unit acquires identification information of a second distributed unit included in the second base station from the registration information, wherein the plurality of first distributed units and the second distributed unit are registered in the same network element; The first centralized unit sends request information to the second distributed unit according to the identification information; The first centralized unit receives the response information sent by the second distributed unit.

2. The method according to claim 1, characterized in that The plurality of first distribution units and the second distribution unit are registered in the first central unit; and / or The plurality of first distribution units and the second distribution unit are registered in a second centralized unit included in the second base station.

3. The method according to claim 1, characterized in that The plurality of first distribution units and the second distribution unit are registered in a logical entity.

4. The method according to claim 1, characterized in that: The first centralized unit, the plurality of first distributed units, the second centralized unit included in the second base station, and the second distributed unit are registered in a logical entity.

5. The method according to any one of claims 2 to 4, characterized in that: The registration information includes a registration identifier, a service name, and a base station identifier; The registration identifier of the first distribution unit includes identification information of the first distribution unit and identification information of the first base station or identification information of an access network to which the first distribution unit belongs; The registration identifier of the second distribution unit includes identification information of the second distribution unit and identification information of the second base station or identification information of the access network to which the second distribution unit belongs; The registration identifier of the first centralized unit includes identification information of the first centralized unit and identification information of the first base station or identification information of an access network to which the first centralized unit belongs; The registration identification of the second centralized unit includes identification information of the second centralized unit and identification information of the second base station or identification information of an access network to which the second centralized unit belongs.

6. The method according to claim 1, characterized in that The first centralized unit sends request information to the second distributed unit according to the identification information, including: The first centralized unit receives the request information sent by the first distributed unit; The first centralized unit sends the request information to the second distributed unit according to the identification information.

7. The method according to claim 1, characterized in that The first centralized unit sends request information to the second distributed unit according to the identification information, including: In the process of terminal equipment switching from the second base station to the first base station, the first centralized unit sends a terminal context release request to the second distributed unit according to the identification information; The first centralized unit receives the response information sent by the second distributed unit, including: After the second centralized unit in the second base station completes the bearer context release process, the first centralized unit receives a terminal context release response sent by the second distributed unit.

8. The method according to claim 1, characterized in that The method further comprises: Any two of the multiple first distribution units transmit data via a service-based interface.

9. The method according to claim 8, characterized in that The any two first distribution units include a source distribution unit and a target distribution unit; The data transmission between any two first distribution units through the service-oriented interface includes: In the process of the terminal device switching from the source distribution unit to the target distribution unit, the target distribution unit sends a downlink message transmission request to the source distribution unit through a service-oriented interface, wherein the downlink message transmission request includes radio resource control reconfiguration information; The target distribution unit receives the uplink message transmission response sent by the source distribution unit through the service-oriented interface.

10. The method according to claim 9, characterized in that The target distribution unit is a target distribution unit selected by the terminal device from a plurality of candidate distribution units.

11. A data transmission method, characterized in that: The method is applicable to a second base station, the second base station includes a second centralized unit and a plurality of second distributed units, the second centralized unit and the second distributed units interact with each other through a service-based interface, and different second distributed units interact with each other through a service-based interface, and the method includes: The second distribution unit receives the request information sent by the first centralized unit included in the first base station, the first centralized unit is used to obtain the identification information of the second distribution unit from the registration information, and send the request information to the second distribution unit according to the identification information; The second distributed unit sends response information to the first centralized unit.

12. The method according to claim 11, characterized in that The second distribution unit receives the request information sent by the first centralized unit included in the first base station, including: In the process of the terminal device switching from the second base station to the first base station, the second distribution unit receives a terminal context release request sent by the first centralized unit included in the first base station; The second distribution unit sends response information to the first centralized unit, including: After the second centralized unit completes the bearer context release process, the second distributed unit sends a terminal context release response to the first centralized unit.

13. A data transmission device, characterized in that: The data transmission device is configured at the first base station, and the data transmission device includes: An acquisition module, configured to acquire identification information of a second distribution unit included in the second base station from registration information, wherein the plurality of first distribution units included in the first base station and the second distribution unit are registered in the same network element; A sending module, configured to send request information to the second distribution unit according to the identification information; The receiving module is used to receive the response information sent by the second distribution unit.

14. A data transmission device, characterized in that: The data transmission device is configured at the second base station, and the data transmission device includes: a receiving module, configured to receive request information sent by a first centralized unit included in a first base station, wherein the first centralized unit is configured to obtain identification information of a second distributed unit included in the second base station from registration information, and send the request information to the second distributed unit according to the identification information; A sending module is used to send response information to the first centralized unit.

15. A first base station, characterized in that: Including memory, transceiver, processor: A memory for storing a computer program; a transceiver for transmitting and receiving data under the control of the processor; and a processor for reading the computer program in the memory and performing the following operations: Acquire identification information of a second distribution unit included in the second base station from the registration information, where the plurality of first distribution units and the second distribution unit are registered in the same network element; sending request information to the second distribution unit according to the identification information; Receive response information sent by the second distribution unit.

16. The first base station according to claim 15, characterized in that: The plurality of first distribution units and the second distribution unit are registered in a first centralized unit; and / or The plurality of first distribution units and the second distribution unit are registered in a second centralized unit included in the second base station.

17. The first base station according to claim 15, characterized in that: The plurality of first distribution units and the second distribution unit are registered in a logical entity.

18. The first base station according to claim 15, characterized in that: The first centralized unit, the plurality of first distributed units, the second centralized unit included in the second base station, and the second distributed unit are registered in a logical entity.

19. The first base station according to any one of claims 16 to 18, characterized in that: The registration information includes a registration identifier, a service name, and a base station identifier; The registration identifier of the first distribution unit includes identification information of the first distribution unit and identification information of the first base station or identification information of an access network to which the first distribution unit belongs; The registration identifier of the second distribution unit includes identification information of the second distribution unit and identification information of the second base station or identification information of the access network to which the second distribution unit belongs; The registration identification of the first centralized unit includes identification information of the first centralized unit and identification information of the first base station or identification information of the access network to which the first centralized unit belongs; The registration identification of the second centralized unit includes identification information of the second centralized unit and identification information of the second base station or identification information of an access network to which the second centralized unit belongs.

20. The first base station according to claim 15, characterized in that: When the processor sends the request information to the second distribution unit according to the identification information, it is specifically used to: receiving request information sent by the first distribution unit; The request information is sent to the second distribution unit according to the identification information.

21. The first base station according to claim 15, characterized in that: When the processor sends the request information to the second distribution unit according to the identification information, it is specifically used to: During the process of the terminal device switching from the second base station to the first base station, sending a terminal context release request to the second distribution unit according to the identification information; When the processor receives the response information sent by the second distribution unit, it is specifically used to: After the second centralized unit in the second base station completes the bearer context release process, it receives a terminal context release response sent by the second distributed unit.

22. The first base station according to claim 15, characterized in that: Any two of the multiple first distribution units are used for data transmission through the service-based interface.

23. The first base station according to claim 22, characterized in that: The any two first distribution units include a source distribution unit and a target distribution unit; In the process of the terminal device switching from the source distribution unit to the target distribution unit, the target distribution unit is used to send a downlink message transmission request to the source distribution unit through a service interface, wherein the downlink message transmission request includes radio resource control reconfiguration information; The target distribution unit is used to receive the uplink message transmission response sent by the source distribution unit through the service-oriented interface.

24. A second base station, characterized in that: Including memory, transceiver, processor: A memory for storing a computer program; a transceiver for transmitting and receiving data under the control of the processor; and a processor for reading the computer program in the memory and performing the following operations: receiving request information sent by a first centralized unit included in the first base station, wherein the first centralized unit is used to obtain identification information of a second distributed unit from registration information, and send the request information to the second distributed unit according to the identification information; Send response information to the first centralized unit.

25. The second base station according to claim 24, characterized in that: When the processor receives request information sent by the first centralized unit included in the first base station, it is specifically configured to: In the process of the terminal device switching from the second base station to the first base station, receiving a terminal context release request sent by a first centralized unit included in the first base station; When the processor sends the response information to the first centralized unit, it is specifically used to: After the second centralized unit completes the bearer context release process, a terminal context release response is sent to the first centralized unit.

26. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the method according to any one of claims 1 to 12 is implemented.

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