WO2021238383A1 - Communication method and apparatus - Google Patents

Abstract

A communication method and apparatus. The method comprises: a CU-CP of a radio access network device receiving control port information from a core network element; when a terminal device is switched from a source DU of the radio access network device to a target DU of the radio access network device, the CU-CP acquiring, from the target DU, downlink tunnel information of the target DU for establishing a first F1 user plane connection; and the CU-CP sending the downlink tunnel information to a CU-UPF network element by means of a control port indicated by the control port information, such that the CU-UPF network element establishes the first F1 user plane connection according to the downlink tunnel information, and downlink tunnel information of the CU-UPF network element, thereby ameliorating the problems of great service delays and high signaling overheads caused by F1 user plane interface reconstruction.

Description

Communication method and device

Cross-references to related applications

This application claims the priority of a Chinese patent application filed with the Chinese Patent Office, the application number is 202010460755.5, and the application name is "a communication method and device" on May 27, 2020, the entire content of which is incorporated into this application by reference.

Technical field

This application relates to the field of communication technology, and in particular to a communication method and device.

Background technique

In the fifth generation mobile communication technology (the 5 ^th generation, 5G) new radio (NR) system ^{completed by the 3 rd} generation partnership project (3 rd generation partnership project, 3GPP), a network architecture is proposed. Under this network architecture, the functions of the access network are divided into two units: a centralized unit (CU) and a distributed unit (DU). Among them, the function of the CU is further divided into a control plane entity (CU-CP, central unit-control plane) and a user plane entity (CU-UP, central unit-user plane). At present, the entire access network may include one CU-CP and multiple CU-UPs.

At present, the CU is usually deployed in the same physical computer room as the sinking user plane function (UPF) network element. In order to reduce the number of data plane transmission hops, save costs, and set the data plane security nodes in the core network Considering moderately, it is very likely that the UPF network element and the CU-UP will be combined as one network element in the end, that is, the CU-UP and the sinking UPF network element will be combined and recorded as the CU-UPF network element. The CU-UPF network The element is uniformly scheduled and managed by the session management function (SMF) network element. In this joint architecture, when the access network device connected to the terminal device is switched, it will cause the F1 user plane interface to be rebuilt. Because the F1 user plane interface needs to be regenerated, the user plane context of the F1 interface needs to be regenerated, and F1 The generation process of the user plane context of the interface requires the participation of the core network element, which causes the signaling process to be too long and cannot meet the delay requirements of terminal handover.

Summary of the invention

The present application provides a communication method and device to improve the problem of large service delay and large signaling overhead caused by F1 user plane interface reconstruction.

In the first aspect, the embodiments of the present application provide a communication method. The applicable scenario of the method is that the terminal device switches from the source DU of the RAN to the target DU of the RAN within the service range of the CU of the same RAN. The network architecture to which the method is applicable The CU and DU of the middle RAN are separated, and the UPF network element and CU-UP are combined as one network element. The method can be executed by the CU-CP or the internal chip of the CU-CP. The method includes: the CU-CP receives control port information from the core network element, and the control port indicated by the control port information corresponds to the PDU session, and is The control port of the CU-UPF network element. When the terminal device switches from the source DU of the radio access network device to the target DU of the radio access network device, the CU-CP obtains the downlink tunnel information of the target DU used to establish the first F1 user plane connection from the target DU, The CU-CP sends downlink tunnel information to the CU-UPF network element through the control port indicated by the control port information, so that the CU-UPF network element establishes the first F1 user according to the downlink tunnel information and the downlink tunnel information of the CU-UPF network element The plane connection is to establish a downlink user plane connection between the target DU and the CU-UPF network element.

In the embodiment of this application, when the DU of the RAN accessed by the terminal device is switched, the CU-CP can communicate with the CU-UPF network element based on the control port obtained in advance from the core network element, and the CU-UPF network element can be based on The control port obtains the downlink tunnel information of the target DU from the CU-UP, so as to complete the update of the user plane context between the target DU accessed by the terminal device and the CU-UPF network element after the terminal device is switched, so as to avoid the execution of the target DU and CU- The reconstruction of the F1 user plane interface between UPF network elements can reduce the handover delay and improve the problems of large service delay and high signaling overhead caused by the reconstruction of the F1 interface.

In a possible design, the above method may further include: the CU-CP obtains the uplink tunnel information of the CU-UPF network element from the CU-UPF network element through the control port, and the CU-CP sends the CU-UPF network element to the target DU According to the uplink tunnel information of the CU-UPF network element and the uplink tunnel information of the target DU, the target DU establishes an uplink user plane connection between the target DU and the CU-UPF network element, so that the target DU can pass the uplink The user plane connection receives the uplink data from the terminal equipment.

In a possible implementation, the above method may further include: the CU-CP also sends verification information to the CU-UPF network element through the control port, and the CU-UPF network element determines whether the CU-CP has obtained uplink tunnel information according to the verification information. When the CU-UPF network element determines that the CU-CP has the authority to obtain the uplink tunnel information, it sends the uplink tunnel information of the CU-UPF network element to the CU-UPF network element, otherwise, it does not send it.

In the second aspect, the embodiments of the present application provide a communication method. The applicable scenario of the method is that the terminal device switches from the source DU of the RAN to the target DU of the RAN within the range of the CU service of the same RAN. The network architecture to which the method is applicable The CU and DU of the middle RAN are separated, and the UPF network element and CU-UP are combined as one network element. The method can be executed by the CU-UPF network element or the internal chip of the CU-UPF network element. The method includes: when the terminal device switches from the source DU of the wireless access network device to the target DU of the wireless access network device, the CU -The UPF network element receives the second message from the CU-CP of the wireless access network device through the control port. The control port indicated by the control port information corresponds to the PDU session and is the control port of the CU-UPF network element. The second message includes the downlink tunnel information of the target DU, so the CU-UPF network element establishes the first F1 user plane connection according to the downlink tunnel information and the downlink tunnel information of the CU-UPF network element.

In a possible design, the CU-UPF network element receives the request message from the CU-CP through the control port, because the request message is used to request the second F1 user plane connection between the CU-UPF network element and the source DU The uplink tunnel information; the CU-UPF network element sends the uplink tunnel information to the CU-CP through the control port, and the uplink tunnel information is used for the uplink user plane connection between the target DU and the CU-UPF network element Established so that the target DU can receive the uplink data from the terminal device through the uplink user plane connection.

In a possible design, the CU-UPF network element receives the verification information from the CU-CP through the control port, and the CU-UPF network element determines whether the CU-CP has the authority to obtain the uplink tunnel information according to the verification information. When the UPF network element determines that the CU-CP has the authority to obtain the upstream tunnel information, it sends the upstream tunnel information of the CU-UPF network element to the CU-UPF network element, otherwise, it does not send it.

In a possible design, the CU-UPF network element sends the downlink tunnel information of the target DU, and the uplink tunnel information and downlink tunnel information of the CU-UPF network element to the core network element, so that the core network element can be timely Update context information.

In the third aspect, the embodiments of the present application provide a communication method. The applicable scenario of the method is that the terminal device switches from the source DU of the RAN to the target DU of the RAN within the range of the CU service of the same RAN. The network architecture to which the method is applicable The CU and DU of the middle RAN are separated, and the UPF network element and CU-UP are combined as one network element. The method may be executed by the target DU network element or the internal chip of the target DU. The method includes: the target DU of the radio access network device receives the first information from the core network element through the CU-CP of the radio access network device, When the terminal device switches from the source DU of the radio access network device to the target DU, the target DU sends a user plane data packet carrying the downlink tunnel information of the target DU to the CU-UPF network element according to the first information. The tunnel information is used to establish a downlink user plane connection between the target DU and the CU-UPF network element.

In the embodiment of the present application, when the DU of the RAN accessed by the terminal device is switched, the CU-CP can authorize the user plane data packet of the target DU that the terminal device needs to switch to have the authority to send control plane data, so that it can use The user plane data packet sends the downlink tunnel information to the CU-UPF network element to complete the update of the user plane context between the target DU and the CU-UPF network element accessed after the terminal device is switched, so as to avoid the execution of the target DU and CU- The reconstruction of the F1 user plane context between UPF network elements can reduce the handover delay and improve the problems of large service delay and high signaling overhead caused by the reconstruction of the F1 interface.

In a possible design, the foregoing method may further include: the target DU obtains the uplink tunnel information of the CU-UPF network element from the CU-UPF network element through the CU-CP, and the target DU obtains the uplink tunnel information of the CU-UPF network element according to the CU-UPF network element. With the uplink tunnel information of the target DU, an uplink user plane connection between the target DU and the CU-UPF network element is established, so that the target DU can receive uplink data from the terminal device through the uplink user plane connection.

In a possible implementation, the above method may further include: the target DU may also send verification information to the CU-UPF network element through a user plane data packet, and the CU-UPF network element determines whether the target DU has obtained the uplink tunnel according to the verification information Information authority. When the CU-UPF network element determines that the target DU has the authority to obtain the upstream tunnel information, it sends the upstream tunnel information of the CU-UPF network element to the target DU; otherwise, it does not send it.

In a fourth aspect, the embodiments of the present application provide a communication method. The applicable scenario of the method is that the terminal device switches from the source DU of the RAN to the target DU of the RAN within the service range of the CU of the same RAN. The network architecture to which the method is applicable The CU and DU of the middle RAN are separated, and the UPF network element and CU-UP are combined as one network element. The method can be executed by the CU-UPF network element or the internal chip of the CU-UPF network element. The method includes: when the terminal device switches from the source DU of the wireless access network device to the target DU, the CU-UPF network element Receive the user plane data packet from the target DU. Because the user plane data packet carries the downlink tunnel information of the target DU, the CU-UPF network element establishes the first F1 according to the downlink tunnel information and the downlink tunnel information of the CU-UPF network element User plane connection, that is, establishing the first F1 user plane connection as a downlink user plane connection between the target DU and the CU-UPF network element.

In the embodiment of the present application, when the DU of the RAN accessed by the terminal device is switched, the CU-CP can authorize the user plane data packet of the target DU that the terminal device needs to switch to have the authority to send control plane data, so that it can use The user plane data packet sends the downlink tunnel information to the CU-UPF network element to complete the update of the user plane context between the target DU and the CU-UPF network element accessed after the terminal device is switched, so as to avoid the execution of the target DU and CU- The reconstruction of the F1 user plane context between UPF network elements can reduce the handover delay and improve the problems of large service delay and high signaling overhead caused by the reconstruction of the F1 interface.

In a possible design, the above method further includes: the CU-UPF network element also sends uplink tunnel information to the target DU through the CU-CP, and the target DU according to the uplink tunnel information of the CU-UPF network element and the uplink tunnel of the target DU Information, establish an uplink user plane connection between the target DU and the CU-UPF network element, so that the target DU can receive uplink data from the terminal device through the uplink user plane connection.

In a possible implementation, the above method may further include: the target DU may also send verification information to the CU-UPF network element through a user plane data packet, and the CU-UPF network element determines whether the target DU has obtained the uplink tunnel according to the verification information Information authority. When the CU-UPF network element determines that the target DU has the authority to obtain the upstream tunnel information, it sends the upstream tunnel information of the CU-UPF network element to the target DU; otherwise, it does not send it.

In a fifth aspect, the embodiments of the present application provide a communication method. The applicable scenario of the method is that the terminal device switches from the source DU of the source RAN to the target DU of the target RAN within the scope of different RAN services. The network architecture to which the method is applicable The CU and DU of the middle RAN are separated, and the UPF network element and CU-UP are combined as one network element. The method can be executed by the target CU-CP or the internal chip of the target CU-CP. The method includes: the target control plane entity CU-CP of the target radio access network device receives through the source CU-CP of the source radio access network device The control port information from the core network element, the control port indicated by the control port information corresponds to the protocol data unit PDU session, and is the control port of the CU-UPF network element, when the terminal device accesses the source DU of the network device from the source wireless When switching to the target DU of the target radio access network device, the target CU-CP obtains from the target DU the downlink tunnel information of the target DU used to establish the first F1 user plane connection; where the first F1 user plane connection is the target DU and Downlink user plane connection between CU-UPF network elements; the target CU-CP sends downlink tunnel information to the CU-UPF network element through the control port, so that the CU-UPF network element can establish the first F1 user plane connection.

In the embodiment of this application, the terminal device switches from the source DU of the source RAN to the target DU of the target RAN within the range of different RAN services. The target CU-CP of the target RAN may be based on the control port and the control port obtained from the core network element in advance. CU-UPF network element communication, the CU-UPF network element can obtain the downlink tunnel information of the target DU from the target CU-UP based on the control port, so as to complete the connection between the target DU connected to the CU-UPF network element after the terminal device is switched The establishment of the downlink user plane connection can avoid the implementation of the F1 user plane interface reconstruction between the target DU and the CU-UPF network element, thereby reducing the handover delay and improving the service delay and signaling caused by the F1 interface reconstruction The problem of high overhead.

In a possible implementation, the above method may further include: the target CU-CP of the target RAN obtains the uplink tunnel information of the CU-UPF network element from the CU-UPF network element through the control port, and the target CU-CP sends the information to the target DU. The uplink tunnel information of the CU-UPF network element, the target DU establishes the uplink user plane connection between the target DU and the CU-UPF network element according to the uplink tunnel information of the CU-UPF network element and the uplink tunnel information of the target DU, so as to facilitate The target DU receives the uplink data from the terminal device through the uplink user plane connection.

In a possible implementation, the above method may further include: the target CU-CP also sends verification information to the CU-UPF network element through the control port, and the CU-UPF network element determines whether the target CU-CP has acquired the uplink according to the verification information. Tunnel information authority. When the CU-UPF network element determines that the target CU-CP has the authority to obtain uplink tunnel information, it sends the CU-UPF network element's upstream tunnel information to the CU-UPF network element to the target CU-CP, otherwise , It will not be sent.

In a possible implementation, the target CU-CP updates the context information of the terminal device, the target CU-CP sends the updated context information of the terminal device to the core network element, and the context information of the terminal device includes the terminal device The information of the target radio access network device of the service, so that the core network element can update the context information of the terminal device in time.

In a sixth aspect, the embodiments of the present application provide a communication method. The applicable scenario of the method is that the terminal device switches from the source DU of the source RAN to the target DU of the target RAN within the scope of different RAN services. The network architecture to which the method is applicable The CU and DU of the middle RAN are separated, and the UPF network element and CU-UP are combined as one network element. The method can be executed by the CU-UPF network element or the internal chip of the CU-UPF network element. The method includes: when the terminal device switches from the source DU of the source wireless access network device to the target DU of the target access network device, The CU-UPF network element receives the second message from the target CU-CP of the target radio access network device through the control port; wherein the second message includes the downlink tunnel information of the target DU, and the control port is the core network element. The control port of the CU-UPF network element assigned by the CU-UPF network element and corresponding to the PDU session of the protocol data unit; the CU-UPF network element establishes the control port according to the downlink tunnel information of the target DU and the downlink tunnel information of the CU_UPF network element The first F1 user plane connection is to establish a downlink user plane connection between the target DU and the CU-UPF network element.

In the embodiment of this application, the terminal device switches from the source DU of the source RAN to the target DU of the target RAN within the range of different RAN services. The target CU-CP of the target RAN may be based on the control port and the control port obtained from the core network element in advance. CU-UPF network element communication, the CU-UPF network element can obtain the downlink tunnel information of the target DU from the target CU-UP based on the control port, so as to complete the connection between the target DU connected to the CU-UPF network element after the terminal device is switched The establishment of the downlink user plane connection can avoid the implementation of the F1 user plane interface reconstruction between the target DU and the CU-UPF network element, thereby reducing the handover delay and improving the service delay and signaling caused by the F1 interface reconstruction The problem of high overhead.

In a possible implementation, the above method may further include: the CU-UPF network element further receives a request message from the CU-CP through the control port, the request message is used to request uplink tunnel information, and the uplink tunnel information is the CU-UPF network element The uplink tunnel information of the second F1 user plane connection with the source DU; the CU-UPF network element sends the uplink tunnel information to the target CU-CP through the control port, and the uplink tunnel information is used between the target DU and the CU-UPF network element The establishment of an uplink user plane connection between the two; so that the target DU can receive uplink data from the terminal device through the uplink user plane connection.

In a possible implementation, the above method may further include: the target CU-CP also sends verification information to the CU-UPF network element through the control port, and the CU-UPF network element determines whether the target CU-CP has acquired the uplink according to the verification information. Tunnel information authority. When the CU-UPF network element determines that the target CU-CP has the authority to obtain uplink tunnel information, it sends the CU-UPF network element's upstream tunnel information to the CU-UPF network element to the target CU-CP, otherwise , It will not be sent.

In a possible implementation, the target CU-CP updates the context information of the terminal device, the target CU-CP sends the updated context information of the terminal device to the core network element, and the context information of the terminal device includes the terminal device The information of the target radio access network device of the service, so that the core network element can update the context information of the terminal device in time.

In the seventh aspect, the embodiments of the present application provide a communication method. The applicable scenario of the method is that the terminal device switches from the source DU of the source RAN to the target DU of the target RAN within the range of different RAN services. The network architecture to which the method is applicable The CU and DU of the middle RAN are separated, and the UPF network element and CU-UP are combined as one network element. The method can be executed by the target DU network element or the internal chip of the target DU. The method includes: the target DU of the target radio access network device obtains data from the source radio access network device through the target CU-CP of the target radio access network device. The source CU-CP receives the first information; when the terminal device switches from the source DU of the source wireless access network device to the connected target DU, the target DU sends the downlink tunnel carrying the target DU to the CU-UPF network element according to the first information The user plane data packet of the information, and the downlink tunnel information is used to establish a downlink user plane connection between the target DU and the CU-UPF network element.

In the embodiment of the present application, when the DU of the RAN accessed by the terminal device is switched, the target CU-CP can authorize the user plane data packet of the target DU that the terminal device needs to switch to have the authority to send control plane data, so that Use user plane data packets to send downlink tunnel information to the CU-UPF network element, thereby completing the update of the user plane context between the target DU and CU-UPF network element accessed after the terminal device is switched, so as to avoid executing the target DU and CU -The F1 user plane context reconstruction between UPF network elements can reduce the handover delay and improve the problem of large service delay and high signaling overhead caused by F1 interface reconstruction.

In a possible design, the target DU obtains uplink tunnel information from the source CU-CP through the target CU-CP, where the uplink tunnel information is the uplink of the second F1 user plane connection between the CU-UPF network element and the source DU Tunnel information; the target DU establishes an uplink user plane connection between the target DU and the CU-UPF network element according to the uplink tunnel information and the uplink tunnel information of the target DU; so that the target DU receives from the terminal device through the uplink user plane connection Upstream data.

In a possible implementation, the above method may further include: the target DU may also send verification information to the CU-UPF network element through a user plane data packet, and the CU-UPF network element determines whether the target DU has obtained the uplink tunnel according to the verification information Information authority. When the CU-UPF network element determines that the target DU has the authority to obtain the upstream tunnel information, it sends the upstream tunnel information of the CU-UPF network element to the target DU; otherwise, it does not send it.

In an eighth aspect, the embodiments of the present application provide a communication method. The applicable scenario of the method is that the terminal device switches from the source DU of the source RAN to the target DU of the target RAN within the range of different RAN services. The network architecture to which the method is applicable The CU and DU of the middle RAN are separated, and the UPF network element and CU-UP are combined as one network element. The method can be executed by the CU-UPF network element or the internal chip of the CU-UPF network element. The method includes: when the terminal device switches from the source DU of the source wireless access network device to the target DU of the target wireless access network device The CU-UPF network element receives the user plane data packet of the target DU from the target radio access network device. The user plane data packet carries the downlink tunnel information of the target DU. The CU-UPF network element is connected to the target radio access network device. The user plane entity CU-UP corresponding to the centralized unit CU and the user plane function UPF network element are composed; the CU-UPF network element establishes the first F1 user plane connection according to the downlink tunnel information and the downlink tunnel information of the CU-UPF network element, that is, the establishment Downlink user plane connection between the target DU and the CU-UPF network element.

In the embodiment of the present application, when the DU of the RAN accessed by the terminal device is switched, the target CU-CP can authorize the user plane data packet of the target DU that the terminal device needs to switch to have the authority to send control plane data, so that Use user plane data packets to send downlink tunnel information to the CU-UPF network element, thereby completing the update of the user plane context between the target DU and CU-UPF network element accessed after the terminal device is switched, so as to avoid executing the target DU and CU -The F1 user plane context reconstruction between UPF network elements can reduce the handover delay and improve the problem of large service delay and high signaling overhead caused by F1 interface reconstruction.

In a possible design, the CU-UPF network element sends uplink tunnel information to the target DU through the target CU-CP; wherein, the uplink tunnel information is the second F1 user between the CU-UPF network element and the source DU The uplink tunnel information of the plane connection, where the uplink tunnel information and the downlink tunnel information include at least one of an Internet Protocol IP address and a tunnel endpoint identifier. The target DU establishes an uplink user plane connection between the target DU and the CU-UPF network element according to the uplink tunnel information and the uplink tunnel information of the target DU; so that the target DU receives uplink data from the terminal device through the uplink user plane connection .

In a possible implementation, the above method may further include: the target DU may also send verification information to the CU-UPF network element through a user plane data packet, and the CU-UPF network element determines whether the target DU has obtained the uplink tunnel according to the verification information Information authority. When the CU-UPF network element determines that the target DU has the authority to obtain the upstream tunnel information, it sends the upstream tunnel information of the CU-UPF network element to the target DU; otherwise, it does not send it.

In a ninth aspect, this application provides a communication device. The communication device may be a CU-CP or a chip set inside the CU-CP. The communication device is capable of realizing the functions performed by the CU-CP or a chip set inside the CU-CP. For example, the communication device includes modules or units or means corresponding to the steps involved in the first and fifth aspects. (means), the function or unit or means can be realized by software, or by hardware, or by hardware executing corresponding software.

In a possible design, the communication device includes a processing unit and a communication unit. The communication unit can be used to send and receive signals to achieve communication between the communication device and other devices. For example, the communication unit is used to receive Relay the first message of the UE; the processing unit may be used to perform some internal operations of the communication device. The functions performed by the processing unit and the communication unit may correspond to the steps involved in the CU-CP in the above aspects.

In a possible design, the communication device includes a processor, and may also include a transceiver. The transceiver is used to send and receive signals, and the processor executes program instructions to complete any possible design or implementation of the above aspects. The method in the way. Wherein, the communication device may further include one or more memories, and the memories are used for coupling with the processor. The one or more memories may be integrated with the processor, or may be provided separately from the processor, which is not limited in this application. The memory can store the necessary computer programs or instructions to realize the functions involved in the above-mentioned various aspects. The processor can execute the computer program or instruction stored in the memory, and when the computer program or instruction is executed, the communication device realizes any of the possible designs or implementations related to the CU-CP in the above aspects. method.

In a possible design, the communication device includes a processor and a memory, and the memory can store necessary computer programs or instructions for realizing the functions involved in the first aspect. The processor can execute the computer program or instruction stored in the memory, and when the computer program or instruction is executed, the communication device realizes any of the possible designs or implementations related to the CU-CP in the above aspects. method.

In a possible design, the communication device includes at least one processor and an interface circuit, where at least one processor is used to communicate with other devices through the interface circuit and execute any possible design or implementation of the above aspects The method implemented by the CU-CP in.

In a tenth aspect, this application provides a communication device. The communication device may be a CU-UPF network element or a chip set inside the CU-UPF network element. The communication device is capable of implementing the functions performed by the CU-UPF network element or a chip set inside the CU-UPF network element. For example, the communication device includes performing the second aspect, the fourth aspect, or the sixth aspect, and the The eight aspects relate to modules or units or means corresponding to the steps, and the functions or units or means can be realized by software, or by hardware, or by hardware executing corresponding software.

In a possible design, the communication device includes a processing unit and a communication unit. The communication unit can be used to send and receive signals to achieve communication between the communication device and other devices. For example, the communication unit is used to receive Relay the first message of the UE; the processing unit may be used to perform some internal operations of the communication device. The functions performed by the processing unit and the communication unit may correspond to the steps involved in the CU-UPF network elements in the above aspects.

In a possible design, the communication device includes a processor, and may also include a transceiver. The transceiver is used to send and receive signals, and the processor executes program instructions to complete any possible design or implementation of the above aspects. The method in the way. Wherein, the communication device may further include one or more memories, and the memories are used for coupling with the processor. The one or more memories may be integrated with the processor, or may be provided separately from the processor, which is not limited in this application. The memory can store the necessary computer programs or instructions to realize the functions involved in the above-mentioned various aspects. The processor can execute the computer program or instruction stored in the memory, and when the computer program or instruction is executed, the communication device realizes any possible design or implementation manner involved in the CU-UPF network element in the above aspects In the method.

In a possible design, the communication device includes a processor and a memory, and the memory can store necessary computer programs or instructions for realizing the functions involved in the first aspect. The processor can execute the computer program or instruction stored in the memory, and when the computer program or instruction is executed, the communication device realizes any possible design or implementation manner involved in the CU-UPF network element in the above aspects In the method.

In a possible design, the communication device includes at least one processor and an interface circuit, where at least one processor is used to communicate with other devices through the interface circuit and execute any possible design or implementation of the above aspects The method executed by the CU-UPF network element.

In an eleventh aspect, the present application provides a communication device. The communication device may be a target DU or a chip set inside the target DU. The communication device is capable of realizing the functions performed by the target DU or a chip set inside the target DU. For example, the communication device includes modules or units corresponding to the steps involved in the third aspect, the seventh aspect, or the sixth aspect. Or means, the function or unit or means can be realized by software, or by hardware, or by hardware executing corresponding software.

In a possible design, the communication device includes a processing unit and a communication unit. The communication unit can be used to send and receive signals to achieve communication between the communication device and other devices. For example, the communication unit is used to receive Relay the first message of the UE; the processing unit may be used to perform some internal operations of the communication device. The functions performed by the processing unit and the communication unit may correspond to the steps involved in the target DU in each aspect described above.

In a possible design, the communication device includes a processor, and may also include a transceiver. The transceiver is used to send and receive signals, and the processor executes program instructions to complete any possible design or implementation of the above aspects. The method in the way. Wherein, the communication device may further include one or more memories, and the memories are used for coupling with the processor. The one or more memories may be integrated with the processor, or may be provided separately from the processor, which is not limited in this application. The memory can store the necessary computer programs or instructions to realize the functions involved in the above-mentioned various aspects. The processor can execute the computer program or instruction stored in the memory, and when the computer program or instruction is executed, the communication device realizes the method in any possible design or implementation manner involved in the above-mentioned various aspects of the target DU. .

In a possible design, the communication device includes a processor and a memory, and the memory can store necessary computer programs or instructions for realizing the functions involved in the first aspect. The processor can execute the computer program or instruction stored in the memory, and when the computer program or instruction is executed, the communication device realizes the method in any possible design or implementation manner involved in the above-mentioned various aspects of the target DU. .

In a possible design, the communication device includes at least one processor and an interface circuit, where at least one processor is used to communicate with other devices through the interface circuit and execute any possible design or implementation of the above aspects In the method executed by the target DU.

In a twelfth aspect, this application provides a computer-readable storage medium that stores computer-readable instructions. When the computer reads and executes the computer-readable instructions, the computer can execute the above-mentioned aspects. Any possible design method.

In a thirteenth aspect, this application provides a computer program product, which when a computer reads and executes the computer program product, causes the computer to execute any of the possible design methods in the above-mentioned various aspects.

In a fourteenth aspect, an embodiment of the present application provides a communication system, which includes CU-CP and CU-UPF network elements, wherein:

The CU-CP can be used to implement the first aspect or any one of the methods in the first aspect.

The CU-UPF network element may be used to execute any one of the above-mentioned second aspect or the second aspect.

In a fifteenth aspect, an embodiment of the present application provides a communication system. The communication system includes a target DU and a CU-UPF network element, where:

The target DU can be used to perform the third aspect or any one of the methods in the third aspect.

The CU-UPF network element may be used to execute any one of the foregoing fourth aspect or the fourth aspect.

In a sixteenth aspect, an embodiment of the present application provides a communication system, which includes target CU-CP and CU-UPF network elements of a target radio access network device, wherein:

The target CU-CP of the target radio access network device may be used to execute any one of the above-mentioned fifth aspect or the fifth aspect.

The CU-UPF network element may be used to execute any one of the above-mentioned sixth aspect or the sixth aspect.

In a seventeenth aspect, an embodiment of the present application provides a communication system. The communication system includes a target DU and a CU-UPF network element of a target radio access network device, wherein:

The target DU of the target radio access network device may be used to execute any one of the above-mentioned seventh aspect or the seventh aspect.

The CU-UPF network element may be used to execute any one of the eighth aspect or the eighth aspect described above.

In an eighteenth aspect, the present application provides a chip that includes a processor, and the processor is coupled to a memory, and is configured to read and execute a software program stored in the memory to implement any of the above aspects. A possible design approach.

Description of the drawings

FIG. 1 is a schematic diagram of a communication system provided by an embodiment of the application;

2A to 2C are schematic diagrams of the separated architecture of radio access network devices provided by embodiments of this application;

Fig. 3 is a schematic diagram of a RAN handover procedure of a terminal device in the prior art;

FIG. 4A is a schematic diagram of a communication system applicable to an embodiment of the present application;

4B to 4C are schematic diagrams of user plane protocols and control plane protocols applicable to embodiments of the present application;

5A and 5B are schematic diagrams of handover scenarios applicable to embodiments of the present application;

FIG. 6 is a schematic diagram of the first communication method provided by an embodiment of this application;

7A and 7B are schematic diagrams of a communication method in a handover scenario provided by an embodiment of this application;

FIG. 8 is a schematic diagram of a second communication method provided by an embodiment of this application;

9A and 9B are schematic diagrams of a communication method in a handover scenario provided by an embodiment of the application;

FIG. 10 is a schematic diagram of a second communication method provided by an embodiment of this application;

11A and 11B are schematic diagrams of a communication method in a handover scenario provided by an embodiment of this application;

FIG. 12 is a schematic diagram of a third communication method provided by an embodiment of this application;

13A and 13B are schematic diagrams of a communication method in a handover scenario provided by an embodiment of this application;

FIG. 14 is a schematic structural diagram of a communication device provided by an embodiment of this application;

15 is a schematic structural diagram of a communication device provided by an embodiment of this application;

FIG. 16 is a schematic structural diagram of a communication device provided by an embodiment of this application.

Detailed ways

In order to make the purpose, technical solutions and advantages of this application clearer, the application will be further described in detail below in conjunction with the accompanying drawings.

First, the communication system to which the technical solution provided in this application is applicable will be explained.

The technical solutions provided in this application can be applied to various communication systems, such as long term evolution (LTE) systems, fifth generation (5G) communication systems, and other similar communication systems. Fig. 1 exemplarily shows a network architecture diagram of a 5G communication system. in:

Terminal devices may include handheld devices with wireless communication functions, vehicle-mounted devices, wearable devices, computing devices, or other processing devices connected to wireless modems, as well as various forms of user equipment (UE), and mobile stations (mobile stations). station, MS), terminal equipment (terminal equipment), etc.

(Radio access network, (R)AN) equipment can be used to implement functions such as wireless physical layer functions, wireless resource management, wireless access control, and mobility management. RAN equipment may include base stations, such as access point (AP) in 5G system, next generation Node B (gNB), next generation evolved Node B (ng-eNB, gNB), transceiver Point (transmission receive point, TRP), transmission point (transmission point, TP), or some other access node, etc. It should be understood that, in the following description, (R)AN devices are collectively referred to as RAN devices for ease of description.

The user plane function (UPF) network element, as a user plane function network element, can be connected to external data networks. The main functions include: data packet routing and transmission, packet inspection, service usage reporting, QoS processing, legal monitoring, User plane related functions such as upstream packet inspection and downstream data packet storage.

AMF network element, its main functions include: connection management, mobility management, registration management, access authentication and authorization, reachability management, security context management and other access and mobility-related functions.

SMF network element, its main functions include: session management (such as session establishment, modification and release, including tunnel maintenance between UPF and RAN), UPF selection and control, service and session continuity (service and session continuity, SSC) Session-related functions such as mode selection and roaming.

The main functions of the PCF network element include: unified policy formulation, policy control provision and acquisition of policy-related contract information and other policy-related functions.

The application function (AF) network element can be either a third-party application control platform or a device deployed by an operator. Its main functions include providing application-related information and providing services for multiple application servers.

The main function of a data network (DN) is to provide specific data services, such as operator services, Internet access, or third-party services.

As shown in Figure 2A, CU/DU separation is an important feature in 5G. By splitting the RAN into a centralized processing node (centralized unit, CU) and a distributed processing node (distributed unit, DU), the base station can be flexibly Adjusting the network layout has good benefits for load balancing and maximum utilization of resources. In addition, under this architecture, there is better support for solving tidal effects, deploying dual connectivity, edge computing, business offloading, and intelligent operation and maintenance.

Among them, the radio access network equipment can be divided into a CU and at least one DU. Wherein, the CU may be used to manage or control at least one DU, and it may also be referred to as the CU being connected to at least one DU. This structure can disassemble the protocol layer of the wireless access network equipment in the communication system, where part of the protocol layer is placed under the centralized control of the CU, and the remaining part or all of the protocol layer functions are distributed in the DU, and the CU is centrally controlled by the DU. Taking the gNB as an example of the radio access network equipment, the protocol layer of gNB includes the radio resource control (radio resource control, RRC) layer, the service data adaptation protocol (SDAP) layer, and the packet data aggregation protocol (packet data). The convergence protocol (PDCP) layer, the radio link control (RLC) layer, the media access control (MAC) layer, and the physical layer. Among them, exemplarily, the CU can be used to implement the functions of the RRC layer, the SDAP layer, and the PDCP layer, and the DU can be used to implement the functions of the RLC layer, the MAC layer, and the physical layer. The embodiment of the present application does not specifically limit the protocol stack included in the CU and DU.

Among them, for the centralized processing node, according to the different functions, it can be further divided into the control plane entity (CU-control plane, CU-CP) of the centralized processing node and the user plane entity (CU-user plane, CU-UP) of the centralized processing node. ). Among them, CU-CP can be used for control plane management, and CU-UP can be used for user plane data transmission. The interface between CU-CP and CU-UP can be an E1 interface. The interface between CU-CP and DU can be F1-C, which is used for the transmission of control plane signaling. The interface between CU-UP and DU can be F1-U, which is used for user plane data transmission. CU-UP and CU-UP can be connected through the Xn-U port for user plane data transmission. In other words, taking gNB as an example, as shown in FIG. 2B, under the CU/DU separation architecture, gNB is disassembled into gNB-CU-CP, gNB-CU-UP, and gNB-DU. The interface between gNB-CU-CP and gNB-DU can be F1-C, and the interface between gNB-CU-UP and gNB-DU can be F1-U. For another example, as shown in Fig. 2C, taking gNB as an example, under the CU/DU separation architecture, gNB-CU-CP of gNB controls gNB-CU-UP through E1 interface, and SMF network element controls UPF network element through N4 interface.

In the current related technology, under the CU/DU separation architecture of the above-mentioned RAN, the UPF network element and CU-UP are deployed independently, and the RAN handover process of the terminal equipment is shown in Figure 3. In Figure 3, gNB is taken as an example. The schematic diagram of the process of UE handover from the source gNB-DU to the target gNB-DU is shown. The interaction process between each network element or device includes:

Step 301: The UE sends a measurement report to the source gNB-DU of the gNB.

Step 302: The source gNB-DU forwards the measurement report to the gNB-CU-CP through an RRC message.

For example, the source gNB-DU forwards the measurement report to the gNB-CU-CP through an uplink RRC transmission message (UL RRC MESSAGE TRANSFER).

Step 303: According to the received measurement report, the gNB-CU-CP determines that the UE needs to switch from the source gNB-DU to the gNB target gNB-DU, and sends a UE context establishment request to the gNB-CU-UP, and the UE context establishment The request is used to request the uplink tunnel information of the gNB-CU-UP in the user plane context of the F1-U interface between the gNB-CU-UP and the source gNB-DU.

Step 304: The gNB-CU-UP sends a UE context establishment response to gNB-CU-CP. The UE context establishment response includes gNB- in the user plane context of the F1-U interface between the gNB-CU-UP and the source gNB-DU. Upstream tunnel information of CU-UP.

Step 305: When the gNB-CU-CP determines that the UE needs to switch from the source gNB-DU to the target gNB-DU of the gNB, the gNB-CU-CP sends a UE context establishment request to the target gNB-DU, and the UE context establishment request includes the gNB -CU-UP uplink tunnel information, and the UE context establishment request is used to request the F1-U downlink tunnel port information of the target gNB-DU.

Step 306: The target gNB-DU sends a UE context establishment response to the gNB-CU-CP. The UE context establishment response includes the F1-U downlink tunnel port information of the target gNB-DU.

Step 307, the gNB-CU-CP sends a UE context modification request to the source gNB-DU, where the UE context modification request includes an RRC reconfiguration (RRC Reconfiguration) message, and the RRC reconfiguration message is used to instruct the UE to end the connection with the source gNB-DU. DU connection, establish a connection with the target gNB-DU through a random access procedure.

Step 308: The source gNB-DU forwards the RRC Reconfiguration (RRC Reconfiguration) message to the UE.

Step 309: The source gNB-DU sends a downlink data delivery status (downlink data delivery status) to the gNB-CU-CP. The downlink data delivery status is used to instruct the gNB-CU-CP to stop sending downlink data to the UE.

Step 310: The source gNB-DU sends a UE context modification response to the gNB-CU-CP. The UE context modification response includes that the source gNB-DU disconnects from the UE.

Step 311, gNB-CU-CP sends a F1 interface user plane context modification request to gNB-CU-UP. The modification request includes F1-U downlink tunnel port information of the target gNB-DU, which is used to request the establishment of gNB-CU-UP and The F1 interface between the target gNB-DU side is a downlink user plane connection.

Step 312, the gNB-CU-UP modifies and updates the F1 interface user plane context based on the F1-U downlink tunnel port information of the target gNB-DU and the F1-U downlink tunnel port information of the gNB-CU-UP, and establishes the F1 interface Downlink user plane connection, and send F1 interface user plane context modification response to gNB-CU-CP.

Step 313: The UE disconnects from the source gNB-DU, and establishes a connection with the target gNB-DU through a random access process.

Step 314: The target gNB-DU sends a downlink data transmission status message to the gNB-CU-CP, where the message is used to instruct the gNB-CU-CP to send downlink data to the target gNB-DU.

Step 315: The UE switches to the target gNB-DU, and sends the RRC reconfiguration complete message to the target gNB-DU.

Step 316: The target gNB-DU forwards the RRC reconfiguration complete message to the gNB-CU-CP.

Step 317: The gNB-CU-CP instructs the source gNB-DU to delete the relevant UE context and release the relevant resources occupied by the context.

Step 318: The source gNB-DU sends a UE context release complete message to the gNB-CU-CP.

Step 319: The gNB-CU-CP sends a request to the gNB-CU-UP to release the F1-U interface user plane context between the gNB-CU-UP and the source gNB-DU.

Step 320: The gNB-CU-UP releases the F1-U interface user plane context between the gNB-CU-UP and the source gNB-DU, and sends a release complete message to the gNB-CU-CP.

At present, the CU is usually deployed in the same physical computer room as the sinking user plane function (UPF) network element. In order to reduce the number of data plane transmission hops, save costs, and set the data plane security nodes in the core network Considering moderately, it is very likely that the UPF network element and the CU-UP will be combined as one network element in the end, that is, the CU-UP and the sinking UPF network element will be combined and recorded as the CU-UPF network element. The CU-UPF network The element is uniformly scheduled and managed by the session management function (SMF) network element. During the transmission of the PDU session, the CU-UP can directly communicate with the UPF network element that is set together with it. The transmission distance is short, the communication rate is fast, and the resource utilization rate is improved. In a joint installation scenario, FIG. 4A exemplarily shows a network architecture diagram of a 5G communication system. The interface between gNB-CU-CP and gNB-DU can be F1-C, the interface between gNB-DU and CU-UPF network element can be F1-U, one of gNB-CU-CP and CU-UPF network element The interface between the two can be an E1 interface, and the SMF network element controls the CU-UPF network element through the N4 interface.

It should be noted that in this embodiment of the application, the F1 interface is an interface between functional entities within a RAN. For example, under the CU/DU separation architecture of the above-mentioned RAN, the F1 interface can be a DU in the RAN and the RAN. The interface between the CUs within. The F1 interface can also be referred to as F1* interface and other names. For the convenience of description, in the embodiments of the present application, it can be collectively referred to as the F1 interface, but the name is not limited.

The F1 interface involved in the embodiment of the present application supports a user plane protocol and a control plane protocol. Exemplarily, as shown in FIG. 4B, a schematic diagram of a protocol stack of a control plane protocol provided in an embodiment of this application.

In FIG. 4B, the peer-to-peer protocol between the terminal device and the CU-CP of the RAN includes a radio resource control (radio resource control, RRC) layer and a PDCP layer. The peer-to-peer protocol between the terminal equipment and the DU of the RAN includes the RLC layer, the MAC layer, and the PHY layer.

Among them, the DU of the RAN and the CU-CP of the RAN are on the control plane of the F1 interface. The equivalent protocols include the F1 application protocol (F1 application protocol, F1AP) layer and the stream control transport protocol (SCTP) Layer and IP layer. Optionally, the control plane protocol layer of the F1 interface further includes one or more of a PDCP layer, an IPsec layer, and a datagram transport layer security (DTLS) layer. In a possible implementation, the IPsec layer, the PDCP layer, or the DTLS layer is located above the IP layer and below the F1AP layer.

Exemplarily, as shown in FIG. 4C, a schematic diagram of a protocol stack of a user plane protocol provided in an embodiment of this application. In FIG. 4C, description is made by taking the link between the terminal device and the CU-CP including the terminal device, the CU_UPF network element, and the CU-CP as an example.

In FIG. 4C, the equivalent protocol layer between the terminal device and the CU-UP includes the Service Data Application Protocol (SDAP) layer and the Packet Data Convergence Protocol (PDCP) layer. The peer-to-peer protocol between the terminal device and the DU includes a radio link control (radio link control, RLC) layer, a medium access control (medium access control, MAC) layer, and a physical (Physical, PHY) layer.

The user plane of the F1 interface between the CU-UPF network element and the DU of the RAN. The peer-to-peer protocol includes the general packet radio service (General Packet Radio Service, GPRS) tunneling protocol user plane (GPRS Tunnelling Protocol User Plane, GTP-U) Layer, user datagram protocol (UDP) layer, and internet protocol (IP) layer. Optionally, the user plane protocol layer of the F1 interface further includes a PDCP layer and/or an IP security (IP Security, referred to as IPsec) layer. In a possible implementation, the IPsec layer or the PDCP layer is located above the IP layer and below the GTP-U layer.

It is understandable that the protocol stack architecture shown in FIG. 4B to FIG. 4C in the embodiment of the present application is only an example, and the method provided in the embodiment of the present application does not rely on this example, but makes the implementation of this application possible through this example. The method provided by the example is easier to understand.

Considering that under the architecture where UPF network elements and CU-UP are combined as one network element, since the control of CU-UPF network elements by gNB-CU-CP has been cancelled, security and quality of service flow (QoS Flow) control are related The PDCP and SDAP configuration (SDAP Config) messages need to be sent to the CU-UPF network element through the path of CU-CP->AMF->SMF->CU-UPF on the control plane. When the terminal device undergoes a RAN handover, it needs to change the CU-UPF interface. At this time, it needs to forward the F1 interface user plane/control plane context modification through the path of gNB-CU-CP->AMF->SMF->CU-UPF The message and signaling process is too long, which may not meet the delay requirements of terminal handover.

In order to solve the above-mentioned problems, the embodiment of the application proposes a communication method and device. In the method, the control port information is pre-transmitted in the PDU session establishment process through SMF to instruct the gNB-CU-CP to switch between the terminal equipment and the gNB-DU. Use the preset control port to control the PDU session to quickly complete the gNB-DU switching, or, through the SMF network element to authorize the user plane data packet to control the PDU session to quickly complete the gNB-DU switching.

It should be understood that the scenario where the DU of the RAN is switched in the embodiment of the present application is not limited to the scenario where the terminal device switches between the RAN devices, and may also be other scenarios where the radio bearer may switch between the RAN devices. For example, when the terminal device is restored to the RRC connected state (connected) from the inactive state (radio resource control, RRC), the radio bearer (Radio Bearer) switch between RAN devices may also occur . For another example, in a scenario where a terminal device establishes a dual connection for a PDU session with a master RAN device and a slave RAN device, the radio bearer may also be switched from the master RAN device to the slave RAN device, or from the slave RAN device. Switch to the main RAN device. These scenarios are also applicable to the embodiments of the present application.

The network architecture and business scenarios described in the embodiments of this application are intended to more clearly illustrate the technical solutions of the embodiments of this application, and do not constitute a limitation to the technical solutions provided in the embodiments of this application. Those of ordinary skill in the art will know that with the network With the evolution of architecture and the emergence of new business scenarios, the technical solutions provided in the embodiments of this application are equally applicable to similar technical problems.

The communication method provided in this application will be described in detail below in conjunction with specific embodiments. Among them, it should be understood that the terms "first" and "second" mentioned below are only used for the purpose of distinguishing description, and cannot be understood as indicating or implying relative importance, nor as indicating or implying order. Wait. For example, in the following description, the source RAN corresponding to the terminal device before handover is also called the first RAN, and the target RAN corresponding to the terminal device after the handover is also called the second RAN; the source DU corresponding to the terminal device before the handover is also called The first DU, the corresponding target DU after the terminal device is switched is also called the second DU; the corresponding source CU-CP before the terminal device is switched is also called the first CU-CP, and the corresponding target CU-CP after the terminal device is switched is again Called the second CU-CP.

The following describes the communication method provided by the embodiments of the present application in the following scenario 1 and scenario 2. In scenario 1, the terminal device switches from the first DU of the RAN to the first DU of the RAN within the scope of the CU service of the same RAN. Two DU. Exemplarily, as shown in FIG. 5A, taking the RAN as a gNB as an example, the UE is connected to the first gNB-DU of the gNB before handover, and the UE is connected to the second gNB-DU of the gNB after the handover. In the second scenario, the terminal device switches from the DU of the first RAN to the DU of the second RAN within the range of different RAN services. Exemplarily, as shown in FIG. 5B, taking the RAN as a gNB as an example, the UE is connected to the first gNB-DU of the first gNB before handover, and the UE is connected to the second gNB-DU of the second gNB after the handover.

scene one

Embodiment 1, combined with the description of scenario 1, as shown in FIG. 6, is a schematic flowchart of the first communication method provided in this embodiment of the application. Referring to Figure 6, the method includes the following steps.

Step 601: The CU-CP of the RAN receives the control port information from the SMF network element.

Wherein, the control port information may be referred to as a temporary E1 port, and the control port indicated by the control port information is the control port of the CU-UPF network element, and is the control port corresponding to the PDU session of the terminal device. In other words, the control port corresponds to the session one-to-one.

In a possible implementation, the control port information may be carried in an N2 message, and the SMF network element may send the control port information to the CU-CP of the RAN through the AMF network element.

Step 602: When the CU-CP of the RAN determines that the terminal device needs to switch from the first DU to the second DU, the CU-CP obtains the downlink tunnel information of the second DU from the second DU.

Specifically, the terminal device may send a measurement report to the CU-CP of the RAN through the first DU currently accessed, and the CU-CP of the RAN determines that the terminal device needs to switch to the second DU according to the measurement report from the terminal device. Wherein, the measurement report may include information such as the received signal power of the surrounding RAN DU measured by the UE.

Among them, the first DU is the source DU accessed by the terminal device before the handover, and the second DU is the target DU accessed by the terminal device after the handover. The downlink tunnel information of the second DU may include the IP address and the GTP tunnel endpoint identifier (tunnel endpoint identifier). , At least one of TEID). Exemplarily, the downlink tunnel information of the second DU may include a first IP address, and the first IP address is an IP address used for communication between the second DU and the CU-UPF network element.

In a possible implementation, the specific way for the CU-CP to obtain the downlink tunnel information of the second DU from the second DU may be: when the CU-CP determines that the terminal device needs to switch to the second DU, the CU-CP may first The second DU sends a request message, which is used to request the downlink tunnel information of the second DU. After receiving the request message, the second DU sends a response message to the CU-CP, and the response message carries the downlink tunnel information.

Step 603: During the process of the terminal device switching from the first DU to the second DU, the CU-CP sends the downlink tunnel information to the CU-UPF network element through the control port.

Step 604: The CU-UPF network element establishes an F1 downlink user plane connection between the CU-UPF network element and the second DU according to the downlink tunnel information of the second DU and the downlink tunnel information of the CU-UPF network element.

Hereinafter, the F1 downlink user plane connection between the CU-UPF network element and the second DU is referred to as the first F1 user plane connection. The downlink tunnel information of the CU-UPF network element is the downlink tunnel information of the second F1 user plane connection between the CU-UPF network element and the first DU.

The downlink tunnel information of the CU-UPF network element may include at least one of an IP address and a GTP tunnel endpoint identifier (tunnel endpoint identifier, TEID). Exemplarily, the downlink tunnel information of the CU-UPF network element may include a second IP address, and the second IP address is the IP used when the CU-UPF network element communicates with the CU-UPF network element through the first DU address.

In a possible implementation, the above method may further include: the CU-CP obtains the uplink tunnel information of the CU-UPF network element from the CU-UPF network element through the control port, and the CU-CP sends the CU-UPF network element to the target DU According to the uplink tunnel information of the CU-UPF network element and the target DU’s uplink tunnel information, the second DU establishes an uplink user plane connection between the second DU and the CU-UPF network element to facilitate the second DU Receive the uplink data from the terminal device through the uplink user plane connection.

In a possible implementation, the above method may further include: the CU-CP also sends verification information to the CU-UPF network element through the control port, and the CU-UPF network element determines whether the CU-CP has obtained uplink tunnel information according to the verification information. When the CU-UPF network element determines that the CU-CP has the authority to obtain the uplink tunnel information, it sends the uplink tunnel information of the CU-UPF network element to the CU-UPF network element, otherwise, it does not send it.

The verification information in the embodiment of the present application may be a kind of certificate information, and the authority is verified according to the certificate information; it may also be a kind of instruction information indicating related authority.

In addition, the verification information is also used to determine whether the CU-CP has the authority to modify the uplink tunnel information.

In the embodiment of this application, when the DU of the RAN accessed by the terminal device is switched, the CU-CP can communicate with the CU-UPF network element based on the control port obtained in advance from the core network element, and the CU-UPF network element can be based on The control port obtains the downlink tunnel information of the second DU from the CU-UP, so as to complete the update of the user plane context between the second DU accessed after the terminal device is switched and the CU-UPF network element, so that the second DU can be avoided. The reconstruction of the F1 user plane interface with the CU-UPF network element can reduce the handover delay and improve the problem of large service delay and high signaling overhead caused by the reconstruction of the F1 interface.

In FIG. 7A, the embodiment of the present application further takes as an example the UE switching from the first gNB-DU connected to the gNB to the second gNB-DU of the gNB to illustrate the foregoing communication method.

Step 700: During the establishment of the PDU session, the SMF network element sends the CU-UPF network element side control port information corresponding to the PDU session to the gNB-CU-CP of the gNB through the AMF network element.

In other words, the SMF network element sends the CU-UPF network element side control port information to the gNB-CU-CP when the PDU session is established. In this way, the gNB-CU-CP can communicate with the control port indicated by the control port information. The CU-UPF network element establishes communication, so that the gNB-CU-CP of the gNB can send control plane data to the CU-UPF network element. Equivalently, the SMF network element authorizes the gNB-CU-CP to have the authority to modify the user plane context of the CU-UPF network element.

In a possible embodiment, the first message may also include verification information, for example, the verification information is a token. Or, the SMF network element sends the verification information to the gNB-CU-CP through other messages. The verification information is used for the CU-UPF network element to determine the authority of gNB-CU-CP, for example, for the CU-UPF network element to determine whether the gNB-CU-CP has the authority to obtain the uplink tunnel information of the CU-UPF network element, or In other words, for the CU-UPF network element to determine whether the gNB-CU-CP has the authority to modify the user plane context of the CU-UPF network element, or for the CU-UPF network element to determine whether the gNB-CU-CP has the ability to modify the CU -The authority of the F1 interface of the UPF network element.

In step 701 and step 702, the UE sends a measurement report to the gNB-CU-CP through the first gNB-DU.

Wherein, the first gNB-DU is the source gNB-DU connected before the UE handover, the measurement report may include information such as the received signal power of the surrounding gNB-DU measured by the UE, and the UE sends the measurement report to the gNB-CU-CP, The gNB-CU-CP determines whether the UE needs to switch gNB-DU.

Step 703: When the gNB-CU-CP determines that the UE needs to switch the gNB-DU, the gNB-CU-CP requests the CU-UPF network element through the control port for the uplink tunnel information of the CU-UPF network element.

Wherein, the uplink tunnel information of the CU-UPF network element refers to the uplink tunnel information of the CU-UPF network element in the F1 user plane connection between the CU-UPF network element and the first gNB-DU, for example, the CU-UPF network The meta uplink tunnel information may include the IP address and the GTP tunnel endpoint identifier.

In a possible embodiment, in this step 703, the gNB-CU-CP may also send verification information to the CU-UPF network element through the control port. For example, the gNB-CU-CP may also send the verification information to the CU-UPF network element through the control port. The UPF network element sends a bearer context modification request (BEARER CONTEXT MODIFICATION REQUEST), where the bearer context modification request carries a token. When this step is included in step 703, the method embodiment may further include the following step 704.

In step 704, the CU-UPF network element verifies the authority of the gNB-CU-CP according to the verification information. For example, the CU-UPF network element determines whether the gNB-CU-CP has the authority to obtain the uplink tunnel information according to the token. If so, the CU-UPF network element performs step 705; otherwise, step 705 is not performed.

Step 705: The CU-UPF network element sends the uplink tunnel information of the CU-UPF network element to the gNB-CU-CP.

Step 706, the gNB-CU-CP forwards the uplink tunnel information of the CU-UPF network element to the second gNB-DU, and also sends a request to the second gNB-DU, the request is used to request the downlink tunnel of the second gNB-DU information.

Step 707: After receiving the uplink tunnel information of the CU-UPF network element, the second gNB-DU establishes the second gNB-DU and CU-DU according to the uplink tunnel information of the CU-UPF network element and the uplink tunnel information of the second gNB-DU. F1 uplink user plane connection between UPF network elements, so that the second gNB-DU can receive the uplink data of the terminal equipment. In addition, the second gNB-DU also sends the downlink tunnel information of the second gNB-DU to the gNB-CU-CP.

In step 708 and step 709, the gNB-CU-CP sends a handover instruction to the first gNB-DU, where the handover instruction is used to instruct the UE to switch from connecting to the first gNB-DU to connecting to the second gNB-DU.

For example, the handover command is a UE context modification request (UE CONTEXT MODIFICATION REQUEST) message. The UE context modification request message may include an RRC reconfiguration handover command (Reconfiguration Handover Command) for instructing the UE to perform handover. When the UE receives an RRC reconfiguration After the handover instruction is configured, it is necessary to disconnect the wireless connection with the first gNB-DU, and try to access the second gNB-DU through the random access procedure.

Step 710: After sending the RRC reconfiguration signaling to the UE, the first gNB-DU stops sending downlink data to the UE.

Optionally, the first gNB-DU may also send a downlink data transmission status message to the CU-UPF network element to notify the CU-UPF of the transmission status of the downlink data packet (for example, to inform which SN number of the downlink data packet has been successfully transmitted, Mainly used to synchronize the SN number of PDCP data packets).

Step 711: The first gNB-DU sends a handover result to the gNB-CU-CP. The handover result is used to indicate that the first gNB-DU has interrupted the wireless connection with the UE and instruct the gNB-CU-CP to stop sending data to it.

Exemplarily, the handover result may be carried in a UE context modification response (UE CONTEXT MODIFICATION RESPONSE) message, and the UE context modification response message may include an RRC reconfiguration complete message.

Step 712: The gNB-CU-CP sends a second message to the CU-UPF network element. For example, the second message is a bearer context modification request (BEARER CONTEXT MODIFICATION REQUEST) message, and the message carries the downlink tunnel information of the second gNB-DU.

It should be noted that the second message is used to modify the user plane context of the CU-UPF network element. At this time, the uplink and downlink connection between the CU-UPF and the F1 interface of the second gNB-DU has been established, and there is no user plane data interaction with the first gNB-DU.

Step 713: The CU-UPF network element establishes an F1 downlink user between the second gNB-DU and the CU-UPF network element according to the downlink tunnel information of the second gNB-DU and the downlink tunnel information of the CU-UPF network element stored by itself Plane connection, generate F1 user plane context information between the second gNB-DU and CU-UPF network element, and report the modified F1 user plane context information to the SMF network element. The F1 user plane context information includes gNB-DU The downlink tunnel information of the CU-UPF network element, and the uplink tunnel information and downlink tunnel information of the CU-UPF network element.

In step 714, the SMF network element feeds back a bearer context modification response (BEARER CONTEXT MODIFICATION RESPONSE) to the CU-UPF network element through an N4 message. The bearer context modification response includes the completion of the F1 user plane context information modification.

In step 715, the CU-UPF network element sends a response message to the gNB-CU-CP. For example, the response message is a port context modification response (BEARER CONTEXT MODIFICATION RESPONSE) message, which is used to inform the gNB-CU-CP that the CU-UPF and the first The F1 interface of the second gNB-DU has uplink and downlink connections, and the user plane context modification of the F1 interface of the CU-UPF and the second gNB-DU.

Step 716: The UE establishes a wireless connection with the second gNB-DU through a random access procedure.

In step 717 and step 718, the UE sends an RRC reconfiguration complete (RRC Reconfiguration Complete) message to the gNB-CU-CP through the second gNB-DU. The RRC reconfiguration complete message is used to report that the radio connection with the second gNB-DU has been completed. The establishment is complete.

Step 719: After the second gNB-DU establishes a successful wireless connection with the UE, the second gNB-DU sends a downlink data transmission status to the CU-UPF network element. The downlink data transmission status is used to instruct the CU-UPF network element to start sending The second gNB-DU sends downlink data.

This step 715 to step 719 can be performed in parallel with step 714, that is, the CU-UPF network element can perform step 715 to step 719 without waiting for the SMF response message.

In step 720 and step 721, the gNB-CU-CP instructs the first gNB-DU to release the context information of the UE, and the first gNB-DU feeds back the context release completion message of the UE to the gNB-CU-CP.

With reference to Figure 7B, in this embodiment of the application, the SMF network element sends the control port information and verification information of the CU-UPF to the gNB-CU-CP when the session is established, thereby authorizing the gNB-CU-CP to be in the gNB-CU-CP. In the DU switching process, first modify the downlink user plane connection between the CU-UPF network element and the second gNB-DU, and finally report the modified user plane context to the SMF network element for synchronization, thereby ensuring the gNB-DU Switch quickly. It should be noted that the control connection in Figure 7B is different from the traditional E1 interface. It is a temporary connection similar to the user plane connection. It is not a device-level connection of the E1 interface. It is only associated with the session service. There is no device-level association. CU- UPF upgrade adjustments, etc., and gNB-CU-CP settings do not affect each other.

In the embodiment of this application, when the DU of the base station to which the UE is connected is switched, the CU-UPF uses the control port to obtain the downlink tunnel information of the second DU. Based on the downlink tunnel information of the second DU and the downlink tunnel information of the CU-UPF, the completion The F1 interface between the CU-UPF and the target DU is updated in the downlink user plane context to avoid the service delay and signaling overhead caused by the reconstruction of the F1 interface. In this way, after the UE handover is completed, the user plane communication of the F1 interface can be carried out between the second DU and the CU-UPF network element, so that the UE can perform uplink and downlink data transmission as soon as possible after the handover is completed, and reduce the delay caused by the terminal service Influence.

The second embodiment, combined with the description of scenario 1, as shown in FIG. 8, is a schematic flowchart of the second communication method provided in this embodiment of the application. The method includes the following steps.

Step 801: The second DU of the RAN receives the first information from the CU-CP of the RAN.

Wherein, the first information is used to authorize the user plane data packet sent by the second DU to have the authority to transmit control plane data. The first information may be carried in the N2 message. For example, the first message is a UE context modification/establishment request (UE context Modification/Establishment request) message.

Step 802: In the process of the terminal device switching from the first DU to the second DU, the second DU sends a user plane data packet carrying the downlink tunnel information of the second DU to the CU-UPF network element.

Wherein, the downlink tunnel information of the second DU may include at least one of an IP address and a GTP tunnel endpoint identifier (tunnel endpoint identifier, TEID). Exemplarily, the downlink tunnel information of the second DU may include a first IP address, and the first IP address is an IP address used for communication between the second DU and the CU-UPF network element.

In a possible embodiment, the CU-CP of the RAN may also obtain verification information from the SMF network element, and the CU-CP of the RAN may send the verification information to the second DU, so that the second DU sends the verification information to the CU-UPF network element. The sent user plane data packet may also carry the verification information, so that the CU-UPF network element can confirm whether the second DU has the authority to request the establishment of the first F1 user plane connection.

Step 803: The CU-UPF network element establishes a first F1 user plane connection between the CU-UPF network element and the second DU according to the downlink tunnel information on the second DU side and the downlink tunnel information of the CU-UPF network element.

Wherein, the uplink tunnel information is the uplink tunnel information of the F1 user plane connection between the CU-UPF network element and the first DU.

The downlink tunnel information of the CU-UPF network element may include at least one of an IP address and a GTP tunnel endpoint identifier (tunnel endpoint identifier, TEID). Exemplarily, the downlink tunnel information of the CU-UPF network element may include a second IP address, and the second IP address is the IP used when the CU-UPF network element side communicates between the first DU and the CU-UPF network element. address.

In a possible implementation, the above method may further include: the second DU obtains the uplink tunnel information of the CU-UPF network element from the CU-UPF network element through the CU-CP, and the second DU obtains the uplink tunnel information of the CU-UPF network element according to the CU-UPF network element. The tunnel information and the uplink tunnel information of the target DU establish an uplink user plane connection between the second DU and the CU-UPF network element, so that the second DU receives uplink data from the terminal device through the uplink user plane connection.

In a possible implementation, the above method may further include: the second DU may also send verification information to the CU-UPF network element through a user plane data packet, and the CU-UPF network element determines whether the second DU has acquired according to the verification information For the authority of the upstream tunnel information, when the CU-UPF network element determines that the second DU has the authority to obtain the upstream tunnel information, it sends the upstream tunnel information of the CU-UPF network element to the second DU; otherwise, it does not send it.

In the embodiment of this application, when the DU of the RAN accessed by the terminal device is switched, the CU-CP can authorize the user plane data packet of the second DU to which the terminal device needs to switch to have the authority to send control plane data, so that Utilize user plane data packets to send downlink tunnel information to the CU-UPF network element, thereby completing the update of the user plane context between the second DU accessed after the terminal device is switched and the CU-UPF network element, so as to avoid executing the second DU The F1 user plane context reconstruction between the CU-UPF network element and the CU-UPF network element can reduce the handover delay and improve the problem of large service delay and high signaling overhead caused by the F1 interface reconstruction.

In FIG. 9A, the embodiment of the present application further takes as an example the UE switching from the first gNB-DU connected to the gNB to the second gNB-DU of the gNB to illustrate the foregoing communication method.

Optionally, in step 900, during the PDU session establishment process, the SMF network element sends verification information to the gNB-CU-CP of the gNB through the AMF network element. The verification information may include a token, and the verification information is used for the CU. -The UPF network element determines the authority of the second gNB-DU, for example, for the CU-UPF network element to determine whether the second gNB-DU has the authority to obtain the uplink tunnel information of the CU-UPF network element, or in other words, for the CU- The UPF network element determines whether the second gNB-DU has the authority to modify the user plane context of the CU-UPF network element, in other words, it is used for the CU-UPF network element to determine whether the second gNB-DU has F1 to modify the CU-UPF network element The permissions of the interface.

From step 901 to step 902, the UE sends a measurement report to the gNB-CU-CP through the first gNB-DU to trigger the handover procedure.

The measurement report may include information such as the received signal power of the surrounding gNB-DU measured by the UE. The UE sends the measurement report to the gNB-CU-CP, and the gNB-CU-CP determines whether the UE needs to switch the gNB-DU.

Step 903: When the gNB-CU-CP determines that the UE needs to switch to the second gNB-DU, the gNB-CU-CP forwards the uplink tunnel information of the CU-UPF network element to the second gNB-DU. The gNB-DU sends a request, which is used to request the establishment of an F1 uplink user plane connection.

Wherein, the uplink tunnel information of the CU-UPF network element refers to the uplink tunnel information of the CU-UPF network element in the F1 user plane connection between the CU-UPF network element and the first gNB-DU, for example, the CU-UPF network The meta uplink tunnel information may include the IP address and the GTP tunnel endpoint identifier.

Wherein, the downlink tunnel information of the second gNB-DU is used to establish an F1 downlink user plane connection between the CU-UPF network element and the second gNB-DU, where the downlink tunnel information of the second gNB-DU may include an IP address And GTP tunnel endpoint identification.

Step 904: After receiving the uplink tunnel information of the CU-UPF network element, the second gNB-DU establishes the second gNB-DU and CU-DU according to the uplink tunnel information of the CU-UPF network element and the uplink tunnel information of the second gNB-DU. F1 uplink user plane connection between UPF network elements, so that the second gNB-DU can receive the uplink data of the terminal equipment. In addition, the second gNB-DU sends a response to the gNB-CU-CP, and the response includes the completion of the F1 uplink user plane connection establishment.

Step 905: The gNB-CU-CP sends a handover instruction to the first gNB-DU, where the handover instruction is used to instruct the UE to switch from connecting to the first gNB-DU to connecting to the second gNB-DU.

For example, the handover command is a UE context modification request (UE CONTEXT MODIFICATION REQUEST) message. The UE context modification request message may include an RRC reconfiguration handover command (Reconfiguration Handover Command) for instructing the UE to perform handover. When the UE receives an RRC reconfiguration After the handover instruction is configured, it is necessary to disconnect the wireless connection with the first gNB-DU, and try to access the second gNB-DU through the random access procedure.

Step 906: After the first gNB-DU sends RRC reconfiguration signaling to the UE, it stops sending downlink data to the UE.

Step 907: The first gNB-DU sends a Downlink Data Delivery Status (Downlink Data Delivery Status) message to the CU-UPF network element, which is used to report the data transmission status and instruct the CU-UPF to stop sending downlink data to it.

Step 908: The first gNB-DU sends a handover result to the gNB-CU-CP. The handover result is used to indicate that the first gNB-DU has interrupted the wireless connection with the UE and instruct the gNB-CU-CP to stop sending data to it.

Exemplarily, the handover result may be carried in a UE context modification response (UE CONTEXT MODIFICATION RESPONSE) message, and the UE context modification response message may include an RRC reconfiguration complete message.

Step 909: The UE establishes a wireless connection with the second gNB-DU through a random access procedure.

Step 910: The second gNB-DU sends a user plane data packet carrying downlink tunnel information, such as a user plane data packet, such as a Downlink Data Delivery Status message, to the CU-UPF network element, the user plane data packet Contains the downlink tunnel information of the second gNB-DU.

In a possible embodiment, the user plane data packet may further include verification information. When the verification information is included in step 910, the method embodiment may further include the following step 911.

In step 911, the CU-UPF network element performs verification according to the second gNB-CU authority of the verification information. For example, the CU-UPF network element determines whether the second gNB-CU has the authority to modify the F1 user plane connection according to the token. If so, the CU-UPF network element performs step 912; otherwise, step 912 is not performed.

In step 912, the CU-UPF network element sends the downlink data of the UE to the second gNB-DU after the verification is passed.

Step 913: The CU-UPF network element modifies the F1 user plane context information between the second gNB-DU and the CU-UPF network element, and reports the modified F1 user plane context information to the SMF network element.

In step 914, the SMF network element feeds back a bearer context modification response (BEARER CONTEXT MODIFICATION RESPONSE) to the CU-UPF network element through an N4 message, and the bearer context modification response includes the completion of the F1 user plane context information modification.

In step 915 and step 916, the UE sends an RRC reconfiguration complete (RRC Reconfiguration Complete) message to the gNB-CU-CP through the second gNB-DU. The RRC reconfiguration complete message is used to report that the radio connection with the second gNB-DU has been completed. The establishment is complete.

In step 917 and step 918, the gNB-CU-CP instructs the first gNB-DU to release the context information of the UE, and the first gNB-DU feeds back the context release completion message of the UE to the gNB-CU-CP.

In step 918, the SMF network element feeds back a UE context modification response message to the gNB-CU-CP through the AMF network element, and the UE context modification response message includes update information of the F1 user plane context.

With reference to Figure 9B, in this embodiment of the application, the core network element can authorize user plane data so that the user plane data packet sent by the second DU to the CU-UPF network element can carry the downlink tunnel information of the second DU Therefore, in the gNB-DU handover process, first modify the downlink user plane connection between the CU-UPF network element and the second gNB-DU, and finally report the modified user plane context to the SMF network element for synchronization to ensure Fast handover of gNB-DU.

In the embodiment of this application, when the DU of the base station to which the UE is connected is switched, the second DU uses user plane data packets to send downlink tunnel information to the CU-UPF network element, and the CU-UPF network element is based on the downlink tunnel information of the second DU and The uplink tunnel information of the CU-UPF completes the update of the user plane context of the F1 interface between the CU-UPF and the target DU, and avoids the service delay and signaling overhead caused by the reconstruction of the F1 interface. In this way, after the UE handover is completed, the user plane communication of the F1 interface can be carried out between the second DU and the CU-UPF network element, so that the UE can transmit uplink and downlink data as soon as possible after the handover is completed, and reduce the delay caused by the terminal service. Influence.

Scene two

Example three

Combined with the description of scenario 2, as shown in FIG. 10, it is a schematic flow diagram of the third communication method provided by the embodiment of this application. Referring to Figure 10, the method includes the following steps.

Step 1001: The second CU-CP of the second RAN receives control port information from the SMF network element through the first CU-CP of the first RAN.

Among them, the control port indicated by the control port information can be called a temporary E1 port, and the control port indicated by the control port information is the control port of the CU-UPF network element and corresponds to the PDU session of the terminal device Control port. In other words, the control port corresponds to the session one-to-one.

In a possible implementation, the control port information can be carried in the N2 message.

Step 1002: When the terminal device switches from the first DU of the first RAN to the second DU of the second RAN, the second CU-CP obtains from the second DU the downlink of the second DU used to establish the first F1 user plane connection Tunnel information.

Specifically, the terminal device may send a measurement report to the CU-CP of the first RAN through the first DU currently accessed, and the CU-CP of the first RAN forwards the measurement report to the CU-CP of the second RAN, and the second RAN According to the measurement report from the terminal device, the CU-CP determines that the terminal device needs to switch to the second DU. Wherein, the measurement report may include information such as the received signal power of the surrounding RAN DU measured by the UE.

Among them, the first DU is the source DU accessed by the terminal device before the handover, and the second DU is the target DU accessed by the terminal device after the handover. The downlink tunnel information of the second DU may include the IP address and the GTP tunnel endpoint identifier (tunnel endpoint identifier). , At least one of TEID). Exemplarily, the downlink tunnel information of the second DU may include a first IP address, and the first IP address is an IP address used for communication between the second DU and the CU-UPF network element.

In a possible implementation, the specific manner in which the CU-CP obtains the downlink tunnel information of the second DU from the second DU may refer to the foregoing step 602, which will not be repeated here.

Step 1003: In the process of the terminal device switching from the first DU to the second DU, the second CU-CP sends the downlink tunnel information to the CU-UPF network element through the control port.

Step 1004: The CU-UPF network element establishes an F1 downlink user plane connection between the CU-UPF network element and the second DU according to the downlink tunnel information of the second DU and the downlink tunnel information of the CU_UPF network element.

Among them, the F1 downlink user plane connection between the CU-UPF network element and the second DU is also referred to as the first F1 user plane connection in this article. The downlink tunnel information of the CU-UPF network element is the downlink tunnel information of the second F1 user plane connection between the CU-UPF network element and the first DU. The downlink tunnel information of the CU-UPF network element may include at least one of an IP address and a GTP tunnel endpoint identifier (tunnel endpoint identifier, TEID).

In a possible implementation, the foregoing method may further include: the second CU-CP of the second RAN obtains the uplink tunnel information of the CU-UPF network element from the CU-UPF network element through the control port, and the second CU-CP sends the information to the second CU-UPF network element. The second DU sends the uplink tunnel information of the CU-UPF network element, and the second DU establishes the uplink between the second DU and the CU-UPF network element according to the uplink tunnel information of the CU-UPF network element and the uplink tunnel information of the target DU The user plane connection, so that the second DU receives the uplink data from the terminal device through the uplink user plane connection.

In a possible implementation, the foregoing method may further include: the second CU-CP further sends verification information to the CU-UPF network element through the control port, and the CU-UPF network element determines whether the second CU-CP has the verification information according to the verification information. The authority to obtain the uplink tunnel information. When the CU-UPF network element determines that the second CU-CP has the authority to obtain the uplink tunnel information, it sends the uplink tunnel of the CU-UPF network element to the CU-UPF network element to the second CU-CP Information, otherwise, it is not sent.

In a possible implementation, the CU-UPF network element sends the downlink tunnel information of the second DU, and the uplink tunnel information and downlink tunnel information of the CU-UPF network element to the core network element.

In the embodiment of the present application, when the terminal device is switched from the first DU of the first RAN to the second DU of the second RAN within the service range of different RANs, the second CU-CP of the second RAN may be based on the The control port obtained by the element communicates with the CU-UPF network element. The CU-UPF network element can obtain the downlink tunnel information of the second DU from the second CU-UP based on the control port, thereby completing the second DU accessed after the terminal device is switched. The establishment of the downlink user plane connection between the CU-UPF network element and the CU-UPF network element can avoid the implementation of the F1 user plane interface reconstruction between the second DU and the CU-UPF network element, thereby reducing the handover delay and improving the F1 interface The problems of long service delay and high signaling overhead caused by reconstruction.

In FIG. 11A, the embodiment of the present application further takes as an example the UE switching from the first gNB-DU connected to the first gNB to the second gNB-DU of the second gNB to illustrate the foregoing communication method. It should be noted that the first gNB is the source gNB that the terminal accesses before handover, the second gNB is the target gNB that the terminal accesses after the handover, the first gNB-DU is the distributed unit of the source gNB, and the second gNB-DU is the target In the distributed unit of the gNB, the first gNB-CU-CP is the control plane entity of the source gNB, and the second gNB-CU-CP is the control plane entity of the target gNB.

Step 1100: During the establishment of the PDU session, the SMF network element sends the control port information of the CU-UPF network element corresponding to the PDU session to the first gNB-CU-CP of the first gNB through the AMF network element, The first gNB-CU-CP forwards the control port information to the second gNB-CU-CP of the second gNB.

In other words, the SMF network element issues the CU-UPF network element side control port information to the second gNB-CU-CP when the PDU session is established, so that the second gNB-CU-CP can be indicated by the control port information Establish communication with the CU-UPF network element, so that the second gNB-CU-CP of the second gNB can send control plane data to the CU-UPF network element. It is equivalent to that the SMF network element authorizes the second gNB-CU-CP to have the authority to modify the user plane context of the CU-UPF network element.

In a possible embodiment, the first message may also include verification information, for example, the verification information is a token. Or, the SMF network element sends the verification information to the second gNB-CU-CP through other messages. The verification information is used for the CU-UPF network element to determine the authority of the gNB-CU-CP, for example, for the CU-UPF network element to determine whether the second gNB-CU-CP has the authority to obtain the uplink tunnel information of the CU-UPF network element , In other words, for the CU-UPF network element to determine whether the second gNB-CU-CP has the authority to modify the user plane context of the CU-UPF network element, or for the CU-UPF network element to determine the second gNB-CU -Whether the CP has the authority to modify the F1 interface of the CU-UPF network element.

In step 1101 and step 1102, the UE sends a measurement report to the gNB-CU-CP of the first gNB through the gNB-DU of the first gNB.

Wherein, the first gNB-DU is the source gNB-DU connected before the UE handover, the measurement report may include information such as the received signal power of surrounding gNB-DUs measured by the UE, and the UE sends the measurement report to the first gNB-CU- CP, gNB-CU-CP determines whether the UE needs to switch gNB-DU.

Step 1103: When the first gNB-CU-CP determines that the UE needs to switch gNB-DU according to the measurement report, the first gNB-CU-CP sends a handover request to the second gNB-CU-CP, and the handover request is used to request the terminal The device switches to the second gNB-DU of the second gNB-CU-CP.

Step 1104: The second gNB-CU-CP requests the CU-UPF network element for uplink tunnel information of the CU-UPF network element through the control port.

Wherein, the uplink tunnel information of the CU-UPF network element refers to the uplink tunnel information of the CU-UPF network element in the F1 user plane connection between the CU-UPF network element and the first gNB-DU, for example, the CU-UPF network The meta uplink tunnel information may include the IP address and the GTP tunnel endpoint identifier.

In a possible embodiment, in this step 1104, the second gNB-CU-CP may also send verification information to the CU-UPF network element through the control port. For example, the second gNB-CU-CP may also send verification information through the control port. The port sends a bearer context modification request (BEARER CONTEXT MODIFICATION REQUEST) to the CU-UPF network element, where the bearer context modification request carries a token. When the verification information is included in step 1104, the method embodiment may further include the following step 1105.

Step 1105: The CU-UPF network element verifies the authority of the second gNB-CU-CP according to the verification information. For example, the CU-UPF network element determines whether the second gNB-CU-CP has the authority to obtain uplink tunnel information according to the token. If so, the CU-UPF network element performs step 1106; otherwise, step 1106 is not performed.

Step 1106: The CU-UPF network element sends the uplink tunnel information of the CU-UPF network element to the second gNB-CU-CP.

Step 1107: The second gNB-CU-CP forwards the uplink tunnel information of the CU-UPF network element to the second gNB-DU, and also sends a request to the second gNB-DU. The request is used to request the second gNB-DU Downlink tunnel information.

Step 1108: After receiving the uplink tunnel information of the CU-UPF network element, the second gNB-DU establishes the second gNB-DU and CU-DU according to the uplink tunnel information of the CU-UPF network element and the uplink tunnel information of the second gNB-DU. F1 uplink user plane connection between UPF network elements, so that the second gNB-DU can receive the uplink data of the terminal equipment. In addition, the second gNB-DU also sends the downlink tunnel information of the second gNB-DU to the gNB-CU-CP.

Step 1109: The second gNB-CU-CP sends a handover request response to the first gNB-CU-CP. The handover request response includes indication information for instructing the UE to switch from connecting to the first gNB-DU to connecting to the second gNB-DU .

In step 1110 and step 1111, the first gNB-CU-CP sends a handover instruction to the first gNB-DU, where the handover instruction is used to instruct the UE to switch from connecting to the first gNB-DU to connecting to the second gNB-DU.

For example, the handover command is a UE context modification request (UE CONTEXT MODIFICATION REQUEST) message. The UE context modification request message may include an RRC reconfiguration handover command (Reconfiguration Handover Command) for instructing the UE to perform handover. When the UE receives an RRC reconfiguration After the handover instruction is configured, it is necessary to disconnect the wireless connection with the first gNB-DU, and try to access the second gNB-DU through the random access procedure.

Step 1112: After the first gNB-DU sends RRC reconfiguration signaling to the UE, it stops sending downlink data to the UE.

Optionally, the first gNB-DU may also send a downlink data transmission status message to the CU-UPF network element to notify the CU-UPF of the transmission status of the downlink data packet (for example, to inform which SN number of the downlink data packet has been successfully transmitted, Mainly used to synchronize the SN number of PDCP data packets).

Step 1113: The first gNB-DU sends a handover result to the first gNB-CU-CP. The handover result is used to indicate that the first gNB-DU has interrupted the wireless connection with the UE, and instruct the first gNB-CU-CP to stop sending to it. send data.

Exemplarily, the handover result may be carried in a UE context modification response (UE CONTEXT MODIFICATION RESPONSE) message, and the UE context modification response message may include an RRC reconfiguration complete message.

Step 1114: The second gNB-CU-CP sends a second message to the CU-UPF network element. For example, the second message is a bearer context modification request (BEARER CONTEXT MODIFICATION REQUEST) message, which carries the downlink tunnel of the second gNB-DU information.

It should be noted that the second message is used to modify the user plane context of the CU-UPF network element. At this time, the uplink and downlink connection between the CU-UPF and the F1 interface of the second gNB-DU has been established, and there is no user plane data interaction with the first gNB-DU.

Step 1115: The CU-UPF network element establishes an F1 downlink user between the second gNB-DU and the CU-UPF network element according to the downlink tunnel information of the second gNB-DU and the downlink tunnel information of the CU-UPF network element stored by itself Plane connection, generate F1 user plane context information between the second gNB-DU and CU-UPF network element, and report the modified F1 user plane context information to the SMF network element. The F1 user plane context information includes gNB-DU The downlink tunnel information of the CU-UPF network element, and the uplink tunnel information and downlink tunnel information of the CU-UPF network element.

Step 1116: The SMF network element feeds back a bearer context modification response (BEARER CONTEXT MODIFICATION RESPONSE) to the CU-UPF network element through an N4 message, and the bearer context modification response includes the completion of the F1 user plane context information modification.

Step 1117: The CU-UPF network element sends a response message to the second gNB-CU-CP. For example, the response message is a port context modification response (BEARER CONTEXT MODIFICATION RESPONSE) message, used to inform the gNB-CU-CP that the CU-UPF has been completed The uplink and downlink connection with the F1 interface of the second gNB-DU, and the user plane context modification of the F1 interface between the CU-UPF and the second gNB-DU.

Step 1118: The UE disconnects from the first gNB-DU, and the UE establishes a connection with the second gNB-DU through a random access procedure.

In step 1119 and step 1120, the UE sends an RRC reconfiguration complete (RRC Reconfiguration Complete) message to the second gNB-CU-CP through the second gNB-DU. The RRC reconfiguration complete message is used to report the radio connection with the second gNB-DU. The connection has been established.

Step 1121: After the second gNB-DU establishes a successful wireless connection with the UE, the second gNB-DU sends a downlink data transmission status to the CU-UPF network element. The downlink data transmission status is used to instruct the CU-UPF network element to start sending The second gNB-DU sends downlink data.

This step 1117 to step 1121 can be performed in parallel with step 1116, that is, the CU-UPF network element can perform step 1117 to step 1121 without waiting for the SMF response message.

Step 1122: The second gNB-CU-CP instructs the first gNB-CU-CP to release the context information of the UE.

In step 1123 and step 1124, the first gNB-CU-CP instructs the first gNB-DU to release the context information of the UE, and the first gNB-DU feeds back the context release completion message of the UE to the first gNB-CU-CP.

Step 1125: The second gNB-CU-CP reports the updated context information of the UE to the AMF network element, where the updated context information of the UE includes information about the second gNB-CU-CP serving the UE.

With reference to Figure 11B, in this embodiment of the application, the SMF network element sends the control port information and verification information of the CU-UPF to the target gNB-CU-CP through the source gNB-CU-CP when the session is established, thereby authorizing In the gNB-DU handover process, the target gNB-CU-CP first modifies the downlink user plane connection between the CU-UPF network element and the second gNB-DU, and finally reports the modified user plane context to the SMF network element. Synchronization, thus ensuring fast handover of gNB-DU. It should be noted that the control connection in Figure 11B is different from the traditional E1 interface. It is a temporary connection similar to the user plane connection. It is not a device-level connection of the E1 interface. It is only associated with the session service. There is no device-level association. CU- UPF upgrade adjustments, etc., and the settings of the target gNB-CU-CP do not affect each other.

In the embodiment of this application, when the UE performs a DU handover across RAN, the CU-UPF uses the control port to obtain the downlink tunnel information of the second DU, and completes the CU-UPF based on the downlink tunnel information of the second DU and the downlink tunnel information of the CU-UPF. The F1 interface between the UPF and the target DU is updated in the downlink user plane context to avoid service delay and signaling overhead caused by the reconstruction of the F1 interface. In this way, after the UE handover is completed, the user plane communication of the F1 interface can be carried out between the second DU and the CU-UPF network element, so that the UE can transmit uplink and downlink data as soon as possible after the handover is completed, and reduce the delay caused by the terminal service. Influence.

Combined with the description of the foregoing scenario two, the fourth embodiment, as shown in FIG. 12, is a schematic flow diagram of the fourth communication method provided by the embodiment of this application. Referring to Figure 12, the method includes the following steps.

Step 1201: The second DU of the second RAN receives the first information of the first CU-CP of the first RAN through the second CU-CP of the second RAN, and the first information is that the first CU-CP of the first RAN is from Obtained by SMF network element.

Wherein, the first information is used to authorize the user plane data packet sent by the second DU to have the authority to transmit control plane data. The first information may be carried in the N2 message. For example, the first message is a UE context modification/establishment request (UE context Modification/Establishment request) message.

Step 1202: In the process of the terminal device switching from the first DU to the second DU, the second DU sends a user plane data packet carrying the downlink tunnel information of the second DU to the CU-UPF network element.

Wherein, the downlink tunnel information of the second DU may include at least one of an IP address and a GTP tunnel endpoint identifier (tunnel endpoint identifier, TEID). Exemplarily, the downlink tunnel information of the second DU may include a first IP address, and the first IP address is an IP address used for communication between the second DU and the CU-UPF network element.

In a possible embodiment, the second CU-CP of the second RAN may also obtain verification information from the SMF network element, and the second CU-CP of the second RAN may send the verification information to the second DU, so that the first The user plane data packet sent by the second DU to the CU-UPF network element may also carry the verification information, so that the CU-UPF network element can confirm whether the second DU has the authority to request the establishment of the first F1 user plane connection.

Step 1203: The CU-UPF network element establishes a first F1 user plane connection between the CU-UPF network element and the second DU according to the downlink tunnel information on the second DU side and the downlink tunnel information of the CU-UPF network element.

The downlink tunnel information of the CU-UPF network element may include at least one of an IP address and a GTP tunnel endpoint identifier (tunnel endpoint identifier, TEID). Exemplarily, the downlink tunnel information of the CU-UPF network element may include a second IP address, and the second IP address is the IP used when the CU-UPF network element side communicates between the first DU and the CU-UPF network element. address.

In a possible implementation, the foregoing method may further include: the second DU obtains the uplink tunnel information of the CU-UPF network element from the CU-UPF network element through the second CU-CP, and the second DU obtains the uplink tunnel information of the CU-UPF network element according to the CU-UPF network element. The uplink tunnel information of the target DU and the uplink tunnel information of the target DU establish an uplink user plane connection between the second DU and the CU-UPF network element, so that the second DU receives uplink data from the terminal device through the uplink user plane connection.

In a possible implementation, the above method may further include: the second DU may also send verification information to the CU-UPF network element through a user plane data packet, and the CU-UPF network element determines whether the second DU has acquired according to the verification information For the authority of the upstream tunnel information, when the CU-UPF network element determines that the second DU has the authority to obtain the upstream tunnel information, it sends the upstream tunnel information of the CU-UPF network element to the second DU; otherwise, it does not send it.

In the embodiment of the present application, when the DU of the RAN accessed by the terminal device is switched, the second CU-CP can authorize the user plane data packet of the second DU to which the terminal device needs to switch to have the authority to send control plane data. Therefore, the user plane data packet can be used to send downlink tunnel information to the CU-UPF network element, so as to complete the update of the user plane context between the second DU accessed by the terminal device after the handover and the CU-UPF network element, which can avoid the execution of the first Second, the F1 user plane context reconstruction between the DU and the CU-UPF network element can reduce the handover delay and improve the problem of large service delay and large signaling overhead caused by the reconstruction of the F1 interface.

In FIG. 13A, the embodiment of the present application further uses the UE switching from the first gNB-DU connected to the first gNB to the second gNB-DU of the second gNB as an example to illustrate the foregoing communication method. It should be noted that the first gNB is the source gNB that the terminal accesses before handover, the second gNB is the target gNB that the terminal accesses after the handover, the first gNB-DU is the distributed unit of the source gNB, and the second gNB-DU is the target In the distributed unit of the gNB, the first gNB-CU-CP is the control plane entity of the source gNB, and the second gNB-CU-CP is the control plane entity of the target gNB.

Optionally, in step 1300, during the establishment of the PDU session, the SMF network element sends verification information to the gNB-CU-CP of the gNB through the AMF network element. The verification information may include a token, and the verification information is used for the CU. -The UPF network element determines the authority of the second gNB-DU, for example, for the CU-UPF network element to determine whether the second gNB-DU has the authority to obtain the uplink tunnel information of the CU-UPF network element, or in other words, for the CU- The UPF network element determines whether the second gNB-DU has the authority to modify the user plane context of the CU-UPF network element, in other words, it is used for the CU-UPF network element to determine whether the second gNB-DU has F1 to modify the CU-UPF network element The permissions of the interface.

From step 1301 to step 1302, the UE sends a measurement report to the gNB-CU-CP of the first gNB through the gNB-DU of the first gNB.

Wherein, the first gNB-DU is the source gNB-DU connected before the UE handover, the measurement report may include information such as the received signal power of surrounding gNB-DUs measured by the UE, and the UE sends the measurement report to the first gNB-CU- CP, gNB-CU-CP determines whether the UE needs to switch gNB-DU.

Step 1303: When the first gNB-CU-CP determines that the UE needs to switch gNB-DU according to the measurement report, the first gNB-CU-CP sends a switching request to the second gNB-CU-CP, and the switching request is used to request the terminal The device switches to the second gNB-DU of the second gNB-CU-CP.

Step 1304: When the second gNB-CU-CP determines that the UE needs to switch to the second gNB-DU, the second gNB-CU-CP sends the uplink tunnel information of the CU-UPF network element to the second gNB-DU. In addition, A request is also sent to the second gNB-DU, where the request is used to request downlink tunnel information of the second gNB-DU, where the downlink tunnel information of the second gNB-DU is used to establish an F1 downlink user plane connection.

Wherein, the uplink tunnel information of the CU-UPF network element refers to the uplink tunnel information of the CU-UPF network element in the F1 user plane connection between the CU-UPF network element and the first gNB-DU, for example, the CU-UPF network The meta uplink tunnel information may include the IP address and the GTP tunnel endpoint identifier.

Wherein, the downlink tunnel information of the second gNB-DU is used to establish an F1 downlink user plane connection between the CU-UPF network element and the second gNB-DU, where the downlink tunnel information of the second gNB-DU may include an IP address And GTP tunnel endpoint identification.

Step 1305: After receiving the uplink tunnel information of the CU-UPF network element, the second gNB-DU establishes the second gNB-DU and CU-DU according to the uplink tunnel information of the CU-UPF network element and the uplink tunnel information of the second gNB-DU. F1 uplink user plane connection between UPF network elements, so that the second gNB-DU can receive the uplink data of the terminal equipment. In addition, the second gNB-DU sends a response to the second gNB-CU-CP, and the response includes the completion of the F1 uplink user plane connection establishment.

Step 1306: The second gNB-CU-CP sends a switching instruction to the first gNB-DU, where the switching instruction is used to instruct the UE to switch from connecting to the first gNB-DU to connecting to the second gNB-DU.

For example, the handover command is a UE context modification request (UE CONTEXT MODIFICATION REQUEST) message. The UE context modification request message may include an RRC reconfiguration handover command (Reconfiguration Handover Command) for instructing the UE to perform handover. When the UE receives an RRC reconfiguration After the handover instruction is configured, it is necessary to disconnect the wireless connection with the first gNB-DU, and try to access the second gNB-DU through the random access procedure.

In step 1307 and step 1308, the first gNB-CU-CP sends a handover instruction to the first gNB-DU, where the handover instruction is used to instruct the UE to switch from connecting to the first gNB-DU to connecting to the second gNB-DU.

For example, the handover command is a UE context modification request (UE CONTEXT MODIFICATION REQUEST) message. The UE context modification request message may include an RRC reconfiguration handover command (Reconfiguration Handover Command) for instructing the UE to perform handover. When the UE receives an RRC reconfiguration After the handover instruction is configured, it is necessary to disconnect the wireless connection with the first gNB-DU, and try to access the second gNB-DU through the random access procedure.

Step 1309: The first gNB-DU sends a Downlink Data Delivery Status (Downlink Data Delivery Status) message to the CU-UPF network element, which is used to report the data transmission status and instruct the CU-UPF to stop sending downlink data to it.

Step 1310: The first gNB-DU sends a handover result to the first gNB-CU-CP. The handover result is used to indicate that the first gNB-DU has interrupted the wireless connection with the UE, and instruct the first gNB-CU-CP to stop sending to it. send data.

Exemplarily, the handover result may be carried in a UE context modification response (UE CONTEXT MODIFICATION RESPONSE) message, and the UE context modification response message may include an RRC reconfiguration complete message.

Step 1311: The UE disconnects from the first gNB-DU, and the UE establishes a connection with the second gNB-DU through a random access procedure.

Step 1312: The second gNB-DU sends a user plane data packet carrying downlink tunnel information, such as a user plane data packet, such as a Downlink Data Delivery Status message, to the CU-UPF network element, the user plane data packet Contains the downlink tunnel information of the second gNB-DU.

In a possible embodiment, the user plane data packet may further include verification information. When the verification information is included in step 1312, the method embodiment may further include the following step 1313.

Step 1313: The CU-UPF network element performs verification according to the second gNB-CU authority of the verification information. For example, the CU-UPF network element determines whether the second gNB-CU has the authority to modify the F1 user plane connection according to the token. If so, the CU-UPF network element performs step 1314; otherwise, step 1314 is not performed.

Step 1314: The CU-UPF network element sends the downlink data of the UE to the second gNB-CU after the verification is passed.

Step 1315: The CU-UPF network element modifies the F1 user plane context information between the second gNB-DU and the CU-UPF network element, and reports the modified F1 user plane context information to the SMF network element.

Step 1316: The SMF network element feeds back a bearer context modification response (BEARER CONTEXT MODIFICATION RESPONSE) to the CU-UPF network element through an N4 message, and the bearer context modification response includes the completion of the F1 user plane context information modification.

In steps 1317 and 1318, the UE sends an RRC reconfiguration complete (RRC Reconfiguration Complete) message to the gNB-CU-CP through the second gNB-DU. The RRC reconfiguration complete message is used to report that the radio connection with the second gNB-DU has been completed. The establishment is complete.

Step 1319: The second gNB-CU-CP instructs the first gNB-CU-CP to release the context information of the UE.

In step 1320 and step 1321, the first gNB-CU-CP instructs the first gNB-DU to release the context information of the UE, and the first gNB-DU feeds back the context release completion message of the UE to the first gNB-CU-CP.

Step 1322: The second gNB-CU-CP reports the updated context information of the UE to the AMF network element, where the updated context information of the UE includes information about the second gNB-CU-CP serving the UE.

With reference to Figure 13B, in this embodiment of the application, the core network element can authorize user plane data so that the user plane data packet sent by the second DU to the CU-UPF network element can carry the downlink tunnel information of the second DU Therefore, in the gNB-DU handover process, first modify the downlink user plane connection between the CU-UPF network element and the second gNB-DU, and finally report the modified user plane context to the SMF network element for synchronization to ensure Fast handover of gNB-DU.

In the embodiment of this application, when the DU of the base station to which the UE is connected is switched, the second DU uses user plane data packets to send downlink tunnel information to the CU-UPF network element, and the CU-UPF network element is based on the downlink tunnel information of the second DU and The uplink tunnel information of the CU-UPF completes the update of the user plane context of the F1 interface between the CU-UPF and the target DU, and avoids the service delay and signaling overhead caused by the reconstruction of the F1 interface. In this way, after the UE handover is completed, the user plane communication of the F1 interface can be carried out between the second DU and the CU-UPF network element, so that the UE can perform uplink and downlink data transmission as soon as possible after the handover is completed, and reduce the delay caused by the terminal service Influence.

Regarding the above-mentioned Embodiment 1 to Embodiment 4, it should be noted that: (1) The above-mentioned Embodiment 1 and Embodiment 4 can be implemented separately in different scenarios, or can be implemented in combination in the same scenario, or different implementations The different solutions involved in the examples can also be implemented in combination (for example, part or all of the solutions involved in the first embodiment can be implemented in combination with the third embodiment), which is not specifically limited.

(2) The step numbers of the flowcharts described in the embodiments of the present application are only an example of the execution process, and do not constitute a restriction on the order of execution of the steps. There is no timing dependency between the embodiments of the present application. There is no strict execution order between the steps.

The foregoing mainly introduces the solution provided by the embodiment of the present application from the perspective of the interaction between the network device and the terminal device. It can be understood that, in order to implement the above-mentioned functions, the network device or the terminal device may include a corresponding hardware structure and/or software module for performing each function. Those skilled in the art should easily realize that in combination with the units and algorithm steps of the examples described in the embodiments disclosed herein, the embodiments of the present application can be implemented in the form of hardware or a combination of hardware and computer software. Whether a certain function is executed by hardware or computer software-driven hardware depends on the specific application and design constraint conditions of the technical solution. Professionals and technicians can use different methods for each specific application to implement the described functions, but such implementation should not be considered as going beyond the scope of this application.

The embodiments of the present application may divide the terminal device and the network device into functional units according to the foregoing method examples. For example, each functional unit may be divided corresponding to each function, or two or more functions may be integrated into one unit. The above-mentioned integrated unit can be implemented in the form of hardware or software functional unit.

In the case of using an integrated unit, FIG. 14 shows a possible exemplary block diagram of a device involved in an embodiment of the present application. As shown in FIG. 14, the apparatus 1400 may include: a processing unit 1402 and a communication unit 1403. The processing unit 1402 is used to control and manage the actions of the device 1400. The communication unit 1403 is used to support communication between the apparatus 1400 and other devices. Optionally, the communication unit 1403 is also called a transceiving unit, and may include a receiving unit and/or a sending unit, which are used to perform receiving and sending operations, respectively. The device 1400 may further include a storage unit 1401 for storing program codes and/or data of the device 1400.

The apparatus 1400 may be a radio access network device (such as a control plane entity or a distributed unit of a RAN) in any of the foregoing embodiments, or may also be a chip set in the radio access network device. The processing unit 1402 may support the apparatus 1400 to perform the actions of the radio access network device in the above method examples. Alternatively, the processing unit 1402 mainly executes the internal actions of the radio access network device in the method example, and the communication unit 1403 can support communication between the apparatus 1400 and the radio access network device.

The device 1400 may be the CU-UPF network element in any of the foregoing embodiments, or may also be a chip in the CU-UPF network element. The processing unit 1402 may support the device 1400 to execute the actions of the CU-UPF network element in the above method examples. Alternatively, the processing unit 1402 mainly executes the internal actions of the CU-UPF network element in the method example, and the communication unit 1403 may support communication between the device 1400 and the CU-UPF network element. For example, the processing unit 1402 may be used to perform the internal actions of the CU-UPF network element in the method example; the communication unit 1403 may be used to perform the transceiving actions of the CU-UPF network element in the method example.

It should be understood that the division of units in the above device is only a division of logical functions, and may be fully or partially integrated into one physical entity in actual implementation, or may be physically separated. In addition, the units in the device can be all implemented in the form of software called by processing elements; they can also be all implemented in the form of hardware; part of the units can also be implemented in the form of software called by the processing elements, and some of the units can be implemented in the form of hardware. For example, each unit can be a separately set up processing element, or it can be integrated in a certain chip of the device for implementation. In addition, it can also be stored in the memory in the form of a program, which is called and executed by a certain processing element of the device. Function. In addition, all or part of these units can be integrated together or implemented independently. The processing element described here can also become a processor, which can be an integrated circuit with signal processing capabilities. In the implementation process, each step of the above method or each of the above units may be implemented by an integrated logic circuit of hardware in a processor element or implemented in a form of being called by software through a processing element.

In an example, the unit in any of the above devices may be one or more integrated circuits configured to implement the above method, for example: one or more application specific integrated circuits (ASIC), or, one or Multiple microprocessors (digital singnal processors, DSPs), or, one or more field programmable gate arrays (Field Programmable Gate Arrays, FPGAs), or a combination of at least two of these integrated circuits. For another example, when the unit in the device can be implemented in the form of a processing element scheduler, the processing element can be a processor, such as a general-purpose central processing unit (central processing unit, CPU), or other processors that can call programs. For another example, these units can be integrated together and implemented in the form of a system-on-a-chip (SOC).

The above receiving unit is an interface circuit of the device for receiving signals from other devices. For example, when the device is implemented as a chip, the receiving unit is an interface circuit used by the chip to receive signals from other chips or devices. The above unit for sending is an interface circuit of the device for sending signals to other devices. For example, when the device is implemented as a chip, the sending unit is an interface circuit used by the chip to send signals to other chips or devices.

Please refer to FIG. 15, which is a schematic structural diagram of a radio access network device provided by an embodiment of the application. It may be the terminal device in the above embodiment, and is used to implement the operation of the terminal device in the above embodiment. As shown in FIG. 15, the wireless access network equipment includes: an antenna 1510, a radio frequency part 1520, and a signal processing part 1530. The antenna 1510 is connected to the radio frequency part 1520. In the downlink direction, the radio frequency part 1520 receives the information sent by the wireless access network device through the antenna 1510, and sends the information sent by the wireless access network device to the signal processing part 1530 for processing. In the upstream direction, the signal processing part 1530 processes the information of the terminal equipment and sends it to the radio frequency part 1520, and the radio frequency part 1520 processes the information of the terminal equipment and sends it to the core network equipment via the antenna 1510.

The signal processing part 1530 may include a modem subsystem, which is used to process data at various communication protocol layers; it may also include a central processing subsystem, which is used to process terminal equipment operating systems and application layers.

The modem subsystem may include one or more processing elements 1531, for example, including a main control CPU and other integrated circuits. In addition, the modem subsystem may also include a storage element 1532 and an interface circuit 1533. The storage element 1532 is used to store data and programs, but the program used to execute the method performed by the terminal device in the above method may not be stored in the storage element 1532, but stored in a memory outside the modem subsystem, When in use, the modem subsystem is loaded and used. The interface circuit 1533 is used to communicate with other subsystems.

The modem subsystem can be implemented by a chip. The chip includes at least one processing element and an interface circuit, where the processing element is used to execute each step of any method performed by the above wireless access network device, and the interface circuit is used to communicate with other Device communication. In one implementation, the units of the wireless access network equipment that implement each step in the above method can be implemented in the form of a processing element scheduler. For example, the device for the wireless access network equipment includes a processing element and a storage element, and the processing element calls the storage The program stored by the component to execute the method executed by the terminal device in the above method embodiment. The storage element may be a storage element whose processing element is on the same chip, that is, an on-chip storage element.

In another implementation, the program used to execute the method executed by the wireless access network device in the above method may be a storage element on a different chip from the processing element, that is, an off-chip storage element. At this time, the processing element calls or loads a program from the off-chip storage element on the on-chip storage element to call and execute the method executed by the radio access network device in the above method embodiment.

In another implementation, the unit of the radio access network device that implements each step in the above method may be configured as one or more processing elements, and these processing elements are arranged on the modem subsystem, where the processing elements may be Integrated circuits, for example: one or more ASICs, or, one or more DSPs, or, one or more FPGAs, or a combination of these types of integrated circuits. These integrated circuits can be integrated together to form a chip.

The units of the radio access network device that implement each step in the above method can be integrated together and implemented in the form of an SOC, and the SOC chip is used to implement the above method. At least one processing element and a storage element can be integrated in the chip, and the above method executed by the wireless access network device can be implemented by the processing element calling the stored program of the storage element; or, at least one integrated circuit can be integrated in the chip for The method implemented by the above wireless access network device is implemented; or, the above implementation manners can be combined. The functions of some units are implemented in the form of calling programs by processing elements, and the functions of some units are implemented in the form of integrated circuits.

It can be seen that the above apparatus for wireless access network equipment may include at least one processing element and an interface circuit, wherein at least one processing element is used to execute any method performed by the wireless access network equipment provided in the above method embodiments. The processing element can execute part or all of the steps performed by the wireless access network device in the first way: calling the program stored in the storage element; or in the second way: through the integrated logic of the hardware in the processor element The circuit is combined with instructions to execute part or all of the steps executed by the terminal device; of course, part or all of the steps executed by the terminal device can also be executed by combining the first method and the second method.

The processing element here is the same as that described above, and can be implemented by a processor, and the function of the processing element can be the same as the function of the processing unit described in FIG. 14. Exemplarily, the processing element may be a general-purpose processor, such as a CPU, or one or more integrated circuits configured to implement the above methods, such as: one or more ASICs, or, one or more microprocessors DSP , Or, one or more FPGAs, etc., or a combination of at least two of these integrated circuit forms. The storage element may be realized by a memory, and the function of the storage element may be the same as the function of the storage unit described in FIG. 14. The storage element may be realized by a memory, and the function of the storage element may be the same as the function of the storage unit described in FIG. 14. The storage element can be one memory or a collective term for multiple memories.

The wireless access network device shown in FIG. 15 can implement each of the wireless access network devices in the method embodiments illustrated in FIG. 6, FIG. 7A, FIG. 8, FIG. 9A, FIG. 10, FIG. 11A, FIG. 12, and FIG. 13A. process. The operations and/or functions of the various modules in the radio access network device shown in FIG. 15 are used to implement the corresponding processes in the foregoing method embodiments. For details, please refer to the descriptions in the foregoing method embodiments. To avoid repetition, detailed descriptions are appropriately omitted here.

Please refer to FIG. 16, which is a schematic structural diagram of a CU-UPF network element provided by an embodiment of this application. It is used to implement the operation of the CU-UPF network element in the above embodiment. As shown in FIG. 16, the CU-UPF network element includes: an antenna 1601, a radio frequency device 1602, and a baseband device 1603. The antenna 1601 is connected to the radio frequency device 1602. In the upstream direction, the radio frequency device 1602 receives the information sent by the wireless access network device through the antenna 1601, and sends the information sent by the wireless access network device to the baseband device 1603 for processing. In the downlink direction, the baseband device 1603 processes the information of the wireless access network equipment and sends it to the radio frequency device 1602. The radio frequency device 1602 processes the information of the radio access network equipment and sends it to the radio access network equipment via the antenna 1601.

The baseband device 1603 may include one or more processing elements 16031, for example, a main control CPU and other integrated circuits. In addition, the baseband device 1603 may also include a storage element 16032 and an interface 16033. The storage element 16032 is used to store programs and data; the interface 16033 is used to exchange information with the radio frequency device 1602. The interface is, for example, a common public radio interface. , CPRI). The above device for the CU-UPF network element may be located in the baseband device 1603. For example, the above device for the CU-UPF network element may be a chip on the baseband device 1603. The chip includes at least one processing element and an interface circuit. The element is used to perform the steps of any method performed by the above CU-UPF network element, and the interface circuit is used to communicate with other devices. In one implementation, the unit of the CU-UPF network element that implements each step in the above method can be implemented in the form of a processing element scheduler. For example, the device used for the CU-UPF network element includes a processing element and a storage element, and the processing element calls the storage The program stored by the component is used to execute the method executed by the CU-UPF network element in the above method embodiment. The storage element may be a storage element with the processing element on the same chip, that is, an on-chip storage element, or a storage element on a different chip from the processing element, that is, an off-chip storage element.

In another implementation, the unit of the CU-UPF network element that implements each step in the above method may be configured as one or more processing elements, and these processing elements are arranged on the baseband device, where the processing elements may be integrated circuits, For example: one or more ASICs, or, one or more DSPs, or, one or more FPGAs, or a combination of these types of integrated circuits. These integrated circuits can be integrated together to form a chip.

The units of the CU-UPF network element that implement the steps in the above method can be integrated together and implemented in the form of a system-on-a-chip (SOC). For example, the baseband device includes the SOC chip to implement the above method . At least one processing element and storage element can be integrated in the chip, and the above CU-UPF network element execution method can be implemented by the processing element calling the stored program of the storage element; or, at least one integrated circuit can be integrated in the chip for The method for implementing the above CU-UPF network element is implemented; or, the above implementation manners can be combined. The functions of some units are implemented in the form of processing element calling programs, and the functions of some units are implemented in the form of integrated circuits.

It can be seen that the above apparatus for a CU-UPF network element may include at least one processing element and an interface circuit, wherein at least one processing element is used to execute any of the methods performed by the CU-UPF network element provided in the above method embodiments. The processing element can execute part or all of the steps executed by the CU-UPF network element in the first way: calling the program stored in the storage element; or in the second way: through the integrated logic of the hardware in the processor element The circuit combined with instructions executes some or all of the steps performed by the CU-UPF network element; of course, it is also possible to combine the first method and the second method to execute some or all of the steps performed by the CU-UPF network element.

The processing element here is the same as that described above, and can be implemented by a processor, and the function of the processing element can be the same as the function of the processing unit described in FIG. 14. Exemplarily, the processing element may be a general-purpose processor, such as a CPU, or one or more integrated circuits configured to implement the above methods, such as: one or more ASICs, or, one or more microprocessors DSP , Or, one or more FPGAs, etc., or a combination of at least two of these integrated circuit forms. The storage element may be realized by a memory, and the function of the storage element may be the same as the function of the storage unit described in FIG. 14. The storage element may be realized by a memory, and the function of the storage element may be the same as the function of the storage unit described in FIG. 14. The storage element can be one memory or a collective term for multiple memories.

The CU-UPF network element shown in FIG. 16 can implement each process involving the CU-UPF network element in the foregoing method embodiment. The operations and/or functions of the various modules in the CU-UPF network element shown in FIG. 16 are used to implement the corresponding processes in the foregoing method embodiments. For details, please refer to the descriptions in the foregoing method embodiments. To avoid repetition, detailed descriptions are appropriately omitted here.

Those skilled in the art should understand that the embodiments of the present application can be provided as a method, a system, or a computer program product. Therefore, this application may adopt the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware. Moreover, this 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, CD-ROM, optical storage, etc.) containing computer-usable program codes.

This application is described with reference to flowcharts and/or block diagrams of methods, equipment (systems), and computer program products according to this application. It should be understood that each process and/or block in the flowchart and/or block diagram, and the combination of processes and/or blocks in the flowchart and/or block diagram can be implemented by computer program instructions. These computer program instructions can be provided to the processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing equipment to generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing equipment are used to generate It is a device that realizes the functions specified in one process or multiple processes in the flowchart and/or one block or multiple blocks in the block diagram.

These computer program instructions can also be stored in a computer-readable memory that can direct a computer or other programmable data processing equipment to work in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture including the instruction device. The device implements the functions specified in one process or multiple processes in the flowchart and/or one block or multiple blocks in the block diagram.

These computer program instructions can also be loaded on a computer or other programmable data processing equipment, so that a series of operation steps are executed on the computer or other programmable equipment to produce computer-implemented processing, so as to execute on the computer or other programmable equipment. The instructions provide steps for implementing functions specified in a flow or multiple flows in the flowchart and/or a block or multiple blocks in the block diagram.

Obviously, those skilled in the art can make various changes and modifications to the application without departing from the spirit and scope of the application. In this way, if these modifications and variations of this application fall within the scope of the claims of this application and their equivalent technologies, this application also intends to include these modifications and variations.

Claims (40)

A communication method, characterized in that the method includes: The control plane entity CU-CP of the radio access network device receives control port information from the core network element, and the control port indicated by the control port information corresponds to the protocol data unit PDU session and is the control of the CU-UPF network element Port, the CU-UPF network element is composed of a user plane entity CU-UP corresponding to the centralized unit CU of the radio access network device and a user plane function UPF network element; When the terminal device switches from the source distributed unit DU of the radio access network device to the target DU of the radio access network device, the CU-CP obtains from the target DU for establishing the first F1 user plane Downlink tunnel information of the connected target DU; wherein, the first F1 user plane connection is a downlink user plane connection between the target DU and the CU-UPF network element; Sending, by the CU-CP and the control port, the downlink tunnel information to the CU-UPF network element; Wherein, the downlink tunnel information is used to establish the first F1 user plane connection. The method according to claim 1, further comprising: The CU-CP obtains the uplink tunnel information from the CU-UPF network element through the control port, and the uplink tunnel information is the second F1 user between the CU-UPF network element and the source DU Uplink tunnel information of the connection; Sending, by the CU-CP, the uplink tunnel information to the target DU, where the uplink tunnel information is used to establish an uplink user plane connection between the target DU and the CU-UPF network element; Wherein, the uplink tunnel information and the downlink tunnel information include at least one of an Internet Protocol IP address and a tunnel endpoint identifier. The method according to claim 2, further comprising: The CU-CP receives verification information from the core network element; Sending, by the CU-CP, the verification information to the CU-UPF network element through the control port; Wherein, the verification information is used for determining the authority of the CU-CP to obtain the uplink tunnel information. A communication method, characterized in that it comprises: When the terminal device switches from the source distributed unit DU of the wireless access network device to the target DU of the wireless access network device, the CU-UPF network element receives the control plane entity from the wireless access network device through the control port The second message of the CU-CP; wherein, the second message includes the downlink tunnel information of the target DU, and the CU-UPF network element is composed of a user corresponding to the centralized unit CU of the radio access network device The plane entity CU-UP and the user plane function UPF network element are composed. The control port is allocated by the core network element for the CU-UPF network element and controls the CU-UPF network element corresponding to the protocol data unit PDU session port; The CU-UPF network element establishes a first F1 user plane connection according to the downlink tunnel information and the downlink tunnel information of the CU-UPF network element; Wherein, the first F1 user plane connection is a downlink user plane connection between the target DU and the CU-UPF network element. The method according to claim 4, further comprising: The CU-UPF network element receives a request message from the CU-CP through the control port, the request message is used to request uplink tunnel information, and the uplink tunnel information is the CU-UPF network element and the Uplink tunnel information of the second F1 user plane connection between the source DUs; The CU-UPF network element sends the uplink tunnel information to the CU-CP through the control port, and the uplink tunnel information is used for the uplink user plane between the target DU and the CU-UPF network element Connection establishment; Wherein, the uplink tunnel information and the downlink tunnel information include at least one of an Internet Protocol IP address and a tunnel endpoint identifier. The method according to claim 5, further comprising: The CU-UPF network element receives the verification information from the CU-CP through the control port; The CU-UPF network element determines the authority of the CU-CP to obtain the uplink tunnel information according to the verification information. The method according to claim 5 or 6, further comprising: The CU-UPF network element sends the downlink tunnel information of the target DU, and the uplink tunnel information and downlink tunnel information of the CU-UPF network element to the core network element. A communication method, characterized in that it comprises: The target distributed unit DU of the radio access network device receives the first information from the core network element through the control plane entity CU-CP of the radio access network device; When the terminal device switches from the source DU of the radio access network device to the target DU, the target DU sends the downlink tunnel information carrying the target DU to the CU-UPF network element according to the first information The user plane data packet of the downlink tunnel information is used for the establishment of the first F1 user plane connection; Wherein, the first F1 user plane connection is a downlink user plane connection between the target DU and the CU-UPF network element, and the CU-UPF network element is connected to the radio access network device in a centralized manner. The user plane entity CU-UP corresponding to the unit CU and the user plane function UPF network elements are composed. The method according to claim 8, further comprising: The target DU receives uplink tunnel information from a CU-UPF network element through the CU-CP, where the uplink tunnel information is a second F1 user plane connection between the CU-UPF network element and the source DU The uplink tunnel information; The target DU establishes an uplink user plane connection between the target DU and the CU-UPF network element according to the uplink tunnel information and the uplink tunnel information of the target DU; Wherein, the uplink tunnel information and the downlink tunnel information include at least one of an Internet Protocol IP address and a tunnel endpoint identifier. The method according to claim 9, wherein the user plane data packet further includes verification information; the verification information is used to determine the authority of the target DU to obtain the uplink tunnel information. A communication method, characterized in that it comprises: When the terminal device switches from the source distributed unit DU of the wireless access network device to the target DU of the wireless access network device, the CU-UPF network element receives a user plane data packet from the target DU, and the user plane The data packet carries the downlink tunnel information of the target DU, and the CU-UPF network element is composed of a user plane entity CU-UP corresponding to the centralized unit CU of the radio access network device and a user plane function UPF network element ； Establishing, by the CU-UPF network element, the first F1 user plane connection according to the downlink tunnel information and the downlink tunnel information of the CU-UPF network element; Wherein, the first F1 user plane connection is a downlink user plane connection between the target DU and the CU-UPF network element. The method according to claim 11, further comprising: The CU-UPF network element sends uplink tunnel information to the target DU through the CU-CP; Wherein, the uplink tunnel information is the uplink tunnel information of the second F1 user plane connection between the CU-UPF network element and the source DU, and the uplink tunnel information is used for the target DU and the CU- Establishment of an uplink user plane connection between UPF network elements; the uplink tunnel information and the downlink tunnel information include at least one of an Internet Protocol IP address and a tunnel endpoint identifier. The method according to claim 12, further comprising: The CU-UPF network element receives verification information from the target DU; The verification information is used to determine the authority of the target DU to obtain the uplink tunnel information. A communication method, characterized in that the method includes: The target control plane entity CU-CP of the target radio access network device receives the control port information from the core network element through the source CU-CP of the source radio access network device, the control port and protocol data indicated by the control port information The unit PDU session corresponds and is the control port of the CU-UPF network element. The CU-UPF network element consists of the user plane entity CU-UP and the user plane function UPF network corresponding to the centralized unit CU of the target radio access network device. Element composition When the terminal device switches from the source DU of the source radio access network device to the target DU of the target radio access network device, the target CU-CP obtains the first F1 user plane from the target DU. Downlink tunnel information of the connected target DU; wherein, the first F1 user plane connection is a downlink user plane connection between the target DU and the CU-UPF network element; Sending, by the target CU-CP, the downlink tunnel information to the CU-UPF network element through the control port; Wherein, the downlink tunnel information is used to establish the first F1 user plane connection. The method according to claim 14, further comprising: The target CU-CP obtains the uplink tunnel information from the CU-UPF network element through the control port; the uplink tunnel information is the second F1 between the CU-UPF network element and the source DU Uplink tunnel information of the user plane connection; Sending, by the target CU-CP, the uplink tunnel information to the target DU, where the uplink tunnel information is used to establish an uplink user plane connection between the target DU and the CU-UPF network element; Wherein, the uplink tunnel information and the downlink tunnel information include at least one of an Internet Protocol IP address and a tunnel endpoint identifier. The method according to claim 15, further comprising: The target CU-CP receives verification information from the core network element; Sending, by the target CU-CP, the verification information to the CU-UPF network element through the control port; Wherein, the verification information is used to determine the authority of the target CU-CP to obtain the uplink tunnel information. The method according to any one of claims 14 to 16, characterized by comprising: The target CU-CP updates the context information of the terminal device, and the context information of the terminal device includes information of the target radio access network device serving the terminal device; The target CU-CP sends the updated context information of the terminal device to the core network element. A communication method, characterized in that the method includes: When the terminal device switches from the source distributed unit DU of the source wireless access network device to the target DU of the target access network device, the CU-UPF network element receives the target CU-CP from the target wireless access network device through the control port The second message; wherein, the second message includes the downlink tunnel information of the target DU, and the CU-UPF network element consists of the user plane entity CU-UP corresponding to the centralized unit CU of the target radio access network device And user plane function UPF network element, the control port is the control port of the CU-UPF network element that is allocated by the core network element for the CU-UPF network element and corresponds to the protocol data unit PDU session; The CU-UPF network element establishes the first F1 user plane connection according to the downlink tunnel information of the target DU and the downlink tunnel information of the CU_UPF network element; Wherein, the first F1 user plane connection is a downlink user plane connection between the target DU and the CU-UPF network element. The method according to claim 18, further comprising: The CU-UPF network element receives a request message from the CU-CP through the control port, the request message is used to request the uplink tunnel information, and the uplink tunnel information is the CU-UPF network element and The uplink tunnel information of the second F1 user plane connection between the source DUs; The CU-UPF network element sends the uplink tunnel information to the target CU-CP through the control port, and the uplink tunnel information is used for uplink users between the target DU and the CU-UPF network element The establishment of the connection; Wherein, the uplink tunnel information and the downlink tunnel information include at least one of an Internet Protocol IP address and a tunnel endpoint identifier. The method according to claim 19, further comprising: The verification information of the target CU-CP by the CU-UPF network element through the control port: The CU-UPF network element determines the authority of the target CU-CP to obtain the uplink tunnel information according to the verification information. The method according to claim 19 or 20, further comprising: The CU-UPF network element sends the downlink tunnel information of the target DU, and the uplink tunnel information and downlink tunnel information of the CU-UPF network element to the core network element. A communication method, characterized in that the method includes: The target distributed unit DU of the target wireless access network device receives the first information from the source CU-CP of the source wireless access network device through the target CU-CP of the target wireless access network device; When the terminal device switches from the source DU of the source radio access network device to connect to the target DU, the target DU sends the target DU carrying the target DU to the CU-UPF network element according to the first information A user plane data packet of downlink tunnel information, where the downlink tunnel information is used to establish a first F1 user plane connection; Wherein, the first F1 user plane connection is a downlink user plane connection between the target DU and the CU-UPF network element, and the CU-UPF network element is integrated with the target radio access network device. The user plane entity CU-UP corresponding to the modular unit CU and the user plane function UPF network elements are composed. The method according to claim 22, further comprising: The target DU obtains uplink tunnel information from the source CU-CP through the target CU-CP, where the uplink tunnel information is a second F1 user between the CU-UPF network element and the source DU Uplink tunnel information of the connection; The target DU establishes an uplink user plane connection between the target DU and the CU-UPF network element according to the uplink tunnel information and the uplink tunnel information of the target DU; Wherein, the uplink tunnel information and the downlink tunnel information include at least one of an Internet Protocol IP address and a tunnel endpoint identifier. The method according to claim 23, wherein the user plane data packet further includes verification information; the verification information is used to determine the authority of the target DU to obtain the uplink tunnel information. A communication method, characterized in that it comprises: When the terminal device switches from the source distributed unit DU of the source wireless access network device to the target DU of the target wireless access network device, the CU-UPF network element receives the target DU from the target wireless access network device A user plane data packet, the user plane data packet carries the downlink tunnel information of the target DU, and the CU-UPF network element consists of a user plane entity CU corresponding to the centralized unit CU of the target radio access network device. -UP and user plane function UPF network element composition; Establishing, by the CU-UPF network element, the first F1 user plane connection according to the downlink tunnel information and the downlink tunnel information of the CU-UPF network element; Wherein, the first F1 user plane connection is a downlink user plane connection between the target DU and the CU-UPF network element. The method according to claim 25, further comprising: Sending, by the CU-UPF network element, uplink tunnel information to the target DU through the target CU-CP; Wherein, the uplink tunnel information is the uplink tunnel information of the second F1 user plane connection between the CU-UPF network element and the source DU, and the uplink tunnel information is used for the target DU and the CU- For establishing an uplink user plane connection between UPF network elements, the uplink tunnel information and the downlink tunnel information include at least one of an Internetwork Protocol IP address and a tunnel endpoint identifier. The method according to claim 26, further comprising: The CU-UPF network element receives verification information from the target DU; The verification information is used to determine the authority of the target DU to obtain the uplink tunnel information. A communication method, characterized in that it includes a target distributed unit DU of a radio access network device, and a user plane entity CU-UP and a user plane function UPF corresponding to the centralized unit CU of the radio access network device. CU-UPF network element composed of network elements; The target DU is used to receive the first information from the core network element through the control plane entity CU-CP of the radio access network device; when the terminal device receives the first information from the source distributed unit DU of the radio access network device When switching to the target DU of the radio access network device, send a user plane data packet carrying the downlink tunnel information of the target DU to the CU-UPF network element according to the first information; The CU-UPF network element is configured to receive data packets from the user plane, and establish a first F1 user plane connection according to the downlink tunnel information and the downlink tunnel information of the CU-UPF network element; Wherein, the first F1 user plane connection is a downlink user plane connection between the target DU and the CU-UPF network element. The method according to claim 28, wherein the CU-UPF network element is further configured to send uplink tunnel information to the target DU through the CU-CP; The target DU is also used to receive the uplink tunnel information, and establish an uplink user plane between the target DU and the CU-UPF network element according to the uplink tunnel information and the uplink tunnel information of the target DU connect; Wherein, the uplink tunnel information is the uplink tunnel information of the second F1 user plane connection between the CU-UPF network element and the source DU, and the uplink tunnel information and the downlink tunnel information include Internet Protocol At least one of the IP address and the tunnel endpoint identifier. The method according to claim 29, wherein the CU-UPF network element is further configured to receive verification information from the target DU; The verification information is used to determine the authority of the target DU to obtain the uplink tunnel information. A communication device, characterized in that it comprises at least one processor, the at least one processor is connected to a memory, and the at least one processor is used to read and execute a program stored in the memory, so that the device executes The method of any one of claims 1-3 or 14-17. A communication device, characterized in that it comprises at least one processor, the at least one processor is connected to a memory, and the at least one processor is used to read and execute a program stored in the memory, so that the device executes The method of any one of claims 4-7, 11-13, 18-21, or 25-27. A communication device, characterized in that it comprises at least one processor, the at least one processor is connected to a memory, and the at least one processor is used to read and execute a program stored in the memory, so that the device executes The method of any one of claims 8-10, 22-24, or 28-30. A chip, characterized in that the chip is coupled with a memory, and is used to read and execute program instructions stored in the memory, so as to implement the method according to any one of claims 1-27. A communication system, characterized in that it comprises: a control plane entity CU-CP of a radio access network device that executes the method according to any one of claims 1-3 and executes the control plane entity CU-CP of any one of claims 4-7. CU-UPF network element of the above method. A communication system, characterized by comprising: a target distributed unit DU of a radio access network device that executes the method according to any one of claims 8-10 and executes the target distributed unit DU of any one of claims 11-13 Method of CU-UPF network element. A communication system, comprising: a target control plane entity CU-CP of a target radio access network device that executes the method according to any one of claims 14-17 and executes any one of claims 18-21 CU-UPF network element of the method described in item. A communication system, characterized by comprising: a target distributed unit DU of a target radio access network device that executes the method according to any one of claims 22-24 and executes the target distributed unit DU of a target wireless access network device as claimed in any one of claims 25-27. CU-UPF network element of the above method. A computer-readable storage medium, wherein the computer-readable storage medium stores computer instructions, which when run on a computer, cause the computer to execute the method according to any one of claims 1-30. A computer program product, characterized in that, when the computer program product is called by a computer, the computer executes the method according to any one of claims 1-30.

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