Cell handover method and device, storage medium and electronic device

Abstract

The present application discloses a cell handover method and device, a storage medium and an electronic device. The method comprises: when it is determined that a user terminal is to perform cell handover, sending a handover request message to a target cell; and upon receiving a request acknowledgement message fed back by the target cell on the basis of the handover request message, sending an RRC reconfiguration message to the user terminal by means of an air interface, so as to enable the user terminal to hand over from a source cell to the target cell by means of dual-connectivity handover, wherein the request acknowledgement message at least carries information that the target cell supports dual-connectivity handover, and the dual-connectivity handover is used for indicating that during handover, the source cell and the target cell are allowed to simultaneously connect to the user terminal and support the user terminal in transceiving data. By means of the technical solution, the problem in the related art such as communication interruption of a user terminal during handover from a source cell to other target cells is solved.

Description

Cell switching method and device, storage medium and electronic device

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to the Chinese patent application filed with the China Patent Office on October 27, 2023, with application number 202311421756.9 and invention name “Cell switching method and device, storage medium and electronic device”, the entire contents of which are incorporated by reference into this application. Technical Field

[0003] The present application relates to the field of communications, and in particular to a cell switching method and device, a storage medium, and an electronic device. Background Art

[0004] In traditional 4G LTE (Long-Term Evolution) networks and 5G NR (New Radio) until Release 15, user equipment (UE) typically releases its connection from a source cell before establishing a connection with a target cell, resulting in communication interruptions of tens of milliseconds between the UE and the base station. This interruption is critical for 5G low-latency, high-reliability scenarios.

[0005] In the related art, there are problems such as communication interruption when a user terminal switches from a source cell to another target cell, and no effective solution has been proposed yet.

[0006] Summary of the Invention

[0007] The embodiments of the present application provide a cell switching method and device, a storage medium, and an electronic device to at least solve the problem in the related art that a user terminal suffers from communication interruption during switching from a source cell to another target cell.

[0008] According to one embodiment of the present application, a cell switching method is provided, comprising: when it is determined that a user terminal is to perform cell switching, sending a switching request message to a target cell, wherein the switching request message is used to indicate the switching resources required when the target cell switches to a user terminal connected to a source cell; and when a request confirmation message based on the switching request message is received from the target cell, sending an RRC reconfiguration message to the user terminal via an air interface to trigger the user terminal to use dual-connection switching to switch from the source cell to the target cell, wherein the request confirmation message carries at least information that the target cell supports dual-connection switching, and the dual-connection switching is used to indicate that during the switching process, the source cell and the target cell are allowed to simultaneously connect to the user terminal, and support the user terminal in sending and receiving data.

[0009] Optionally, before sending a switching request message to the target cell, the method further includes: determining a measurement report of a user terminal connected to the source cell; and determining whether the user terminal needs to perform a cell switch based on the measurement report and the RRM information corresponding to the source cell and the user terminal.

[0010] Optionally, after sending an RRC (Radio Resource Control) reconfiguration message to the user terminal through the air interface to trigger the user terminal to switch from the source cell to the target cell using dual-connection switching, the method further includes: allocating a sequence code of a PDCP (Packet Data Convergence Protocol) data packet for supporting data synchronization to the downlink corresponding to the user terminal; determining the forwarding result of the user terminal forwarding the sequence code and the data service unit corresponding to the downlink to the target cell; and when the target cell receives the RRC reconfiguration completion message sent by the user terminal and the forwarding result indicates that the forwarding is successful, determining that the switching is completed and stopping allocating the sequence code to the downlink.

[0011] Optionally, after sending an RRC reconfiguration message to the user terminal through the air interface to trigger the user terminal to switch from the source cell to the target cell using dual-connection switching, the method also includes: upon receiving a switching success message sent by the target cell, sending a notification message to the user terminal indicating that the target cell has been successfully accessed; obtaining the synchronization status of the DL / UL data of the source cell and the target cell corresponding to the user terminal after receiving the notification message; and when the synchronization status indicates that synchronization is completed, determining that the current source cell allows the cell release operation to be performed.

[0012] Optionally, after sending an RRC reconfiguration message to the user terminal via the air interface to trigger the user terminal to switch from the source cell to the target cell using dual connection switching, the method further includes: receiving an operation command corresponding to the dual connection switching sent by the user terminal; determining a first connection mode between the source cell and the user terminal and a second connection mode between the source cell and the target device according to the operation command, wherein the first connection mode is used to indicate that the source cell continues to be connected to the user terminal when it does not receive a switching success message sent by the target device, and the second connection mode is used to indicate that the target cell continues to maintain a synchronous connection with the source cell to the user terminal when it does not receive the RRC reconfiguration completion message.

[0013] According to another embodiment of the embodiment of the present application, another cell switching method is also provided, including: when it is determined that the user terminal is to perform cell switching, a corresponding request confirmation message is fed back to the source cell according to the switching request message sent by the source cell, so as to instruct the user terminal to perform dual-connection switching between the source cell and the target cell based on the request confirmation message; wherein the switching request message is used to indicate the switching resources required when the target cell switches to the user terminal connected to the source cell, and the request confirmation message carries at least information that the target cell supports dual-connection switching, and the dual-connection switching is used to indicate that during the switching process, the source cell and the target cell are allowed to connect to the user terminal at the same time, and support the user terminal to send and receive data.

[0014] Optionally, the above method further includes: obtaining a switching result of the user terminal switching from the source cell to the target cell using dual connectivity switching; and sending a switching success message to the source cell when the switching result indicates a successful switching.

[0015] According to another embodiment of the embodiment of the present application, a cell switching device is also provided, including: a first sending module, which is configured to send a switching request message to the target cell when it is determined that the user terminal is to perform cell switching, wherein the switching request message is used to indicate the switching resources required when the target cell switches to the user terminal connected to the source cell; a second sending module, which is configured to send an RRC reconfiguration message to the user terminal through the air interface when it receives a request confirmation message fed back by the target cell based on the switching request message, so as to trigger the user terminal to use dual connection switching to switch from the source cell to the target cell, wherein the request confirmation message carries at least information that the target cell supports dual connection switching, and the dual connection switching is used to indicate that the source cell and the target cell are allowed to connect to the user terminal at the same time during the switching process, and support the user terminal to send and receive data.

[0016] According to another embodiment of the embodiment of the present application, another cell switching device is also provided, including: a feedback module, which is configured to, when determining that a user terminal is to perform cell switching, feedback a corresponding request confirmation message to the source cell based on the switching request message sent by the source cell, so as to instruct the user terminal to perform dual-connection switching between the source cell and the target cell based on the request confirmation message; wherein the switching request message is used to indicate the switching resources required when the target cell switches to the user terminal connected to the source cell, and the request confirmation message carries at least information that the target cell supports dual-connection switching, and the dual-connection switching is used to indicate that during the switching process, the source cell and the target cell are allowed to connect to the user terminal at the same time, and support the user terminal to send and receive data.

[0017] According to another aspect of the embodiments of the present application, a computer-readable storage medium is provided, in which a computer program is stored. The computer program is configured to execute the above-mentioned cell switching method when running.

[0018] According to another aspect of an embodiment of the present application, an electronic device is provided, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the cell switching method through the computer program.

[0019] In an embodiment of the present application, after the user terminal is connected to the source cell and the target cell, a dual-connection handover process is performed, so that when the user terminal is switching from the source cell to the target cell, even if the handover is not completely completed, the source cell is guaranteed to send and receive user data corresponding to the user terminal. Until the user data can be sent and received in the target cell, by adopting the above-mentioned embodiment, the problem of communication interruption in the process of switching from the source cell to other target cells in the related art is solved, and it is ensured that there will be no communication interruption when switching between different cells, which greatly improves the stability and reliability of the communication process and achieves the technical effect of reducing communication latency. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The drawings described herein are used to provide an understanding of the present application and constitute a part of the present application. The exemplary embodiments of the present application and their descriptions are used to explain the present application and do not constitute an improper limitation on the present application. In the drawings:

[0021] FIG1 is a hardware structure block diagram of a device terminal of a cell switching method according to an embodiment of the present application;

[0022] FIG2 is a flow chart of a cell switching method according to an embodiment of the present application;

[0023] FIG3 is a flow chart of another cell switching method according to an embodiment of the present application;

[0024] FIG4 is an application scenario diagram of a method for optimizing handover delay based on NR according to an embodiment of the present application;

[0025] FIG5 is a schematic diagram of a DCHO switching process according to an embodiment of the present application;

[0026] FIG6 is a structural block diagram of a cell switching device according to an embodiment of the present application;

[0027] FIG7 is a structural block diagram of another cell switching device according to an embodiment of the present application. DETAILED DESCRIPTION

[0028] In order to enable those skilled in the art to better understand the present invention, the following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts should fall within the scope of protection of this application.

[0029] It should be noted that the terms "first", "second", etc. in the specification and claims of the present application and the above-mentioned drawings are used to distinguish similar objects and are not necessarily used to describe a specific order or sequential order. It should be understood that the data used in this way can be interchangeable where appropriate, so that the embodiments of the present application described herein can be implemented in a sequence other than those illustrated or described herein. In addition, the terms "including" and "having" and any of their variations are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device comprising a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0030] The method embodiments provided in the embodiments of the present application can be executed in a device terminal, a mobile terminal or a similar computing device. Taking the operation on the device terminal as an example, Figure 1 is a hardware structure block diagram of the device terminal of a cell switching method in an embodiment of the present application. As shown in Figure 1, the device terminal may include one or more (only one is shown in Figure 1) processors 102 (the processor 102 may include but is not limited to a processing device such as a microprocessor MCU (Micro Control Unit) or a programmable logic device FPGA (Field Programmable Gate Array)) and a memory 104 configured to store data. In an exemplary embodiment, the above-mentioned device terminal may also include a transmission device 106 and an input and output device 108 configured to have a communication function. It can be understood by those skilled in the art that the structure shown in Figure 1 is only for illustration and does not limit the structure of the above-mentioned device terminal. For example, the device terminal may also include more or fewer components than those shown in Figure 1, or have a different configuration with the same function as shown in Figure 1 or more functions than those shown in Figure 1.

[0031] The memory 104 can be configured to store computer programs, for example, software programs and modules of application software, such as the computer program corresponding to the cell switching method in the embodiment of the present application. The processor 102 executes various functional applications and data processing by running the computer program stored in the memory 104, that is, implementing the above method. The memory 104 may include a high-speed random access memory, and may also include a non-volatile memory, such as one or more magnetic storage devices, flash memory, or other non-volatile solid-state memory. In some instances, the memory 104 includes a memory remotely located relative to the processor 102, and these remote memories can be connected to the device terminal via a network. Examples of the above-mentioned network include, but are not limited to, the Internet, an intranet, a local area network, a mobile communication network, and combinations thereof.

[0032] The transmission device 106 is configured to receive or transmit data via a network. A specific example of the aforementioned network may include a wireless network provided by the device's communications provider. In one embodiment, the transmission device 106 includes a network interface controller (NIC) that can be connected to other network devices via a base station to enable communication with the Internet. In another embodiment, the transmission device 106 may be a radio frequency (RF) module configured to communicate with the Internet wirelessly.

[0033] In this embodiment, a cell switching method is provided, which is applied to the above-mentioned device terminal. FIG2 is a flow chart of the cell switching method according to an embodiment of the present application. As shown in FIG2 , the process includes the following steps:

[0034] Step S202: If it is determined that the user terminal is to perform cell handover, a handover request message is sent to the target cell, wherein the handover request message is used to indicate the handover resources required for the target cell to hand over the user terminal connected to the source cell;

[0035] Step S204: Upon receiving a request confirmation message fed back by the target cell based on the switching request message, an RRC reconfiguration message is sent to the user terminal through the air interface to trigger the user terminal to switch from the source cell to the target cell using dual connection switching, wherein the request confirmation message carries at least information that the target cell supports dual connection switching, and the dual connection switching is used to indicate that the source cell and the target cell are allowed to connect to the user terminal at the same time during the switching process, and support the user terminal for sending and receiving data.

[0036] Through the above steps, after the user terminal connects to the source cell and the target cell, a dual-connection handover process is executed. This ensures that, during the handover process from the source cell to the target cell, the source cell can transmit and receive user data corresponding to the user terminal, even if the handover is not fully completed. Until the user data can be transmitted and received in the target cell, the above implementation solves the problem of communication interruption during the handover process from the source cell to another target cell in the related art, ensuring that communication interruption will not occur when handing over between different cells, greatly improving the stability and reliability of the communication process, and achieving the technical effect of reducing communication latency.

[0037] As an optional implementation, before sending a switching request message to the target cell, the above method also includes: determining a measurement report of a user terminal connected to the source cell; and determining whether the user terminal needs to perform a cell switch based on the measurement report and the RRM information corresponding to the source cell and the user terminal.

[0038] It can be understood that in order to ensure that the user terminal can continuously maintain a communication connection with a cell with higher communication quality, when sending a switching request message to the target cell, the communication quality between the user terminal and the current source cell is determined by obtaining the measurement report of the user terminal connected to the source cell, and the effectiveness and reliability of the current source cell are determined through the RRM (Radio Resource Management, wireless resource management, referred to as RRM) information corresponding to the source cell. Then, the determined communication quality is compared with the preset user terminal communication preset quality, and it is determined whether the effectiveness and reliability of the current source cell meet the minimum communication requirements of the user terminal. For example, when the communication quality is lower than the preset quality, and / or the current source cell cannot meet the minimum communication requirements of the user terminal, it is determined that the current user terminal needs to perform cell switching, so as to adjust to a cell with better communication effect through switching to reside.

[0039] Optionally, after sending an RRC reconfiguration message to the user terminal via the air interface to trigger the user terminal to switch from the source cell to the target cell using dual-connection switching, the method further includes: allocating a sequence code of a PDCP data packet for supporting data synchronization to the downlink corresponding to the user terminal; determining the forwarding result of the user terminal forwarding the sequence code and the data service unit corresponding to the downlink to the target cell; and when the target cell receives the RRC reconfiguration completion message sent by the user terminal and the forwarding result indicates that the forwarding is successful, determining that the switching is completed and stopping allocating the sequence code to the downlink.

[0040] That is, when a user terminal performs a handover between a target cell and a source cell, a migration channel needs to be established between the target cell and the source cell during the handover preparation process. The source cell is responsible for allocating downlink PDCP SNs (equivalent to the sequence code mentioned above) until the SN allocation is handed over to the target cell and data is forwarded. In other words, the source cell will not stop allocating PDCP SNs to downlink data packets until it receives a handover success message and sends an SN status transfer message to the target cell. When the source cell allocates downlink PDCP SNs, it begins scheduling downlink data on the source cell radio link and begins forwarding downlink PDCP SDUs (PDCP service data units) along with the specified PDCP SNs to the target cell. Then, if the forwarding is successful and the user terminal completes RRC reconfiguration, it will stop allocating downlink sequence codes.

[0041] It should be noted that during a handover, the user terminal receives user data from both the source and target cells. The corresponding PDCP Packet Data Convergence Protocol layer is reconfigured as a common PDCP entity for the user plane protocol stacks of both the source and target cells. To ensure in-sequence delivery of user data, PDCP sequence number (SN) continuity is maintained throughout the handover process. Therefore, a common (source and target) reordering and replication function is provided within a single PDCP entity. Encryption / decryption and header compression / decompression are handled separately within the common PDCP entity, depending on the source / destination of the downlink / uplink data packet.

[0042] Optionally, after sending an RRC reconfiguration message to the user terminal through the air interface to trigger the user terminal to switch from the source cell to the target cell using dual-connection switching, the method also includes: upon receiving a switching success message sent by the target cell, sending a notification message to the user terminal indicating that the target cell has been successfully accessed; obtaining the synchronization status of the DL / UL data of the source cell and the target cell corresponding to the user terminal after receiving the notification message; and when the synchronization status indicates that synchronization is completed, determining that the current source cell allows the cell release operation to be performed.

[0043] That is, when it is determined that the user terminal can transmit data on the target cell, the target cell will send a corresponding notification message to the source cell. Then, when the corresponding notification message appears when the source cell interacts with the user terminal, it means that the data in the source cell has been synchronized to the target cell. At this time, the source cell can be released, that is, the synchronization of upload (UL (Upload)) / download (DL (Download)) data between the source cell and the target cell is determined, and then the user terminal can smoothly execute the data tasks between them after switching to the target cell, thereby ensuring the continuity of the user terminal's communication. In simple terms, the user terminal can terminate the communication interaction with the source cell and only interact with the target cell to ensure the continuation of communication.

[0044] Optionally, after sending an RRC reconfiguration message to the user terminal via the air interface to trigger the user terminal to switch from the source cell to the target cell using dual connection switching, the method further includes: receiving an operation command corresponding to the dual connection switching sent by the user terminal; determining a first connection mode between the source cell and the user terminal and a second connection mode between the source cell and the target device according to the operation command, wherein the first connection mode is used to indicate that the source cell continues to be connected to the user terminal when it does not receive a switching success message sent by the target device, and the second connection mode is used to indicate that the target cell continues to maintain a synchronous connection with the source cell to the user terminal when it does not receive the RRC reconfiguration completion message.

[0045] That is, when the user terminal receives a prompt from the source cell and determines that a cell needs to be switched, a corresponding operation command is issued to ensure that the current switching is controlled by the user terminal.

[0046] In this embodiment, another cell switching method is provided, which is applied to the above-mentioned device terminal. FIG3 is a flow chart of another cell switching method according to an embodiment of the present application. As shown in FIG3 , the process includes the following steps:

[0047] Step S302. When it is determined that the user terminal is to perform cell switching, a corresponding request confirmation message is fed back to the source cell according to the switching request message sent by the source cell, so as to instruct the user terminal to perform dual-connection switching between the source cell and the target cell based on the request confirmation message; wherein the switching request message is used to indicate the switching resources required when the target cell switches to the user terminal connected to the source cell, and the request confirmation message carries at least information that the target cell supports dual-connection switching, and the dual-connection switching is used to indicate that the source cell and the target cell are allowed to connect to the user terminal at the same time during the switching process, and support the user terminal to send and receive data.

[0048] Through the above steps, after the user terminal connects to the source cell and the target cell, a dual-connection handover process is executed. This ensures that, during the handover process from the source cell to the target cell, the source cell can transmit and receive user data corresponding to the user terminal, even if the handover is not fully completed. Until the user data can be transmitted and received in the target cell, the above implementation solves the problem of communication interruption during the handover process from the source cell to another target cell in the related art, ensuring that communication interruption will not occur when handing over between different cells, greatly improving the stability and reliability of the communication process, and achieving the technical effect of reducing communication latency.

[0049] Optionally, the above method further includes: obtaining a switching result of the user terminal switching from the source cell to the target cell using dual connectivity switching; and sending a switching success message to the source cell when the switching result indicates a successful switching.

[0050] As an optional implementation, another cell switching method is provided in this embodiment, which is characterized in that, when applied to a user terminal, the method includes: receiving an RRC reconfiguration message sent by a source cell through an air interface; using the RRC reconfiguration message to trigger a dual-connection switching process between the source cell and the target cell; and determining to disconnect communication with the source cell when a switching success message sent by the target cell to the source cell is received from the communication channel corresponding to the user terminal and the source cell.

[0051] It should be noted that, in actual applications, the source cell is equivalent to a source base station, and the target cell is equivalent to a target base station to be switched to.

[0052] In order to better understand the process of the switching method of the above-mentioned cell, the implementation method flow of the switching of the above-mentioned cell is described below in combination with an optional embodiment, but it is not used to limit the technical solution of the embodiment of the present application.

[0053] In this embodiment, a method for optimizing handover delay based on NR is provided. FIG4 is an application scenario diagram of the method for optimizing handover delay based on NR according to an embodiment of the present application. As shown in FIG4 , in order to support DCHO (Dual Connectivity Handover, DCHO for short), the UE must keep Dual Connectivity active. A user plane protocol stack of the target cell includes a PHY (Physical Layer, physical layer), a MAC (Media Access Control, media access control) and an RLC (Radio link Control) layer, while keeping the second user plane protocol stack active to transmit and receive user data in the source cell.

[0054] The UE receives user data from both the source and target cells simultaneously. The Packet Data Convergence Protocol (PDCP) layer is reconfigured as a common PDCP entity for both the source and target user plane protocol stacks. To ensure in-sequence delivery of user data, PDCP sequence number (SN) continuity is maintained throughout the handover process. Therefore, a common (for both source and target) reordering and duplication functionality is provided within a single PDCP entity. Encryption / decryption and header compression / decompression are handled separately within the common PDCP entity, depending on the source / destination of the downlink / uplink data packet.

[0055] As an optional implementation manner, FIG5 is a schematic diagram of a DCHO handover process according to an embodiment of the present application.

[0056] It should be noted that DCHO switching can be performed on both the Xn interface and the N2 interface. The DCHO process is described here based on the HO (Handover) switching of the Xn interface, as follows.

[0057] Step 1. The source base station Source gNB (equivalent to the source cell in the above embodiment) issues a measurement configuration to the UE (equivalent to the user terminal in the above embodiment); the UE reports a measurement report.

[0058] Among them, gNB stands for the next Generation NodeB, which is the base station of the 5G network.

[0059] Step 2. HO decision, i.e. the source base station determines the UE handover based on the measurement report and RRM information;

[0060] Step 3. The Source gNB sends a Handover Request message to the Target gNB (equivalent to the target cell in the above embodiment). The message includes the information required for target cell preparation (handover entry).

[0061] Step 4. The target base station prepares for handover (resources) and sends a Handover Request Acknowledgement (HANDOVERREQUESTACKNOWLEDGE) message to the source base station; that is, an ACK (Acknowledge character) confirmation character. The target base station also indicates in the message whether it accepts DCHO handover;

[0062] Step 5. The source base station sends an RRC reconfiguration message to the UE via the air interface (Uu, where U stands for User to Network Interface (UNI) and u stands for Universal), triggering the handover.

[0063] Step 6. For DRBs configured using DCHO, the source base station sends an Early State Transmission (EARLYSTATUSTRANSFER) and enters the RACH (Random Access Channel) Procedure.

[0064] Step 7. After the user terminal is synchronized with the target cell, it sends an RRC reconfiguration complete message to the target base station, and the handover is completed;

[0065] Step 8. The target base station sends a handover success message to the source base station, notifying the UE that it has successfully accessed the target cell;

[0066] Step 9. The source base station sends a status transmission based on the SNSTATUSTRANSFER of the DRB configured by DCHO for the very early status transmission;

[0067] Step 10. The UE completes Dual Connectivity of DL / UL data on the source base station and the target base station, and finally completes the transmission of DL / UL data on the target base station;

[0068] Step 11: The target base station sends a UEContextRelease message to the source base station, thus completing the DCHO handover process.

[0069] As an optional embodiment, in order to better understand the solution of the present application, the specific steps are described from the downlink and uplink respectively according to the specific service direction:

[0070] The corresponding downlink processing in the user terminal is as follows:

[0071] S601. During the handover preparation process, a migration channel needs to be established;

[0072] S602. The source base station is responsible for allocating downlink PDCP SNs until the SN allocation is handed over to the target base station and data forwarding is completed. That is, the source base station will not stop allocating PDCP SNs to downlink data packets until it receives a handover success message and sends an SN status transfer message to the target base station.

[0073] S603. When the source base station allocates downlink PDCPSNs, it starts scheduling downlink data on the source cell radio link and starts forwarding downlink PDCP SDUs together with the specified PDCPSNs to the target base station;

[0074] S604. For secure synchronization, the HFN (Hyper Frame Number) is also maintained, and the source base station provides the target with a reference HFN for UL and a reference HFN for DL, ie, the HFN and the corresponding SN;

[0075] S605. The source base station sends an early status transmission message to transfer the downlink (DL) count value, indicating that the source base station forwards the PDCPSN and HFN of the first PDCP SDU to the target base station;

[0076] S606. After the source base station passes the SN value to the target base station, it will maintain the HFN and PDCPSN. Even in RLC-UM (Unacknowledged Mode), the SN Status Transfer message will indicate the next DL PDCP SN assigned to a data packet that does not have a PDCP sequence number.

[0077] S607. During the handover execution, the source base station and the target base station respectively perform ROHC (Robust Header Compression) header compression, encryption and PDCP header addition;

[0078] S608. During the handover execution, the UE continues to receive downlink data from the source base station and the target base station; until an explicit release command is received from the target base station in the connection of the source base station;

[0079] S609. During handover execution, the UE DCHO PDCP maintains independent security and ROHC header decompression for each gNB, while maintaining common reordering, duplicate detection, and discard functionality. PDCP SDUs are delivered to upper layers in sequence. Continuity of RLC AM (Acknaw|edged Mode) and UMDRBs configured using DCHO is supported.

[0080] The corresponding uplink processing in the user terminal is as follows:

[0081] S701. The UE sends uplink data to the source base station until the random access procedure at the target base station is completed. The UE then switches its uplink data transmission to the target base station.

[0082] S702. Even after switching UL data transmission, the UE continues to send uplink L1 CSI, HARQ, L2 RLC, ROHC feedback, HARQ data retransmissions, and RLC data retransmissions to the source gNB.

[0083] S703. During handover execution, the UE maintains separate security contexts and ROHC header compression contexts for uplink transmission between the source and target base stations. The UE maintains common UL PDC PSN allocations and supports continuity of RLC A M and UMDRB configured using DCHO.

[0084] S704. During the handover execution, the source base station and the target base station maintain their respective security, ROHC header decompression and context processing of UL data received from the UE;

[0085] S705. Whether to establish a forwarding tunnel is optional;

[0086] S706. The HFN and PDCPSN are maintained in the target base station. That is, in RLC-UM mode, the first UL data lost during the SN state transition is also transmitted to the 5GC.

[0087] S707. Once the DCHO handover command message is received, the UE hangs up the source cell SRBs, stops sending and receiving any RRC control signaling to the source cell, and establishes SRBs for the target cell;

[0088] S708. After successfully performing DCHO handover, the UE releases the source cell SRBs configuration after receiving the source cell release indication from the target cell;

[0089] S709. When DCHO handover to the target cell fails, if the source cell link is available, the UE will return to the source cell configuration and activate the source cell SRBs to run control (plane) signaling.

[0090] In summary, dual connectivity handover (DCHO) allows the UE to maintain RX and TX processing of user data with the source cell during the handover process until it can send and receive user data in the target cell. This means that during the handover process, the UE maintains simultaneous connections with both the source and target cells for a short period of time, and simultaneously transmits and receives data in both cells.

[0091] Through the description of the above implementation methods, those skilled in the art can clearly understand that the method according to the above embodiment can be implemented by means of software plus the necessary general hardware platform, and of course it can also be implemented by hardware, but in many cases the former is a better implementation method. Based on this understanding, the technical solution of the present application, or the part that contributes to the prior art, can be embodied in the form of a software product, which is stored in a storage medium (such as ROM / RAM, magnetic disk, optical disk), and includes a number of instructions for enabling a terminal device (which can be a mobile phone, computer, server, or network device, etc.) to execute the methods of each embodiment of the present application.

[0092] FIG6 is a structural block diagram of a cell switching device according to an embodiment of the present application; as shown in FIG6 , the device includes:

[0093] A first sending module 62 is configured to send a handover request message to a target cell when it is determined that the user terminal is to perform cell handover, wherein the handover request message is used to indicate the handover resources required for the target cell to hand over to the user terminal connected to the source cell;

[0094] The second sending module 64 is configured to send an RRC reconfiguration message to the user terminal through the air interface upon receiving a request confirmation message fed back by the target cell based on the handover request message, so as to trigger the user terminal to switch from the source cell to the target cell using dual connection handover, wherein the request confirmation message carries at least information that the target cell supports dual connection handover, and the dual connection handover is used to indicate that the source cell and the target cell are allowed to connect to the user terminal at the same time during the handover process, and support the user terminal to send and receive data.

[0095] Through the above embodiment, after the user terminal connects to the source cell and the target cell, a dual-connection handover process is executed. This ensures that, during the handover process from the source cell to the target cell, the source cell can send and receive user data corresponding to the user terminal, even if the handover is not fully completed. Until the user data can be sent and received in the target cell, the above implementation solves the problem of communication interruption in the related art when the user terminal switches from the source cell to another target cell, ensuring that communication interruption will not occur when switching between different cells, greatly improving the stability and reliability of the communication process, and achieving the technical effect of reducing communication latency.

[0096] In an exemplary embodiment, the above-mentioned device also includes: a third determination module 60, which determines a measurement report of the user terminal connected to the source cell before sending a handover request message to the target cell; and determines whether the user terminal needs to perform cell handover based on the measurement report and the RRM information corresponding to the source cell and the user terminal.

[0097] In an exemplary embodiment, the above-mentioned device also includes: a fourth determination module 66, which sends an RRC reconfiguration message to the user terminal through the air interface to trigger the user terminal to use dual-connection switching to switch from the source cell to the target cell, and allocates a sequence code of the PDCP data packet for supporting data synchronization to the downlink corresponding to the user terminal; determines the forwarding result of the user terminal forwarding the sequence code and the data service unit corresponding to the downlink to the target cell; when the target cell receives the RRC reconfiguration completion message sent by the user terminal and the forwarding result indicates that the forwarding is successful, determines that the switching is completed and stops allocating the sequence code to the downlink.

[0098] In an exemplary embodiment, the above-mentioned device also includes: a fifth determination module 68, which sends an RRC reconfiguration message to the user terminal through the air interface to trigger the user terminal to switch from the source cell to the target cell using dual-connection switching, and after receiving a switching success message sent by the target cell, sends a notification message to the user terminal that the target cell has been successfully accessed; obtains the synchronization status of the DL / UL data of the source cell and the target cell corresponding to the user terminal after receiving the notification message; and when the synchronization status indicates that synchronization is completed, determines that the current source cell allows the cell release operation to be performed.

[0099] In an exemplary embodiment, the above-mentioned device also includes: a sixth determination module 70, which is configured to send an RRC reconfiguration message to the user terminal through the air interface to trigger the user terminal to switch from the source cell to the target cell using dual connection switching, and then receive an operation command corresponding to the dual connection switching sent by the user terminal; determine the first connection mode between the source cell and the user terminal and the second connection mode between the source cell and the target device according to the operation command, wherein the first connection mode is used to indicate that the source cell continues to be connected to the user terminal when it does not receive the switching success message sent by the target device, and the second connection mode is used to indicate that the target cell continues to maintain a synchronous connection with the source cell to the user terminal when it does not receive the RRC reconfiguration completion message.

[0100] FIG7 is a structural block diagram of another cell switching device according to an embodiment of the present application; as shown in FIG7 , it includes:

[0101] The feedback module 74 is configured to, when it is determined that the user terminal is to perform cell switching, feedback a corresponding request confirmation message to the source cell based on the switching request message sent by the source cell, so as to instruct the user terminal to perform dual-connection switching between the source cell and the target cell based on the request confirmation message; wherein the switching request message is used to indicate the switching resources required when the target cell switches to the user terminal connected to the source cell, and the request confirmation message carries at least information that the target cell supports dual-connection switching, and the dual-connection switching is used to indicate that during the switching process, the source cell and the target cell are allowed to connect to the user terminal at the same time, and support the user terminal in sending and receiving data.

[0102] Through the above embodiment, after the user terminal connects to the source cell and the target cell, a dual-connection handover process is executed. This ensures that, during the handover process from the source cell to the target cell, the source cell can send and receive user data corresponding to the user terminal, even if the handover is not fully completed. Until the user data can be sent and received in the target cell, the above implementation solves the problem of communication interruption in the related art when the user terminal switches from the source cell to another target cell, ensuring that communication interruption will not occur when switching between different cells, greatly improving the stability and reliability of the communication process, and achieving the technical effect of reducing communication latency.

[0103] Optionally, the above-mentioned device also includes: a sending module 76, which is configured to obtain the switching result of the user terminal switching from the source cell to the target cell using dual connection switching; when the switching result indicates that the switching is successful, send a switching success message to the source cell.

[0104] An embodiment of the present application further provides a storage medium, which includes a stored program, wherein the program executes any of the above methods when it is run.

[0105] Optionally, in this embodiment, the storage medium may be configured to store program codes configured to execute the following steps:

[0106] S1, when it is determined that the user terminal is to perform cell handover, sending a handover request message to the target cell, wherein the handover request message is used to indicate the handover resources required for the target cell to hand over the user terminal connected to the source cell;

[0107] S2. Upon receiving a request confirmation message fed back by the target cell based on the switching request message, an RRC reconfiguration message is sent to the user terminal through the air interface to trigger the user terminal to switch from the source cell to the target cell using dual-connection switching, wherein the request confirmation message carries at least information that the target cell supports dual-connection switching, and the dual-connection switching is used to indicate that the source cell and the target cell are allowed to connect to the user terminal at the same time during the switching process, and support the user terminal in sending and receiving data.

[0108] Optionally, in this embodiment, the storage medium may also be configured to store program codes configured to execute the following steps:

[0109] S1. When it is determined that the user terminal is to perform cell switching, a corresponding request confirmation message is fed back to the source cell according to the handover request message sent by the source cell, so as to instruct the user terminal to perform dual-connection switching between the source cell and the target cell based on the request confirmation message; wherein the handover request message is used to indicate the handover resources required when the target cell switches to the user terminal connected to the source cell, and the request confirmation message carries at least information that the target cell supports dual-connection switching, and the dual-connection switching is used to indicate that during the handover process, the source cell and the target cell are allowed to simultaneously connect to the user terminal, and support the sending and receiving of data by the user terminal.

[0110] An embodiment of the present application further provides an electronic device, comprising a memory and a processor, wherein the memory stores a computer program, and the processor is configured to run the computer program to execute the steps in any one of the above method embodiments.

[0111] Optionally, the electronic device may further include a transmission device and an input / output device, wherein the transmission device is connected to the processor, and the input / output device is connected to the processor.

[0112] Optionally, in this embodiment, the processor may be configured to execute the following steps through a computer program:

[0113] S1, when it is determined that the user terminal is to perform cell handover, sending a handover request message to the target cell, wherein the handover request message is used to indicate the handover resources required for the target cell to hand over the user terminal connected to the source cell;

[0114] S2. Upon receiving a request confirmation message fed back by the target cell based on the switching request message, an RRC reconfiguration message is sent to the user terminal through the air interface to trigger the user terminal to switch from the source cell to the target cell using dual-connection switching, wherein the request confirmation message carries at least information that the target cell supports dual-connection switching, and the dual-connection switching is used to indicate that the source cell and the target cell are allowed to connect to the user terminal at the same time during the switching process, and support the user terminal in sending and receiving data.

[0115] Optionally, in this embodiment, the processor may be further configured to execute the following steps through a computer program:

[0116] S1. When it is determined that the user terminal is to perform cell switching, a corresponding request confirmation message is fed back to the source cell according to the handover request message sent by the source cell, so as to instruct the user terminal to perform dual-connection switching between the source cell and the target cell based on the request confirmation message; wherein the handover request message is used to indicate the handover resources required when the target cell switches to the user terminal connected to the source cell, and the request confirmation message carries at least information that the target cell supports dual-connection switching, and the dual-connection switching is used to indicate that during the handover process, the source cell and the target cell are allowed to simultaneously connect to the user terminal, and support the sending and receiving of data by the user terminal.

[0117] Optionally, in this embodiment, the above-mentioned storage medium may include but is not limited to: a USB flash drive, a read-only memory (ROM), a random access memory (RAM), a mobile hard disk, a magnetic disk or an optical disk, and other media that can store program codes.

[0118] Optionally, specific examples in this embodiment may refer to the examples described in the above embodiments and optional implementation modes, and this embodiment will not be described in detail here.

[0119] Obviously, those skilled in the art should understand that the modules or steps of the present application described above can be implemented using a general-purpose computing device, they can be concentrated on a single computing device, or distributed on a network composed of multiple computing devices. Alternatively, they can be implemented using program code executable by the computing device, so that they can be stored in a storage device and executed by the computing device. In some cases, the steps shown or described can be performed in a different order than herein, or they can be made into separate integrated circuit modules, or multiple modules or steps can be made into a single integrated circuit module for implementation. Thus, the present application is not limited to any specific combination of hardware and software.

[0120] The above description is merely an optional embodiment of the present application and is not intended to limit the present application. Various modifications and variations are possible for those skilled in the art. Any modifications, equivalent substitutions, improvements, etc. made within the principles of the present application shall be included within the scope of protection of the present application.

Claims

1. A cell handover method, applied to a source cell, the method comprising: When it is determined that the user terminal is to perform a cell handover, sending a handover request message to the target cell, wherein the handover request message is used to indicate the handover resources required for the target cell to switch to the user terminal connected to the source cell; Upon receiving a request confirmation message fed back by the target cell based on the switching request message, an RRC reconfiguration message is sent to the user terminal through the air interface to trigger the user terminal to switch from the source cell to the target cell using dual connection switching, wherein the request confirmation message carries at least information that the target cell supports dual connection switching.

2. The method according to claim 1, wherein: Before sending the handover request message to the target cell, the method further includes: Determining a measurement report of a user terminal connected to the source cell; Determine whether the user terminal needs to perform cell switching according to the measurement report and RRM information corresponding to the source cell and the user terminal.

3. The method according to claim 1, wherein: After sending an RRC reconfiguration message to the user terminal through an air interface to trigger the user terminal to switch from the source cell to the target cell using dual connectivity switching, the method further includes: Allocating a sequence code of a PDCP data packet for supporting data synchronization to a downlink corresponding to the user terminal; Determine a forwarding result of the user terminal forwarding the sequence code and the data service unit corresponding to the downlink to the target cell; When the target cell receives the RRC reconfiguration completion message sent by the user terminal and the forwarding result indicates that the forwarding is successful, it is determined that the handover is completed, and the sequence code is stopped being allocated to the downlink.

4. The method according to claim 1, wherein: After sending an RRC reconfiguration message to the user terminal through an air interface to trigger the user terminal to switch from the source cell to the target cell using dual connectivity switching, the method further includes: Upon receiving the handover success message sent by the target cell, The terminal sends a notification message that it has successfully accessed the target cell; Acquire synchronization status of DL / UL data of the source cell and the target cell corresponding to the user terminal after receiving the notification message; When the synchronization status indicates that the synchronization is completed, it is determined that the source cell currently allows a cell release operation to be performed.

5. The method according to claim 1, wherein: After sending an RRC reconfiguration message to the user terminal through an air interface to trigger the user terminal to switch from the source cell to the target cell using dual connectivity switching, the method further includes: Receiving an operation command corresponding to the dual connection switching sent by the user terminal; A first connection mode between the source cell and the user terminal and a second connection mode between the source cell and the target device are determined according to the operation command, wherein the first connection mode is used to indicate that the source cell continues to be connected to the user terminal when the source cell has not received a switching success message sent by the target device, and the second connection mode is used to indicate that the target cell continues to maintain a synchronous connection with the source cell to the user terminal when the target cell has not received the RRC reconfiguration completion message.

6. A cell handover method, applied to a target cell, the method comprising: When it is determined that the user terminal is to perform a cell handover, a corresponding request confirmation message is fed back to the source cell according to the handover request message sent by the source cell, so as to instruct the user terminal to perform a dual-connection handover between the source cell and the target cell based on the request confirmation message; wherein the handover request message is used to indicate the handover resources required when the target cell switches to the user terminal connected to the source cell, and the request confirmation message carries at least information that the target cell supports dual-connection handover.

7. The method according to claim 6, wherein: The method further comprises: Obtaining a handover result of the user terminal switching from the source cell to the target cell using dual connectivity handover; When the handover result indicates that the handover is successful, a handover success message is sent to the source cell.

8. A cell switching device, applied to a source cell, comprising: The first sending module is configured to, when it is determined that the user terminal is about to perform cell switching, Sending a handover request message to the target cell, wherein the handover request message is used to indicate the handover resources required when the target cell switches to the user terminal connected to the source cell; The second sending module is configured to send an RRC reconfiguration message to the user terminal through the air interface when receiving a request confirmation message fed back by the target cell based on the switching request message, so as to trigger the user terminal to switch from the source cell to the target cell using dual connection switching, wherein the request confirmation message carries at least information that the target cell supports dual connection switching.

9. A cell switching device, applied to a target cell, comprising: A feedback module is configured to, when it is determined that the user terminal is to perform cell switching, feedback a corresponding request confirmation message to the source cell according to the switching request message sent by the source cell, so as to instruct the user terminal to perform dual connection switching between the source cell and the target cell based on the request confirmation message; wherein the switching request message is used to indicate the switching resources required when the target cell switches to the user terminal connected to the source cell, and the request confirmation message carries at least information that the target cell supports dual connection switching.

10. A computer-readable storage medium, the computer-readable storage medium comprising a stored program, wherein: When the program is executed, the method described in any one of claims 1 to 5 or 6 to 7 is executed.

11. An electronic device comprising a memory and a processor, wherein the memory stores a computer program, and the processor is configured to execute the method according to any one of claims 1 to 5 or 6 to 7 through the computer program.

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