Data transmission method, device, storage medium, and computer program product

Abstract

The present disclosure relates to the technical field of communications, and in particular, to a data transmission method, a network device, a storage medium, and a computer program product. The data transmission method is applied to a first network device, and comprises: receiving data forwarding information from one or more second network devices, wherein the data forwarding information at least indicates a data forwarding address of the one or more second network devices; and sending the data forwarding information to the one or more second network devices. According to the present disclosure, a first network device can communicate with a second network device on the basis of data forwarding information, thereby enabling data interaction between a network device currently providing an access service for a terminal and a network device that will subsequently provide an access service for the terminal, such that when the terminal switches between the first network device and the second network device, data can be smoothly forwarded from one network device to another network device, thereby maintaining the service continuity performance of the terminal.

Description

A data transmission method, device, storage medium and computer program product

[0001] Cross-reference to Related Applications

[0002] This application is based on and claims priority to Chinese Patent Application No. 202411085277.9, filed on August 8, 2024, the entire contents of which are incorporated herein by reference. TECHNICAL FIELD

[0003] The present disclosure relates to the technical field of communication, and in particular, to a data transmission method, network device, storage medium and computer program product. BACKGROUND

[0004] With the continuous development of communication technology, the Layer 1 / 2 triggered mobility (LTM) handover mechanism has been extended to support the terminal device to switch from one network device (e.g., a base station) to another network device during the handover process. Since the terminal device can quickly and frequently perform multiple consecutive LTM handovers, the network device serving the terminal device is frequently replaced, and multiple data forwarding between network devices needs to be performed to maintain the data reception of the terminal device. Therefore, consecutive LTM handovers across multiple network devices pose higher requirements for the guarantee of service continuity.

[0005] However, the above-mentioned LTM handover mechanism has a key problem: only the original network device that initially serves the terminal device, i.e., the source base station that triggers the first LTM handover of the terminal, will interact with the candidate network device for data forwarding addresses. When the terminal device is consecutively handed over to multiple new network devices, the subsequent serving network devices lack data forwarding address information between the new target network devices, which makes it impossible to effectively perform data forwarding during the handover process, thereby interrupting the service continuity of the terminal device. SUMMARY

[0006] The present disclosure is proposed in view of the above problems. The present disclosure provides a data transmission method, network device, storage medium and computer program product.

[0007] According to one aspect of the present disclosure, a data transmission method is provided, applied to a first network device, comprising: receiving data forwarding information from one or more second network devices, wherein the data forwarding information indicates at least data forwarding addresses of the one or more second network devices; and sending the data forwarding information to the one or more second network devices, wherein the first network device is a current serving network device, and the one or more second network devices are candidate network devices.

[0008] Further, the data transmission method according to one aspect of the present disclosure, the sending of the data forwarding information to the one or more second network devices comprises: sending the data forwarding information of the one or more second network devices to the one or more second network devices before sending a radio resource control (RRC) reconfiguration message to the terminal.

[0009] Further, the data transmission method according to one aspect of the present disclosure, the sending of the data forwarding information to the one or more second network devices comprises: sending the data forwarding information of the one or more second network devices to the target network device after sending a layer 1 / 2 triggered mobility (LTM) cell handover message to the terminal, wherein the target network device is one of the one or more second network devices.

[0010] Further, the data transmission method according to one aspect of the present disclosure, the sending of the data forwarding information to the one or more second network devices comprises: requesting the data forwarding information of the one or more second network devices from a previous serving network device after the terminal performs a cell handover at least once; and receiving the data forwarding information of each of the one or more second network devices from the previous serving network device.

[0011] Further, the data transmission method according to one aspect of the present disclosure, the sending of the data forwarding information to the one or more second network devices comprises: requesting the data forwarding information of a target network device of a next handover from the target network device after the terminal performs a cell handover at least once; and receiving the data forwarding information from the target network device.

[0012] Further, the data transmission method according to one aspect of the present disclosure, the sending of the data forwarding information to the one or more second network devices comprises: requesting the data forwarding information of a target network device of a next handover from an initial serving network device after the terminal performs a cell handover at least once; and receiving the data forwarding information from the initial serving network device.

[0013] Further, the data transmission method according to one aspect of the present disclosure, the sending of the data forwarding information to the one or more second network devices comprises: requesting the data forwarding information of the one or more second network devices from an initial serving network device after the terminal performs a cell handover at least once; and receiving the data forwarding information from the initial serving network device.

[0014] Further, the data transmission method according to one aspect of the present disclosure, further comprising: receiving a radio resource control (RRC) reconfiguration complete message from the terminal, and sending data to the one or more second network devices.

[0015] Further, the data transmission method according to one aspect of the present disclosure further comprises: receiving a radio resource control (RRC) reconfiguration complete message from the terminal, and transmitting data from the initial serving network device and / or the serving network device to a target network device determined based on the measurement result of the terminal, wherein the target network device is one of the one or more second network devices.

[0016] Further, the data transmission method according to one aspect of the present disclosure, the data forwarding information comprises an uplink and downlink data forwarding address.

[0017] Further, the data transmission method according to one aspect of the present disclosure, the data forwarding information comprises a data forwarding address of the initial serving network device.

[0018] Further, the data transmission method according to one aspect of the present disclosure further comprises: disconnecting the path to the core network after the terminal accesses the target network device, wherein the target network device is one of the one or more second network devices.

[0019] According to still another aspect of the present disclosure, a data transmission method is provided, applied to a second network device, comprising: receiving data from a first network device; and deleting the data when no cell handover message from the first network device is received within a predetermined time.

[0020] Further, the data transmission method according to still another aspect of the present disclosure further comprises: sending a path switching request to the core network after the terminal accesses the second network device; and starting to receive data related to the terminal from the core network after the path switching.

[0021] Further, the data transmission method according to still another aspect of the present disclosure further comprises: reserving resources in advance for the terminal to access and preparing corresponding beam access after receiving the cell handover message from the first network device within a predetermined time.

[0022] According to still another aspect of the present disclosure, a first network device is provided, comprising: a communication interface configured to perform wireless communication with a terminal; a memory for storing computer readable instructions; and a processor for running the computer readable instructions, so that the first network device performs the data transmission method as described above.

[0023] According to still another aspect of the present disclosure, a second network device is provided, comprising: a communication interface configured to perform wireless communication with a terminal; a memory for storing computer readable instructions; and a processor for running the computer readable instructions, so that the first network device performs the data transmission method as described above.

[0024] According to still another aspect of the present disclosure, a computer readable storage medium is provided, having stored thereon a computer program which, when executed by a processor, implements the data transmission method as described above.

[0025] According to still another aspect of the present disclosure, a computer program product is provided, comprising a computer program which, when executed by a processor, implements the data transmission method as described above. BRIEF DESCRIPTION OF DRAWINGS

[0026] The above and other objects, features and advantages of the present disclosure will become more apparent from the following detailed description taken in conjunction with the accompanying drawings, in which like reference characters designate like elements in the figures. The accompanying drawings are intended to provide a further understanding of embodiments of the present disclosure and are incorporated in and constitute a part of this specification, illustrate embodiments of the present disclosure and serve to explain the principles of the present disclosure, but do not limit the present disclosure. In the drawings:

[0027] FIG. 1 is a schematic diagram illustrating a communication system according to an embodiment of the present disclosure.

[0028] FIG. 2 is a flow diagram illustrating a data transmission method according to an embodiment of the present disclosure.

[0029] FIG. 3 is an interaction diagram illustrating a data transmission method according to an embodiment of the present disclosure.

[0030] FIG. 4 is an interaction diagram illustrating another data transmission method according to an embodiment of the present disclosure.

[0031] FIG. 5 is an interaction diagram illustrating another data transmission method according to an embodiment of the present disclosure.

[0032] FIG. 6 is an interaction diagram illustrating another data transmission method according to an embodiment of the present disclosure.

[0033] FIG. 7 is an interaction diagram illustrating another data transmission method according to an embodiment of the present disclosure.

[0034] FIG. 8 is an interaction diagram illustrating another data transmission method according to an embodiment of the present disclosure.

[0035] FIG. 9 is a flow diagram illustrating a data transmission method according to an embodiment of the present disclosure.

[0036] FIG. 10 is a functional block diagram illustrating a first network device according to an embodiment of the present disclosure.

[0037] FIG. 11 is a functional block diagram illustrating a second network device according to an embodiment of the present disclosure.

[0038] FIG. 12 is a hardware block diagram illustrating a computer readable storage medium according to an embodiment of the present disclosure.

[0039] FIG. 13 is a hardware block diagram of a computer program product according to an embodiment of the present disclosure. DETAILED DESCRIPTION

[0040] In order to make the objectives, technical solutions and advantages of the present disclosure more obvious, the following will describe the example embodiments according to the present disclosure in detail with reference to the drawings. Obviously, the described embodiments are only a part of the embodiments of the present disclosure, rather than all the embodiments of the present disclosure, and it should be understood that the present disclosure is not limited to the example embodiments described herein.

[0041] The technical solutions of the embodiments of the present disclosure can be applied to various communication systems. For example, the technical solutions provided by the embodiments of the present disclosure can be applied to a Long Term Evolution (LTE) system, and can also be applied to an LTE Frequency Division Duplex (FDD) system, an LTE Time Division Duplex (TDD) system, a Universal Mobile Telecommunications System (UMTS), a Worldwide Interoperability for Microwave Access (WiMAX) communication system, a UMTS Terrestrial Radio Access Network (UTRAN) system, or a Global System for Mobile Communication (GSM) / Enhanced Data Rates for GSM Evolution (EDGE) system radio access network (GSM EDGE Radio Access Network, GERAN) system. In addition, the technical solutions provided by the embodiments of the present disclosure can also be applied to any other wireless communication system with similar structures and functions, such as a Public Land Mobile Network (PLMN) system, a 5th Generation (5G) communication system, a communication system after 5G, a New Radio Access Technology (NR) system, a Vehicle-to-X (V2X) system, and the like.The V2X system can include a vehicle to network (V2N) system, a vehicle to vehicle (V2V) system, a vehicle to infrastructure (V2I) system, a vehicle to pedestrian (V2P) system, a long term evolution-vehicle (LTE-V) system, a vehicle to everything (V2X) system, a machine type communication (MTC) system, an internet of things (IoT) system, a long term evolution-machine (LTE-M) system, a machine to machine (M2M) system, and the like. The embodiments of the present disclosure are not limited in this regard.

[0042] To clearly describe the technical solutions of the embodiments of the present disclosure, a communication system applicable to the embodiments of the present disclosure is exemplarily described in combination with FIG. 1. FIG. 1 is a schematic diagram of a communication system provided by the embodiments of the present disclosure.

[0043] As shown in FIG. 1, the communication system 100 can include a plurality of network devices (such as a first network device 110 and a second network device 120), a terminal device 130, and a core network device 140. The terminal device 130 can be mobile or fixed. The first network device 110 and the second network device 120 are devices that can communicate with the terminal device 130 through a wireless link. The network device is, for example, a base station or a base station controller. The terminal device 130 accesses the core network device 140 through the first network device 110 and the second network device 120. Each network device can cover a cell, provide network services for the cell, and communicate with terminal devices located in the corresponding coverage cell.

[0044] The base station can be a base station (base transceiver station, BTS) in a global system for mobile communication (GSM), a base station (node B) in a wideband code division multiple access (WCDMA), a base station (eNB) in an internet of things (IoT) or narrow band-internet of things (NB-IoT), a base station in a future 5G mobile communication network or a future evolved public land mobile network (PLMN), and the embodiments of the present application do not make any limitation in this regard.

[0045] In actual applications, when the network device is a base station, the coverage of the base station is fixed, and when the position of the terminal device changes, the serving base station of the terminal device can change.

[0046] For example, when the terminal device 130 moves from the coverage of the first network device 110 to the coverage of the second network device 120, the serving base station of the terminal device 130 is switched from the first network device 110 to the second network device 120. In this case, the first network device 110 is the initial base station, which can also be the serving base station, and the second network device 120 is the target base station.

[0047] The core network device 140 in FIG. 1 can be a user plane function (UPF) of a public network or a device deployed in a public network including a UPF, and is used to establish a communication connection between the terminal device and the device of the public network.

[0048] The public network is the Internet, which is a collection of computer networks formed by connecting computer networks of different locations and different sizes (including local area networks, metropolitan area networks, and wide area networks) around the world.

[0049] FIG. 1 exemplarily shows two network devices and one terminal device. Optionally, the communication system 100 can include multiple network devices, and each network device can include other numbers of terminal devices within the coverage cell, and the embodiments of the present application do not make any limitation in this regard.

[0050] FIG. 2 is a diagram illustrating a data transmission method according to an embodiment of the present disclosure, which is performed by the first network device 110.

[0051] The data transmission method according to the embodiments of the present disclosure as shown in FIG. 2 includes the following operations.

[0052] In operation S201, data forwarding information is received from one or more second network devices, wherein the data forwarding information indicates at least a data forwarding address of the one or more second network devices.

[0053] In some embodiments, the first network device can receive data forwarding information from one or more second network devices during the LTM handover preparation phase. The data forwarding information can indicate a data forwarding address of the one or more second network devices. Here, the data forwarding information refers to information used to guide how a data packet or message is forwarded from one network device to another network device during network communication. For example, in order to perform network communication, the one or more second network devices can actively or passively (e.g., in response to a request from the first network device side) send the data forwarding information to the first network device. The first network device can also actively or passively (e.g., in response to a request from the second network device side) receive the data forwarding information from the second network device.

[0054] In operation S202, data forwarding information is sent to one or more second network devices, wherein the first network device is a current service network device, and the one or more second network devices are candidate network devices.

[0055] In some embodiments, after the one or more second network devices send the data forwarding information to the first network device, the first network device can send the received data forwarding information to the one or more second network devices. Illustratively, to perform network communication, the first network device can send the data forwarding information to the one or more second network devices actively or passively (e.g., in response to a request from the second network device side). Here, the first network device is a serving network device currently providing access services for the terminal. It can be a base station, an access point (AP), a router, or any other device capable of connecting the terminal and providing network services. The second network device is a candidate network device for providing access services for the terminal. It can be a base station, an access point (AP), a router, or any other device capable of connecting the terminal and providing network services. The terminal can be a user equipment (UE), an access terminal, a subscriber unit, a subscriber station, a mobile station, a mobile, a remote station, a remote terminal, a mobile device, a user terminal, a smart terminal, a wireless communication device, a user agent, or a user device. The terminal can also be a cellular phone, a cordless phone, a Session Initiation Protocol (SIP) phone, a Wireless Local Loop (WLL) station, a Personal Digital Assistant (PDA), a handheld device with wireless communication capabilities, a computing device, or other processing devices connected to a wireless modem, a relay device, a vehicle-mounted device, a wearable device, a terminal in a next-generation communication system such as an NR network, or a terminal in a future evolved Public Land Mobile Network (PLMN), etc., without specific limitation. Illustratively, when the terminal needs to switch from the first network device to another network device, the second network device can be used as a candidate network device.

[0056] In actual scenarios, to avoid the problem that the terminal service of the network device that needs to provide access services for the terminal in the future cannot obtain the data forwarding address of other candidate network devices when the terminal switches, in the LTM handover preparation phase, when the terminal needs to switch from the first network device currently providing access services for the terminal to another network device, the first network device can obtain the data forwarding information of all candidate network devices (one or more second network devices). The first network device can forward the obtained data forwarding addresses of all candidate network devices to the candidate network devices.

[0057] The first network device can be the first network device 110 in FIG. 1, the second network device can be the second network device 120 in FIG. 1, and the terminal can be the terminal device 130 in FIG. 1.

[0058] In summary, the technical solution provided by the embodiments of the present disclosure enables the first network device to communicate with the second network device based on the data forwarding information, thereby realizing data interaction between the network device currently providing access services for the terminal and the network device subsequently providing access services for the terminal, so that when the terminal switches between the first network device and the second network device, data can be successfully forwarded from one network device to another network device, thereby maintaining the service continuity of the terminal.

[0059] Further, the sending of the data forwarding information to the one or more second network devices comprises: sending the data forwarding information of the one or more second network devices to the one or more second network devices before sending a radio resource control (RRC) reconfiguration message to the terminal.

[0060] In some embodiments, RRC refers to wireless resource management, control and scheduling through certain strategies and means, under the requirement of quality of service, to make the best use of limited wireless network resources as much as possible, to ensure reaching the planned coverage area, and to improve business capacity and resource utilization as much as possible. The radio resource control RRC reconfiguration message can refer to a message for modifying the current RRC connection configuration. In the LTM handover preparation phase, when the first network device needs to modify the wireless resource configuration between the terminal, the data forwarding information of the one or more second network devices is sent to the one or more second network devices before the radio resource control RRC reconfiguration message is sent to the terminal. Exemplarily, in a communication network, when a terminal (such as a mobile phone, a tablet computer, etc.) communicates with a network device (such as a base station, etc.) through a wireless link, in order to optimize network performance and user experience, the network may dynamically adjust the connection between the terminal and different network devices according to real-time network conditions, terminal location, service demand, etc. In this process, the RRC reconfiguration message plays a crucial role, which is used to modify the wireless resource configuration between the terminal and the network device. After receiving the data forwarding information of the one or more second network devices, the first network device can send the data forwarding information of the one or more second network devices to the candidate network device (one or more second network devices), so that the candidate network device can obtain the data forwarding information of other network devices, facilitating the terminal to ensure data continuity when subsequently switching network devices.

[0061] In summary, the technical solution provided by the embodiments of the present disclosure can ensure smooth transition of data transmission of the terminal during network adjustment, and avoid data loss or interruption, by sending data forwarding information to one or more second network devices before sending the RRC reconfiguration message to the terminal.

[0062] To clearly illustrate the technical solutions of the present disclosure, the interaction process between the terminal and different network devices in the data transmission method according to the embodiments of the present disclosure is described with reference to FIG. 3.

[0063] In one embodiment, FIG. 3 illustrates the interaction process between the first network device, the second network device, and the terminal in the data transmission method provided by the present disclosure. As shown in FIG. 3, the first network device can be the initial base station in FIG. 3, and the second network device can be base station 1 and base station 2. The second network device can be two as shown in FIG. 4, or can be multiple. The data transmission method provided by the present disclosure can be applied to the LTM handover scenario, and the data transmission method includes the following operations:

[0064] The flow in the LTM handover preparation phase:

[0065] 1. When the terminal needs to move from one base station to another base station, in order to ensure the continuity of communication and the quality of service, a handover process needs to be performed. In this process, the initial base station (i.e., the first network device) needs to evaluate and select appropriate candidate base stations (i.e., base station 1 and base station 2) for handover. In order to achieve this goal, the initial base station sends a handover request to base station 1 and base station 2 to collect the configuration information of the candidate cells. Exemplarily, the handover request can also include the data forwarding information of the initial base station.

[0066] 2. Base station 1 and base station 2 will reply to the initial base station with a message containing the configuration information of the candidate cells in the received handover request message. The configuration information includes the data forwarding information of the candidate base stations (i.e., the data forwarding information of base station 1 and the data forwarding information of base station 2). The data forwarding information includes the uplink and downlink data forwarding addresses.

[0067] 3. After receiving the data forwarding information of all candidate base stations (i.e., base station 1 and base station 2), the initial base station initiates a new flow to send the collected data forwarding information of all candidate base stations to all candidate base stations (i.e., base station 1 and base station 2), so that each candidate base station can know the data forwarding information of other candidate base stations. Exemplarily, the data forwarding information forwarded to base station 1 and base station 2 can also include the data forwarding information of the initial base station.

[0068] 4. After sending the data forwarding information of all candidate base stations to base station 1 and base station 2, the initial base station sends an RRC reconfiguration message to the terminal, and the RRC reconfiguration message contains all the configuration information required by the new base station to which the terminal is to be handed over.

[0069] 5. After receiving the RRC reconfiguration message, the terminal performs the handover process according to the indication in the message. After the handover is successfully completed, the terminal sends an RRC reconfiguration complete message to the initial base station. After receiving the RRC reconfiguration complete message from the terminal, the initial base station can initiate a data forwarding flow to the terminal to ensure the continuity and integrity of data during the handover process. At this time, the initial base station can send data to multiple candidate base stations (such as base station 1 and base station 2). The data can be data related to the communication between the terminal and the candidate base station.

[0070] Further, the data forwarding information is sent to one or more second network devices, including: after sending the cell handover message to the terminal, sending the data forwarding information of the one or more second network devices to the target network device, wherein the target network device is one of the one or more second network devices.

[0071] In some embodiments, in the LTM handover, the cell handover message is a message sent by the first network device (such as a base station) currently serving the terminal to the terminal, indicating that the terminal is about to perform channel switching to connect to the target network device (such as a "new base station"). After the first network device sends the cell handover message to the terminal (such as a mobile phone), the first network device determines the target network device from the one or more second network devices according to the cell handover message, which is the network device that the terminal needs to move from the first network device, that is, one of the one or more second network devices.

[0072] In summary, the technical solution provided by the embodiments of the present disclosure ensures the data continuity during the cell handover process, optimizes resource allocation, reduces handover delay, enhances network flexibility, improves user experience, and lays the foundation for the intelligent development of the network.

[0073] In order to clearly illustrate the technical solutions of the present disclosure, in one embodiment, FIG. 4 shows the interaction process of the first network device, the second network device and the terminal in the data transmission method provided by the present disclosure. As shown in FIG. 4, when performing LTM handover for the first time, the first network device can be the initial base station in FIG. 4, and the second network device can be base station 1 and base station 2. Among them, the second network device can be two as shown in FIG. 4, or multiple. The data transmission method provided by the present disclosure can be applied to the LTM handover scene, and the data transmission method includes the following operations:

[0074] In the LTM handover preparation phase:

[0075] 1. The initial base station (i.e. the first network device) collects the cell configuration information of all candidate base stations (i.e. base station 1 and base station 2) through the handover request process, and also forwards the data forwarding information of the initial base station to the candidate base stations.

[0076] 2. The candidate base stations reply the candidate cell configuration information to the initial base station in the handover request message. The candidate cell configuration information includes the data forwarding information of the candidate base stations, and the data forwarding information includes the uplink and downlink data forwarding addresses.

[0077] 3. The initial base station sends an RRC configuration message to the terminal.

[0078] First LTM handover execution phase:

[0079] 4. The distributed unit (DU) of the initial base station determines the target cell (i.e. the base station) for the final handover according to the layer 1 measurement results reported from the terminal.

[0080] 5. The initial base station sends a cell handover message to the terminal through layer 1 / layer 2 signaling (which can be a MAC CE or a DCI).

[0081] In some embodiments, the DU of the initial base station sends a cell handover message to the centralized unit (CU) of the initial base station through the F1 interface, indicating the target cell (including the target cell ID, the target base station ID, and the TCI state) to which the terminal is to be handed over. Then, the initial base station sends a cell handover notification message to the target base station through the Xn interface, indicating the target cell (including the target cell ID and the TCI state) to which the terminal is to be accessed. After receiving the message, the target base station can reserve resources in advance and prepare the corresponding beam access for the terminal to be accessed.

[0082] 6. The initial base station (i.e. the serving base station currently serving the terminal) sends the data forwarding information of all candidate base stations (i.e. base station 1 and base station 2) to the target base station (i.e. base station 1).

[0083] 7. The terminal starts to perform LTM handover.

[0084] Continuous LTM handover (after the first LTM handover), at this time, the serving base station is base station 1, and the second network device is base station 2:

[0085] 8. The terminal reports a measurement message to the serving base station (i.e. the first network device) currently providing access services for the terminal.

[0086] 9. After determining the target base station according to the measurement message, the serving base station sends a cell handover message to the terminal.

[0087] 10. The serving base station sends data forwarding information of all candidate base stations to the target base station (i.e. one of the one or more second network devices).

[0088] 11. The terminal starts to perform the LTM handover.

[0089] If the terminal needs to perform cell handover again in the future, the above processes 8-11 are repeated.

[0090] In the LTM handover execution phase, whenever the serving base station issues a cell handover message to the terminal, the serving base station performs data forwarding to the target base station, and the target base station receives the forwarded data from the serving base station. When the terminal accesses the target cell of the target base station, the target base station initiates a path switching request procedure to the core network device, the path of the serving base station and the user plane function UPF is disconnected, and the target base station starts to receive data from the user plane function UPF.

[0091] Further, after the terminal performs cell handover at least once, data forwarding information of the one or more second network devices is requested from the previous serving network device, and the data forwarding information of each of the one or more second network devices is received from the previous serving network device. The cell handover in the above "after the terminal performs cell handover at least once" can refer to LTM cell handover.

[0092] In some embodiments, after the terminal performs cell handover at least once, when cell handover needs to be performed again, the serving network device (i.e. the first network device) currently providing access service for the terminal decides the target network device for the terminal, and requests data forwarding information of the one or more second network devices from the previous serving network device (i.e. the serving network device providing access service for the terminal before the handover). The previous serving network device sends the data forwarding information of the one or more second network devices according to the request received from the serving network device currently providing access service for the terminal, and the first network device receives the data forwarding information of the one or more second network devices from the previous serving network device.

[0093] In actual scenarios, in order to avoid the problem that the network device serving the terminal after the handover cannot obtain the data forwarding address of other candidate network devices, causing the terminal service to terminate. When the terminal needs to perform cell handover again after performing cell handover at least once, when the terminal needs to be handed over from the first network device currently providing access service for the terminal to other network devices, the first network device can request data forwarding information of all candidate network devices (i.e. the one or more second network devices) from the previous serving network device. The first network device can forward the obtained data forwarding addresses of all candidate network devices to the candidate network devices.

[0094] In conclusion, the technical solution provided by the embodiments of the present disclosure can ensure that the data transmission of the terminal will not be interrupted or lost during and after the handover by requesting and receiving the data forwarding information of the previous serving network device, thereby improving the user experience.

[0095] In order to clearly illustrate the technical solutions of the present disclosure, in one embodiment, FIG. 5 shows the interaction process of the first network device, the second network device and the terminal in the data transmission method provided by the present disclosure. The data transmission method provided by the present disclosure can be applied in the LTM handover scenario. After the LTM handover, the data transmission method is executed again in the LTM handover. The current serving base station requests the data forwarding information of all candidate base stations from the initial base station. At this time, the execution subject of the first network device is already the base station 1 or the base station 2. The data transmission method includes the following operations:

[0096] As shown in FIG. 5, when the terminal needs to perform LTM handover again after the first LTM handover is completed (continuous LTM handover 1):

[0097] 1. The terminal reports a measurement message to the base station 1 (i.e. the first network device) currently providing access services for the terminal. The measurement message can be the layer 1 measurement result of the terminal.

[0098] 2. After the base station 1 decides the target cell (base station) for LTM handover according to the received measurement message, it will request the data forwarding information of all candidate base stations (one or more second network devices) from the initial base station (the previous serving network device) which previously provided access services for the terminal.

[0099] 3. The initial base station sends the data forwarding information of all candidate base stations to the base station 1 according to the received request.

[0100] 4. After receiving the data forwarding information of all candidate base stations, the base station 1 sends a cell handover message to the terminal. For example, the cell handover message can be sent to the terminal through layer 1 / layer 2 signaling.

[0101] 5. After receiving the cell handover message sent by the base station 1, the terminal will start to perform LTM handover.

[0102] When LTM handover needs to be performed again (continuous LTM handover 2):

[0103] 6. The terminal reports a measurement message to the base station currently providing access services for the terminal.

[0104] 7. After receiving the measurement message, the base station currently providing access services for the terminal decides the target cell (base station) for LTM handover according to the measurement message, and then requests the data forwarding information of all candidate base stations from the base station previously providing access services for the terminal.

[0105] 8. The previous base station providing access services for the terminal sends data forwarding information of all candidate base stations to the current base station providing access services for the terminal after receiving the request from the current base station providing access services for the terminal.

[0106] 9. The current base station providing access services for the terminal sends a cell handover message to the terminal.

[0107] 10. The terminal starts to perform LTM handover after receiving the cell handover message.

[0108] If the terminal needs to perform cell handover again in the future, the above processes 6-10 are repeated. It should be noted that in the continuous handover, the "previous base station providing access services for the terminal" can change, depending on the current serving cell (base station) of the terminal.

[0109] Further, sending the data forwarding information to one or more second network devices includes: after the terminal performs cell handover at least once, requesting data forwarding information of a target network device from the target network device; and receiving the data forwarding information from the target network device.

[0110] In some embodiments, when the terminal needs to perform cell handover again after performing cell handover once, the current first network device providing access services for the terminal requests data forwarding information of a target network device of the next handover from the target network device after determining the target network device of the next handover for the terminal. The target network device sends the data forwarding information of the target network device to the first network device according to the request from the current first network device providing access services for the terminal. The first network device receives the data forwarding information sent by the target network device.

[0111] In summary, the technical solution provided by the embodiments of the present disclosure can ensure that when the terminal performs cell handover, the data connection of the terminal can be quickly and smoothly transferred from the current serving first network device to the target network device, by timely requesting and receiving data forwarding information between network devices. This reduces the data interruption time in the handover process and improves the communication experience of users.

[0112] In order to clearly describe the technical solutions of the present disclosure, in an embodiment, FIG. 6 shows the interaction process of the first network device, the second network device and the terminal in the data transmission method provided by the present disclosure. The data transmission method provided by the present disclosure can be applied to the LTM handover scenario. After LTM handover, the current serving base station requests data forwarding information of a target base station in the next handover, at this time, the "first network device" performing the subject is already "base station 1", and the "target network device" is "base station 2".

[0113] The data transmission method includes the following operations:

[0114] 1. The terminal reports a measurement message to the base station 1 (i.e. the first network device) currently providing the terminal with access services. The measurement message can be the layer 1 measurement result of the terminal.

[0115] 2. After deciding the target cell (base station) for LTM switching according to the received measurement message, the base station 1 requests the data forwarding information of the target base station (base station 2) from the target base station.

[0116] 3. The base station 2 sends the data forwarding information of the base station 2 to the base station 1 according to the received request.

[0117] 4. After receiving the data forwarding information of the base station 2, the base station 1 sends a cell switching message to the terminal. For example, the cell switching message can be sent to the terminal through layer 1 / layer 2 signaling.

[0118] 5. After receiving the cell switching message sent by the base station 1, the terminal starts to perform LTM switching.

[0119] Further, the sending of the data forwarding information to one or more second network devices comprises: after the terminal performs a cell switching at least once, requesting the data forwarding information of the target network device for the next switching from the initial service network device, wherein the first network device serves as the initial service network device when the network triggers the first LTM switching of the terminal; and receiving the data forwarding information from the initial service network device. In some embodiments, after the terminal performs a cell switching once, when the cell switching needs to be performed again, the first network device requests the data forwarding information of the target network device determined for the next switching from the initial service network device (i.e. the network device initially providing the terminal with access services) after determining the target service network device. The initial service network device returns the data forwarding information of the target network device in response to the request of the first network device. Meanwhile, the first network device receives the data forwarding information returned by the initial service network device.

[0120] In summary, the technical solution provided by the embodiments of the present disclosure enables the current service network device (the first network device) to prepare and perform the switching operation more quickly by requesting the data forwarding information of the target network device from the initial service network device. This reduces the delay and uncertainty in the switching process, improves the efficiency and continuity of the switching, and thus improves the user experience.

[0121] In an embodiment, FIG. 7 shows the interaction process of the first network device, the second network device and the terminal in the data transmission method provided by the present disclosure. The data transmission method provided by the present disclosure can be applied in the LTM switching scenario, after the LTM switching, in the re-switching, the current serving base station requests the data forwarding information of the target base station from the initial base station, at this time, the "first network device" performing the subject has become "base station 1" or "base station 2", and the data transmission method includes the following operations:

[0122] 1. The terminal reports a measurement message to the base station 1 (i.e. the first network device) currently providing access service for the terminal. The measurement message can be the layer 1 measurement result of the terminal.

[0123] 2. The base station 1 decides the target cell (base station) for LTM switching according to the received measurement message, and after deciding the target base station, requests the data forwarding information of the target base station from the initial base station (initial serving network device).

[0124] 3. The initial base station sends the data forwarding information of the target base station to the base station 1 according to the received request.

[0125] 4. The base station 1 sends a cell switching message to the terminal after receiving the data forwarding information of the target base station. For example, the cell switching message can be sent to the terminal through layer 1 / layer 2 signaling.

[0126] 5. The terminal starts to perform LTM switching after receiving the cell switching message sent by the base station 1.

[0127] When LTM switching again (continuous LTM switching 2 shown in the figure), at this time, the base station currently providing access service for the terminal becomes base station 2:

[0128] 6. The terminal reports a measurement message to the base station currently providing access service for the terminal.

[0129] 7. The base station currently providing access service for the terminal decides the target cell (base station) for LTM switching according to the measurement message after receiving the measurement message, and requests the data forwarding information of the target base station from the initial base station.

[0130] 8. The initial base station sends the data forwarding information of the target base station to the base station currently providing access service for the terminal after receiving the request from the base station currently providing access service for the terminal.

[0131] 9. The base station currently providing access service for the terminal sends a cell switching message to the terminal.

[0132] 10. The terminal starts to perform LTM switching after receiving the cell switching message.

[0133] Further, the sending of the data forwarding information to the one or more second network devices comprises: after the terminal performs the cell switching at least once, requesting the initial serving network device for the data forwarding information of the one or more second network devices; and receiving the data forwarding information from the initial serving network device.

[0134] In some embodiments, after the terminal performs the cell switching once, when the cell switching needs to be performed again, the first network device can request the initial serving network device for the data forwarding information of the one or more second network devices. The initial serving network device sends the data forwarding information of the one or more second network devices to the first network device in response to the request. The first network device receives the data forwarding information of the one or more second network devices from the initial serving network device.

[0135] In summary, the technical solution provided by the embodiments of the present disclosure is that the first network device requests the initial serving network device for the data forwarding information of the candidate network device (one or more second network devices), so that the current serving network device (the first network device) can prepare and perform the switching operation more quickly. This reduces the delay and uncertainty in the switching process, improves the efficiency and continuity of the switching, and thus improves the user experience.

[0136] In an embodiment, FIG. 8 shows the interaction process of the first network device, the second network device and the terminal in the data transmission method provided by the present disclosure. The data transmission method provided by the present disclosure can be applied in the LTM switching scenario. After the LTM switching, when the switching is performed again, the current serving base station requests the initial base station for the data forwarding information of all candidate base stations. At this time, the first network device performing the subject is already the base station 1 or the base station 2. The data transmission method comprises the following operations:

[0137] 1. The terminal reports a measurement message to the base station 1 (i.e. the first network device) currently providing access service for the terminal. The measurement message can be the layer 1 measurement result of the terminal.

[0138] 2. The base station 1 decides the target cell (base station) for LTM switching according to the received measurement message. After deciding the target base station, the base station 1 requests the initial base station for the data forwarding information of all candidate base stations (i.e. one or more second network devices).

[0139] 3. The initial base station sends the data forwarding information of all candidate base stations to the base station 1 according to the received request.

[0140] 4. After receiving the data forwarding information of the candidate base stations, the base station 1 sends a cell switching message to the terminal. For example, the cell switching message can be sent to the terminal through layer 1 / layer 2 signaling.

[0141] 5. The terminal starts to perform LTM handover after receiving the cell handover message sent by the base station 1.

[0142] When the LTM handover is performed again (the second LTM handover 2 shown in the figure), at this time, the base station currently providing access service for the terminal becomes the base station 2.

[0143] 6. The terminal reports a measurement message to the base station currently providing access service for the terminal.

[0144] 7. After receiving the measurement message, the base station currently providing access service for the terminal decides the target cell (base station) for LTM handover according to the measurement message, and then requests the initial base station for data forwarding information of all candidate base stations.

[0145] 8. After receiving the request from the base station currently providing access service for the terminal, the initial base station sends the data forwarding information of all candidate base stations to the base station currently providing access service for the terminal.

[0146] 9. The base station currently providing access service for the terminal sends a cell handover message to the terminal.

[0147] 10. The terminal starts to perform LTM handover after receiving the cell handover message.

[0148] Further, the above-mentioned data transmission method further comprises: receiving a radio resource control (RRC) reconfiguration complete message from the terminal, and sending data to one or more second network devices.

[0149] In some embodiments, after the cell handover is successfully completed, the terminal sends a reconfiguration complete message to the first network device. After receiving the RRC reconfiguration complete message from the terminal, the first network device can initiate a data forwarding flow to the terminal in order to ensure the continuity and integrity of data during the handover process. At this time, the first network device can send data to one or more second network devices.

[0150] Further, a radio resource control (RRC) reconfiguration complete message is received from the terminal, and data is sent from the initial service network device and / or the service network device to a target network device determined based on the measurement result of the terminal, wherein the target network device is one of the one or more second network devices.

[0151] In some embodiments, the data can refer to data related to the communication of the terminal with the first network device. The target network device can refer to a network device determined by the first network device to be switched to according to the measurement result of the terminal. After the first network device ends from the terminal to the RRC reconfiguration completion message, the data can be sent to the target network device by the initial service network device. The data can also be sent to the target network device by the service network device. The data can also be sent to the target network device by the initial service network device and the service network device together. The specific adjustment can be made according to the actual business needs. The service network device is the network device currently providing access service for the terminal.

[0152] Exemplarily, in each LTM handover execution phase, after the network device (such as a service base station) currently providing access service for the terminal, i.e., the first network device, decides the target network device (such as a target base station) to be switched for the terminal, and before the first network device issues a cell handover message to the terminal, the first network device performs data forwarding to the target network device (target base station), and the target network device receives the forwarded data from the first network device. When the terminal accesses the target cell of the target network device (target base station), the target network device initiates a path switching request process to the core network device, the path of the service network device and the UPF is disconnected, and the target base station starts to receive data from the UPF. At this time, the first network device can be the initial service network device.

[0153] Exemplarily, in the LTM handover execution phase, after the service network device (such as a service base station) currently providing access service for the terminal, i.e., the first network device, issues a cell handover message to the terminal, the first network device performs data forwarding to the target network device (such as a target base station), and the target network device receives the forwarded data from the first network device. When the terminal accesses the target cell of the target network device (target base station), the target network device (target base station) initiates a path switching request process to the core network device, the path of the service network device and the UPF is disconnected, and the target network device starts to receive data from the UPF.

[0154] Exemplarily, in the LTM handover execution phase, after the service network device (such as a service base station) currently providing access service for the terminal, i.e., the first network device, receives data forwarding information from one or more second network devices (all candidate base stations) sent by the previous service network device (service base station), the first network device performs data forwarding to the target network device (target base station), and the target network device receives the forwarded data from the service base station. When the terminal accesses the target cell of the target network device, the target network device initiates a path switching request process to the core network device, the path of the first network device and the UPF is disconnected, and the target network device starts to receive data from the UPF.

[0155] Exemplarily, in the LTM handover execution phase, whenever the serving network device, i.e., the first network device (such as a serving base station), receives the data forwarding information of the target network device (target base station) sent by the initial network device, the first network device performs data forwarding to the target network device, and the target network device receives the forwarding data from the first network device. When the terminal accesses to the target cell of the target network device, the target network device initiates a path switching request process to the core network device, the path of the first network device and the UPF is disconnected, and the target network device starts to receive data from the UPF.

[0156] Exemplarily, in the LTM handover execution phase, whenever the serving network device, i.e., the first network device (such as a serving base station), receives the data forwarding information of the target network device (target base station) sent by the initial network device, the first network device performs data forwarding to the target network device, and the target network device receives the forwarding data from the first network device. When the terminal accesses to the target cell of the target network device, the target network device initiates a path switching request process to the core network device, the path of the first network device and the UPF is disconnected, and the target network device starts to receive data from the UPF.

[0157] Exemplarily, in the LTM handover execution phase, whenever the serving network device (serving base station) receives the data forwarding information of all candidate network devices (candidate base stations) sent by the initial serving network device (initial base station), the serving network device performs data forwarding to the target network device (target base station), and the target network device receives the forwarding data from the serving network device. When the terminal accesses to the target cell of the target network device, the target network device initiates a path switching request process to the core network device, the path of the serving network device and the UPF is disconnected, and the target network device starts to receive data from the UPF.

[0158] Exemplarily, in the LTM handover execution phase, whenever the serving network device (serving base station) receives the data forwarding information request of the target network device (target base station) / all candidate network devices (candidate base stations) sent by the initial serving network device (initial base station), the initial serving network device can directly perform data forwarding to the target base station, and the target network device receives the forwarding data from the initial serving network device. When the terminal accesses to the target cell of the target network device, the target network device initiates a path switching request process to the core network device, and the target network device starts to receive data from the UPF.

[0159] In conclusion, the technical solution provided by the embodiments of the present disclosure can ensure that the communication data between the terminal and the network device will not be lost or interrupted during the cell handover process by sending data from the initial service network device (i.e., the network device first accessed by the terminal) and / or the service network device (i.e., the network device providing service for the terminal before handover) to the target network device (i.e., the network device determined to be switched to according to the terminal measurement result). This is crucial for maintaining user experience and ensuring service quality.

[0160] FIG. 9 is a data transmission method provided by a second network device according to an embodiment of the present disclosure, which includes the following operations:

[0161] In operation S901, data is received from a first network device.

[0162] In some embodiments, the first network device is a service network device currently providing access service for the terminal. It can be a base station, an access point (AP), a router or any other device capable of connecting the terminal and providing network service. The second network device is a candidate network device for providing access service for the terminal. It can be a base station, an access point (AP), a router or any other device capable of connecting the terminal and providing network service. The terminal can be a user equipment (UE), an access terminal, a subscriber unit, a subscriber station, a mobile station, a mobile, a remote station, a remote terminal, a mobile device, a user terminal, a smart terminal, a wireless communication device, a user agent or a user device. The terminal can also be a cellular phone, a cordless phone, a Session Initiation Protocol (SIP) phone, a Wireless Local Loop (WLL) station, a Personal Digital Assistant (PDA), a handheld device with wireless communication function, a computing device or other processing device connected to a wireless modem, a relay device, a vehicle-mounted device, a wearable device, a terminal in a next-generation communication system such as an NR network, or a terminal in a future evolved Public Land Mobile Network (PLMN), etc., without specific limitation. The data is data related to the communication of the terminal with the first network device. The predetermined time refers to a time point set in advance for the start or end of a task, or a period of time. During the LTM handover of the terminal, the first network device currently providing access service for the terminal (which can be the initial service network device) can send data to the second network device. Thus, the second network device receives the data from the first network device.

[0163] In operation S902, the data is deleted if no cell handover message from the first network device is received within a predetermined time.

[0164] In some embodiments, when the terminal is in the preparation phase of the LTM handover, the second network device deletes the data if no cell handover message sent by the first network device is received within a predetermined time. Illustratively, the second network device maintains a set of timers. When the second network device receives data from the initial service network device (the first network device), the timer starts the timing function. The second network device is configured by the operation, management and maintenance (OAM) with a certain time threshold t. If the second network device does not receive a cell handover indication sent by the initial service network device within the time t, the second network device determines that it is not selected as the target network device by the initial service network device, and the second network device will discard the cached data in order to save the cache resources.

[0165] Further, the terminal sends a path switching request to the core network after accessing the second network device, and starts to receive data related to the terminal from the core network after the path switching.

[0166] In some embodiments, the terminal establishes a connection with the second network device after completing the access process with the second network device. After accessing the second network device, the terminal sends a path switching request to the core network device. The purpose of this request is to inform the core network device that the communication path of the terminal has changed, and the routing information in the core network device needs to be updated in order to correctly send subsequent data packets to the second network device. After the path switching is completed, the second network device will start to receive data related to the terminal from the core network device. Illustratively, the second network device can initiate a path switching request process to the UPF, and after the path switching, the second network device receives data from the UPF.

[0167] FIG. 10 is a functional block diagram illustrating a first network device according to an embodiment of the present disclosure.

[0168] As shown in FIG. 10, the first network device 1000 according to an embodiment of the present disclosure includes a communication interface 1001, a memory 1002, and a processor 1003.

[0169] The communication interface 1001 is configured to perform wireless communication with a terminal.

[0170] The memory 1002 is configured to store computer readable instructions.

[0171] The processor 1003 is configured to execute the computer readable instructions, so that the first network device performs the data transmission method as described above.

[0172] FIG. 11 is a functional block diagram illustrating a second network device according to an embodiment of the present disclosure.

[0173] As shown in FIG. 11, the second network device 1100 according to the embodiments of the present disclosure includes a communication interface 1101, a memory 1102, and a processor 1103.

[0174] The communication interface 1101 is configured to perform wireless communication with a terminal.

[0175] The memory 1102 is configured to store computer readable instructions.

[0176] The processor 1103 is configured to run the computer readable instructions, so that the second network device performs the data transmission method as described above.

[0177] FIG. 12 is a schematic diagram illustrating a computer readable storage medium according to an embodiment of the present disclosure. As shown in FIG. 12, the computer readable storage medium 1200 according to the embodiments of the present disclosure has computer readable instructions 1201 stored thereon. When the computer readable instructions 1201 are run by a processor, the data transmission method according to the embodiments of the present disclosure described with reference to the above figures is performed. The computer readable storage medium includes, but is not limited to, for example, volatile memory and / or non-volatile memory. The volatile memory may, for example, include random access memory (RAM) and / or cache memory, etc. The non-volatile memory may, for example, include read-only memory (ROM), hard disk, flash memory, optical disc, magnetic disc, etc.

[0178] FIG. 13 is a schematic diagram illustrating a computer program product according to an embodiment of the present disclosure. As shown in FIG. 13, the computer program product 1300 according to the embodiments of the present disclosure has a computer program 1301 stored thereon. The computer program 1301 is executed by a processor to implement the data transmission method as described above. The computer program product 1300 includes, but is not limited to, system software, application software, and games, etc. The system software is the basic software of a computer, responsible for managing the hardware and application programs of the computer, including operating systems, device drivers, etc. The application software is software designed to meet specific needs, such as office software, image processing software, etc. Games are software for entertainment, providing various gaming experiences. In addition, the computer program product can also include embedded software, firmware, etc., for controlling and operating various hardware devices.

[0179] The data transmission method and device, the network device, the storage medium and the computer program product are described above with reference to the drawings according to the embodiments of the present disclosure. The first network device of the present disclosure can communicate with the second network device based on the data forwarding information, thereby realizing data interaction between the network device currently providing access services for the terminal and the network device subsequently providing access services for the terminal, so that when the terminal performs switching between the first network device and the second network device, data can be successfully forwarded from one network device to another network device, thereby maintaining the service continuity performance of the terminal.

[0180] The data transmission method, the network device, the storage medium and the computer program product are described above with reference to the drawings according to the embodiments of the present disclosure. The first network device of the present disclosure can communicate with the second network device based on the data forwarding information, thereby realizing data interaction between the network device currently providing access services for the terminal and the network device subsequently providing access services for the terminal, so that when the terminal performs switching between the first network device and the second network device, data can be successfully forwarded from one network device to another network device, thereby maintaining the service continuity performance of the terminal.

[0181] Those skilled in the art can realize that the units and algorithm operations of the examples described in combination with the embodiments disclosed herein can be realized by electronic hardware or a combination of computer software and electronic hardware. Whether the functions are realized in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to realize the described functions for each specific application, but such implementation should not be considered beyond the scope of the present disclosure.

[0182] The basic principles of the present disclosure are described above in combination with specific embodiments, but it should be pointed out that the advantages, advantages, effects and the like mentioned in the present disclosure are only examples and are not limited, and these advantages, advantages, effects and the like cannot be considered as the various embodiments of the present disclosure must have. In addition, the above specific details are only for the purpose of example and for the purpose of understanding, and are not limited to the above specific details, and the above details do not limit the present disclosure to the above specific details.

[0183] The block diagrams of devices, apparatuses, devices, and systems disclosed herein are merely illustrative examples and are not intended to require or imply that they must be connected, arranged, or configured in the manner shown in the block diagrams. As those skilled in the art will recognize, these devices, apparatuses, devices, and systems can be connected, arranged, and configured in any manner. Words such as “comprising,” “including,” “having,” etc., are open-ended terms meaning “including but not limited to,” and are used interchangeably with them. The terms “or” and “and” as used herein refer to the terms “and / or,” and are used interchangeably with them unless the context clearly indicates otherwise. The term “such as” as used herein refers to the phrase “such as but not limited to,” and is used interchangeably with it.

[0184] Additionally, as used herein, the “or” used in a list of items beginning with “at least one” indicates a separate list, such that a list of, for example, “at least one of A, B, or C” means A or B or C, or AB or AC or BC, or ABC (i.e., A and B and C). Furthermore, the word “exemplary” does not imply that the described example is preferred or better than other examples.

[0185] It should also be noted that in the systems and methods of this disclosure, the components or operations can be decomposed and / or recombined. These decompositions and / or recombinations should be considered as equivalent solutions to this disclosure.

[0186] Various changes, substitutions, and modifications can be made to the technology herein without departing from the teachings defined by the appended claims. Furthermore, the scope of the claims of this disclosure is not limited to the specific aspects of the processes, machines, manufactures, events, means, methods, and actions described above. Currently existing or later-developed processes, machines, manufactures, events, means, methods, or actions that perform substantially the same function or achieve substantially the same result as the corresponding aspects herein can be utilized. Therefore, the appended claims include such processes, machines, manufactures, events, means, methods, or actions within their scope.

[0187] The above description of the disclosed aspects is provided to enable any person skilled in the art to make or use this disclosure. Various modifications to these aspects will be readily apparent to those skilled in the art, and the general principles defined herein may be applied to other aspects without departing from the scope of this disclosure. Therefore, this disclosure is not intended to be limited to the aspects shown herein, but rather to be carried out within the widest scope consistent with the principles and novel features disclosed herein.

[0188] The above description has been given for purposes of illustration and description. Furthermore, this description is not intended to limit the embodiments of this disclosure to the forms disclosed herein. Although numerous exemplary aspects and embodiments have been discussed above, those skilled in the art will recognize certain variations, modifications, alterations, additions, and sub-combinations therein.

Claims

1. A data transmission method applied to a first network device, comprising: receiving data forwarding information from one or more second network devices, wherein the data forwarding information indicates at least data forwarding addresses of the one or more second network devices; sending the data forwarding information to the one or more second network devices, wherein the first network device is a current serving network device, and the one or more second network devices are candidate network devices. The sending of the data forwarding information to the one or more second network devices comprises:

2. The data transmission method of claim 1, wherein, sending the data forwarding information of the one or more second network devices to the one or more second network devices before sending a radio resource control (RRC) reconfiguration message to a terminal. The sending of the data forwarding information to the one or more second network devices comprises:

3. The data transmission method of claim 1, wherein, sending the data forwarding information of the one or more second network devices to a target network device after sending a layer 1 / 2 triggered mobility (LTM) cell handover message to a terminal, wherein the target network device is one of the one or more second network devices. The sending of the data forwarding information to the one or more second network devices comprises:

4. The data transmission method of claim 1, wherein, requesting the data forwarding information of the one or more second network devices from a previous serving network device after the terminal performs cell handover at least once; and receiving the data forwarding information of each of the one or more second network devices from the previous serving network device. The sending of the data forwarding information to the one or more second network devices comprises:

5. The data transmission method of claim 1, wherein, requesting the data forwarding information of a target network device of next handover from the target network device after the terminal performs cell handover at least once; and receiving the data forwarding information from the target network device. The sending of the data forwarding information to the one or more second network devices comprises:

6. The data transmission method of claim 1, wherein, requesting the data forwarding information of a target network device of next handover from an initial serving network device after the terminal performs cell handover at least once; and receiving the data forwarding information from the initial serving network device. The sending of the data forwarding information to the one or more second network devices comprises:

7. The data transmission method of claim 1, wherein, requesting the data forwarding information of the one or more second network devices from an initial serving network device after the terminal performs cell handover at least once; and receiving the data forwarding information from the initial serving network device. Further comprising:

8. The data transmission method of claim 2, wherein, receiving a radio resource control (RRC) reconfiguration complete message from the terminal, and sending data to the one or more second network devices. Further comprising:

9. The data transmission method of any of claims 3 to 7, wherein, receiving a radio resource control (RRC) reconfiguration complete message from the terminal, and sending data from an initial serving network device and / or the serving network device to a target network device determined based on measurement results of the terminal, wherein the target network device is one of the one or more second network devices. The data forwarding information comprises uplink and downlink data forwarding addresses.

10. The data transmission method of claim 1, wherein, The data forwarding information comprises a data forwarding address of an initial serving network device.

11. The data transmission method of claim 1, wherein, Further comprising:

12. The data transmission method of claim 1, wherein, ​ After the terminal accesses the target network device, the path with the core network is disconnected, wherein the target network device is one of the one or more second network devices.

13. A data transmission method applied to a second network device, comprising: receiving data from a first network device; and deleting the data if no cell handover message from the first network device is received within a predetermined time.

14. The data transmission method of claim 13, wherein, Further comprising: after a terminal accesses the second network device, sending a path switching request to a core network; and starting to receive data related to the terminal from the core network after path switching.

15. The data transmission method of claim 13, wherein, Further comprising: if the cell handover message from the first network device is received within a predetermined time, reserving resources and preparing corresponding beam access in advance for the terminal about to access.

16. A first network device, comprising: a communication interface configured to perform wireless communication with a terminal; a memory configured to store computer readable instructions; and a processor configured to run the computer readable instructions, so that the first network device performs the data transmission method according to any one of claims 1 to 12.

17. A second network device, comprising: a communication interface configured to perform wireless communication with a terminal; a memory configured to store computer readable instructions; and a processor configured to run the computer readable instructions, so that the second network device performs the data transmission method according to any one of claims 13 to 15.

18. A computer readable storage medium having stored thereon a computer program, the computer program being executed by a processor to implement the data transmission method according to any one of claims 1 to 15.

19. A computer program product comprising a computer program, the computer program being executed by a processor to implement the data transmission method according to any one of claims 1 to 15.

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