Communication method and apparatus

Abstract

A communication method and apparatus, which are used for ensuring that, during movement of a terminal device, two base stations complete data dual-streaming with a core network after the terminal device has moved. A first network device acquires information of a second network device and a first policy, and, on the basis of the information of the second network device and the first policy, determines whether a third network device exists. The first network device and the second network device provide a data transmission service for a terminal device, and the third network device is a target network device to which the terminal device is handed over from the first network device. In this way, the first network device senses the information of another network device and the first policy, so that the first network device may be enabled to select an appropriate target network device during a handover decision, thereby ensuring that the network device after handover meets the dual-stream data requirements of a core network.

Description

Communication method and device

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to the Chinese patent application filed with the State Intellectual Property Office of the People's Republic of China on October 30, 2023, with application number 202311429899.4 and application name "A Communication Method and Device", the entire contents of which are incorporated by reference into this application. Technical Field

[0003] The present application relates to the field of communication technology, and in particular to a communication method and device. Background Art

[0004] In a dual-connectivity scenario, a terminal device is allowed to connect to two base stations simultaneously. Both base stations provide services to the terminal device, effectively improving the speed and reliability of the terminal device. Typically, the dual-connectivity mechanism requires an interface between base stations to enable the necessary negotiation between base stations to complete terminal device configuration, or to enable dual-stream data between base stations. However, in certain scenarios, there may not be an interface between base stations, or the base station capabilities may not support dual connectivity. In this case, to improve the speed of the terminal device, there is a candidate solution: regarding the data link, the terminal device can transmit data to the core network through two base stations separately. At the same time, the terminal device can establish a control plane connection with the core network through two base stations separately. This specific scenario can be called a core network dual-stream scenario, or a core network offload scenario.

[0005] During the mobility of a terminal device, if an interface exists between base stations, negotiation between base stations can ensure that the base station after the terminal device moves can simultaneously serve the terminal device. However, in a core network dual-stream scenario where no interface exists between base stations, since the two base stations have relatively independent connections to the terminal device, negotiation between the base stations is impossible. This may result in the two base stations after the terminal device moves being unable to meet the core network dual-stream requirements. Therefore, a method is urgently needed to ensure that the two base stations after the terminal device moves can complete dual-stream data with the core network during the mobility of the terminal device.

[0006] Summary of the Invention

[0007] The embodiments of the present application provide a communication method and apparatus for ensuring that, during the movement of a terminal device, two base stations after the terminal device moves complete dual data flows with a core network.

[0008] In a first aspect, the present application provides a communication method, which can be applied to a first network device, or a component configured in the first network device (such as a processor, chip, chip system, circuit or other, etc.), or a software module. Taking the application of this method to the first network device as an example, the method may include: the first network device obtains information and a first policy of the second network device, and determines whether a third network device exists based on the information and the first policy of the second network device. The first network device and the second network device provide data transmission services for the terminal device; the third network device is the target network device for the terminal device to switch from the first network device.

[0009] Through the above method, the first network device perceives the information of another network device and the first strategy, so that the first network device can select a suitable target network device when making a switching decision, thereby ensuring that the switched network device meets the dual-stream requirements of the core network data.

[0010] In one possible design, the first network device can obtain the information about the second network device and the first policy by the following methods: the first network device obtains the information about the second network device and the first policy from the first core network device; or the first network device obtains the information about the second network device from the terminal device and obtains the first policy from the first core network device; or the first network device obtains the information about the second network device and the first policy from the terminal device. In this way, the first network device can accurately and flexibly obtain the information about the second network device and the first policy, so that it can subsequently select an appropriate target network device.

[0011] In one possible design, the first network device may send a first measurement configuration to the terminal device based on the information of the second network device and the first policy. Furthermore, the first network device may receive a measurement result from the terminal device, where the measurement result satisfies the first policy. This allows the terminal device to report the measurement result that satisfies the first policy, and the first network device may make a handover decision based on the measurement result.

[0012] In one possible design, the first network device sends a second measurement configuration to the terminal device; the first network device receives a measurement result from the terminal device, where the measurement result satisfies the first policy and is determined by the terminal device based on information about the second network device and the first policy. In this way, the first network device can obtain a measurement result that satisfies the first policy and make a handover decision based on the measurement result.

[0013] In one possible design, the first network device determines whether a third network device exists based on the information of the second network device and the first policy. This may be done by: the first network device determines whether the third network device exists based on the information of the second network device, the first policy, and the measurement result. In this way, the first network device can accurately determine whether the third network device exists.

[0014] In one possible design, the first network device determines whether the third network device exists based on the information of the second network device, the first policy, and the measurement result. The method may be: the first network device determines whether the measurement result includes the measurement result of a network device that is different from the second network device and satisfies the first policy with the second network device based on the information of the second network device; if so, the first network device determines that the third network device exists; otherwise, the first network device determines that the third network device does not exist. In this way, the first network device can accurately determine whether the third network device exists.

[0015] In one possible design, when the first network device determines the existence of the third network device, the first network device determines that one of the network devices corresponding to the measurement result of the network device that is different from that of the second network device and satisfies the first policy with the second network device is the third network device. In this way, the first network device can subsequently switch to the third network device that meets the dual-stream requirement, ensuring that the two network devices complete the dual-stream data flow with the core network after the terminal device moves.

[0016] In one possible design, when the first network device determines that the third network device does not exist, and when the first network device determines that the quality of the service cell of the first network device is less than a first threshold, the first network device releases the connection between the first network device and the terminal device, or suspends the data transmission of the terminal device; or, the first network device determines that the terminal device is switched to a fourth network device, and the first network device stops or suspends the data transmission of the terminal device. In this way, when no target network device that meets the dual-stream requirement is found, data dual-streaming is not performed.

[0017] In one possible design, the first strategy may include at least one of the following: the two network devices providing data transmission services for the terminal device are different, a combination of networks to which the network devices allowed to perform dual-stream operations belong, a combination of air interface access technologies RATs of the network devices allowed to perform dual-stream operations, or a combination of working frequency bands or frequency points of the network devices allowed to perform dual-stream operations.

[0018] In one possible design, the information of the second network device may include at least one of the following: an identifier of the second network device, a network to which the second network device belongs, an air interface access technology RAT of the second network device, and service frequency band or frequency information of the second network device.

[0019] In the second aspect, the present application provides a communication method, which can be applied to a first network device, or a component configured in the first network device (such as a processor, chip, chip system, circuit or other, etc.), or a software module. Taking the application of this method to the first network device as an example, the method may include: after the first network device determines at least one candidate network device, it sends a first request message to the first core network device, and the first request message is used to request the first core network device to determine whether the at least one candidate network device can be used as the target network device for the terminal device to switch from the first network device; wherein, the first network device and the second network device provide data transmission services for the terminal device, and the target network device can provide data transmission services for the terminal device with the second network device; thereafter, the first network device receives a first response message from the first core network device, and the first response message is used to indicate whether the at least one candidate network device can be used as the target network device for the terminal device to switch from the first network device.

[0020] Based on the above communication method, the first network device queries the core network in advance to select a target cell or target network device that complies with the first strategy, thereby ensuring that the terminal device can maintain dual-stream transmission of services during mobility.

[0021] In one possible design, the first network device may determine the at least one candidate network device by: sending a measurement configuration to the terminal device and receiving a measurement result from the terminal device; and determining the at least one candidate network device based on the measurement result. In this way, the first network device can accurately determine the at least one candidate network device.

[0022] In one possible design, the measurement result may be determined based on the information of the first network device, the information of the second network device, and the first policy. This may result in a measurement result that satisfies the policy, thereby increasing the success rate of the first network device in finding a target terminal device that satisfies the policy.

[0023] In one possible design, the first strategy may include at least one of the following: the two network devices providing data transmission services for the terminal device are different, a combination of networks to which the network devices allowed to perform dual-stream operations belong, a combination of air interface access technologies RATs of the network devices allowed to perform dual-stream operations, or a combination of working frequency bands or frequency points of the network devices allowed to perform dual-stream operations.

[0024] In one possible design, the first request message may include information about the at least one candidate network device; the first response message may include information about the at least one candidate network device that can serve as a candidate network device for the target network device; or the first response message may include information indicating whether the at least one candidate network device can serve as the target network device. In this way, it can be made clear whether the at least one candidate network device can serve as the target network device.

[0025] In one possible design, the first request message includes information about a first candidate network device; the first response message includes information indicating whether the first candidate network device can serve as a target network device; and the first candidate network device is any one of the at least one candidate network device. This makes it clear whether the at least one candidate network device can serve as a target network device.

[0026] In one possible design, when at least one of the candidate network devices cannot serve as the target network device for the terminal device to switch from the first network device, the first network device may determine that the quality of the service cell of the first network device is less than a first threshold, and release the connection between the first network device and the terminal device, or suspend the data transmission of the terminal device; or the first network device determines that the terminal device switches to a third network device, and the first network device stops or suspends the data transmission of the terminal device. In this way, when no target network device that meets the dual-stream requirements can be found, data dual streaming will not be performed.

[0027] In a third aspect, the present application provides a communication method, which can be applied to a first core network device, or a component (such as a processor, chip, chip system, circuit or other, etc.) configured in the first core network device, or a software module. Taking the application of this method to the first core network device as an example, the method may include: the first core network device receives a first request message from the first network device, and the first request message is used to request the first core network device to determine whether at least one candidate network device can be used as the target network device for the terminal device to switch from the first network device; wherein, the first network device and the second network device provide data transmission services for the terminal device, and the target network device can provide data transmission services for the terminal device with the second network device; the first core network device determines whether the at least one candidate network device can be used as the target network device for the terminal device to switch from the first network device according to the first policy; finally, the first core network device sends a first response message to the first network device, and the first response message is used to indicate whether the at least one candidate network device can be used as the target network device for the terminal device to switch from the first network device.

[0028] Based on the above communication method, the first network device queries the core network in advance to select a target cell or target network device that complies with the first strategy, thereby ensuring that the terminal device can maintain dual-stream transmission of services during mobility.

[0029] In one possible design, the first strategy may include at least one of the following: the two network devices providing data transmission services for the terminal device are different, a combination of networks to which the network devices allowed to perform dual-stream operations belong, a combination of air interface access technologies RATs of the network devices allowed to perform dual-stream operations, or a combination of working frequency bands or frequency points of the network devices allowed to perform dual-stream operations.

[0030] In one possible design, the first request message may include information about the at least one candidate network device; the first response message may include information about the at least one candidate network device that can serve as a candidate network device for the target network device; or the first response message may include information indicating whether the at least one candidate network device can serve as the target network device. In this way, it can be made clear whether the at least one candidate network device can serve as the target network device.

[0031] In one possible design, the first request message may include information about a first candidate network device; the first response message includes information indicating whether the first candidate network device can serve as a target network device; and the first candidate network device is any one of the at least one candidate network device. This makes it clear whether the at least one candidate network device can serve as a target network device.

[0032] In a fourth aspect, the present application provides a communication method, which can be applied to a terminal device, or a component configured in the terminal device (such as a processor, chip, chip system, circuit, or other, etc.), or a software module. Taking the application of this method to a terminal device as an example, the method may include: the terminal device maintains a first cell of a first network device as a serving cell, and determines a second cell of a second network device as a serving cell; wherein the first network device and the second network device are capable of providing data transmission services for the terminal device; and the first network device and the second network device comply with a first policy.

[0033] Based on the above communication method, the terminal device can select a second cell that meets the dual-stream requirement, thereby ensuring that the dual-stream requirement of service data is met.

[0034] In one possible design, the terminal device maintains the first cell of the first network device as a service cell, and the method may be: the terminal device resides in the first cell; or the terminal device communicates with the first cell.

[0035] In one possible design, before the terminal device determines that the second cell of the second network device is the serving cell, the terminal device determines that there is a demand for dual service flow; or, the terminal device receives a first message from the first core network device, the first message being used to instruct the terminal device to determine that the second cell of the second network device is the serving cell; or, the terminal device receives a second message from the first network device, the second message being used to instruct the terminal device to perform dual service flow. This can trigger the terminal device to select the second cell to implement dual service data flow.

[0036] In one possible design, the first message is a paging message or a service establishment message.

[0037] In one possible design, when the terminal device moves, the terminal device determines that a third cell of a third network device is a serving cell, the third cell being a reselected cell for the second cell, the first network device and the third network device are capable of providing data transmission services for the terminal device, and the first network device and the third network device comply with the first policy. In this way, when the terminal device moves, cell reselection is performed to meet the dual-stream requirements of service data.

[0038] In one possible design, the terminal device determines that the third cell of the third network device is the serving cell. The method may be: the terminal device determines that the third cell of the third network device is the cell with the highest cell quality among the cells of at least one network device that complies with the first policy as the first network device; or, the terminal device determines that the third cell of the third network device is the cell with the highest cell quality among the cells that meet the conditions and that complies with the first policy as the first network device among the cells whose cell quality meets the conditions. In this way, the third cell that meets the requirements can be accurately determined.

[0039] In one possible design, the first strategy may include at least one of the following: the two network devices providing data transmission services for the terminal device are different, a combination of networks to which the network devices allowed to perform dual-stream operations belong, a combination of air interface access technologies RATs of the network devices allowed to perform dual-stream operations, or a combination of working frequency bands or frequency points of the network devices allowed to perform dual-stream operations.

[0040] In a fifth aspect, the present application further provides a communication device, which can be applied to a first network device, and has the function of implementing the method in the above-mentioned first aspect or each possible design example of the first aspect, or the above-mentioned second aspect or each possible design example of the second aspect. The function can be implemented by hardware, or can be implemented by hardware executing corresponding software. The hardware or software includes one or more modules corresponding to the above-mentioned functions.

[0041] In one possible design, the structure of the communication device may include a transceiver unit and a processing unit, which can execute the detailed description in the above-mentioned first aspect or each possible design example of the first aspect, or the above-mentioned second aspect or each possible design example of the second aspect, which will not be repeated here.

[0042] In one possible design, the communication device includes a processor and, optionally, a memory and / or a transceiver. The transceiver is used to transmit and receive signals, data, messages, or information, and to communicate and interact with other devices in a communication system. The processor is configured to support the communication device in performing the corresponding functions of the first aspect or each possible design example of the first aspect, or the second aspect or each possible design example of the second aspect. The memory is coupled to the processor and stores program instructions and data necessary for the communication device.

[0043] In a sixth aspect, the present application further provides a communication device, which can be applied to a first core network device, and has the function of implementing the method in the third aspect or each possible design example of the third aspect. The function can be implemented by hardware or by hardware executing corresponding software. The hardware or software includes one or more modules corresponding to the above functions.

[0044] In one possible design, the structure of the communication device may include a transceiver unit and a processing unit, which can execute the detailed description of the above-mentioned third aspect or various possible design examples of the third aspect, and will not be repeated here.

[0045] In one possible design, the communication device includes a processor and, optionally, a memory and / or a transceiver. The transceiver is used to transmit and receive signals, data, messages, or information, and to communicate and interact with other devices in the communication system. The processor is configured to support the communication device in performing the corresponding functions of the third aspect or each possible design example of the third aspect. The memory is coupled to the processor and stores program instructions and data necessary for the communication device.

[0046] In a seventh aspect, the present application further provides a communication device, which can be applied to a terminal device and has the function of implementing the method in the fourth aspect or each possible design example of the fourth aspect. The function can be implemented by hardware or by hardware executing corresponding software. The hardware or software includes one or more modules corresponding to the above functions.

[0047] In one possible design, the structure of the communication device may include a transceiver unit and a processing unit, which can execute the detailed description of the above-mentioned fourth aspect or each possible design example of the fourth aspect, which will not be repeated here.

[0048] In one possible design, the communication device includes a processor and, optionally, a memory and / or a transceiver. The transceiver is used to transmit and receive signals, data, messages, or information, and to communicate and interact with other devices in the communication system. The processor is configured to support the communication device in performing the corresponding functions of the fourth aspect or each possible design example of the fourth aspect. The memory is coupled to the processor and stores program instructions and data necessary for the communication device.

[0049] In an eighth aspect, an embodiment of the present application provides a communication system, which may include a terminal device, a first network device, a second network device, etc. The first network device is configured to implement the method in the first aspect or each possible design example of the first aspect.

[0050] In a ninth aspect, an embodiment of the present application provides a communication system, which may include a terminal device, a first network device, a second network device, and a first core network device. The first network device is configured to implement the method described in the second aspect or each possible design example of the second aspect. The first core network device is configured to implement the method described in the third aspect or each possible design example of the third aspect.

[0051] In a tenth aspect, an embodiment of the present application provides a communication system, which may include a terminal device, a first network device, a second network device, etc. The terminal device is used to implement the method in the fourth aspect or each possible design example of the fourth aspect.

[0052] On the eleventh aspect, an embodiment of the present application provides a computer-readable storage medium, which stores program instructions. When the program instructions are run on a computer, the computer executes the method described in the first aspect of the embodiment of the present application and any possible design thereof, or the second aspect and any possible design thereof, or the third aspect and any possible design thereof, or the fourth aspect and any possible design thereof. Exemplarily, the computer-readable storage medium can be any available medium that can be accessed by a computer. Taking this as an example but not limited to: the computer-readable medium can include non-transitory computer-readable media, random-access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), CD-ROM or other optical disk storage, magnetic disk storage medium or other magnetic storage device, or any other medium that can be used to carry or store desired program code in the form of instructions or data structures and can be accessed by a computer.

[0053] In the twelfth aspect, an embodiment of the present application provides a computer program product, comprising instructions, which, when executed on a computer, causes the method described in the first aspect or any possible design of the first aspect, or the second aspect or any possible design of the second aspect, or the third aspect or any possible design of the third aspect, or the fourth aspect or any possible design of the fourth aspect to be executed.

[0054] In the thirteenth aspect, the present application also provides a chip, including a processor, which is coupled to a memory and is used to read and execute program instructions stored in the memory, so that the chip implements the method described in the above-mentioned first aspect or any possible design of the first aspect, or the above-mentioned second aspect or any possible design of the second aspect, or the above-mentioned third aspect or any possible design of the third aspect, or the above-mentioned fourth aspect or any possible design of the fourth aspect.

[0055] For each of the above-mentioned aspects from the fifth to the thirteenth aspects and the technical effects that may be achieved by each of the aspects, please refer to the above-mentioned description of the technical effects that can be achieved by the first aspect or the various possible solutions in the first aspect, or the above-mentioned second aspect or the various possible solutions in the second aspect, or the above-mentioned third aspect or the various possible solutions in the third aspect, or the above-mentioned fourth aspect or the various possible solutions in the fourth aspect, and no further details will be given here. BRIEF DESCRIPTION OF THE DRAWINGS

[0056] FIG1 is a schematic diagram of the architecture of a communication system provided in an embodiment of the present application;

[0057] FIG2 is a schematic diagram of a dual-stream core network service data according to an embodiment of the present application;

[0058] FIG3 is a schematic diagram of a data network dual stream provided by an embodiment of the present application;

[0059] FIG4 is a flow chart of a communication method provided in an embodiment of the present application;

[0060] FIG5 is a flow chart of an example of a communication method provided in an embodiment of the present application;

[0061] FIG6 is a flow chart of another communication method provided in an embodiment of the present application;

[0062] FIG7 is a flow chart of another communication method provided in an embodiment of the present application;

[0063] FIG8 is a schematic diagram of a cell reselection provided by the present application;

[0064] FIG9 is a schematic structural diagram of a communication device provided by the present application;

[0065] FIG10 is a structural diagram of a communication device provided in this application. DETAILED DESCRIPTION

[0066] The present application will be described in further detail below with reference to the accompanying drawings.

[0067] The embodiments of the present application provide a communication method and apparatus for ensuring that, during the movement of a terminal device, two base stations complete dual data streams with the core network. The method and apparatus described herein are based on the same technical concept. Since the method and apparatus solve similar problems, the implementation of the apparatus and method can refer to each other, and any repetitions will not be repeated.

[0068] In the description of this application, words such as "first" and "second" are only used for the purpose of distinguishing the description and cannot be understood as indicating or implying relative importance or order.

[0069] In the description of this application, "at least one" means one or more, and "more" means two or more. "At least one of the following" or similar expressions refers to any combination of these items, including any combination of single or plural items. For example, at least one of a, b, or c can mean: a, b, c, a and b, a and c, b and c, or a, b, and c, where a, b, and c can be single or plural.

[0070] In the description of this application, "and / or" describes the relationship between associated objects, indicating that three relationships can exist. For example, "A and / or B" can represent: A exists alone, A and B exist simultaneously, and B exists alone. A and B can be singular or plural. " / " means "or", for example, a / b means a or b.

[0071] In order to more clearly describe the technical solutions of the embodiments of the present application, the communication method and device provided by the embodiments of the present application are described in detail below with reference to the accompanying drawings.

[0072] The communication method provided in the embodiment of the present application can be applied to the core network data dual-stream architecture. For example, a terminal device can be connected to two network devices at the same time and obtain business data transmission services through the two network devices at the same time.

[0073] Exemplarily, Figure 1 shows the architecture of a communication system to which the communication method provided by an embodiment of the present application can be applied. Among them, the architecture of the communication system may include terminal devices, network devices, and core networks, etc. Among them, as shown in Figure 1 (a), the two network devices (shown as network device 1 and network device 2) to which the terminal device is simultaneously connected can be connected to the same core network. As shown in Figure 1 (b), the two network devices (shown as network device 1 and network device 2) to which the terminal device is simultaneously connected can be connected to different core networks. As shown in Figure 1 (b), network device 1 can be connected to core network 1, and network device 2 can be connected to core network 2.

[0074] Terminal equipment, also known as user equipment (UE), mobile station (MS), or mobile terminal (MT), provides voice and / or data connectivity to users. For example, terminal equipment can include handheld devices and vehicle-mounted devices with wireless connectivity. Currently, terminal devices may be: cellular phones, smart phones, wireless data cards, personal digital assistants (PDAs), computers, mobile phones, tablet computers, laptop computers, handheld computers, wireless modems, laptop computers, mobile internet devices (MIDs), wearable devices, virtual reality (VR) devices, augmented reality (AR) devices, extended reality (XR) devices, mixed reality (MR) devices, wireless terminals in industrial control, wireless terminals in self-driving, wireless terminals in remote medical surgery, wireless terminals in smart grids, wireless terminals in transportation safety, wireless terminals in smart cities, or wireless terminals in smart homes, etc.

[0075] The terminal device may also be a D2D terminal device, a V2X communication terminal device, an intelligent vehicle, a vehicle-to-vehicle system (or a telematics box, TBOX), a machine-to-machine / machine-type communications (M2M / MTC) terminal device, or an Internet of Things (IoT) terminal device. For example, the terminal device may be a vehicle, ship, or aircraft, or a terminal-type roadside unit, or a communication module or chip built into a vehicle or roadside unit. For example, the terminal device may be an on-board module. The various terminal devices described above, if located on a vehicle, such as placed inside or installed inside a vehicle, may be considered on-board terminal devices. For example, an on-board terminal device may also be referred to as an on-board unit (OBU).

[0076] As an example and not a limitation, in the embodiments of the present application, the terminal device may also be a wearable device. Wearable devices may also be referred to as wearable smart devices or smart wearable devices, etc., which are a general term for wearable devices that are intelligently designed and developed using wearable technology for daily wear, such as glasses, gloves, watches, clothing, and shoes. A wearable device is a portable device that is worn directly on the body or integrated into the user's clothes or accessories. Wearable devices are not only hardware devices, but also achieve powerful functions through software support, data interaction, and cloud interaction. Broadly speaking, wearable smart devices include those that are fully functional, large in size, and can achieve complete or partial functions without relying on smartphones, such as smart watches or smart glasses, etc., as well as those that only focus on a certain type of application function and need to be used in conjunction with other devices such as smartphones, such as various smart bracelets, smart helmets, and smart jewelry for vital sign monitoring.

[0077] The terminal device can also be an amusement device, smart appliance or other smart device or a drone.

[0078] In this application, the terminal device may also be a functional module, a chip or a chip system. Optionally, the functional module, the chip or the chip system may be provided in the terminal device.

[0079] A network device is a device that provides access to a terminal device. A network device may include a radio access network (RAN) device, such as a base station. A network device may be a base station, an evolved Node B (eNB or e-NodeB) in a long term evolution (LTE) system or long term evolution-advanced (LTE-A), a transmission reception point (TRP), a next generation NodeB (gNB) or new radio (NR) base station in a fifth generation (5G) mobile communication system, a next generation base station in a sixth generation (6G) mobile communication system, a base station in a future mobile communication system, or an access node in a wireless local area network (WiFi) system. It may also be an access network device in an open access network (ORAN) system. Optionally, the network device may also be a module or unit that performs some of the functions of the base station. For example, the network device may be a centralized unit (CU), a distributed unit (DU), a CU-control plane (CP), a CU-user plane (UP), or a radio unit (RU). The CU here performs the functions of the radio resource control protocol and the packet data convergence protocol (PDCP) of the base station, and may also perform the functions of the service data adaptation protocol (SDAP); the DU performs the functions of the radio link control layer and the medium access control (MAC) layer of the base station, and may also perform the functions of part or all of the physical layer. In different systems, CU (or CU-CP and CU-UP), DU, or RU may also have different names, but those skilled in the art will understand their meanings. For example, in the ORAN system, CU can also be called O-CU, DU can also be called open (open, O)-DU, CU-CP can also be called O-CU-CP, CU-UP can also be called O-CUP-UP, and RU can also be called O-RU.

[0080] Exemplarily, the network device may be a macro base station, a micro base station (also known as a small station) or an indoor station, or a relay node or a donor node, etc. The network device may also be a ground base station, a satellite (base station), etc. The network device may also be a radio network controller (RNC), a node B (NB), a base station controller (BSC), a base transceiver station (BTS), a home base station (e.g., a home evolved NodeB, or home Node B, HNB), a base band unit (BBU) or a remote radio unit (RRU), or a wireless fidelity (Wifi) access point (AP), or a baseband pool (BBU pool) and RRU in a cloud radio access network (CRAN), etc. The embodiments of the present application do not limit the specific technology and specific device form adopted by the network device. For example, the network device may correspond to an eNB in ​​a 4G system and to a gNB in ​​a 5G system.

[0081] In this application, the network device may also be a central processing element (CPE), a router, etc.

[0082] In this application, the network device may also be a functional module, a chip or a chip system. Optionally, the functional module, the chip or the chip system may be provided in the network device.

[0083] The core network may include control plane functional network elements and user plane functional network elements. The control plane network elements are responsible for access and mobility management of terminal devices, while the user plane network elements are responsible for service data transmission of terminal devices.

[0084] Among them, the user plane function network element can be responsible for forwarding and receiving user data in the terminal device. The user plane function network element can receive user data from the data network and transmit it to the terminal device through the network device; the user plane function network element can also receive user data from the terminal device through the network device and forward it to the data network. The transmission resources and scheduling functions that provide services to the terminal device in the user plane function network element are managed and controlled by the session management function network element (session management function, SMF) network element in the core network. For example, in 5G, the user plane function network element can be a user plane function (UPF) network element; in future communications, such as 6G, the user plane function network element can still be a UPF network element, or have other names, which are not limited in this application.

[0085] It should be understood that the core network may also include multiple other network elements, which will not be described one by one in this application.

[0086] In some implementations, the two network devices connected to the terminal device can both be NR base stations, or one can be an NR base station and the other an LTE base station, with no restriction on the air interface standard. Furthermore, this application does not limit the base station type; for example, both base stations can be terrestrial base stations, both can be satellite base stations, or one can be a terrestrial base station and the other a satellite.

[0087] It should be understood that the communication system shown in Figure 1 may also include other devices, and this application does not limit this. The number of devices shown in Figure 1 is also only an example. For example, multiple network devices may be included between the terminal device and the core network for simultaneous data transmission, and this application does not limit this.

[0088] In the embodiments of the present application, dual core network data flow can be understood as dual flow of service data within the core network. For example, in the scenario shown in Figure 1(a) where there is a single core network, the UPF of the core network can distribute service data to two network devices (e.g., gNB1 and gNB2) for transmission, as shown in Figure 2(a). Alternatively, in the scenario shown in Figure 1(b) where there are two core networks, UPF1 of core network 1 can distribute service data to UPF2 of core network 2, and then the two core networks will distribute the service data to their respective network devices (e.g., gNB1 and gNB2) for transmission, as shown in Figure 2(b).

[0089] Furthermore, the dual-stream of core network data can also be included in the scenario of dual-stream of data network (DN), that is, the data link between DN and the UPF of the core network is divided into two, and the dual-stream (downlink) and aggregation (uplink) of data are performed by DN, where the data network can also be understood as an application server, which is not limited in this application. For example, Figure 3 (a) shows a schematic diagram of dual-stream of data network in the scenario shown in Figure 1 (a) with one core network, and Figure 3 (b) shows a schematic diagram of dual-stream of data network in the scenario shown in Figure 1 (a) with two core networks.

[0090] It should be understood that this application does not distinguish between the core network data dual stream and the data network / server data dual stream. For the convenience of description, the following description will only use the core network data dual stream as an example.

[0091] In the dual-stream architecture of core network data, if the connection between the terminal device and the two network devices is relatively independent, the network devices do not support signaling negotiation for the terminal device. Therefore, in the dual-stream architecture of core network data, the two service network devices of the terminal device will each be responsible for the mobility of the terminal device, that is, each selects the target network device according to its own implementation algorithm. At this time, it may result in the inability to execute dual-stream core network data between the selected target network devices, or between the selected target network device and another current service network device. Based on this, an embodiment of the present application provides a communication method that can ensure that during the movement of the terminal device, two suitable service network devices can be found for the terminal device, enabling the terminal device to conduct dual-stream services with the core network through the two service network devices after movement.

[0092] In the embodiments of the present application, the operations performed by a terminal device, network device, or core network device may also be performed by a processor, chip, chip system, or a functional module in the terminal device, network device, or core network device, and this application does not limit this. For example, the operations performed by the first network device below may also be performed by a processor, chip, or a functional module in the first network device.

[0093] Based on the above description, an embodiment of the present application provides a communication method. Referring to FIG4 , the process of the method may include:

[0094] Step 401: The first network device obtains information about the second network device and a first policy, and the first network device and the second network device provide data transmission services for the terminal device.

[0095] In some embodiments, the terminal device establishes an RRC connection with the first network device and the second network device respectively, and transmits service data with the data network or application server through the first network device and the second network device.

[0096] Optionally, the terminal device establishes a non-access stratum (NAS) connection with the core network through the first network device and the second network device respectively. For example, taking the 5G network as an example, the NAS connection can be understood as a logical connection between the terminal device and the AMF.

[0097] Optionally, in this embodiment, the first network device and the second network device may sense that the current terminal device is in a dual-stream mode of core network service data.

[0098] The first strategy may be used to determine two network devices that simultaneously provide data transmission services to the terminal device. Alternatively, the first strategy may be used to determine two network devices that can implement dual-stream data services for the terminal device.

[0099] Exemplarily, the first strategy may include at least one of the following: the two network devices providing data transmission services to the terminal device are different, a combination of networks to which the network devices allowed to perform dual-stream operations belong, a combination of radio access technologies (RATs) of the network devices allowed to perform dual-stream operations, or a combination of working frequency bands or frequency points of the network devices allowed to perform dual-stream operations.

[0100] For example, the combination of networks to which the network devices allowed to perform dual-stream operation belong may be that the two network devices allowed to perform dual-stream operation belong to the same public land mobile network (PLMN), or a preset PLMN pairing, or a PLMN and non-public network (NPN) combination.

[0101] The combination of RATs of network devices allowed to perform dual-stream operation can also be understood as a combination of types of network devices allowed to perform dual-stream operation. For example, the two network devices allowed to perform dual-stream operation can both be NR base stations, or respectively be an LTE base station and an NR base station, or both be terrestrial base stations, or both be satellite base stations, or respectively be a terrestrial base station and a satellite base station.

[0102] Optionally, the first strategy may include one of the above-listed items, or multiple items listed above arranged in descending order of priority.

[0103] In an optional implementation, the first network device may obtain the information of the second network device and the first policy through the following three methods:

[0104] Method a1: The first network device obtains information about the second network device and the first policy from the first core network device.

[0105] Method a2: The first network device obtains information about the second network device from the terminal device, and obtains the first policy from the first core network device.

[0106] Method a3: The first network device obtains the information of the second network device and the first policy from the terminal device.

[0107] In one example, the information of the second network device may include at least one of the following: an identifier of the second network device, a network to which the second network device belongs, a RAT of the second network device, service band or frequency information of the second network device, etc.

[0108] For example, the network to which the second network device belongs can be embodied as a PLMN ID or a standalone non-public network (SNPN), etc. The RAT of the second network device can be NR, LTE, 6G, a terrestrial network (TN), a non-terrestrial network (NTN), etc.

[0109] Optionally, when the first core network device provides the first policy to the first network device, it may be notified to the first network device in an explicit manner as described above (such as method a1 and method a2), or it may be notified in an implicit manner. For example, the mobility restriction list (MRL) provided by the existing core network to the network device may be reused. For example, in the MRL provided to the first network device, the equivalent PLMN information only includes the PLMN ID or NPN ID that can be paired with the PLMN to which the current second network device belongs in accordance with the network type policy; the RAT restriction includes all RATs that cannot be paired with the RAT corresponding to the current second network device in accordance with the base station type policy.

[0110] Step 402: The first network device determines whether a third network device exists based on the information of the second network device and the first policy. The third network device is the target network device for the terminal device to switch from the first network device.

[0111] In some embodiments, the first network device typically provides a measurement configuration for the terminal device, and the terminal device performs measurements based on the measurement configuration and reports the measurement results to the first network device when the measurement reporting conditions are met, so as to report the currently measured cell information that meets the conditions. In order to enable the terminal device to report measurement results that comply with the policy, based on the measurement configuration and / or different situations in which the terminal device performs measurements, the above-mentioned measurement process can be implemented through the following implementation methods:

[0112] Implementation method b1: The first network device sends a first measurement configuration to the terminal device based on the information of the second network device and the first policy; the first terminal device performs measurement based on the first measurement configuration information and sends the measurement result to the first network device, where the measurement result satisfies the first policy.

[0113] Exemplarily, the first measurement configuration may have at least one of the following situations: in the first measurement configuration, the service cell of the second network device may be allocated to the terminal device as an item in a blacklist (excluded cell list); the first measurement configuration may only include measurement objects (measurement objectives) corresponding to network device types that comply with the first policy; the network type is restricted in the first measurement configuration, etc.

[0114] In this implementation b1, since the first measurement configuration has taken the restrictions of the first policy into consideration, the terminal device can perform measurements according to the first measurement configuration without performing additional judgments or operations.

[0115] Implementation method b2: The first network device sends a second measurement configuration to the terminal device; the terminal device performs measurement according to the first policy, information of the second network device and the second measurement configuration, and sends the measurement result to the first network device, where the measurement result satisfies the first policy.

[0116] For example, the terminal device finds that based on the second measurement configuration and the information of the second network device, if the terminal device still needs to measure the service cell of the second network device according to the current mechanism, and reports the measurement results of the service cell of the second network device when the measurement reporting conditions are met, then the terminal device itself determines based on the first strategy that it may not measure the service cell of the second network device or trigger measurement reporting.

[0117] For another example, the terminal device finds that based on the second measurement configuration, the terminal device needs to measure or report measurements on cells of the first network type or the first network device type, and the first network type or the first network device type and the network type or network device type corresponding to the current second network device do not comply with the first policy. The terminal device can skip measuring such cells or skip triggering measurement reporting for such cells.

[0118] Due to the measurement configuration restrictions imposed by the first network device in Implementation b1, or the behavior restrictions imposed by the terminal device in Implementation b2, the cell information ultimately measured by the terminal device satisfies the first policy. In other words, even if the terminal device is able to measure a cell quality that satisfies the measurement event, the terminal device will not report the cell information to the first network device because the cell's corresponding network attributes or network device type do not comply with the first policy.

[0119] In addition to the above implementation methods, it is also possible that the first network device does not generate the first measurement configuration based on the first strategy, or the terminal device does not adjust the measurement or measurement reporting behavior based on the first strategy. At this time, the terminal device performs measurement reporting according to the current existing mechanism, that is, the measurement report may include cell information that meets the first strategy, and may also include cell information that does not meet the first strategy. At this time, the first network device is subsequently required to ensure that the selection of the target cell meets the first strategy.

[0120] In one possible manner, the first network device determines whether the third network device exists based on the information of the second network device and the first policy. The method may be: the first network device determines whether the third network device exists based on the information of the second network device, the first policy, and the measurement result.

[0121] Exemplarily, the first network device determines whether a third network device exists based on the information of the second network device, the first policy, and the measurement results. The method may be: the first network device determines whether the measurement results include the measurement results of a network device that is different from the second network device and satisfies the first policy with the second network device based on the information of the second network device; if included, the first network device determines that the third network device exists; otherwise, the first network device determines that the third network device does not exist.

[0122] For example, when the first network device determines, based on the information of the second network device, whether the measurement result includes the measurement result of a network device that is different from the second network device and satisfies the first policy with the second network device, the first network device can determine whether the network type and / or network device type corresponding to the cell in the measurement result, combined with the network type and / or network device type of the second network device, satisfies the first policy.

[0123] In some embodiments, when the first network device determines the presence of a third network device, the first network device determines that one of the network devices corresponding to the measurement results of the network devices that differ from those of the second network device and that satisfy the first policy with the second network device is the third network device. Alternatively, the first network device selects a suitable target cell from the cell information included in the measurement results, namely the cell of the third network device, and then initiates a handover for the terminal device. In other words, the first network device selects a target cell that satisfies the first policy and further initiates a handover process.

[0124] In other embodiments, when the first network device determines that the third network device does not exist, and when the first network device determines that the service cell quality of the first network device is less than a first threshold, the connection between the first network device and the terminal device is released, or the data transmission of the terminal device is suspended or paused; or, the first network device determines that the terminal device switches to a fourth network device, and the first network device stops or suspends the data transmission of the terminal device.

[0125] Optionally, the terminal device may not trigger measurement reporting because it cannot obtain a cell that complies with the first strategy, or the cells in the measurement results reported by the terminal device do not comply with the first strategy, resulting in the first network device being unable to determine the third network device.

[0126] The first network device releasing the connection between the first network device and the terminal device can also be understood as the first network device releasing the service transmission (data transmission) between the first network device and the terminal device.

[0127] For example, when the first network device determines that the quality of the serving cell of the first network device is less than a first threshold, the first network device may send a radio resource control (RRC) release message to the terminal device, instructing the terminal device to enter an idle state or an inactive state.

[0128] In one example, when the first network device suspends or pauses data transmission from the terminal device, it may simultaneously indicate to the first core network device that the first network device has suspended or paused data transmission from the terminal device. Optionally, the first network device may also indicate to the first core network device the reason for suspending or pausing data transmission from the terminal device. For example, the reason may be network unavailability.

[0129] Optionally, the fourth network device may be a network device whose signal quality satisfies the switching conditions and is selected by the first network device without considering the restrictions of the first policy. In this case, the first network device does not switch the current service to the fourth network device. For example, the first network device does not carry data radio bearer (DRB) information in the switching command to the fourth network device; or, the first network device carries DRB information in the switching command to the fourth network device, and additionally carries indication information indicating the release or suspension of the transmission of the DRB, and then the fourth network device indicates the release or suspension of the DRB in the configuration to the terminal device, and indicates the release or suspension of the protocol data unit (PDU) session corresponding to the DRB in the path switching request message sent by the core network.

[0130] It should be understood that in this embodiment, only the switching of the first network device is used as an example for explanation. In practice, the second network device can also be switched, and the switching process of the second network device is similar to that of the first network device. For example, the process of the second network device obtaining the information of the first network device and the first strategy, etc. is similar to the subsequent switching decision process of the first network device, and they can refer to each other and will not be described in detail here.

[0131] In some embodiments, the two networks to which the terminal device is connected distinguish between a primary network connection and a secondary network connection, and the network connection may include a connection from the terminal device to the core network via a network device. Under this assumption, the above-mentioned handover restriction may only apply to the network device on the secondary network connection, or the handover restriction may apply to both network devices, but when a suitable target cell or target network device cannot be found, only the network device on the secondary network connection will perform the above-mentioned operation of releasing or suspending the terminal device connection or service transmission. Optionally, the network device may obtain indication information from the core network or the terminal device to know that it belongs to the secondary network connection.

[0132] Based on the above communication method, the first network device perceives the information of another network device and the first strategy, so that the first network device can select a suitable target network device when making a switching decision, thereby ensuring that the switched network device meets the dual-stream requirements of the core network data.

[0133] Based on the embodiment shown in Figure 4, the communication method provided by the embodiment of the present application is explained below through an example of a communication method shown in Figure 5. In the example shown in Figure 5, the first network device and the second network device are gNB1 and gNB2 respectively, the terminal device is UE, and the first core network device is a core network (CN) device. When the UE moves, gNB1 and gNB2 will respectively execute the switching decision for the UE. In order to ensure that after any network device makes a switching decision, the selected target network device can still support the provision of core network business data dual-stream service for the UE, this can be achieved through the process shown in Figure 5. Among them, in the example shown in Figure 5, only the switching of gNB1 is used as an example. It should be understood that the same applies to gNB2, and no detailed explanation is given.

[0134] Exemplarily, the communication method shown in FIG5 may include the following steps:

[0135] Step 501: gNB1 obtains gNB2 information and the first strategy.

[0136] Optionally, step 501 may be implemented by the three methods shown in FIG5 , specifically including:

[0137] Method 1, Step 501a: gNB1 receives information about gNB2 and the first strategy from the CN.

[0138] Method 2, Step 501b: gNB1 receives information about gNB2 from the UE; Step 501c: gNB1 receives the first strategy from the CN.

[0139] It should be understood that in method 2, the order of step 501b and step 501c is not limited.

[0140] Method 3: Step 501d: gNB1 receives information about gNB2 and the first strategy from the UE.

[0141] Among them, the information of gNB2 and the related description of the first strategy can be found in the relevant description of the embodiment shown in Figure 4, which will not be repeated here.

[0142] Step 502: gNB1 sends measurement configuration to the UE.

[0143] The measurement configuration may be the first measurement configuration or the second measurement configuration in the embodiment shown in FIG4 . For details, please refer to the above description and will not be described in detail here.

[0144] Step 503: The UE performs measurement.

[0145] Specifically, the relevant description of UE measurement can refer to the relevant description involved in the embodiment shown in Figure 4, which will not be repeated here.

[0146] Step 504: The UE sends the measurement results to gNB1.

[0147] Specifically, the measurement results can be found in the relevant description of the embodiment shown in FIG4 , which will not be repeated here.

[0148] Step 505: gNB1 makes a handover decision.

[0149] When making a switching decision, gNB1 can determine whether there is a target network device that can be switched (i.e., the aforementioned third network device). For details, please refer to the relevant description involved in the embodiment shown in Figure 4 above, which will not be repeated here.

[0150] Based on the above example, by having one network device perceive the information of another network device and the first strategy, the network device can select a suitable target network device when making a switching decision, thereby ensuring that the switched network device meets the dual-stream requirements of the core network data.

[0151] In the embodiments shown in FIG. 4 or FIG. 5 , a network device can sense the information and strategy of another network device to assist the network device in providing a reasonable configuration and selecting a target cell that complies with the strategy. The embodiment of the present application provides another communication method, in which the network device can verify with the core network in advance before initiating the handover preparation process. For example, another communication method provided by the embodiment of the present application can be shown in FIG. 6 , and the process of the method may include:

[0152] Step 601: A first network device determines at least one candidate network device.

[0153] In an optional implementation, before the first network device determines at least one candidate network device, step 600a is performed: the first network device sends a measurement configuration to the terminal device; and step 600b is performed: the first network device receives a measurement result from the terminal device.

[0154] Furthermore, the first network device determines at least one candidate network device based on the measurement result. It can also be understood that the first network device selects at least one candidate cell based on the measurement result, and each candidate cell corresponds to a candidate network device.

[0155] In some embodiments, since the terminal device can know the information of the first network device and the second network device that provide data transmission services for the terminal device, as well as the first policy, the terminal device can determine the measurement result based on the information of the first network device, the information of the second network device, and the first policy. For example, the terminal device can decide whether to measure a certain cell, or decide whether to trigger measurement reporting for a certain cell based on the information of the first network device, the information of the second network device, and the first policy. For details, please refer to the relevant description of the terminal device in the aforementioned implementation b2, which will not be described in detail here.

[0156] For the relevant description of the first strategy, please refer to the description of the first strategy involved in the embodiment shown in FIG4 , which will not be repeated here.

[0157] Step 602: The first network device sends a first request message to the first core network device. In response, the first core network device receives the first request message from the first network device. The first request message is used to request the first core network device to determine whether at least one candidate network device can serve as a target network device for handover from the first network device to the terminal device; the target network device can provide data transmission services to the terminal device in conjunction with the second network device.

[0158] In an optional implementation c1, the first request message may include information of at least one candidate network device.

[0159] In an optional implementation c2, the first request message may include information of the first candidate network device; the first candidate network device is any one of the at least one candidate network device.

[0160] Optionally, if the method in implementation mode c2 is adopted, the first network device may send at least one first request message to the first core network, and each first request message includes information of a candidate network device.

[0161] Step 603: The first core network device determines, based on the first policy, whether at least one candidate network device can serve as a target network device for handover from the first network device to the terminal device.

[0162] For example, the first core network device determines that a candidate network device is not the second network device, and the network type and network device type of the candidate network device comply with the first policy. At this time, the first core network device can determine that the candidate network device can be used as a target network device for the terminal device to switch from the first network device, otherwise it cannot be used as a target network device for the terminal device to switch from the first network device.

[0163] Step 604: The first core network device sends a first response message to the first network device. Accordingly, the first network device receives the first response message from the first core network device. The first response message indicates whether at least one candidate network device can serve as the target network device for handover from the first network device to the terminal device.

[0164] Corresponding to the above implementation c1, the first response message may include information of at least one candidate network device that can serve as the target network device; or, the first response message may include indication information of whether at least one candidate network device can serve as the target network device.

[0165] Alternatively, the first response message may also include information of a corresponding candidate cell of at least one candidate network device that can serve as the target network device.

[0166] For example, the candidate cell information may include a cell identifier, a network device identifier to which the cell belongs, information about the network to which the cell belongs (such as a PLMN ID or NPN ID), and a network device type to which the cell belongs. The candidate network device information may include a network device identifier, information about the network to which the network device belongs, and a network device type of the network device.

[0167] Corresponding to the above-mentioned implementation c2, the first response message may include indication information of whether the first candidate network device can be used as the target network device. For example, the first response message may include indication information of whether the first candidate network device is qualified or not.

[0168] Correspondingly, if the first network device sends at least one first request message to the first core network device, the first core network device may return at least one corresponding first response message to the first network device.

[0169] In some embodiments, when the first network device determines, based on the first response message, that a candidate network device exists that can serve as a target network device to which the terminal device can be switched from the first network device, the first network device may further perform the following steps: Step 605: The first network device determines the target network device and initiates a handover preparation process with the target network device. Step 606: The first network device sends a handover command to the terminal device, instructing the terminal device to switch to the target network device.

[0170] In other embodiments, when at least one candidate network device cannot serve as the target network device for the terminal device to switch from the first network device, the first network device determines that the service cell quality of the first network device is less than a first threshold, and releases the connection between the first network device and the terminal device, or suspends the data transmission of the terminal device; or, the first network device determines that the terminal device switches to a third network device, and the first network device stops or suspends the data transmission of the terminal device.

[0171] For example, when at least one candidate network device cannot serve as the target network device for the terminal device to switch from the first network device, it can also be understood that the first network device has not found a suitable target network device. In this case, the operation of the first network device can be specifically referred to in the embodiment shown in FIG4 above, where the first network device determines that the third network device does not exist, and no further description is given here. It should be noted that in the embodiment shown in FIG6, the first network device determines that the terminal device switches to the third network device, which is similar to the embodiment shown in FIG4 where the first network device determines that the terminal device switches to the fourth network device, and they can be referred to each other.

[0172] It should be noted that the above process is only described using the first network device as an example and does not limit the behavior of the second network device. It should be understood that the second network device can perform the same operations as the first network device, and the first network device and the second network device can perform the same operations in parallel, and this application does not limit this.

[0173] Optionally, before sending the first request information to the first core network device, the first network device may receive first indication information from the terminal device or the first core network device. The first indication information may indicate that the first network device needs to perform the above-mentioned operation of querying the target network device with the core network when serving the current terminal device. The same applies to the second network device.

[0174] Optionally, the two networks to which the terminal device is connected can distinguish between a primary network connection and a secondary network connection, and can limit the query process between the network device on the secondary network connection and the core network to that on which the terminal device is connected. Alternatively, both network devices need to interact with the core network, but only the network device on the secondary network connection needs to release or suspend the RRC connection or service data transmission of the terminal device when it cannot find a suitable target cell or target network device.

[0175] Based on the above communication method, the first network device queries the core network in advance to select a target cell or target network device that complies with the first strategy, thereby ensuring that the terminal device can maintain dual-stream transmission of services during mobility.

[0176] It should be understood that in the description of the aforementioned embodiments, only the target network device and the like are taken as examples. The target network device and the like can also be implemented through the target cell, and this application does not limit this.

[0177] In the aforementioned embodiment, the focus is on the mobility of connected terminal devices, that is, the handover scenario. In addition to the above embodiments, the embodiments of the present application also provide another communication method that can consider the mobility of idle or inactive terminal devices, that is, the cell selection or reselection behavior of the terminal device. For example, when the terminal device selects the second serving cell to reside in, it must consider the information and policy information of the first serving cell. For example, another communication method provided by the embodiment of the present application can be shown in Figure 7. The process of this method may include:

[0178] Step 701: The terminal device maintains the first cell of the first network device as a service cell.

[0179] In an optional implementation manner, the terminal device maintains the first cell of the first network device as the serving cell, which may include the following two situations:

[0180] Case d1: The terminal device resides in the first cell.

[0181] In this situation d1, the terminal device may be in an idle or inactive state.

[0182] Case d2: The terminal device communicates with the first cell.

[0183] In this situation d2, the terminal device can be connected to the first cell in a connected state.

[0184] Step 702: The terminal device determines that the second cell of the second network device is a serving cell, wherein the first network device and the second network device can provide data transmission services for the terminal device; and the first network device and the second network device comply with the first policy.

[0185] In some embodiments, the terminal device may determine that the second cell of the second network device is the serving cell only when it is about to initiate a dual-stream service. Optionally, initiating a dual-stream service can also be understood as initiating a dual-stream service. One possible scenario is that the service currently exists and the dual-stream is triggered only when a preset condition is met. Another possible scenario is that the service is currently initiated and a dual-stream operation is required when it is initiated. The initiation of the dual-stream service can be initiated by the terminal device or by the server or network, and this application does not limit this.

[0186] Illustratively, before the terminal device determines the second cell of the second network device as the serving cell, the following three scenarios may trigger the terminal device to determine the second cell of the second network device as the serving cell:

[0187] Scenario e1: The terminal device determines that there is a demand for dual service flows. Optional, as shown in step 702a in FIG7 .

[0188] In this scenario e1, a terminal device in an idle or inactive state can initiate an RRC connection establishment or RRC connection reply process on the first cell to enter a connected state, thereby establishing a DRB for the service and transmitting the service data.

[0189] Alternatively, the terminal device in the connected state establishes a connection with the first cell and has data service transmission.

[0190] Scenario e2: The terminal device receives a first message from the first core network device, where the first message is used to instruct the terminal device to determine the second cell of the second network device as the service cell.

[0191] In one example, the first message may be a paging message. In this case, a new service arrives, and the service requires dual-stream operation, so the first core network device initiates paging.

[0192] When the first message is a paging message, the first core network device sends the paging message to the terminal device through the first network device, such as shown in step 702b in Figure 7.

[0193] In another example, the first message may be a service establishment message, such as that shown in step 702c of Figure 7 . Optionally, the service establishment message may be NAS signaling. In this case, when a new service arrives that requires dual-stream operation, the first core network device performs NAS signaling with the terminal device for the new service. Alternatively, after the service has been established, the first core network device instructs the terminal device to perform dual-stream operation via a service establishment message.

[0194] Scenario e3: The terminal device receives a second message from the first network device, where the second message is used to instruct the terminal device to perform dual-stream services.

[0195] Optionally, the second message may be an RRC reconfiguration message, such as shown in step 702d shown in FIG. 7 .

[0196] In some embodiments, after the service has been established, the first network device instructs the terminal device to perform dual-stream operation through an RRC reconfiguration message.

[0197] In an optional embodiment, when the terminal device determines that the second cell of the second network device is the serving cell, the second cell needs to meet preset conditions, for example, the measurement result of the second cell must meet the cell residence condition. In addition, the second cell and the first cell must belong to different network devices, the network to which the second cell belongs and the network to which the first cell belongs are combined to comply with the first strategy, and the type of network device to which the second cell belongs and the type of network device to which the first cell belongs must comply with the first strategy.

[0198] For the description of the first strategy, please refer to the description of the first strategy in the embodiment shown in FIG4 , which will not be repeated here.

[0199] Further optionally, the frequencies of the second cell and the first cell are different, or the frequencies of the second cell and the first cell need to meet the first strategy, or the combination of frequency bands to which the frequencies of the second cell and the first cell belong is supported by the terminal device capabilities.

[0200] In an optional implementation, after the terminal device determines that the second cell of the second network device is the serving cell, step 703 may be executed: the terminal device establishes a connection with the second network device, that is, the terminal device establishes a connection with the second cell of the second network device.

[0201] For example, after the terminal device determines that the second cell of the second network device is the serving cell, the terminal device enters a connected state, establishes a DRB for the service, and performs data transmission.

[0202] In some examples, when the terminal device determines that the second cell of the second network device is the serving cell, it is possible that the terminal device cannot find a qualified second cell. In this case, the terminal device does not perform the service dual-stream operation. Optionally, the terminal device may also inform the network. For example, the terminal device may inform the core network through a NAS message or inform the current serving network through an RRC message that no suitable second cell has been found.

[0203] In some other embodiments, even if there is no demand for service diversion, the terminal device can select a second cell to reside, that is, the terminal device determines the second cell of the second network device as the service cell and is ready to perform service diversion transmission at any time, which can shorten the delay of the terminal device initiating service data transmission on the second cell connection. At this time, the terminal device always has two service cells, the first cell and the second cell. When there is no service diversion, the terminal device can remain idle or inactive in the second cell, and the status of the terminal device in the first cell is not restricted. Optionally, after the terminal device is started, the terminal device can select the first cell and the second cell.

[0204] In this case, the method for the terminal device to select the second cell is the same as described above and will not be repeated here.

[0205] Optionally, the first cell may correspond to a primary network connection, and the second cell may correspond to a secondary network connection, which is not limited in this application.

[0206] Furthermore, when the dual-stream service is completed, or when the service no longer requires dual-stream operation, the terminal device itself or the network (core network or second network device) can release the second cell initially selected by the terminal device, or release a cell different from the second cell initially selected. Optionally, if the second cell is a cell connected to the auxiliary network, the terminal device releases the second cell when the transmission of the dual-stream service is completed or when the service no longer requires dual-stream operation. This can be understood as the terminal device can release the auxiliary network connection when the transmission of the dual-stream service is completed or when the service no longer requires dual-stream operation.

[0207] After the terminal device determines that the second cell of the second network device is the serving cell, as shown in Figure 8, when the terminal device moves, the terminal device can reselect the second cell and determine that the third cell of the third network device is the serving cell, wherein the first network device and the third network device comply with the first policy. Subsequently, when a service requires dual flow, the terminal device enters a connected state in the third cell and transmits service data, thereby realizing service dual flow.

[0208] Exemplarily, the terminal device may determine that the third cell of the third network device is the service cell by the following method: the terminal device determines that the third cell of the third network device is the cell with the highest cell quality among the cells of at least one network device that complies with the first policy with the first network device; or, the terminal device determines that the third cell of the third network device is the cell with the highest cell quality among the cells that meet the conditions and complies with the first policy with the first network device among the cells whose cell quality meets the conditions.

[0209] Optionally, when the terminal device reselects a cell, it may not find a suitable cell, that is, the third cell does not exist. In this case, the terminal device may perform the following operations:

[0210] Operation f1: The terminal device falls back to the current mechanism and selects the cell that meets the quality requirements and resides in the first cell. However, when there is a demand for dual-stream services, the terminal device cannot enter the connected state in the cell to transmit service data.

[0211] Operation f2: The terminal device does not trigger cell reselection and remains in the second cell that originally meets the policy until the second cell no longer meets the stay condition. After that, the terminal device can re-initiate the cell selection process.

[0212] Based on the above communication method, the terminal device can select a second cell that meets the dual-stream requirement, thereby ensuring that the dual-stream requirement of service data is met.

[0213] Based on the above embodiments, the embodiments of the present application further provide a communication device. Referring to FIG9 , the communication device 900 may include a transceiver unit 901 and a processing unit 902. The transceiver unit 901 is used for the communication device 900 to communicate, such as receiving information (messages or data) or sending information (messages or data), and the processing unit 902 is used to control and manage the actions of the communication device 900. The processing unit 902 may also control the steps performed by the transceiver unit 901.

[0214] Exemplarily, the communication device 900 may specifically be the first network device in the above embodiment, the processor of the first network device, or a chip, or a chip system, or a functional module, etc. Alternatively, the communication device 900 may specifically be the first core network device in the above embodiment, the processor in the first core network device, or a chip, or a chip system, or a functional module, etc. Alternatively, the communication device 900 may specifically be the terminal device in the above embodiment, the processor in the terminal device, or a chip, or a chip system, or a functional module, etc.

[0215] In one embodiment, when the communication device 900 is used to implement the function of the first network device (such as gNB1) in the embodiment described in Figure 4 or 5 above, the transceiver unit 901 can be used for communication; the processing unit 902 can be used to obtain information and a first policy of the second network device, and the first network device and the second network device provide data transmission services for the terminal device; and determine whether there is a third network device based on the information of the second network device and the first policy, and the third network device is the target network device for the terminal device to switch from the first network device.

[0216] In an optional embodiment, when obtaining the information of the second network device and the first policy, the processing unit 902 can be used to: control the transceiver unit 901 to obtain the information of the second network device and the first policy from the first core network device; or, control the transceiver unit 901 to obtain the information of the second network device from the terminal device, and to obtain the first policy from the first core network device; or, control the transceiver unit 901 to obtain the information of the second network device and the first policy from the terminal device.

[0217] In one example, the processing unit 902 can also be used to control the transceiver unit 901 to send a first measurement configuration to the terminal device based on the information of the second network device and the first policy; the transceiver unit 901 can also be used to receive measurement results from the terminal device, and the measurement results meet the first policy.

[0218] In another example, the transceiver unit 901 can also be used to send a second measurement configuration to the terminal device; and receive a measurement result from the terminal device, wherein the measurement result satisfies the first policy, and the measurement result is determined by the terminal device based on the information of the second network device and the first policy.

[0219] Optionally, when determining whether a third network device exists based on the information of the second network device and the first policy, the processing unit 902 is configured to: determine whether the third network device exists based on the information of the second network device, the first policy, and the measurement result.

[0220] Exemplarily, when the processing unit 902 determines whether the third network device exists based on the information of the second network device, the first policy, and the measurement result, it can be used to: determine whether the measurement result includes the measurement result of a network device that is different from the second network device and satisfies the first policy with the second network device based on the information of the second network device; if included, determine that the third network device exists; otherwise, determine that the third network device does not exist.

[0221] In one possible embodiment, the processing unit 902 can also be used to: when it is determined that the third network device exists, determine that one of the network devices corresponding to the measurement results of the network device that is different from the second network device in the measurement results and satisfies the first policy with the second network device is the third network device.

[0222] In another possible embodiment, the processing unit 902 can also be used to: when it is determined that the third network device does not exist, when it is determined that the service cell quality of the first network device is less than a first threshold, release the connection between the first network device and the terminal device, or suspend the data transmission of the terminal device; or determine that the terminal device switches to a fourth network device, and the first network device stops or suspends the data transmission of the terminal device.

[0223] Exemplarily, the first strategy may include at least one of the following: the two network devices providing data transmission services for the terminal device are different, a combination of networks to which the network devices allowed to perform dual-stream operations belong, a combination of air interface access technologies RATs of the network devices allowed to perform dual-stream operations, or a combination of working frequency bands or frequency points of the network devices allowed to perform dual-stream operations.

[0224] Optionally, the information of the second network device may include at least one of the following: an identifier of the second network device, a network to which the second network device belongs, an air interface access technology RAT of the second network device, and service band or frequency information of the second network device.

[0225] In another embodiment, when the communication device 900 is used to implement the function of the first network device in the embodiment described in Figure 6 above, the processing unit 902 can be used to determine at least one candidate network device; the transceiver unit 901 can be used to send a first request message to the first core network device, and the first request message is used to request the first core network device to determine whether the at least one candidate network device can be used as the target network device for the terminal device to switch from the first network device; wherein the first network device and the second network device provide data transmission services for the terminal device, and the target network device can provide data transmission services for the terminal device with the second network device; and, receive a first response message from the first core network device, and the first response message is used to indicate whether the at least one candidate network device can be used as the target network device for the terminal device to switch from the first network device.

[0226] In an optional embodiment, when determining the at least one candidate network device, the processing unit 902 can be used to: control the transceiver unit 901 to send a measurement configuration to the terminal device, and receive a measurement result from the terminal device; and determine the at least one candidate network device based on the measurement result.

[0227] The measurement result may be determined based on the information of the first network device, the information of the second network device, and the first policy.

[0228] Exemplarily, the first strategy may include at least one of the following: the two network devices providing data transmission services for the terminal device are different, a combination of networks to which the network devices allowed to perform dual-stream operations belong, a combination of air interface access technologies RATs of the network devices allowed to perform dual-stream operations, or a combination of working frequency bands or frequency points of the network devices allowed to perform dual-stream operations.

[0229] In one example, the first request message includes information about the at least one candidate network device; the first response message includes information that the at least one candidate network device can serve as a candidate network device for the target network device; or, the first response message includes indication information about whether the at least one candidate network device can serve as a target network device.

[0230] In another example, the first request message includes information of a first candidate network device; the first response message includes indication information of whether the first candidate network device can serve as a target network device; and the first candidate network device is any one of the at least one candidate network device.

[0231] Optionally, the processing unit 902 can also be used to: when at least one candidate network device cannot serve as the target network device for the terminal device to switch from the first network device, and when it is determined that the service cell quality of the first network device is less than a first threshold, release the connection between the first network device and the terminal device, or suspend the data transmission of the terminal device; or determine that the terminal device switches to a third network device, and the first network device stops or suspends the data transmission of the terminal device.

[0232] In another embodiment, when the communication device 900 is used to implement the function of the first core network device in the embodiment described in Figure 6 above, the transceiver unit 901 can be used to receive a first request message from the first network device, and the first request message is used to request the first core network device to determine whether at least one candidate network device can be used as the target network device for the terminal device to switch from the first network device; wherein, the first network device and the second network device provide data transmission services for the terminal device, and the target network device can provide data transmission services for the terminal device with the second network device; the processing unit 902 can be used to determine whether the at least one candidate network device can be used as the target network device for the terminal device to switch from the first network device according to a first strategy; the transceiver unit 901 can also be used to send a first response message to the first network device, and the first response message is used to indicate whether the at least one candidate network device can be used as the target network device for the terminal device to switch from the first network device.

[0233] Among them, the first strategy may include at least one of the following: the two network devices providing data transmission services for the terminal device are different, a combination of networks to which the network devices allowed to perform dual-stream operations belong, a combination of air interface access technologies RATs of the network devices allowed to perform dual-stream operations, or a combination of working frequency bands or frequency points of the network devices allowed to perform dual-stream operations.

[0234] In one example, the first request message includes information about the at least one candidate network device; the first response message includes information that the at least one candidate network device can serve as a candidate network device for the target network device; or, the first response message includes indication information about whether the at least one candidate network device can serve as a target network device.

[0235] In another example, the first request message includes information of a first candidate network device; the first response message includes indication information of whether the first candidate network device can serve as a target network device; and the first candidate network device is any one of the at least one candidate network device.

[0236] In another embodiment, when the communication device 900 is used to implement the functions of the terminal device in the embodiment described in Figure 7 or Figure 8 above, the processing unit 902 can be used to maintain the first cell of the first network device as the service cell; and determine the second cell of the second network device as the service cell; wherein the first network device and the second network device are capable of providing data transmission services for the terminal device; and the first network device and the second network device comply with the first strategy.

[0237] In an optional implementation, when maintaining the first cell of the first network device as a serving cell, the processing unit 902 may be configured to: reside in the first cell; or control the transceiver unit 901 to communicate with the first cell.

[0238] Optionally, the processing unit 902 can also be used to: before determining that the second cell of the second network device is a service cell, determine whether there is a demand for dual service flow; or, control the transceiver unit 901 to receive a first message from the first core network device, and the first message is used to instruct the terminal device to determine that the second cell of the second network device is a service cell; or, control the transceiver unit 901 to receive a second message from the first network device, and the second message is used to instruct the terminal device to perform dual service flow.

[0239] For example, the first message may be a paging message or a service establishment message.

[0240] In one possible embodiment, the processing unit 902 can also be used to: when the terminal device moves, determine that the third cell of the third network device is the service cell, the third cell is the cell reselected for the second cell, and the first network device and the third network device can provide data transmission services for the terminal device; the first network device and the third network device comply with the first strategy.

[0241] In some embodiments, when determining that the third cell of the third network device is a service cell, the processing unit 902 can be used to: determine that the third cell of the third network device is the cell with the highest cell quality among the cells of at least one network device that complies with the first policy with the first network device; or, among the cells whose cell quality meets the conditions, determine that the third cell of the third network device is the cell with the highest cell quality among the cells that meet the conditions and is the cell of the network device that complies with the first policy with the first network device.

[0242] Exemplarily, the first strategy may include at least one of the following: the two network devices providing data transmission services for the terminal device are different, a combination of networks to which the network devices allowed to perform dual-stream operations belong, a combination of air interface access technologies RATs of the network devices allowed to perform dual-stream operations, or a combination of working frequency bands or frequency points of the network devices allowed to perform dual-stream operations.

[0243] It should be noted that the division of units in the embodiments of the present application is schematic and is merely a logical functional division. In actual implementation, other division methods may be used. The functional units in the embodiments of the present application may be integrated into a single processing unit, or each unit may exist physically separately, or two or more units may be integrated into a single unit. The aforementioned integrated units may be implemented in the form of hardware or software functional units.

[0244] If the integrated unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present application is essentially or the part that contributes to the prior art or all or part of the technical solution can be embodied in the form of a software product, and the computer software product is stored in a storage medium, including a number of instructions for enabling a computer device (which can be a personal computer, server, or network device, etc.) or a processor to execute all or part of the steps of the method described in each embodiment of the present application. The aforementioned storage medium includes: various media that can store program codes, such as a USB flash drive, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk or an optical disk.

[0245] Based on the above embodiments, embodiments of the present application further provide a communication device. Referring to FIG. 10 , the communication device 1000 may include a processor 1002. Optionally, the communication device 1000 may further include a transceiver 1001. Optionally, the communication device 1000 may further include a memory 1003. The memory 1003 may be disposed within the communication device 1000 or external to the communication device 1000. The processor 1002 may control the transceiver 1001 to receive and transmit information, messages, or data.

[0246] Specifically, the processor 1002 may be a central processing unit (CPU), a network processor (NP), or a combination of a CPU and an NP. The processor 1002 may further include a hardware chip. The hardware chip may be an application-specific integrated circuit (ASIC), a programmable logic device (PLD), or a combination thereof. The PLD may be a complex programmable logic device (CPLD), a field-programmable gate array (FPGA), a generic array logic (GAL), or any combination thereof.

[0247] The transceiver 1001, the processor 1002, and the memory 1003 are interconnected. Optionally, the transceiver 1001, the processor 1002, and the memory 1003 are interconnected via a bus 1004; the bus 1004 may be a Peripheral Component Interconnect (PCI) bus or an Extended Industry Standard Architecture (EISA) bus. The bus may be classified as an address bus, a data bus, a control bus, etc. For ease of illustration, FIG10 shows only one thick line, but this does not mean that there is only one bus or only one type of bus.

[0248] In an optional embodiment, the memory 1003 is used to store programs, etc. Specifically, the programs may include program code, which includes computer operating instructions. The memory 1003 may include RAM, or may also include non-volatile memory (non-volatile memory), such as one or more disk storage devices. The processor 1002 executes the application program stored in the memory 1003 to implement the above functions, thereby realizing the functions of the communication device 1000.

[0249] Exemplarily, the communication device 1000 may be the first network device in the above embodiment; may also be the first core network device in the above embodiment; or may also be the terminal device in the above embodiment.

[0250] In one embodiment, when the communication device 1000 implements the functions of the first network device in the embodiment shown in FIG4, FIG5, or FIG6, the transceiver 1001 can implement the transceiver operations performed by the first network device in the embodiment shown in FIG4, FIG5, or FIG6; the processor 1002 can implement other operations other than the transceiver operations performed by the first network device in the embodiment shown in FIG4, FIG5, or FIG6. For specific related descriptions, please refer to the relevant descriptions of the embodiment shown in FIG4, FIG5, or FIG6, and will not be described in detail here.

[0251] In another embodiment, when the communication device 1000 implements the functions of the first core network device in the embodiment shown in FIG6 , the transceiver 1001 may implement the transceiver operations performed by the first core network device in the embodiment shown in FIG6 ; and the processor 1002 may implement other operations performed by the first core network device in the embodiment shown in FIG6 , except for the transceiver operations. For specific related descriptions, please refer to the relevant descriptions in the embodiment shown in FIG6 above, and will not be described in detail here.

[0252] In another embodiment, when the communication device 1000 implements the functions of the terminal device in the embodiment shown in FIG7 or FIG8, the transceiver 1001 can implement the transceiver operations performed by the terminal device in the embodiment shown in FIG7 or FIG8; the processor 1002 can implement other operations performed by the terminal device in the embodiment shown in FIG7 or FIG8 in addition to the transceiver operations. Specific related descriptions can be found in the relevant descriptions of the embodiment shown in FIG7 or FIG8 above, and will not be described in detail here.

[0253] Based on the above embodiments, an embodiment of the present application provides a communication system, which may include the first network device, the second network device, the first core network device and the terminal device involved in the above embodiments.

[0254] An embodiment of the present application further provides a computer-readable storage medium, which is used to store a computer program. When the computer program is executed by a computer, the computer can implement the communication method provided by the above method embodiment.

[0255] An embodiment of the present application further provides a computer program product, which is used to store a computer program. When the computer program is executed by a computer, the computer can implement the communication method provided by the above method embodiment.

[0256] An embodiment of the present application also provides a chip, including a processor, which is coupled to a memory and is used to call a program in the memory so that the chip implements the communication method provided by the above method embodiment.

[0257] An embodiment of the present application further provides a chip, which is coupled to a memory and is used to implement the communication method provided in the above method embodiment.

[0258] Those skilled in the art will appreciate that the embodiments of the present application can be provided as methods, systems, or computer program products. Therefore, the present application can adopt the form of a complete hardware embodiment, a complete software embodiment, or an embodiment in combination with software and hardware. Moreover, the present application can adopt the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to magnetic disk storage, CD-ROM, optical storage, etc.) that contain computer-usable program code.

[0259] The present application is described with reference to the flowcharts and / or block diagrams of the methods, devices (systems), and computer program products according to the present application. It should be understood that each flow and / or box in the flow chart and / or block diagram, as well as the combination of the flow chart and / or box in the flow chart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device produce a device for implementing the functions specified in one or more flow charts and / or one or more boxes in the block diagram.

[0260] These computer program instructions may also be stored in a computer-readable memory that can direct a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce a product including an instruction device that implements the functions specified in one or more processes in the flowchart and / or one or more boxes in the block diagram.

[0261] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, so that the instructions executed on the computer or other programmable device provide steps for implementing the functions specified in one or more processes in the flowchart and / or one or more boxes in the block diagram.

[0262] Obviously, those skilled in the art may make various changes and modifications to the present application without departing from the scope of the present application. Thus, if these modifications and variations of the present application fall within the scope of the claims of the present application and their equivalents, the present application is intended to include these modifications and variations.

Claims

1. A communication method, characterized in that: include: The first network device acquires information and a first policy of the second network device, and the first network device and the second network device provide a data transmission service for the terminal device; The first network device determines whether there is a third network device according to the information of the second network device and the first policy, and the third network device is the target network device for the terminal device to switch from the first network device.

2. The method according to claim 1, characterized in that The first network device acquires the information of the second network device and the first policy, including: The first network device obtains the information of the second network device and the first policy from the first core network device; or The first network device obtains information about the second network device from the terminal device, and obtains the first policy from the first core network device; or The first network device obtains the information of the second network device and the first policy from the terminal device.

3. The method according to claim 1 or 2, characterized in that The method further comprises: The first network device sends a first measurement configuration to the terminal device according to the information of the second network device and the first policy; The first network device receives a measurement result from the terminal device, where the measurement result satisfies the first policy.

4. The method according to claim 1 or 2, characterized in that: The method further comprises: The first network device sends a second measurement configuration to the terminal device; The first network device receives a measurement result from the terminal device, where the measurement result satisfies the first policy and is determined by the terminal device according to information of the second network device and the first policy.

5. The method according to claim 3 or 4, characterized in that The first network device determines whether a third network device exists according to the information of the second network device and the first policy, including: The first network device determines whether the third network device exists according to the information of the second network device, the first policy, and the measurement result.

6. The method according to claim 5, characterized in that The first network device determines whether the third network device exists according to the information of the second network device, the first policy, and the measurement result, including: The first network device determines, according to the information of the second network device, whether the measurement result includes a measurement result of a network device that is different from the second network device and satisfies the first policy with the second network device; If included, the first network device determines that the third network device exists; Otherwise, the first network device determines that the third network device does not exist.

7. The method according to claim 6, characterized in that When the first network device determines that the third network device exists, the method further includes: The first network device determines that one of the network devices corresponding to the measurement results of the network devices that are different from the second network device and that satisfy the first policy with the second network device is the third network device.

8. The method according to any one of claims 1 to 6, characterized in that: When the first network device determines that the third network device does not exist, the method further includes: When the first network device determines that the quality of the service cell of the first network device is less than a first threshold, the first network device releases the connection between the first network device and the terminal device, or suspends data transmission of the terminal device; or The first network device determines that the terminal device switches to the fourth network device, and the first network device stops or suspends data transmission of the terminal device.

9. The method according to any one of claims 1 to 8, characterized in that The first strategy includes at least one of the following: the two network devices providing data transmission services for the terminal device are different, a combination of networks to which the network devices allowed to perform dual-stream operations belong, a combination of air interface access technologies RATs of the network devices allowed to perform dual-stream operations, or a combination of working frequency bands or frequency points of the network devices allowed to perform dual-stream operations.

10. The method according to any one of claims 1 to 9, characterized in that: The information of the second network device includes at least one of the following: an identifier of the second network device, a network to which the second network device belongs, an air interface access technology RAT of the second network device, and service frequency band or frequency point information of the second network device.

11. A communication device, characterized in that: The method comprises a module or a unit for executing the method according to any one of claims 1 to 10.

12. A communication device, characterized in that: comprising a processor, wherein: The processor is coupled to the memory, and is used to call the computer instructions in the memory to execute the method according to any one of claims 1-10.

13. The device according to claim 12, characterized in that The device further comprises a memory and / or a transceiver, wherein the memory is used to store the computer instructions, and the transceiver is used for the communication device to communicate.

14. The device according to claim 12 or 13, characterized in that The communication device is a chip or a chip system.

15. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores computer-executable instructions, and when the computer-executable instructions are called by the computer, the method according to any one of claims 1 to 10 is executed.

16. A computer program product, characterized in that The method comprises instructions which, when executed on a computer, perform the method according to any one of claims 1 to 10.

17. A chip, characterized in that: The chip is coupled to a memory and is used to read and execute program instructions stored in the memory to implement the method according to any one of claims 1 to 10.

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