Ttt-based handover method, apparatus, communication system, and storage medium

Abstract

The application provides a TTT-based switching method and device, a communication system and a storage medium, and can be applied to the technical field of wireless communication. In the scheme, a terminal device can acquire a moving speed measured by an L1 layer, and a neighbor cell load and a service quality requirement measured by an L3 layer, and report the data to a source base station, so that the source base station can dynamically adjust TTT according to the data, and improve network adaptability. For example, in a high-speed moving scenario, TTT is shortened to reduce switching delay; in a low load, TTT is extended to reduce signaling overhead and avoid resource waste caused by static configuration. In addition, the terminal device can predict future resource requirements based on historical data, and trigger a target base station to perform dynamic resource pre-allocation for the terminal device in advance, so that the terminal device directly accesses a cell using the reserved resources, skips the traditional random access process, reduces negotiation time during switching, and realizes seamless switching.

Description

Technical Field

[0001] This application relates to the field of wireless communication technology, and in particular to a switching method, apparatus, communication system and storage medium based on time-to-trigger (TTT). Background Technology

[0002] With the development of high-speed mobile terminals such as high-speed rail and in-vehicle systems, optimizing handover robustness has become particularly important. In high-speed mobile scenarios, when the channel quality of the source cell deteriorates sharply, if the traditional handover (HO) method is used to trigger the handover by the source base station, the handover may be triggered too late, leading to handover failure.

[0003] Related technologies have proposed Layer 1 or Layer 2 triggered mobility (LTM) mechanisms to shorten handover latency. In LTM, target beams or cells can be quickly selected through event assessment (such as LTM3 / LTM5). To avoid excessively frequent event-triggered reports, Time-to-Trip (TTT) can be applied during LTM event assessment. After the timer reaches the TTT duration, the terminal device sends a measurement report to the source base station. However, if the TTT is statically configured by network equipment, it may lead to inaccurate handover decisions. For example, in high-speed mobile scenarios, a fixed TTT may cause handovers to occur too early or too late, resulting in ping-pong effects or service interruptions. Summary of the Invention

[0004] This application provides a TTT-based handover method, apparatus, communication system, and storage medium to solve the technical problem that fixed TTT leads to inaccurate handover decisions, causing ping-pong effects or service interruptions.

[0005] To achieve the above objectives, this application adopts the following technical solution:

[0006] Firstly, a TTT-based handover method is provided. This method can be executed by a terminal device, or by a component configured in the terminal device (such as a circuit, chip, or chip system), or by a logic module or software capable of implementing all or part of the terminal device's functions. The following description uses a terminal device as an example.

[0007] The method may include: a terminal device sending a MAC CE to a source base station, the MAC CE including a first field indicating the moving speed of the terminal device, a second field indicating the neighboring cell load, and a third field indicating the service quality requirement, the first field, the second field, and the third field being used to determine the TTT; the terminal device receiving a first TTT from the source base station; and, if the L1 measurement result meets the event condition and the timer duration reaches the first TTT, the terminal device sending a measurement report to the source base station, the measurement report being used to trigger cell handover.

[0008] Among the beneficial effects of the above scheme, the terminal device can obtain the mobile speed measured at L1 layer and the neighboring cell load and service quality requirements measured at L3 layer, and report this data to the source base station. The source base station can then dynamically adjust the TTT based on this data. This allows the terminal device to trigger handover decisions based on LTM events and optimized TTT values. For example, in high-speed mobile scenarios, shortening the TTT reduces handover latency; in low-load scenarios, extending the TTT reduces signaling overhead and avoids resource waste caused by static configuration.

[0009] In one possible implementation, the terminal device's moving speed is determined by L1 measurement; the neighboring cell load is determined by L3 measurement; and the service quality requirements are determined by L3 measurement. It is understood that by fusing L1 and L3 measurement data, data diversity can be increased, making the optimized TTT value more accurate.

[0010] In one possible implementation, different encoding values ​​for the first field represent different mobile speeds; different encoding values ​​for the second field represent different neighboring cell loads; and different encoding values ​​for the third field represent different service quality requirements. It can be understood that in MAC CE, corresponding encoding values ​​can be set based on the specific values ​​or types of data indicated by each field, so that the source base station can parse the corresponding information based on the encoding values ​​of each field and then dynamically adjust the TTT.

[0011] In one possible implementation, the first, second, and third fields are consecutive fields, each with a data length of 2 bits. It can be understood that after classifying mobile speed, neighboring cell load, and service requirements, each type of information requires fewer bits; for example, 2 bits are sufficient for data encoding. Thus, these three types of data can be transmitted using only one byte, resulting in lower signaling overhead.

[0012] In one possible implementation, the MAC CE may further include: a fourth field indicating the C-RNTI of the cell where the terminal device is located; a fifth field indicating the predicted number of resource blocks allocated to the terminal device; and a sixth field indicating the HARQ status. It is understood that the terminal device and the candidate base station cannot communicate directly, and resource allocation can be coordinated through the source base station. By carrying the C-RNTI of the cell where the terminal device is located, the predicted number of resource blocks allocated to the terminal device, and the HARQ status in the MAC CE, the target cell can reserve resources for the terminal device in advance.

[0013] In one possible implementation, the fourth, fifth, and sixth fields are consecutive. The fourth field has a data length of 2 bytes, the fifth field has a data length of 1 byte, and the sixth field has a data length of 2 bits. It can be understood that by using a single MAC CE to merge the data indicated by the first to fourth fields, air interface signaling overhead can be reduced, and additional latency introduced by multiple signaling interactions can be avoided.

[0014] In one possible implementation, the method may further include: the terminal device predicting the number of resource blocks allocated to it based on its historical data. It is understood that traditional CSI measurement and handover decision-making mechanisms may be outdated, leading to handover decision lags and resource reservation redundancy. Historical data from the terminal device can assist in determining the future number of resource blocks needed; therefore, the terminal device can predict the future number of resource blocks needed using historical data.

[0015] In one possible implementation, receiving the first TTT from the source base station may include: the terminal device receiving an RRC message from the source base station. The RRC message may include the first TTT and pre-configuration information for at least one candidate cell. This pre-configuration information can be used to indicate the resources allocated to the terminal device. For example, the pre-configuration information includes: the coding frequency of the CSI-RS, the coding period of the CSI-RS, the port number of the CSI-RS, and the synchronization signal block index. It is understood that the terminal device and the candidate base station cannot communicate directly; resource allocation can be coordinated through the source base station. Therefore, the candidate base station can return pre-configuration information to the terminal device through the source base station, allowing the terminal device to directly use reserved resources to access the cell, skipping the traditional random access process, achieving seamless handover, and improving the access success rate.

[0016] In one possible implementation, the pre-configuration information of at least one candidate cell includes the pre-configuration information of the target cell. After sending a measurement report to the source base station, the method may further include: the terminal device receiving a cell handover instruction from the source base station; and the terminal device, in response to the cell handover instruction, using the pre-configuration information of the target cell, accessing the target cell.

[0017] Secondly, a TTT-based handover method is provided. This method can be executed by the source base station, or by components (such as circuits, chips, or chip systems) configured in the source base station, or by logic modules or software that can implement all or part of the functions of the source base station. The following description uses the source base station as an example.

[0018] The method may include: a source base station receiving a MAC CE from a terminal device, the MAC CE including a first field indicating the moving speed of the terminal device, a second field indicating the neighboring cell load, and a third field indicating the service quality requirements; the source base station determining a first TTT based on the first field, the second field, and the third field; the source base station sending the first TTT to the terminal device, the first TTT being used to determine the timing of sending a measurement report; the source base station receiving the measurement report from the terminal device; and the source base station selecting a target cell for the terminal device based on the measurement report.

[0019] Among the beneficial effects of the above scheme, since the terminal device reports its mobile speed, neighboring cell load, and service quality requirements, the source base station can dynamically adjust the TTT based on this data. This allows the terminal device to determine when to send the measurement report based on the optimized TTT value. Dynamically adjusting the TTT can improve network adaptability. For example, in high-speed mobile scenarios, shortening the TTT reduces handover latency; under low load conditions, extending the TTT reduces signaling overhead and avoids resource waste caused by static configuration.

[0020] In one possible implementation, determining the first TTT based on the first, second, and third fields can include: modifying the second TTT based on the first, second, and third fields to obtain the first TTT, where the second TTT is a pre-configured fixed value. It can be understood that compared to a traditional fixed TTT, modifying the TTT can improve network adaptability.

[0021] In one possible implementation, the first field, when set to different encoding values, represents different movement speeds; the second field, when set to different encoding values, represents different neighbor cell loads; and the third field, when set to different encoding values, represents different service quality requirements.

[0022] In one possible implementation, the first, second, and third fields are consecutive fields, and the data length of each of the first, second, and third fields is 2 bits.

[0023] In one possible implementation, the MAC CE may further include: a fourth field indicating the C-RNTI of the cell where the terminal device is located; a fifth field indicating the number of resource blocks predicted to be allocated to the terminal device; and a sixth field indicating the HARQ status.

[0024] In one possible implementation, the fourth, fifth, and sixth fields are consecutive fields, with the fourth field having a data length of 2 bytes, the fifth field having a data length of 1 byte, and the sixth field having a data length of 2 bits.

[0025] In one possible implementation, the method may include: a source base station sending a request message to a target base station, the request message including the C-RNTI of the cell where the terminal device is located, the predicted number of resource blocks to be allocated to the terminal device, and the HARQ status; the source base station receiving a response message from the target base station, the response message including pre-configuration information of at least one candidate cell corresponding to at least one candidate base station, the pre-configuration information being used to indicate the resources allocated to the terminal device. For example, the pre-configuration information may include: the coding frequency of CSI-RS, the coding period of CSI-RS, the port number of CSI-RS, and the synchronization signal block index.

[0026] In one possible implementation, the method may include: a source base station sending an RRC message to a terminal device, the RRC message including a first TTT and pre-configuration information of at least one candidate cell. The pre-configuration information of the at least one candidate cell includes pre-configuration information of the target cell to be accessed.

[0027] In one possible implementation, after selecting a target cell for the terminal device, the method may further include: the source base station sending a cell handover instruction to the terminal device, the cell handover instruction being used to indicate handover to the target cell.

[0028] The second aspect is the implementation on the source base station side, which corresponds to the first aspect. The explanations, supplements, and descriptions of the beneficial effects of the first aspect also apply to the second aspect, and will not be repeated here.

[0029] Thirdly, a TTT-based handover method is provided. This method can be executed by at least one candidate base station, or by a component (such as a circuit, chip, or chip system) configured in at least one candidate base station, or by a logic module or software capable of implementing all or part of the target base station's functions. At least one candidate base station includes the target base station to which the terminal device will access. The following description uses one candidate base station as an example.

[0030] The method may include: a candidate base station receiving a request message from a source base station, the request message including the C-RNTI of the cell where the terminal device is located, the predicted number of resource blocks allocated to the terminal device, and the HARQ status; the candidate base station sending a response message to the source base station, the response message including pre-configuration information of the candidate cell corresponding to the candidate base station. For example, the coding frequency of CSI-RS, the coding period of CSI-RS, the port number of CSI-RS, and the synchronization signal block index.

[0031] Among the beneficial effects of the above scheme, the terminal device and the target base station cannot communicate directly, and resource allocation can be coordinated through the source base station. The candidate base station can return pre-configuration information to the terminal device through the source base station, enabling the terminal device to directly use the reserved resources to access the cell, skipping the traditional random access process, achieving seamless handover, and improving the access success rate.

[0032] Fourthly, an electronic device is provided, comprising a transceiver module. The transceiver module is configured to: send a MAC CE to a source base station, the MAC CE including a first field indicating the moving speed of a terminal device, a second field indicating the load of neighboring cells, and a third field indicating the service quality demand, the first, second, and third fields being used to determine the time-to-use (TTT); receive a first TTT from the source base station; and, after the L1 measurement result meets an event condition and the timer duration reaches the first TTT, send a measurement report to the source base station, the measurement report being usable for triggering cell handover through event assessment.

[0033] Fifthly, an electronic device is provided, comprising a transceiver module and a processing module. The transceiver module is configured to: receive a MAC CE from a terminal device, the MAC CE including a first field indicating the mobile speed of the terminal device, a second field indicating neighboring cell load, and a third field indicating service quality requirements. The processing module is configured to: determine a first TTT based on the first, second, and third fields. The transceiver module is further configured to: send a first TTT to the terminal device, the first TTT being used to determine the timing of measurement report transmission, and receive a measurement report from the terminal device. The processing module is further configured to: perform event assessment based on the measurement report and select a target cell for the terminal device.

[0034] Sixthly, an electronic device is provided, comprising a transceiver module. The transceiver module is configured to: receive a request message from a source base station, the request message including the C-RNTI of the cell where the terminal device is located, the predicted number of resource blocks allocated to the terminal device, and the HARQ status; and send a response message to the source base station, the response message including pre-configuration information of a candidate cell corresponding to a target base station. For example, the pre-configuration information may include: the coding frequency of CSI-RS, the coding period of CSI-RS, the port number of CSI-RS, and the synchronization signal block index.

[0035] The fourth, fifth, and sixth aspects are the device-side implementations corresponding to the first, second, and third aspects. The explanations, supplements, and descriptions of beneficial effects regarding the first, second, and third aspects also apply to the fourth, fifth, and sixth aspects, and will not be repeated here.

[0036] A seventh aspect provides a communication device including a processor. The processor is coupled to a memory and can be used to execute instructions or data in the memory to implement the method in any possible implementation of the first aspect. Optionally, the communication device further includes a memory. Optionally, the communication device further includes a communication interface, and the processor is coupled to the communication interface.

[0037] Eighthly, a communication device is provided, including a processor. The processor is coupled to a memory and can be used to execute instructions or data in the memory to implement the method in any possible implementation of the second aspect described above. Optionally, the communication device further includes a memory. Optionally, the communication device further includes a communication interface, and the processor is coupled to the communication interface.

[0038] A ninth aspect provides a communication device including a processor. The processor is coupled to a memory and can be used to execute instructions or data in the memory to implement the method in any possible implementation of the third aspect described above. Optionally, the communication device further includes a memory. Optionally, the communication device further includes a communication interface, and the processor is coupled to the communication interface.

[0039] In a tenth aspect, a processor is provided, comprising: an input circuit, an output circuit, and a processing circuit. The processing circuit is used to receive signals through the input circuit and to transmit signals through the output circuit, causing the processor to execute a method in any possible implementation of any aspect.

[0040] In specific implementation, the processor can be one or more chips, the input circuit can be input pins, the output circuit can be output pins, and the processing circuit can be transistors, gate circuits, flip-flops, and various logic circuits. The input signal received by the input circuit can be received and input by, for example, but not limited to, a receiver, and the signal output by the output circuit can be output to, for example, but not limited to, a transmitter and transmitted by the transmitter. Furthermore, the input circuit and the output circuit can be the same circuit, which is used as the input circuit and the output circuit at different times. This application does not limit the specific implementation of the processor and various circuits.

[0041] Eleventhly, a computer program product is provided, comprising: a computer program (also referred to as code or instructions) that, when run, causes a computer to perform a method in any possible implementation of any of the preceding aspects.

[0042] In a twelfth aspect, a computer-readable storage medium is provided, which stores a computer program (also referred to as code or instructions). When executed on a computer, the program causes the computer to perform the methods in any possible implementation of any of the above aspects.

[0043] In a thirteenth aspect, embodiments of this application provide a chip system including one or more processors for calling and executing instructions stored in memory, causing the methods in any of the above aspects or possible implementations to be executed. The chip system may be composed of chips or may include chips and other discrete devices. The chip system may include input circuitry or interfaces for transmitting information or data, and output circuitry or interfaces for receiving information or data.

[0044] In a fourteenth aspect, a communication system is provided, including a terminal device, a source base station, and at least one candidate base station, wherein the at least one candidate base station may include a target base station to which the terminal device needs to access. In one possible implementation, the communication system may further include other devices that communicate with the terminal device, the source base station, and the target base station, such as an LMF or an AMF. Attached Figure Description

[0045] Figure 1 A schematic diagram of a communication system provided in an embodiment of this application;

[0046] Figure 2 A schematic diagram of a communication system suitable for LTM handover provided in an embodiment of this application;

[0047] Figure 3 A schematic diagram of the L3 handover process provided in an embodiment of this application;

[0048] Figure 4 A schematic diagram of the LTM switching process provided in an embodiment of this application;

[0049] Figure 5 Two timing schemes based on TTT provided for embodiments of this application;

[0050] Figure 6 A flowchart illustrating the switching method based on dynamic TTT provided in this application embodiment;

[0051] Figure 7 A flowchart illustrating the channel prediction-based handover method provided in an embodiment of this application;

[0052] Figure 8 A flowchart illustrating the handover method based on dynamic TTT and channel prediction provided in this application embodiment;

[0053] Figure 9 A schematic block diagram of an electronic device provided in the embodiments of this application;

[0054] Figure 10 A schematic block diagram of a communication device provided in an embodiment of this application. Detailed Implementation

[0055] The terms "first" and "second," etc., used in the specification and drawings of this application are used to distinguish different objects or different treatments of the same object, rather than to describe a specific order of objects. Furthermore, the terms "comprising" and "having," and any variations thereof, mentioned in the description of this application are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or device that includes a series of steps or units is not limited to the listed steps or units, but may optionally include other steps or units not listed, or may optionally include other steps or units inherent to these processes, methods, products, or devices. In the embodiments of this application, "multiple" includes two or more. In the embodiments of this application, words such as "exemplary" or "for example" are used to indicate examples, illustrations, or explanations. Additionally, the network architecture and business scenarios described in the embodiments of this application are for the purpose of more clearly illustrating the technical solutions of the embodiments of this application, and do not constitute a limitation on the technical solutions provided by the embodiments of this application. Those skilled in the art will understand that with the evolution of network architecture and the emergence of new business scenarios, the technical solutions provided by the embodiments of this application are also applicable to similar technical problems.

[0056] The technical solutions provided in this application can be applied to various communication systems, such as: Global System for Mobile Communications (GSM), General Packet Radio Service (GPRS), Wireless Local Area Network (WLAN), Long Term Evolution (LTE), LTE Frequency Division Duplex (FDD), LTE Time Division Duplex (TDD), sidelink communication systems, Universal Mobile Telecommunication System (UMTS), Worldwide Interoperability for Microwave Access (WiMAX), non-terrestrial network (NTN), 5th generation (5G) mobile communication systems, or NR systems, etc. Among them, 5G mobile communication systems can include non-standalone (NSA) and / or standalone (SA) networking. The technical solutions provided in this application can also be applied to future communication systems, and this application does not limit their application.

[0057] Figure 1 This is a schematic diagram of a communication system 100 provided in an embodiment of this application.

[0058] Communication system 100 may include network devices, such as Figure 1 The network device 110 is shown. The communication system 100 may also include terminal devices, such as... Figure 1 The terminal device 120 shown. The network device 110 and the terminal device 120 can communicate via a wireless link.

[0059] Figure 1 An exemplary network device 110 and a terminal device 120 are shown. In one possible implementation, the communication system 100 may also include multiple network devices and / or multiple terminal devices.

[0060] The network devices in this application embodiment can be network-side devices such as access network devices and core network devices. Access network devices are sometimes also called access nodes. Access network devices have wireless transceiver capabilities and are used to communicate with terminal devices. Access network devices include, but are not limited to, base stations, evolved NodeBs (eNodeBs), transmit / receive points (TRPs) in the aforementioned communication systems, NR nodes (gNBs) in 5G mobile communication systems, next-generation eNodeBs (ng-eNBs) in 5G mobile communication systems, access network devices or modules of access network devices in open RAN (ORAN) systems, satellites in non-terrestrial network (NTN) communication systems, base stations in future mobile communication systems, or access nodes in wireless fidelity (Wi-Fi) systems. Access network devices can also be modules or units capable of implementing some of the functions of a base station. Access network equipment can be macro base stations, micro base stations, indoor stations, relay nodes, donor nodes, or wireless controllers in cloud radio access network (CRAN) scenarios. Access network equipment can also be servers, wearable devices, or vehicle-mounted devices. Multiple access network devices in a communication system can be base stations of the same type or different types. Base stations can communicate directly with terminal devices or through relay stations. Terminal devices can communicate with multiple base stations using different access technologies. This application does not limit the specific technologies or device forms used in the access network equipment.

[0061] In this embodiment of the application, the device used to implement the function of the network device can be the network device itself, or it can be a device that enables the network device to implement the function, such as a processor, circuit, chip or chip system. The device can be installed in the network device or connected to the network device for use.

[0062] The terminal device in this application embodiment can be a wireless terminal device capable of receiving network device scheduling and instruction information. The wireless terminal device can be a device providing voice and / or data connectivity to a user, a handheld device with wireless connectivity, or other processing devices connected to a wireless modem. For example, the terminal device can communicate with one or more core networks or the Internet via a radio access network (RAN). The terminal device can also be referred to as a terminal, user equipment (UE), mobile station, mobile terminal, etc. Terminal devices can be widely used in various scenarios, such as device-to-device (D2D), vehicle-to-everything (V2X) communication, machine-type communication (MTC), Internet of Things (IoT), ultra-reliable low-latency communication (URLLC), virtual reality, augmented reality, industrial control, autonomous driving, telemedicine, smart grids, smart furniture, smart offices, smart wearables, smart transportation, smart cities, or satellite communication, etc. The terminal device can be a mobile phone, tablet computer, computer with wireless transceiver function, wearable device, vehicle, aircraft (such as drone, helicopter, airplane), hot air balloon, ship, robot, robotic arm, or smart home device, etc. The embodiments of this application do not limit the form of the terminal device.

[0063] In this embodiment of the application, the device used to implement the function of the terminal device can be the terminal device itself, or it can be a device that supports the terminal device in implementing the function, such as a processor, circuit, chip or chip system. The device can be installed in the terminal device or connected to the terminal device for use.

[0064] Access network equipment and / or terminal equipment can be fixed or mobile. They can be deployed on land, including indoors or outdoors, handheld or vehicle-mounted; on water; or in the air on aircraft, balloons, and satellites. This application does not limit the application scenarios of the access network equipment and terminal equipment. They can be deployed in the same or different scenarios; for example, both can be deployed on land simultaneously; or the access network equipment can be deployed on land while the terminal equipment is deployed on water, etc., and so on.

[0065] Figure 2 This is a schematic diagram of a communication system suitable for LTM handover, provided as an embodiment of this application.

[0066] A communication system may include functional entities such as terminal devices, access network devices, and core network devices. These functional entities communicate with each other through corresponding interfaces. For example, terminal devices can communicate with each other through the proximity-based services communication 5 (PC5) interface, and terminal devices can connect to access network devices via the gNB through the NR-Uu interface.

[0067] Access network equipment refers to devices within an access network that primarily perform functions such as resource scheduling, radio resource management, and radio resource control for terminal devices. For example, an access network can be a next-generation radio access network (NG-RAN). NG-RAN can include one or more access network devices, such as gNBs. A gNB is a node that provides NR user plane and control plane protocols to terminal devices; for example, a gNB can be a Transmission Reference Module (TRP) or a Transmission Measurement Function (TMF). Access network equipment can communicate with core network equipment via wired or wireless means, such as connecting to the core network through an NG-C interface. Access network equipment can transmit positioning reference signals (PRS), receive sounding reference signals (SRS), and acquire relevant measurement information.

[0068] like Figure 2As shown, in a 5G NR system, a gNB is divided into a centralized unit (CU) and a distributed unit (DU). The CU and DU are connected via the F1 interface. The CU and DU can be configured independently or included in the same network element, such as a baseband unit (BBU). A CU is connected to one or more DUs, such as gNB1-CU connected to gNB1-DU1 and gNB1-DU2, and gNB2-CU connected to gNB2-DU. A DU can cover one or more cells, such as gNB1-DU1 covering Cell1 and Cell2, gNB1-DU2 covering Cell3 and Cell4, and gNB2-DU covering Cell5, Cell6, and Cell7. A terminal device can camp in one of the cells, in a connected state. The terminal device can transition from the connected state to an inactive state, i.e., a disconnected state, through a radio resource control (RRC) release process. A terminal device in a connectionless state can remain in its original cell and perform uplink and / or downlink transmissions with the access network equipment in the original cell, based on its transmission parameters in the original cell. A terminal device in a connectionless state can also move to a new cell and perform uplink and / or downlink transmissions with the access network equipment in the new cell, based on its transmission parameters in the new cell.

[0069] In LTM handover, the CU pre-configures candidate target cells for the terminal device, and the DU issues an LTM handover command to the terminal device. The terminal device then switches to the target cell based on the LTM handover command and the RRC pre-configuration. The LTM mechanism can be executed between different cells within the same base station, such as between gNB1-DU1 and gNB1-DU2; it can also be executed between different base stations, such as between gNB1-DU2 and gNB2-DU.

[0070] Core network equipment is primarily used for network management, control, and data transmission. Core network equipment may include, for example... Figure 2 The functional entities or network elements shown include the access and mobility management function (AMF) and the location management function (LMF).

[0071] AMF can receive location service requests related to terminal devices from the location service (LCS) entity of the 5G core network (5GC) or other network elements. Alternatively, AMF itself can initiate some location services on behalf of a specific terminal device and forward the location service requests to LMF.

[0072] The Location Facilitator (LMF) is responsible for supporting different types of location services for terminal devices, calculating and feeding back location information within the network, and providing functions such as positioning process management, terminal capability acquisition, auxiliary data provision, and terminal location estimation. Specifically, it provides the following functions: supporting terminal device location calculation, obtaining downlink location measurements or estimates from terminal devices, and obtaining uplink location measurements from the NG-RAN. The LMF's control plane and user plane are the Enhance-Serving Mobile Location Center (E-SMLC) and the Secure User Plane Locator Platform (SLP), respectively. The LMF can interact with the NG-RAN and terminal devices. For example, the LMF exchanges information with the gNB or ng-eNB via New Radio Positioning Protocol Annex (NRPPa) messages, such as obtaining PRS and SRS configuration information, cell timing, and cell location information. Furthermore, the LMF communicates with terminal devices via LTE Positioning Protocol (LPP) messages to transmit terminal device capability information, auxiliary information, and measurement information.

[0073] It should be noted that, Figure 2 This is just an example framework diagram. Figure 2 The number of nodes, cells, and the status of terminal devices included are unlimited. Except... Figure 2 In addition to the functional nodes shown, other nodes may also be included, such as gateway devices and application servers.

[0074] To facilitate understanding of the embodiments of this application, the terminology used in these embodiments is briefly explained below. Optionally, the explanation of some terms may also refer to the explanations in the 3rd Generation Partnership Project (3GPP) standard protocol. It should be understood that the technical terminology in the embodiments of this application is only illustrative and not limiting. For example, as technology evolves, technical terminology may also change; where the technical meaning remains the same, other technical terms should also apply to this application.

[0075] In mobile communication networks, when a terminal device is in RRC connection mode, if the terminal device moves from one base station coverage area to another, or if call quality degrades due to external interference, it needs to switch from the original channel to another available channel. This process is called handover. Currently, there are various ways to implement handover, such as Layer 3 (L3) handover, conditional handover (CHO), and LTM handover.

[0076] For example, Figure 3 This is a schematic diagram of the L3 switching process provided in an embodiment of this application.

[0077] Step 1: The source gNodeB sends a measurement control message to the UE via an RRC Reconfiguration message, which may include the measurement object (same frequency / different frequency), measurement report configuration, and measurement gap configuration.

[0078] Step 2: The UE replies to the source gNodeB with an RRC reconfiguration complete message.

[0079] Step 3: The UE performs measurements based on the received measurement control message. After measuring and determining that the event conditions have been met, the UE reports a measurement report to the source gNodeB. Accordingly, the source gNodeB determines the handover strategy and target cell / frequency point based on the measurement results.

[0080] Step 4: The source gNodeB initiates a handover request to the gNodeB where the selected target cell is located (i.e., the target gNodeB). Accordingly, upon receiving the handover request, the target gNodeB performs admission control, allowing post-admission allocation of UE instances and transmission resources.

[0081] Step 5: The target gNodeB replies to the source gNodeB with a HandoverRequestAcknowledge response, allowing the handover access. If some PDU sessions fail to handover access, the message needs to carry a list of failed protocol data unit (PDU) sessions.

[0082] Step 6: The source gNodeB sends an RRC Reconfiguration message to the UE, requesting the UE to perform a handover to the target cell.

[0083] Step 7: The source gNodeB sends the packet data convergence protocol (PDCP) sequence number (SN) to the target gNodeB via a sequence number status transfer (SN Status Transfer).

[0084] Step 8: The UE sends an RRC Reconfiguration Complete message to the target gNodeB, and the UE's air interface handover to the target cell is completed.

[0085] Step 9: The target gNodeB sends a path switch request message to the AMF to notify the UE that it has changed cells. This message contains the target cell identifier and the list of PDU Sessions to be switched. After receiving the message, the AMF updates the downlink General Packet Radio Service Tunneling Protocol user plane (GTPU) and modifies the GTPU address on the radio access network (RAN) side to the target gNodeB.

[0086] Step 10: The AMF replies to the target gNodeB with a PathSwitchRequestAcknowledge message. If the AMF indicates in the PathSwitchRequestAcknowledge message that it failed to establish a PDU Session, the gNodeB deletes the failed PDU Session.

[0087] Step 11: The target gNodeB sends a UE Context Release message to the source gNodeB, and the source gNodeB releases the user that has been switched over.

[0088] Step 12: After switching to the target cell, the target gNodeB sends a measurement control message to the UE via an RRC Reconfiguration message.

[0089] Step 13: After receiving the RRC Reconfiguration message (measurement control) sent by the target gNodeB, the UE replies to the target gNodeB with an RRC Reconfiguration Complete message.

[0090] In the L3 handover process, the terminal device continuously transmits measurement reports from its own device to the source gNodeB according to the RRC protocol. The source gNodeB evaluates these measurement reports to determine whether a handover is needed, and sends a handover request to the target gNodeB when a handover is required. The source gNodeB evaluates all measurement reports reported by each terminal device sequentially, which is a passive process, resulting in a heavy evaluation burden and a high risk of link failures.

[0091] With the continuous development of 5G / 5G-A technologies and the increasing demands of services, future network deployments will continue to evolve towards higher frequencies. High-frequency cells have smaller coverage areas, leading to more frequent cell selection and reselection handover processes for users. To improve network mobility performance, mobility enhancement has become a hot topic. Related technologies have proposed the LTM mechanism, aiming to shorten handover latency. In LTM scenarios, L1 measurement reporting triggered by events (such as LTM3 / LTM5) is supported. LTM needs to quickly select the target beam or target cell through event evaluation.

[0092] For example, Figure 4 This is a schematic diagram of the LTM switching process provided in an embodiment of this application.

[0093] The terminal device in RRC connection state sends a measurement report to the source gNodeB.

[0094] When the terminal device supports LTM, the source gNodeB sends an LTM cell handover request to at least one candidate gNodeB. At least one candidate gNodeB returns an LTM cell handover request response to the source gNodeB, which includes the candidate gNodeB's configuration information.

[0095] The source gNodeB sends RRC reconfiguration information to the terminal device. This RRC reconfiguration information carries the configuration information of candidate gNodeBs. After receiving the configuration information of at least one candidate gNodeB, the terminal device sends an RRC reconfiguration complete message to the source gNodeB.

[0096] The terminal device performs downlink and uplink synchronization for each candidate gNodeB. During uplink synchronization for each candidate gNodeB, if the RRC reconfiguration information indicates that the terminal device itself should measure the timing advance (TA), then the terminal device can measure the timing advance of the source gNodeB and determine the timing advance of the candidate gNodeB based on the reception time difference between the source gNodeB and the candidate gNodeB; alternatively, the source gNodeB can trigger contention-free random access (CFRA) through the physical downlink control channel (PDCCH) order to obtain the timing advance of the candidate gNodeB. The terminal device then initiates CFRA to the candidate gNodeB to obtain its timing advance, and the source gNodeB determines the validity of the timing advance.

[0097] After downlink and uplink synchronization are completed, the terminal device performs L1 measurements on the source gNodeB and candidate gNodeBs, obtaining L1 measurement results. When the L1 measurement results meet the event conditions, the terminal device reports an L1 measurement report to the source gNodeB. After the terminal device reports the L1 measurement report to the source gNodeB, the source gNodeB can select a target beam or target cell for the terminal device based on the L1 measurement report. The source gNodeB issues an LTM handover command to the terminal device, which instructs the device to hand over to the target cell.

[0098] The terminal device disconnects from the source gNodeB and initiates a random access channel (RACH) to the target gNodeB corresponding to the target cell, thereby completing the LTM cell handover.

[0099] In the LTM handover described above, to avoid excessively frequent event triggering reports, TTT can be applied during LTM event evaluation. After the timer reaches the TTT duration, the terminal device sends a measurement report to the source base station.

[0100] For example, Figure 5 Two TTT-based timing schemes are provided for this application.

[0101] like Figure 5 As shown in (a), the L1 layer directly monitors event conditions (such as LTM3) and sends an L1 event indication to the MAC layer when the event conditions are met. The MAC layer starts a TTT timer based on the indication and generates a measurement report after the timer expires.

[0102] like Figure 5As shown in (b), the L1 layer provides the measurement results of the candidate beam and the service beam to the MAC layer. The MAC layer determines the triggering conditions based on the configured event criteria and starts the TTT timer. During the TTT timer, the MAC layer continuously observes whether the triggering conditions are met. If they are met, a measurement report is generated after the timer expires.

[0103] However, in the aforementioned TTT-based timing schemes, the timer's TTT is typically a fixed value statically configured by the network device, which may lead to inaccurate handover decisions. For example, in high-speed mobile scenarios, a fixed TTT may cause handovers to occur too early or too late, resulting in a ping-pong effect or service interruption.

[0104] In view of this, this application provides a switching method. This method can be applied to the communication system provided in the above embodiments, such as... Figure 1 or Figure 2 The communication system shown is described above. In this method, the terminal device can obtain the mobile speed measured at L1 layer and the neighboring cell load and service quality requirements measured at L3 layer, and report this data to the source base station. The source base station can then dynamically adjust the TTT (Time To Handover) based on this data, improving network adaptability. For example, in high-speed mobile scenarios, shortening the TTT reduces handover latency; in low-load scenarios, extending the TTT reduces signaling overhead and avoids resource waste caused by static configuration. Furthermore, the terminal device can predict future resource needs based on historical data and trigger the target base station to dynamically pre-allocate resources for the terminal device, thereby directly using reserved resources to access the cell, skipping the traditional random access process, reducing negotiation time during handover, lowering handover latency, and achieving seamless handover.

[0105] The following detailed description of the solution provided in the embodiments of this application, in conjunction with the corresponding flowcharts, is provided. It is understood that the illustrative flowcharts provided in the embodiments of this application primarily use different devices (e.g., terminal devices, source base stations, and target base stations) as examples of the execution subjects of the interaction to illustrate the method, but this application does not limit the execution subjects of the interaction. For example, the devices (e.g., terminal devices, source base stations, and target base stations) in the illustrative flowcharts can also be chips, chip systems, or processors that support the implementation of the method by the device, or logic modules or software capable of implementing all or part of the functions of the device.

[0106] As a general statement, the message or signaling interactions involved in the interaction process of this application embodiment can be standard messages or signaling or newly introduced messages or signaling. This application embodiment does not make specific limitations on this.

[0107] Figure 6 This is a flowchart illustrating a switching method based on dynamic TTT according to an embodiment of this application. It can be understood that... Figure 6The term "terminal device" can refer to a terminal device or a device within a terminal device (such as a processor, chip, or chip system). Figure 6 The source base station in the text can be a source base station, such as gNB, TRP, CU, DU, or it can refer to a device in the source base station (such as a processor, chip, or chip system).

[0108] like Figure 6 As shown, the method may include the following steps S101 to S108.

[0109] S101, the terminal device collects L1 layer measurement data and L3 layer measurement data.

[0110] In this embodiment, the terminal device can collect L1 layer measurement data and L3 layer measurement data in real time. L1 layer measurement data may include Doppler frequency shift, which can be used to calculate the terminal device's moving speed. L3 layer measurement data may include neighbor cell load and service quality of service (QoS) requirements. Neighbor cell load, also known as the load of neighboring cells, is used to assess the resource availability of the cell, and service QoS requirements are used to determine handover priority. That is, the terminal device's moving speed is determined through L1 measurement, neighbor cell load is determined through L3 measurement, and service QoS requirements are determined through L3 measurement.

[0111] Terminal equipment can aggregate L1 and L3 measurement data and map them to dynamic identification codes. In some embodiments, the medium access control (MAC) control element (CE) can be extended to include a logical channel ID (LCID) to indicate the "MAC CE indicated by the dynamic handover policy". The new LCID can be selected from the 3GPP standardization reservation range.

[0112] In some embodiments, the dynamic identifier may include a first field, a second field, and a third field.

[0113] The first field can be used to indicate the moving speed of the terminal device.

[0114] The second field can be used to indicate the load of neighboring cells.

[0115] The third field can be used to indicate service QoS requirements.

[0116] The first field represents different movement speeds when set to different encoding values.

[0117] The second field represents different neighbor cell loads when set to different encoding values.

[0118] The third field represents different service quality requirements when set to different encoding values.

[0119] For example, the extended design of MAC CE is shown in Table 1. The first, second, and third fields are consecutive fields within a single byte. The data length of each of the first, second, and third fields is 2 bits. For example, the first field corresponds to bits 0-1, the second field corresponds to bits 2-3, and the third field corresponds to bits 4-5.

[0120] Table 1

[0121]

[0122] The terminal device can classify its moving speed based on the Doppler frequency shift. For example, if the terminal device's moving speed is less than or equal to a first speed threshold, it is classified as low speed, and the encoded value of Bit0-1 is 00; if the terminal device's moving speed is greater than the first speed threshold and less than or equal to a second speed threshold, it is classified as medium speed, and the encoded value of Bit0-1 is 01; if the terminal device's moving speed is greater than the second speed threshold, it is classified as high speed, and the encoded value of Bit0-1 is 10.

[0123] The terminal device can classify the load of neighboring cells. For example, if the load of a neighboring cell is less than or equal to the first load threshold, it is classified as low load, and the encoded value of Bit 2-3 is 00; if the load of a neighboring cell is greater than the first load threshold and less than or equal to the second load threshold, it is classified as medium load, and the encoded value of Bit 2-3 is 01; if the load of a neighboring cell is greater than the second load threshold, it is classified as high load, and the encoded value of Bit 2-3 is 10.

[0124] Terminal devices can classify service QoS requirements. For example, if the service QoS requirement is enhanced mobile broadband (eMBB), the encoded value of Bit 4-5 is 01; if the service QoS requirement is URLLC, the encoded value of Bit 4-5 is 10; and if the service QoS requirement is other services, the encoded value of Bit 4-5 is 00.

[0125] After receiving a MAC CE from the terminal device, the source base station can parse the MAC CE, extract the dynamic identifier code, and map it to a predefined policy library on the source gNB side. The predefined policy library is used by the source gNB side to understand the content sent by the terminal device. For example, in the dynamic identifier code, the encoded value of Bit 0-1 is 10, indicating that the terminal device's speed is high; the encoded value of Bit 2-3 is 00, indicating that the neighboring cell load is low; and the encoded value of Bit 4-5 is 01, indicating that the service QoS requirement is eMBB.

[0126] S102, the terminal device sends a MAC CE to the source base station.

[0127] Accordingly, the source base station receives the MAC CE from the terminal device.

[0128] The aforementioned MAC CE may include a first field indicating the mobile speed of the terminal device, a second field indicating the neighboring cell load, and a third field indicating the service QoS requirements. The first, second, and third fields are used to determine the TTT (Time To Trip).

[0129] S103, the source base station determines the first TTT based on the first field, the second field and the third field.

[0130] The aforementioned first TTT can be used to determine when to send the measurement report.

[0131] After receiving a MAC CE from the terminal device, the source base station can parse the MAC CE and generate a dynamic TTT based on the parsed content. Taking the network device's pre-configured TTT as the second TTT as an example, the source base station can modify the second TTT based on the first, second, and third fields to obtain the first TTT.

[0132] For example, the source base station can calculate the first TTT using the following formula:

[0133] .

[0134] in, This represents the first TTT, i.e., the optimized TTT.

[0135] This represents the second TTT, i.e., the TTT before optimization.

[0136] This is a speed factor, divided according to speed. For example, in high-speed scenarios... Medium-speed scenarios Low-speed scenarios It is understandable that the faster the terminal device, the smaller the value of the speed factor. By shortening the TTT (Time To Handover), latency can be reduced and the handover success rate can be improved.

[0137] This is the load factor. For example, if the neighboring cell has a low load, The neighboring cell load is medium load. The neighboring cell is under high load. It is understandable that the smaller the load in the neighboring cell, the smaller the load factor value. By shortening the TTT (Time To Handover), latency can be reduced and the handover success rate can be improved.

[0138] This is a business priority weight. For example, URLLC services... eMBB service Other businesses, It's understandable that for high-priority tasks, reducing... The value of can reduce latency and improve the success rate of handover.

[0139] S104, the source base station sends an RRC message to the terminal device. The RRC message includes the first TTT.

[0140] Accordingly, the terminal device receives an RRC message from the source base station.

[0141] For example, a TTT-ScalingFactors IE can be added to the RRCReconfiguration message sent from the source base station to the terminal device. The TTT-ScalingFactors IE is embedded in the existing RRC reconfiguration message structure through the Critical Extensions mechanism to ensure backward compatibility. The source base station stores the calculated TTT optimization value data in the TTT-ScalingFactors IE and sends it to the terminal device through an RRCReconfiguration message carrying the newly added TTT-ScalingFactors IE.

[0142] S105, if the measurement result of L1 meets the event condition (also known as the trigger condition) and the timer duration reaches the first TTT, the terminal device sends a measurement report to the source base station.

[0143] Accordingly, the source base station receives measurement reports from the terminal equipment.

[0144] In some embodiments, the above event conditions are pre-configured by the network device or the terminal device.

[0145] For example, event conditions may include at least one of the following:

[0146] Event LTM2: The beam quality of the serving cell is below the absolute threshold;

[0147] Event LTM3: The offset of the candidate cell beam is better than the offset of the serving cell beam;

[0148] Event LTM4: The beam quality of the candidate cell is higher than the absolute threshold;

[0149] Event LTM5: The beam quality of the serving cell is below the first absolute threshold, and the beam quality of the candidate cell is above the second absolute threshold.

[0150] The terminal equipment can perform L1 measurements on the serving beam (i.e., the beam of the source base station) and at least one candidate beam (i.e., the beam of at least one candidate cell) to obtain the L1 measurement results. The L1 measurement can be a measurement of the quality of the reference signal received power (RSRP), the channel state information reference signal (CSI-RS), and / or the synchronization signal block (SSB).

[0151] In one possible implementation, such as Figure 5 As shown in (a), after obtaining the L1 measurement results (such as RS-1, RS-2, RS-3...RS-k), the L1 layer of the terminal device directly monitors the event conditions and sends an L1 event indication to the MAC layer of the terminal device when the event conditions are met, such as the L1 event indication for RS-x. Based on the L1 event indication, the MAC layer starts a timer and generates a measurement report after the timer's duration reaches the first TTT. This measurement report can be used to trigger cell handover.

[0152] In one possible implementation, such as Figure 5 As shown in (b), after obtaining the L1 measurement results (such as RS-1, RS-2, RS-3...RS-k), the L1 layer of the terminal device provides the L1 measurement results to the MAC layer. The MAC layer determines whether the L1 measurement results meet the pre-configured event conditions and starts a timer. During the timer period, the MAC layer continuously observes whether the event conditions are met. If they are met, a measurement report is generated after the timer's duration reaches the first TTT. This measurement report can be used to trigger cell handover.

[0153] S106, the source base station selects a target cell for the terminal device based on the measurement report.

[0154] If the beam measurement results of one or more candidate cells in at least one candidate cell meet the event conditions, then the measurement report sent by the terminal device to the source base station carries the one or more candidate cells, so that the source base station can use one of the one or more candidate cells as the target cell.

[0155] S107, the source base station sends a cell handover command to the terminal device, which is used to instruct the user to hand over to the target cell.

[0156] Accordingly, the terminal device receives the cell handover command from the source base station.

[0157] In some embodiments, the cell handover instruction may be a MAC CE. The MAC CE may contain the following information: timing advance (TA), transmission configuration indication state (TCI State) sequence number, CFRA resource information, and configuration information identifier of the target cell.

[0158] S108, the terminal device responds to the cell handover command and performs cell handover.

[0159] In response to a cell handover command, the terminal device can disconnect from the source cell and connect to the target cell.

[0160] To address the issue that LTM primarily relies on L1 layer measurement data, and TTT parameters are statically configured by network devices, lacking dynamic response capabilities to L3 layer measurement data, leading to inaccurate handover decisions, this application proposes the aforementioned handover method based on dynamic TTT. In this method, based on the LTM event triggering mechanism, the terminal device acquires L1 layer measurement data in real time, combines it with L3 layer measurement data to generate multi-dimensional decision input, and maps it to a dynamic identifier code. The source base station's MAC layer parses the received MAC CE, extracts the dynamic identifier, calculates the dynamic TTT optimization value, and sends the optimized TTT value via RRC signaling. This improves network adaptability, reduces handover latency in high-speed scenarios, lowers the risk of service interruption in low-speed scenarios, and enhances reliability. Furthermore, under low load conditions, extending the TTT can reduce signaling overhead and avoid resource waste caused by static configuration.

[0161] Traditional channel state information (CSI) measurement and handover decision-making mechanisms may be outdated. For example, when terminal devices are moving at high speeds (e.g., speeds ≥120 km / h), L1 layer measurement data may be invalid by the time it is reported to the MAC layer, leading to inaccurate allocation of the precoding matrix indicator (PMI) and resource blocks (RBs). This results in delayed handover decisions and redundant resource reservations. Frequent handovers require the target cell to perform resource reservations and releases multiple times, increasing control plane signaling overhead and resource fragmentation. To address this issue, this application also proposes... Figure 7 The handover method based on channel prediction is shown.

[0162] Understandable. Figure 7The term "terminal device" can refer to a terminal device or a device within a terminal device (such as a processor, chip, or chip system). Figure 7 The source base station in the text can be a source base station, such as gNB, TRP, CU, DU, or it can refer to a device in the source base station (such as a processor, chip, or chip system). Figure 7 The candidate base station can refer to a candidate base station or a device (such as a processor, chip, or chip system) in a candidate base station.

[0163] like Figure 7 As shown, the method may include the following steps S201 to S208.

[0164] S201, the terminal device predicts the future channel state based on historical data.

[0165] The aforementioned prediction of future channel conditions can be interpreted as a prediction of the number of resource blocks that need to be allocated to terminal devices in the future.

[0166] In some embodiments, the MAC CE can be extended by adding an LCID to indicate "the number of resource blocks that are predicted to be allocated to the terminal device in the future". The added LCID can be selected from the 3GPP standardization reservation range.

[0167] In some embodiments, the MAC CE described above may include a fourth field, a fifth field, and a sixth field.

[0168] The fourth field can be used to indicate the cell radionetwork temporary identifier (C-RNTI) of the cell where the terminal device is located. The C-RNTI is used for resource binding of the target cell.

[0169] The fifth field can be used to indicate the predicted number of resource blocks allocated to the terminal device.

[0170] The sixth field can be used to indicate the status of a hybrid automatic repeat request (HARQ), which is used to enable fast retransmission. For example, the HARQ status can be either an acknowledgment (ACK) or a negative acknowledgment (NACK).

[0171] For example, the extended design of MAC CE is shown in Table 2. MAC CE includes a fourth field, a fifth field, and a sixth field. The fourth, fifth, and sixth fields are consecutive fields. The data length of the fourth field is 2 bytes, the data length of the fifth field is 1 byte, and the data length of the sixth field is 2 bits.

[0172] Table 2

[0173]

[0174] S202, the terminal device sends a MAC CE to the source base station.

[0175] The aforementioned MAC CE may include a fourth field for indicating the C-RNTI of the cell where the terminal device is located, a fifth field for indicating the number of resource blocks predicted to be allocated to the terminal device, and a sixth field for indicating the HARQ status.

[0176] Accordingly, the source base station receives the MAC CE from the terminal device.

[0177] S203, the source base station parses the MAC CE and triggers a policy decision.

[0178] After the source base station receives the MAC CE from the terminal device, it can parse the MAC CE to obtain the C-RNTI of the cell where the terminal device is located, the predicted number of resource blocks to be allocated to the terminal device, and the HARQ status.

[0179] If the HARQ status is ACK, it means the data is correct and transmission is allowed to continue. The source base station executes the following S204.

[0180] If the HARQ status is NACK, it indicates that the data is incorrect. The source base station sends an instruction to the terminal device, which instructs the terminal device to retransmit the MAC CE carrying the fourth, fifth, and sixth fields, i.e., to re-execute S202.

[0181] S204, the source base station sends a request message to at least one candidate base station.

[0182] Accordingly, at least one candidate base station receives a request message from the source base station.

[0183] The aforementioned request message may include the C-RNTI of the cell where the terminal device is located, the predicted number of resource blocks to be allocated to the terminal device, and the HARQ status. This request message can be used to request the pre-allocation of resources for the terminal device.

[0184] In some embodiments, the source base station can send a request message through the newly added Xn interface ResourcePreAllocationRequest, which includes the C-RNTI of the cell where the terminal device is located, the number of resource blocks predicted to be allocated to the terminal device, and the HARQ status.

[0185] S205, at least one candidate base station triggers resource block reservation and HARQ buffer synchronization.

[0186] The number of resource blocks reserved by at least one candidate base station is determined based on the number of resource blocks predicted to be allocated to the terminal device in the request message. For example, the number of reserved resource blocks is equal to the number of resource blocks predicted to be allocated to the terminal device.

[0187] S206, at least one candidate base station sends a response message to the source base station.

[0188] Accordingly, the source base station receives a response message from at least one candidate base station.

[0189] The response message may include pre-configuration information for at least one candidate cell corresponding to at least one candidate base station. This pre-configuration information can be used to indicate the resources allocated to the terminal device. For example, the pre-configuration information may include: the coding frequency of the CSI-RS, the coding period of the CSI-RS, the port number of the CSI-RS, and the SSB index. The coding frequency of the CSI-RS is used to indicate the frequency domain location of the candidate base station CSI-RS.

[0190] In some embodiments, the source base station can return a response message through the newly added Xn interface ResourcePreAllocationRequest, which contains pre-configuration information of at least one candidate cell corresponding to at least one candidate base station.

[0191] S207, the source base station sends an RRC message to the terminal device.

[0192] Accordingly, the terminal device receives an RRC reconfiguration message from the source base station.

[0193] The aforementioned RRC message may include pre-configuration information for at least one candidate cell.

[0194] In some embodiments, a new targetCell-CSI-RS-Config field is added to the RRC reconfiguration message RRCReconfiguration. The targetCell-CSI-RS-Config field contains pre-configuration information, such as the encoding frequency of CSI-RS, the encoding period of CSI-RS, the port number of CSI-RS, and the SSB index.

[0195] S208, the terminal device uses the pre-configured information of the target cell to access the target cell.

[0196] The target cell is one of at least one candidate cell, and the pre-configuration information of the at least one candidate cell includes the pre-configuration information of the target cell.

[0197] With Figure 4 The difference in the LTM handover process shown is that in S208, the terminal device can directly use the pre-configured information of the target cell to access the target cell, skipping the traditional random access process and achieving seamless handover.

[0198] To address the issue in LTM where L1 layer measurement data becomes invalid by the time it is reported to the MAC layer, leading to inaccurate PMI and resource block allocation, resulting in delayed handover decisions and resource reservation redundancy, this application proposes the aforementioned channel prediction-based handover method. In this method, the terminal device and the target base station cannot communicate directly; resource allocation can be coordinated through the source base station. On one hand, the terminal device can predict future resource needs based on historical data and, by carrying the C-RNTI of the cell where the terminal device resides, the predicted number of resource blocks allocated to the terminal device, and the HARQ status in the MAC CE, facilitates dynamic pre-allocation of resources by the target cell for the terminal device. On the other hand, the candidate base station can return pre-configuration information to the terminal device through the source base station, allowing the terminal device to directly access the cell using reserved resources, skipping the traditional random access process, reducing negotiation time during handover, lowering handover latency, and achieving seamless handover. The rapid feedback of signal quality from L1 layer measurement data and the pre-allocation of resources by the MAC layer enhance real-time performance. Combined with advance prediction, redundant resource occupation and transmission signaling overhead are reduced.

[0199] The above embodiments are respectively combined with Figure 6 This paper introduces a switching method based on dynamic TTT, combined with Figure 7 This paper introduces a handover method based on channel prediction. Both of these methods are solutions to problems existing in LTM (Low-Temperature Mechanism) and share the following common features: 1. An extended design of the MAC CE (Machine-Assisted Message) is implemented, and the MAC CE is sent to the source base station; 2. The source base station sends an RRC (Redirect Rate Message) to the terminal device. Based on this, this application also proposes a handover method combining these two methods.

[0200] like Figure 8 As shown, the method may include the following steps S301 to S312.

[0201] S301, the terminal device collects L1 layer measurement data and L3 layer measurement data, and predicts the future channel state based on historical data.

[0202] The aforementioned "L1 layer measurement data" may include Doppler frequency shift, which can be used to calculate the moving speed of the terminal device; "L3 layer measurement data" may include neighbor cell load and service QoS requirements; "predicting future channel state" may be predicting the number of resource blocks that need to be allocated to the terminal device in the future.

[0203] In some embodiments, the MAC CE can be extended by adding an LCID to indicate the MAC CE. The MAC CE may include a first field, a second field, a third field, a fourth field, a fifth field, and a sixth field.

[0204] The first field can be used to indicate the moving speed of the terminal device.

[0205] The second field can be used to indicate the load of neighboring cells.

[0206] The third field can be used to indicate service QoS requirements.

[0207] The fourth field can be used to indicate the C-RNTI of the cell where the terminal device is located.

[0208] The fifth field can be used to indicate the predicted number of resource blocks allocated to the terminal device.

[0209] The sixth field can be used to indicate the HARQ status.

[0210] For example, the extended design of MAC CE is shown in Table 3. MAC CE consists of two parts: a dynamic identifier for calculating TTT and resource pre-allocation. The dynamic identifier can be 1 byte and includes at least a first field, a second field, and a third field, each with a data length of 2 bits. Resource pre-allocation may include a fourth field, a fifth field, and a sixth field, where the fourth field has a data length of 2 bytes, the fifth field has a data length of 1 byte, and the sixth field has a data length of 2 bits.

[0211] Table 3

[0212]

[0213] For the specific implementation of S301, please refer to the description of S101 and S201 in the above embodiments, which will not be repeated here.

[0214] S302, the terminal device sends a MAC CE to the source base station.

[0215] Accordingly, the source base station receives the MAC CE from the terminal device.

[0216] The aforementioned MAC CE may include: a first field indicating the moving speed of the terminal device, a second field indicating the neighboring cell load, a third field indicating the service QoS requirements, a fourth field indicating the C-RNTI of the cell where the terminal device is located, a fifth field indicating the predicted number of resource blocks allocated to the terminal device, and a sixth field indicating the HARQ status. It can be understood that by combining the transmission of dynamic identifiers and resource pre-allocation through a single MAC CE, air interface signaling overhead can be reduced, and additional latency introduced by multiple signaling interactions can be avoided.

[0217] It should be noted that the above embodiments are illustrated using the example of sending dynamic identifiers and resource pre-allocation via MAC CE. Compared to L3, MAC CE is closer to the physical layer, offering higher real-time performance and reducing signaling overhead. In other embodiments, dynamic identifiers and resource pre-allocation can also be sent via L3 RRC signaling.

[0218] S303, the source base station parses the MAC CE, determines the first TTT based on the parsing result, and triggers a policy decision.

[0219] On the one hand, the source base station can calculate the first TTT based on the parsing results of the first field, the second field, and the third field. Refer to the description of S103 in the above embodiment; it will not be repeated here.

[0220] On the other hand, the source base station can trigger a policy decision based on the parsing results of the fourth, fifth, and sixth fields. Refer to the description of S203 in the above embodiments; it will not be repeated here.

[0221] S304, the source base station sends a request message to at least one candidate base station.

[0222] Accordingly, at least one candidate base station receives a request message from the source base station.

[0223] The aforementioned request message may include the C-RNTI of the cell where the terminal device is located, the predicted number of resource blocks to be allocated to the terminal device, and the HARQ status. This request message can be used to request the pre-allocation of resources for the terminal device.

[0224] S305, at least one candidate base station triggers resource block reservation and HARQ buffer synchronization.

[0225] S306, at least one candidate base station sends a response message to the source base station.

[0226] Accordingly, the source base station receives a response message from at least one candidate base station.

[0227] The response message may include pre-configuration information for at least one candidate cell corresponding to at least one candidate base station. This pre-configuration information can be used to indicate the resources allocated to the terminal device. For example, the pre-configuration information may include: the coding frequency of the CSI-RS, the coding period of the CSI-RS, the port number of the CSI-RS, and the SSB index. The coding frequency of the CSI-RS is used to indicate the frequency domain location of the candidate base station CSI-RS.

[0228] For the specific implementation of S304 to S306, please refer to the description of S204 to S206 in the above embodiments, which will not be repeated here.

[0229] S307, the source base station sends an RRC reconfiguration message to the terminal device.

[0230] Accordingly, the terminal device receives an RRC reconfiguration message from the source base station.

[0231] The aforementioned RRC reconfiguration message may include the first TTT obtained through S303, and the pre-configuration information of at least one candidate cell obtained through S303 to S306. It can be understood that by combining the first TTT and the pre-configuration information of at least one candidate cell into a single RRC reconfiguration message, air interface signaling overhead can be reduced, and additional latency introduced by multiple signaling interactions can be avoided.

[0232] For the specific implementation of S307, please refer to the description of S104 and S207 in the above embodiments, which will not be repeated here.

[0233] S308, the terminal device sends an RRC reconfiguration complete message to the source base station.

[0234] Accordingly, the source base station receives the RRC reconfiguration complete message from the terminal device.

[0235] The aforementioned RRC reconfiguration complete message is used to indicate that the RRC reconfiguration is complete.

[0236] S309, if the measurement result of L1 meets the event condition and the timer duration reaches the first TTT, the terminal device sends a measurement report to the source base station.

[0237] Accordingly, the source base station receives measurement reports from the terminal equipment.

[0238] For the specific implementation of S309, please refer to the description of S105 in the above embodiments, which will not be repeated here.

[0239] S310, the source base station selects the target cell for the terminal device based on the measurement report.

[0240] If the beam measurement results of one or more candidate cells in at least one candidate cell meet the event conditions, then the measurement report sent by the terminal device to the source base station carries the one or more candidate cells, so that the source base station can use one of the one or more candidate cells as the target cell.

[0241] For the specific implementation of S310, please refer to the description of S106 in the above embodiments, which will not be repeated here.

[0242] S311, the source base station sends a cell handover command to the terminal device, which is used to instruct the user to hand over to the target cell.

[0243] Accordingly, the terminal device receives the cell handover command from the source base station.

[0244] For the specific implementation of S311, please refer to the description of S107 in the above embodiments, which will not be repeated here.

[0245] S312, the terminal device uses the pre-configured information of the target cell to access the target cell.

[0246] The target cell is one of at least one candidate cell, and the pre-configuration information of the at least one candidate cell includes the pre-configuration information of the target cell.

[0247] In the method provided in this application, the terminal device and the target base station cannot communicate directly; resource allocation can be coordinated through the source base station. On one hand, by carrying the C-RNTI of the cell where the terminal device resides, the predicted number of resource blocks allocated to the terminal device, and the HARQ status in the MAC CE, the target cell can reserve resources for the terminal device in advance. On the other hand, the candidate base station can return pre-configuration information to the terminal device through the source base station, enabling the terminal device to directly use the reserved resources to access the cell, skipping the traditional random access process, achieving seamless handover, and improving the access success rate.

[0248] It should be understood that Figures 1 to 8 The flowcharts or scene diagrams shown are for illustrative purposes only and are not intended to limit the embodiments of this application to the examples illustrated. In fact, those skilled in the art can interpret the embodiments based on... Figures 1 to 8 The examples in the document can be transformed into equivalent ways to obtain more implementations.

[0249] The above text combined Figures 1 to 8 This document describes in detail the switching method provided in the embodiments of this application. The following will combine... Figures 9 to 10 The device embodiments of this application are described in detail below. It should be understood that the communication device of this application embodiment can execute the various switching methods of the foregoing embodiments of this application, that is, the specific working processes of the various products below can be referred to the corresponding processes in the foregoing method embodiments.

[0250] In the embodiments described above, the terminal device may execute some or all of the steps in each embodiment; the base station may execute some or all of the steps in each embodiment. These steps or operations are merely examples, and the embodiments of this application may also perform other operations or variations thereof. Furthermore, the steps may be executed in different orders as presented in the embodiments, and it is not necessary to execute all the operations in the embodiments of this application. Moreover, the sequence number of each step does not imply the order of execution; the execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of this application.

[0251] Figure 9 This is a schematic block diagram of the electronic device provided in the embodiments of this application. Figure 9 As shown, the electronic device 900 may include a transceiver module 910. The transceiver module 910 can implement corresponding communication functions, which can be internal communication functions of the electronic device 900 or communication functions between the electronic device 900 and other devices. Optionally, the transceiver module 910 may also be referred to as a communication interface or transceiver module. Optionally, the electronic device 900 also includes a processing module 920. The processing module 920 can implement corresponding processing functions.

[0252] Optionally, the electronic device 900 further includes a storage module, which can be used to store instructions and / or data; the processing module 920 can read the instructions and / or data in the storage module so that the electronic device 900 can implement the aforementioned method embodiments.

[0253] In one possible implementation, the electronic device 900 may correspond to the terminal device in the above method embodiments, or to a component (such as a circuit, chip, or chip system) configured in the terminal device. The electronic device 900 can be used to perform the steps or processes performed by the terminal device in any of the above method embodiments.

[0254] For example, the transceiver module 910 can be used to: send a MAC CE to the source base station, the MAC CE including a first field indicating the moving speed of the terminal device, a second field indicating the neighboring cell load and a third field indicating the service quality requirement, the first field, the second field and the third field being used to determine the TTT; receive a first TTT from the source base station; and, after the L1 measurement result meets the event condition and the timer duration reaches the first TTT, send a measurement report to the source base station, the measurement report being used to trigger cell handover through event evaluation.

[0255] The above are merely examples; for detailed steps or procedures, please refer to the descriptions in the foregoing embodiments.

[0256] In another possible implementation, the electronic device 900 may correspond to the source base station in the above method embodiments, or to a component (such as a circuit, chip, or chip system) configured in the source base station. The electronic device 900 can be used to perform the steps or processes performed by the source base station in any of the above method embodiments.

[0257] For example, transceiver module 910 can be configured to: receive a MAC CE from a terminal device, the MAC CE including a first field indicating the mobile speed of the terminal device, a second field indicating the neighboring cell load, and a third field indicating the service quality demand. Processing module 920 can be configured to: determine a first TTT based on the first, second, and third fields. Transceiver module 910 can also be configured to: send the first TTT to the terminal device, the first TTT being used to determine the timing of sending a measurement report, and receive a measurement report from the terminal device. Processing module 920 can also be configured to: perform event assessment based on the measurement report and select a target cell for the terminal device.

[0258] In another possible implementation, the electronic device 900 may correspond to the candidate base station in the above method embodiments, or to a component (such as a circuit, chip, or chip system) configured in the candidate base station. The electronic device 900 may be used to perform the steps or processes performed by the candidate base station in any of the above method embodiments.

[0259] For example, the transceiver module 910 can be configured to: receive a request message from a source base station, the request message including the C-RNTI of the cell where the terminal device is located, the predicted number of resource blocks allocated to the terminal device, and the HARQ status; and send a response message to the source base station, the response message including pre-configuration information of the candidate cell corresponding to the target base station. For example, the pre-configuration information may include: the coding frequency of CSI-RS, the coding period of CSI-RS, the port number of CSI-RS, and the synchronization signal block index.

[0260] The above are merely examples; for detailed steps or procedures, please refer to the descriptions in the foregoing embodiments.

[0261] Figure 10 This is a schematic block diagram of a communication device 1000 provided in an embodiment of this application. The communication device 1000 may be a terminal device, a source base station, or a candidate base station implementing the above-described methods, including chips, chip systems, or processors. The communication device 1000 can be used to implement the methods described in the above-described method embodiments; for details, please refer to the descriptions in the above-described method embodiments.

[0262] like Figure 10As shown, the communication device 1000 may include one or more processors 1010, which may also be referred to as processing units or processing modules, and can implement certain control functions. The processor 1010 may be a general-purpose processor or a dedicated processor, such as a baseband processor or a central processing unit. The baseband processor can be used to process communication protocols and communication data, while the central processing unit can be used to control the communication device 1000 (e.g., a base station, baseband chip, user, user chip), execute software programs, and process data from the software programs.

[0263] In one possible implementation, the processor 1010 may also store instructions and / or data, which can be executed by the processor 1010 to cause the communication device 1000 to perform the method described in the above method embodiments.

[0264] In another possible implementation, the communication device 1000 may include a communication interface 1020 for implementing receiving and transmitting functions. For example, the communication interface 1020 may be a transceiver circuit, interface, interface circuit, or transceiver. The transceiver circuit, interface, interface circuit, or transceiver for implementing receiving and transmitting functions may be separate or integrated. The aforementioned transceiver circuit, interface, interface circuit, or transceiver may be used for reading and writing code / data, or it may be used for transmitting or relaying signals.

[0265] Optionally, the communication device 1000 may include one or more memories 1030, which may store instructions that can be executed on the processor 1010, causing the communication device 1000 to perform the methods described in the above method embodiments. Optionally, the memories 1030 may also store data. Optionally, the processor 1010 may also store instructions and / or data. The processor 1010 and the memories 1030 may be provided separately or integrated together.

[0266] It should be understood that, in one possible implementation, the steps in the method embodiments provided in this application can be completed by integrated logic circuits in the processor hardware or by instructions in software form. The steps of the method disclosed in the embodiments of this application can be directly implemented by a hardware processor, or by a combination of hardware and software modules in the processor. The software modules can reside in random access memory, flash memory, read-only memory, programmable read-only memory, electrically erasable programmable memory, registers, or other mature storage media in the art. This storage medium is located in memory, and the processor reads information from the memory and, in conjunction with its hardware, completes the steps of the above method. To avoid repetition, detailed descriptions are not provided here.

[0267] In one implementation, the communication device 1000 may correspond to the terminal device in the above method embodiments and may be used to execute the various steps and / or processes executed by the terminal device in the above method embodiments. The processor 1010 may be used to execute instructions stored in the memory 1030, and when the processor 1010 executes the instructions stored in the memory, the processor 1010 is used to execute the various steps and / or processes of the above method embodiments corresponding to the terminal device.

[0268] In another implementation, the communication device 1000 may correspond to the source base station in the above method embodiments and may be used to execute the various steps and / or processes executed by the source base station in the above method embodiments. The processor 1010 may be used to execute instructions stored in the memory 1030, and when the processor 1010 executes the instructions stored in the memory, the processor 1010 is used to execute the various steps and / or processes of the above method embodiments corresponding to the source base station.

[0269] In another implementation, the communication device 1000 may correspond to the candidate base station in the above method embodiments and may be used to execute the various steps and / or processes executed by the candidate base station in the above method embodiments. The processor 1010 may be used to execute the instructions stored in the memory 1030, and when the processor 1010 executes the instructions stored in the memory, the processor 1010 is used to execute the various steps and / or processes of the above method embodiments corresponding to the candidate base station.

[0270] It should be understood that the aforementioned processing device can be one or more chips. For example, the processing device can be a field-programmable gate array (FPGA), an application-specific integrated circuit (ASIC), a system-on-chip (SoC), a central processor unit (CPU), a network processor (NP), a digital signal processor (DSP), a microcontroller unit (MCU), a programmable logic device (PLD), or other integrated chips.

[0271] It is understood that the memory in the embodiments of this application can be volatile memory or non-volatile memory, or may include both volatile and non-volatile memory. The non-volatile memory can be read-only memory (ROM), programmable read-only memory (PROM), erasable programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), or flash memory. The volatile memory can be random access memory (RAM), which is used as an external cache. By way of example, but not limitation, many forms of RAM are available, such as static random access memory (SRAM), dynamic random access memory (DRAM), synchronous dynamic random access memory (SDRAM), double data rate synchronous dynamic random access memory (DDR SDRAM), enhanced synchronous dynamic random access memory (ESDRAM), synchronous linked dynamic random access memory (SLDRAM), and direct rambus RAM (DR RAM). It should be noted that the memory used in the systems and methods described herein is intended to include, but is not limited to, these and any other suitable types of memory.

[0272] According to the method provided in the embodiments of this application, this application also provides a chip system, which includes one or more processors for calling and executing instructions stored in memory, causing the method described in the embodiments of this application to be executed. The chip system may be composed of chips or may include chips and other discrete devices. The chip system may include input circuitry or interfaces for transmitting information or data, and output circuitry or interfaces for receiving information or data.

[0273] According to the method provided in the embodiments of this application, this application also provides a communication system, which includes the aforementioned terminal device, source base station, and at least one candidate base station. The at least one candidate base station includes a target base station to which the terminal device needs to access.

[0274] According to the method provided in the embodiments of this application, this application also provides a computer program product, which includes: computer program code, which, when run on a computer, causes the computer to execute the various steps or processes performed by the terminal device, the source base station and at least one candidate base station in any of the foregoing method embodiments.

[0275] According to the method provided in the embodiments of this application, this application also provides a computer-readable storage medium storing program code. When the program code is run on a computer, it causes the computer to execute the various steps or processes performed by the terminal device, source base station, and at least one candidate base station in any of the foregoing method embodiments. The computer-readable storage medium may be the aforementioned volatile memory or non-volatile memory, or it may include both volatile memory and non-volatile memory.

[0276] In the embodiments of this application, the terms and English abbreviations are exemplary examples given for ease of description and should not be construed as limiting the application in any way. This application does not preclude the possibility of defining other terms that can achieve the same or similar functions in existing or future agreements.

[0277] In the above embodiments, implementation can be achieved, in whole or in part, through software, hardware, firmware, or any combination thereof. When implemented in software, it can be implemented, in whole or in part, as a computer program product. A computer program product includes one or more computer instructions. When the computer instructions are loaded and executed on a computer, all or part of the flow or function according to the embodiments of this application is generated.

[0278] In the several embodiments provided in this application, it should be understood that the disclosed systems, apparatuses, and methods can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative; for instance, the division of units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be through some interfaces; the indirect coupling or communication connection between apparatuses or units may be electrical, mechanical, or other forms.

[0279] It should be understood that in the various embodiments of this application, the sequence number of each process does not imply the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of this application.

[0280] In summary, the above are merely preferred embodiments of the technical solutions of this application and are not intended to limit the scope of protection of this application. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the scope of protection of this application.

Claims

1. A TTT-based handover method, characterized in that, The method is applied to a terminal device, and the method includes: A Media Access Control (MAC) CE is sent to the source base station. The MAC CE includes a first field indicating the moving speed of the terminal device, a second field indicating the neighboring cell load, a third field indicating the service quality requirement, a fourth field indicating the Cell Radio Network Temporary Identifier (C-RNTI) of the cell where the terminal device is located, and a fifth field predicting the number of resource blocks to be allocated to the terminal device. The first, second, and third fields are used to determine the Time To Trial (TTT), and the fourth and fifth fields are used to allocate resources to the terminal device. Receive a first TTT and pre-configuration information of at least one candidate cell from the source base station, the pre-configuration information being used to indicate the resources allocated to the terminal device; If the measurement result of Layer 1 meets the event conditions and the timer duration reaches the first TTT, a measurement report is sent to the source base station. The measurement report is used to trigger cell handover.

2. The method according to claim 1, characterized in that, The moving speed of the terminal device is determined by layer 1 measurement; The neighboring cell load is determined by layer 3 measurement; The service quality requirements are determined through Layer 3 measurement.

3. The method according to claim 1, characterized in that, The first field, when set to different encoded values, represents different movement speeds; The second field represents different neighbor cell loads when set to different encoding values; The third field, when set to different encoded values, represents different service quality requirements.

4. The method according to claim 1, characterized in that, The first field, the second field, and the third field are consecutive fields, and the data length of the first field, the second field, and the third field is 2 bits.

5. The method according to any one of claims 1 to 4, characterized in that, The MAC CE also includes: The sixth field indicates the Hybrid Automatic Repeat Request (HARQ) status.

6. The method according to claim 5, characterized in that, The fourth, fifth, and sixth fields are consecutive fields. The fourth field has a data length of 2 bytes, the fifth field has a data length of 1 byte, and the sixth field has a data length of 2 bits.

7. The method according to claim 5, characterized in that, The method further includes: Based on the historical data of the terminal device, the number of resource blocks to be allocated to the terminal device is predicted.

8. The method according to claim 5, characterized in that, The receiving of the first TTT and at least one candidate cell pre-configuration information from the source base station includes: Receive a Radio Resource Control (RRC) message from the source base station, the RRC message including the first TTT and the pre-configuration information of the at least one candidate cell.

9. The method according to claim 8, characterized in that, The pre-configuration information includes: the coding frequency of the Channel State Information Reference Signal (CSI-RS), the coding period of the CSI-RS, the port number of the CSI-RS, and the index of the synchronization signal block.

10. The method according to claim 8, characterized in that, The pre-configuration information of the at least one candidate cell includes the pre-configuration information of the target cell; After sending the measurement report to the source base station, the method further includes: Receive cell handover instructions from the source base station; In response to the cell handover command, the system accesses the target cell using the pre-configured information of the target cell.

11. A TTT-based handover method, characterized in that, The method is applied to a source base station, and the method includes: Receive a MAC CE from a terminal device, the MAC CE including a first field indicating the moving speed of the terminal device, a second field indicating the neighboring cell load, a third field indicating the service quality requirements, a fourth field indicating the C-RNTI of the cell where the terminal device is located, and a fifth field predicting the number of resource blocks to be allocated to the terminal device; Based on the first field, the second field, and the third field, determine the first TTT; Send a request message to at least one candidate base station, the request message including the C-RNTI of the cell where the terminal device is located and the predicted number of resource blocks to be allocated to the terminal device; The terminal device receives a response message from the at least one candidate base station, the response message including pre-configuration information of at least one candidate cell corresponding to the at least one candidate base station, the pre-configuration information being used to indicate the resources allocated to the terminal device; Send the first TTT and the pre-configuration information of the at least one candidate cell to the terminal device, wherein the first TTT is used to determine the timing of sending the measurement report; Receive the measurement report from the terminal device; The target cell is selected for the terminal device based on the measurement report.

12. The method according to claim 11, characterized in that, Determining the first TTT based on the first field, the second field, and the third field includes: Based on the first field, the second field, and the third field, the second TTT is modified to obtain the first TTT, and the second TTT is a pre-configured fixed value.

13. The method according to claim 11, characterized in that, The first field, when set to different encoded values, represents different movement speeds; The second field represents different neighbor cell loads when set to different encoding values; The third field, when set to different encoded values, represents different service quality requirements.

14. The method according to claim 11, characterized in that, The first field, the second field, and the third field are consecutive fields, and the data length of the first field, the second field, and the third field is 2 bits.

15. The method according to claim 11, characterized in that, The MAC CE also includes: The sixth field indicates the HARQ status.

16. The method according to claim 15, characterized in that, The fourth, fifth, and sixth fields are consecutive fields. The fourth field has a data length of 2 bytes, the fifth field has a data length of 1 byte, and the sixth field has a data length of 2 bits.

17. The method according to claim 15, characterized in that, The request message also includes a HARQ status.

18. The method according to claim 17, characterized in that, The pre-configuration information includes: the encoding frequency of CSI-RS, the encoding period of CSI-RS, the port number of CSI-RS, and the synchronization signal block index.

19. The method according to claim 17, characterized in that, Sending the first TTT and the pre-configuration information of the at least one candidate cell to the terminal device includes: An RRC message is sent to the terminal device. The RRC message includes the first TTT and the pre-configuration information of the at least one candidate cell. The pre-configuration information of the at least one candidate cell includes the pre-configuration information of the target cell to be accessed.

20. The method according to any one of claims 11 to 19, characterized in that, After selecting a target cell for the terminal device, the method further includes: A cell handover command is sent to the terminal device, the cell handover command being used to instruct the user to hand over to the target cell.

21. A communication device ， The device is characterized in that it includes at least one processor coupled to a memory storing a program or instructions, wherein the processor executes the program or instructions to cause the device to perform the method as claimed in any one of claims 1 to 10, or to perform the method as claimed in any one of claims 11 to 20.

22. A communication system, characterized in that, The communication system includes a terminal device, a source base station, and at least one candidate base station; wherein the terminal device is used to perform the method as described in any one of claims 1 to 10, and the source base station is used to perform the method as described in any one of claims 11 to 20.

23. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores a computer program or instructions that, when executed, cause a computer to perform the method as described in any one of claims 1 to 10, or the method as described in any one of claims 11 to 20.

Images