Cell switching method and related equipment

Abstract

The present application discloses a cell switching method and related equipment. The method includes: during a call, while residing in a first cell, if it is detected that the signal strength of the first cell is lower than a first threshold and the signal strength of a second cell is higher than a second threshold, sending a first measurement report to a network device; after receiving a first switching instruction from the network device to instruct switching to the second cell, accessing the second cell; if access to the second cell fails, residing in the first cell; while residing in the first cell, if it is detected that the signal strength of a third cell meets a measurement condition, sending a second measurement report to the network device; after receiving a second switching instruction from the network device to instruct switching to the third cell, accessing the third cell. This method can be used to reduce the probability of call anomalies during a call on a terminal device.

Description

Technical Field

[0001] The present application relates to the field of communications, and in particular to a cell switching method and related equipment. Background Art

[0002] Typically, during a terminal device call, when the terminal device detects that the signal strength of the cell it is currently stationed in (NR cell A) is low, the terminal device will report to the network side other nearby cells with high signal strength / signal quality (LTE cell B). After receiving the terminal device's report on cell B, the network side instructs the terminal device to switch to cell B. If the terminal device fails to access cell B, the terminal device will select a new cell (NR cell C) based on the cell selection strategy (preferring cells with high NR signal strength).

[0003] Because cell C is selected by the terminal device, there may be anomalies in the interaction between cell C and the core network. If this occurs, the terminal device will not be able to receive downlink voice packets, causing RTP / RTCP timeouts on the terminal side and the call to be terminated. This is currently the leading cause of dropped calls. Summary of the Invention

[0004] The present application provides a cell switching method and related equipment, which can reduce the probability of call abnormalities during a call on a terminal device.

[0005] In a first aspect, some embodiments of the present application provide a cell switching method. The cell switching method may include: during a call, while residing in a first cell, if it is detected that the signal strength of the first cell is lower than a first threshold and the signal strength of the second cell is higher than a second threshold, sending a first measurement report to a network device, the first measurement report indicating that the signal strength of the first cell is lower than the first threshold and the signal strength of the second cell is higher than the second threshold; after receiving a first switching instruction sent by the network device to instruct switching to the second cell, accessing the second cell; if accessing the second cell fails, residing in the first cell; while residing in the first cell, if it is detected that the signal strength of the third cell meets the measurement condition, sending a second measurement report to the network device; after receiving a second switching instruction sent by the network device to instruct switching to the third cell, accessing the third cell.

[0006] Through the above method, after failing to access the second cell, the terminal device returns to the first cell where it originally resides. Since the first cell where it originally resides can interact with the core network, the terminal device can report to the first cell to avoid the terminal device selecting a cell that interacts abnormally with the core network, thereby reducing the probability of call abnormalities during the terminal device call.

[0007] In a possible embodiment, the first cell is a New Radio (NR) cell, the second cell is a Long Term Evolution (LTE) cell, and the third cell is an NR cell.

[0008] The above method avoids the problem of failed handover between cells of different standards (different systems) and failed voice bearer recovery after returning to the new cell of the original standard (same system), which leads to dropped calls. For example, after failed handover from an NR cell to an LTE cell, failed voice bearer recovery after returning to the new NR cell, resulting in dropped calls.

[0009] In a possible embodiment, if access to the second cell fails, then camp on the first cell. Specifically, if access to the second cell fails and the signal quality of the first cell is higher than a fourth threshold, then camp on the first cell.

[0010] Through the above method, after failing to access the second cell, it is determined whether the signal quality of the first cell is higher than the fourth threshold, ensuring that after residing in the first cell, the first cell can interact normally with the terminal device.

[0011] In a possible embodiment, if access to the second cell fails and the signal quality of the first cell is higher than the fourth threshold, then reside in the first cell, including: if access to the second cell fails, triggering the radio link failure process; if the signal quality of the first cell is higher than the fourth threshold, and the triggering reason of the radio link failure process is the failure of NR cell switching to LTE cell, then reside in the first cell.

[0012] Through the above method, when the triggering reason of the radio link failure process is the failure of the NR cell to switch to the LTE cell, it is ensured that the original NR cell is returned first, thereby avoiding the problem of the voice bearer being unable to be restored.

[0013] In a possible embodiment, if the signal quality of the first cell is higher than the fourth threshold, and the triggering cause of the wireless link failure process is the failure of the NR cell to switch to the LTE cell, then reside in the first cell, specifically: if the signal quality of the first cell is higher than the fourth threshold, and the call is in progress, and the triggering cause of the wireless link failure process is the failure of the NR cell to switch to the LTE cell, then reside in the first cell.

[0014] Through the above method, priority is given to returning to the original NR cell, thereby avoiding the problem of voice bearer being unable to be restored.

[0015] In a possible embodiment, when access to the second cell fails and the radio link failure process is triggered, when the triggering cause of the radio link failure process is not the failure of the NR cell to switch to the LTE cell, based on the detected signal quality / signal strength of each cell, reside in the NR cell with the highest signal quality / signal strength.

[0016] Through the above method, when the triggering reason of the wireless link failure process is not the failure of the NR cell to switch to the LTE cell, the terminal device can also select the NR cell to reside based on the signal quality / signal strength of the cell.

[0017] In a possible embodiment, if the user is not in a call, the user resides in the NR cell with the highest signal quality / signal strength based on the detected signal quality / signal strength of each cell.

[0018] Through the above method, when the terminal device is not in a call, the terminal device selects the NR cell to reside in based on the signal quality / signal strength of the cell.

[0019] In a possible embodiment, after failing to access the second cell, when residing in the first cell, if the signal strength of the second cell is detected to be higher than the second threshold, the signal strength of the second cell being higher than the second threshold is not reported to the network device; or, after failing to access the second cell, when residing in the first cell, if the signal strength of the first cell is detected to be lower than the first threshold and the signal strength of the second cell is higher than the second threshold, the signal strength of the first cell being lower than the first threshold and the signal strength of the second cell being higher than the second threshold is not reported to the network device.

[0020] Through the above method, after residing in the first cell from the second cell, the B1 event of the second cell (the signal strength of the second cell is higher than the second threshold) is not reported to the network device, or / and the B2 event of the second cell (the signal strength of the first cell is lower than the first threshold, and the signal strength of the second cell is higher than the second threshold) is not reported to the network device, so as to avoid the terminal device switching back to the second cell after returning from the second cell to the first cell, so as to realize the terminal device switching to a new NR cell other than the second cell.

[0021] In a second aspect, the present application provides a terminal device comprising one or more processors and one or more memories. The one or more memories are coupled to the one or more processors, and the one or more memories are used to store computer program code, wherein the computer program code comprises computer instructions. When the one or more processors execute the computer instructions, the terminal device executes the cell handover method according to any possible implementation of the first aspect.

[0022] In a third aspect, the present application provides a cell switching device, which may be a terminal device, a device in a terminal device, or a device that can be used in conjunction with a terminal device; wherein, the cell switching device may also be a chip system, and the cell switching device may execute the method executed by the terminal device in the first aspect. The functions of the cell switching device may be implemented by hardware, or by hardware executing corresponding software implementations. The hardware or software includes one or more units corresponding to the above functions. The unit may be software and / or hardware. The operations and beneficial effects performed by the cell switching device may refer to the methods and beneficial effects described in the first aspect above, and repetitions will not be repeated.

[0023] In a fourth aspect, the present application provides a chip comprising a processor and an interface, wherein the processor and the interface are coupled; the interface is used to receive or output signals, and the processor is used to execute code instructions to execute the cell switching method in any possible implementation of the first aspect above.

[0024] In a fifth aspect, the present application provides a computer program product. When the computer program product is run on a computer, it enables the computer to execute the cell switching method in any possible implementation of the first aspect. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1a This is a flow chart of a call drop process of a terminal device provided in an embodiment of the present application;

[0026] Figure 1b This is a schematic diagram of a communication system architecture provided by an embodiment of the present application;

[0027] Figure 1c This is a flowchart of a cell switching method provided by an embodiment of the present application;

[0028] Figure 2 This is a schematic diagram of the hardware structure of a terminal device provided in an embodiment of the present application;

[0029] Figure 3 This is a schematic diagram of the software structure of a terminal device provided in an embodiment of the present application;

[0030] Figure 4 This is a flowchart of another cell switching method provided in an embodiment of the present application;

[0031] Figure 5a This is a schematic diagram of a signal strength grid change provided by an embodiment of the present application;

[0032] Figure 5b This is a flowchart of another cell switching method provided in an embodiment of the present application;

[0033] Figure 6 This is a schematic structural diagram of a cell switching device provided in an embodiment of the present application;

[0034] Figure 7 This is a schematic diagram of the structure of a chip provided in an embodiment of the present application. DETAILED DESCRIPTION

[0035] The following will be combined with the accompanying drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. In the description of the embodiments of the present application, unless otherwise specified, " / " means or, for example, A / B can mean A or B; "and / or" in the text is only a description of the association relationship of associated objects, indicating that there can be three relationships, for example, A and / or B can mean: A exists alone, A and B exist at the same time, and B exists alone. In addition, in the description of the embodiments of the present application, "multiple" means two or more than two.

[0036] It should be understood that the terms "first," "second," and the like in the specification, claims, and drawings of this application are used to distinguish between different objects, rather than to describe a particular order. Furthermore, the terms "including," "having," and any variations thereof, are intended to cover non-exclusive inclusions. For example, a process, method, system, product, or apparatus comprising a series of steps or elements is not limited to the listed steps or elements, but may optionally include steps or elements not listed, or may optionally include other steps or elements inherent to the process, method, product, or apparatus.

[0037] References to "embodiments" in this application mean that a particular feature, structure, or characteristic described in connection with the embodiment may be included in at least one embodiment of the application. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor does it constitute an independent or alternative embodiment that is mutually exclusive of other embodiments. It is understood, both explicitly and implicitly, by those skilled in the art that the embodiments described in this application may be combined with other embodiments.

[0038] To facilitate understanding of the solutions provided by the embodiments of the present application, the following describes the relevant concepts involved in the embodiments of the present application:

[0039] 5G is the latest generation of mobile communication technology. Compared to earlier mobile communication technologies such as 4G, 3G, and 2G, 5G offers higher data rates, lower latency, full connectivity for the Internet of Everything, greater energy efficiency, lower costs, higher system capacity, and large-scale device access. 5G New Radio (NR) is a new radio access technology (RAT) developed by the 3rd Generation Partnership Project (3GPP) for 5G mobile communication networks. It is the global standard for the air interface of 5G networks.

[0040] The existing 5G standard defines multiple networking modes, including standalone (SA) and non-standalone (NSA). Optionally, the core network of both 5G NSA and 5G SA can be the 4G core network (Evolved Packet Core, EPC) or the 5G core network (5GC). 5G NSA networking can also be called 4G-5G radio access dual connectivity (EUTRN-NR dual connectivity, EN-DC) networking. In the early stages of 5G system construction, 5G NSA networking was widely used.

[0041] 1. NR cell: refers to all 5G cells, including SA cells and 5G cells connected to NSA cells after establishing ENDC dual connection in 5G NSA networking.

[0042] 2. LTE cell: refers to all 4G cells, including normal LTE cells and NSA cells / anchor LTE cells.

[0043] 3. LTE measurement events:

[0044] Event A1: indicates that the signal quality of the serving cell is higher than a certain threshold. When an event meeting this condition is reported, the eNodeB (Evolved Node B) stops inter-frequency / inter-system measurement.

[0045] Event A2: indicates that the serving cell signal quality is below a certain threshold. When an event meeting this condition is reported, the eNodeB initiates inter-frequency / inter-system measurement.

[0046] Event A3: Indicates that the quality of the same-frequency or inter-frequency neighboring cell is higher than that of the serving cell. When this event is reported, the source eNodeB initiates an intra-frequency handover request. Generally, this is a coverage-based handover.

[0047] Event A4 indicates that the quality of the inter-frequency neighboring cell exceeds a certain threshold. When an event meeting this condition is reported, the source eNodeB initiates an inter-frequency handover request; generally, the handover is based on load balancing.

[0048] Event A5: indicates that the quality of the serving cell is lower than a certain threshold and the quality of the neighboring cell is higher than a certain threshold.

[0049] B1 event (Event B1): The B1 event is a measurement event for a different system, which means that the signal quality of the neighboring cell of the different system is higher than the B1 event neighboring cell threshold of the different system. The B1 event and threshold are configured on the base station side (or network side). When the base station configures the B1 event measurement, the base station sends measurement configuration information to the UE, which carries the B1 event neighboring cell threshold and the frequency of the neighboring cell of the different system. Correspondingly, the UE receives the measurement configuration information and performs signal measurement of the neighboring cell of the different system according to the frequency. If the UE detects that the signal quality of the neighboring cell of the different system is higher than the B1 event neighboring cell threshold of the different system, the B1 event is reported. Optionally, the B1 event can be used to trigger inter-system switching.

[0050] B2 event (Event B2): The B2 event is a measurement event for a different system, which means that the signal quality of the serving cell is lower than the B2 event serving cell threshold and at the same time the signal quality of the neighboring cell of the different system is higher than the B2 event neighboring cell threshold of the different system. The B2 event and threshold are configured by the network device (or network side). When the network device configures the B2 event measurement, the network device sends measurement configuration information to the UE, which carries the B2 event threshold and frequency. Correspondingly, the UE receives the measurement configuration information and performs signal measurement of the neighboring cell of the different system according to the frequency. If the UE detects that the signal quality of the serving cell is lower than the B2 event serving cell threshold and at the same time the signal quality of the neighboring cell of the different system is higher than the B2 event neighboring cell threshold of the different system, the B2 event is reported. Optionally, the B2 event can be used to trigger inter-system switching.

[0051] 4. Measurement reporting

[0052] According to the provisions of the 3GPP protocol, the terminal device can measure the signals of the serving cell and the adjacent cell. For example, the signal measurement results of the cell can be reference signal received power (RSRP), reference signal received quality (RSRQ), etc. When the terminal device is in a connected state, the terminal device can report a measurement report to the access network device. The ways in which the terminal device reports the measurement report are divided into periodic reporting and event reporting. Event reporting means that once the terminal device finds that the current situation meets the measurement reporting event specified in the protocol, it reports the measurement report. The measurement report may include the measurement reporting event and the signal measurement result of the cell. The access network device can determine whether to perform cell switching for the terminal device based on the measurement report to better serve each terminal device. For example, the measurement reporting event may include event A or event B.

[0053] 5. Real-time Transport Protocol (RTP) / Real-time Transport Control Protocol (RTCP)

[0054] RTP is a transport protocol for multimedia data streams over the Internet, published by the IETF (Internet Engineering Task Force) as RFC 1889. RTP is defined for one-to-one or one-to-many transmission scenarios, providing time information and stream synchronization. RTP itself only guarantees the transmission of real-time data and does not provide a reliable mechanism for in-sequence data packet delivery, flow control, or congestion control. It relies on RTCP to provide these services.

[0055] RTCP: Responsible for managing transmission quality and exchanging control information between current application processes. During an RTP session, each participant periodically transmits RTCP packets, which contain statistics such as the number of packets sent and the number of packets lost. The server can use this information to dynamically adjust the transmission rate and even the payload type. RTP and RTCP, when used together, optimize transmission efficiency with effective feedback and minimal overhead, making them particularly suitable for transmitting real-time data over the Internet.

[0056] 6. Radio Link Failure (RLF) Process

[0057] When a terminal device detects a radio link failure and meets the re-establishment conditions, the terminal device initiates the re-establishment process. Currently, the terminal device initiates re-establishment after detecting an RLF failure, and re-establishment failure is a major factor leading to call drops on the terminal device.

[0058] The following combination Figure 1a This section further describes the process of reestablishing after RLF failure and reestablishing to a new NR cell, and the RTP / RTCP timeout leading to call drop on the terminal device. Figure 1a As shown:

[0059] When the terminal device is in a call, the terminal device exchanges RTP / RTCP packets with the access network device of the currently resident NR cell A, and the access network device of the resident cell exchanges RTP / RTCP packets with the core network. When the terminal device detects that the signal strength of the currently resident cell A (NR cell) is lower than the first threshold (the signal of cell A becomes weaker), and the signal strength of the adjacent cell B (LTE cell) is higher than the second threshold, it sends a B2 event to the access network device corresponding to cell A (the signal strength of NR cell A is lower than the first threshold, and the signal strength of LTE cell B is higher than the second threshold). After the access network device of NR cell A receives the B2 event sent by the terminal device, NR cell A sends a cell switching instruction to the terminal device to guide the terminal device to switch to cell B. Although the signal strength of cell B is good, the signal quality is poor (for example, the surrounding interference of cell B is large, resulting in poor signal quality of cell B), which causes the terminal device to fail to randomly access cell B. After the access failure, the RLF process is triggered.

[0060] After the handover fails and the RLF process is triggered, the terminal device selects the NR cell with high signal quality / signal strength to reside in based on the signal quality / signal strength of each cell detected (in Figure 1a In the illustrated embodiment, NR cell C is an NR cell with high signal quality / signal strength).

[0061] After selecting cell C to reside, the terminal device accesses NR cell C (including the Radio Resource Control (RRC) access process and registration process), and the terminal device receives the RRC reconfiguration message sent by cell C. Although the reconfiguration message configures the DRBs for IMS signaling and voice, due to the abnormal interaction between NR cell C and the core network, the terminal device cannot receive the RTP / RTCP packet through NR cell C, which causes the RTP / RTCP silence timer to time out after a period of time, and the terminal device actively hangs up (the terminal device sends a Bye message to NR cell C, and the Bye message includes the reason for hanging up as the RTP / RTCP silence timer timeout).

[0062] In order to reduce the probability of abnormal calls during a terminal device call, this application provides a cell switching method. The following is a further introduction to the cell switching method:

[0063] The following describes the communication system involved in the embodiments of the present application:

[0064] The embodiments of the present application can be applied to communication systems evolved after 5G, such as long-term evolution (LTE) systems, fifth-generation mobile communication (5G) systems, and sixth-generation mobile communication (6G) systems, as well as satellite communications and short-range wireless communication systems. The wireless communication systems mentioned in the embodiments of the present application include, but are not limited to, the three major application scenarios of 5G / 6G mobile communication systems: enhanced mobile broadband (eMBB), ultra-reliable low latency communication (URLLC), and massive machine type communication (mMTC), long-range Internet of Things (LoRa) systems, or Internet of Vehicles systems.

[0065] Figure 1b A possible, non-limiting system diagram is shown. Figure 1b As shown, the communication system includes an access network device 101 and a terminal device 102. Figure 1b Taking the communication system including three access network devices 101 and one terminal device 102 as an example, the communication system can also include a larger number of access network devices 101 and terminal devices 102, which is not limited in the embodiments of the present application.

[0066] 1. Access Network Equipment 101

[0067] Access network device 101, sometimes also referred to as a radio access network (RAN) node, RAN entity, or access node, constitutes part of a communication system and facilitates wireless access for terminal device 102. In one possible scenario, access network device 101 may be a base station, an evolved NodeB (eNodeB), an access point (AP), a transmission reception point (TRP), a next-generation NodeB (gNB), a next-generation base station in a sixth-generation (6G) mobile communication system, a base station in a future mobile communication system, or an access node in a WiFi system. Access network device 101 may be a macro base station, a micro base station, an indoor station, a relay node or a donor node, or a wireless controller in a CRAN scenario. In one possible embodiment, access network device 101 may also be a server, a wearable device, a vehicle, or an onboard device. For example, the access network device in vehicle-to-everything (V2X) technology may be a roadside unit (RSU).

[0068] 2. Terminal Device 102

[0069] Terminal device 102 may also be referred to as a terminal, user equipment (UE), mobile station, mobile terminal, electronic device, etc. Terminal device 102 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), virtual reality, augmented reality, industrial control, autonomous driving, telemedicine, smart grid, smart furniture, smart office, smart wearable, smart transportation, smart city, etc. Terminal device 102 can be a mobile phone, tablet computer, computer with wireless transceiver function, wearable device, vehicle, drone, helicopter, airplane, ship, robot, robotic arm, smart home device, etc.

[0070] 3. Core Network 103

[0071] The main functions of the core network 103 are to provide user connection access, authentication, billing, user management and service carrying for mobile terminals, allocate corresponding network resources to users, and provide users with voice, data and other service access services.

[0072] Combined with the above-mentioned communication system structure, the cell switching method provided by this application returns to the original NR cell after the switch from the NR cell to the LTE cell fails. When the terminal device resides in the original NR cell, it uses the measurement report to switch to the new NR cell. This avoids the problem of voice bearer recovery failure after returning to the new cell of the original system (same system) after the switch between cells of different standards (different systems) fails, which leads to dropped calls. Figure 1c Further introduction to the process of returning to the original community:

[0073] For example Figure 1c As shown, the steps in the dotted box are: during the call, the terminal device 102 exchanges RTP / RTCP packets with the access network device 101 of the currently residing NR cell A, and the access network device 101 of the currently residing NR cell A exchanges RTP / RTCP packets with the core network 103. When it is detected that the signal strength of the currently residing NR cell A is lower than the first threshold (the signal of cell A becomes weaker), and the signal strength of the adjacent LTE cell B is higher than the second threshold, the B2 event is reported to the access network device 101 corresponding to the NR cell A. After the access network device 101 receives the B2 event sent by the terminal device 102, the access network device 101 sends a cell switching instruction to the terminal device 102 to guide the terminal device 102 to switch to LTE cell B. Although the signal strength of LTE cell B is good, the signal quality is poor (for example, the surrounding interference of cell B is large, resulting in poor signal quality of cell B), resulting in the failure of the terminal device 102 to randomly access cell B. It should be noted that the process in the dotted box is an exemplary process, that is, in actual scenarios, the process in the dotted box may not be as good as Figure 1c As shown, for example, in the process in the dotted box, the terminal device is not in a call.

[0074] When the handover fails and the RLF process is triggered, the terminal device determines whether the reason for triggering the RLF process is the failure of the NR cell to switch to the LTE cell. If so, it then determines whether the current terminal device is in a call. If in a call, it prioritizes searching for the NR source cell (NR cell A) and determines whether the signal quality of NR cell A is higher than the threshold. If so, NR cell A is selected to reside.

[0075] After selecting NR cell A to reside, the terminal device accesses NR cell A. The terminal device exchanges RTP / RTCP packets with the core network through NR cell A.

[0076] Optionally, after the handover fails and the RLF process is triggered, the terminal device determines whether the reason for triggering the RLF process is the failure of the NR cell to switch to the LTE cell. If it is not the reason, the terminal device selects the NR cell with high signal quality / signal strength to reside in based on the signal quality / signal strength of each cell detected (in Figure 1c In the illustrated embodiment, NR cell C is an NR cell with high signal quality / signal strength). After selecting NR cell C to reside, the NR cell C is accessed. The terminal device may not be able to exchange RTP / RTCP packets with the core network through NR cell C.

[0077] Alternatively, after the handover fails and the RLF process is triggered, the terminal device determines that the reason for triggering the RLF process is that the NR cell fails to switch to the LTE cell, but the terminal device is not in a call. The terminal device selects the NR cell with high signal quality / signal strength to reside based on the signal quality / signal strength of each cell detected. After selecting NR cell C to reside, access NR cell C.

[0078] Alternatively, after the handover fails and the RLF process is triggered, the terminal device determines that the reason for triggering the RLF process is that the NR cell fails to switch to the LTE cell, and the terminal device is in a call, but the signal quality of NR cell A is lower than the threshold, then the terminal device selects the NR cell with high signal quality / signal strength to reside based on the signal quality / signal strength of each cell detected. After selecting NR cell C to reside, access NR cell C.

[0079] The following describes the hardware and software structures of the terminal device 102 involved in the embodiment of the present application:

[0080] The hardware structure of the terminal device 102 is introduced below. Figure 2 , Figure 2 It is a hardware structure diagram of the terminal device 102 provided in an embodiment of the present application.

[0081] The terminal device 102 may include a processor 110, an external memory interface 120, an internal memory 121, a universal serial bus (USB) interface 130, a charging management module 140, a power management module 141, a battery 142, an antenna 1, an antenna 2, a mobile communication module 150, a wireless communication module 160, an audio module 170, a speaker 170A, a receiver 170B, a microphone 170C, an earphone interface 170D, a sensor module 180, a button 190, a motor 191, an indicator 192, a camera 193, a display screen 194, and a subscriber identification module (SIM) card interface 195, etc. The sensor module 180 may include a pressure sensor 180A, a gyroscope sensor 180B, an air pressure sensor 180C, a magnetic sensor 180D, an acceleration sensor 180E, a distance sensor 180F, a proximity light sensor 180G, a fingerprint sensor 180H, a temperature sensor 180J, a touch sensor 180K, an ambient light sensor 180L, a bone conduction sensor 180M, etc.

[0082] It should be understood that the structure illustrated in the embodiments of the present invention does not constitute a specific limitation on the terminal device 102. In other embodiments of the present application, the terminal device 102 may include more or fewer components than shown, or may combine or separate certain components, or arrange the components differently. The illustrated components may be implemented in hardware, software, or a combination of software and hardware.

[0083] The processor 110 may include one or more processing units. For example, the processor 110 may include an application processor (AP), a modem processor, a graphics processing unit (GPU), an image signal processor (ISP), a controller, a memory, a video codec, a digital signal processor (DSP), a baseband processor, and / or a neural-network processing unit (NPU). The different processing units may be independent devices or integrated into one or more processors.

[0084] The controller may be the nerve center and command center of the terminal device 102. The controller may generate an operation control signal based on the instruction operation code and the timing signal to complete the control of instruction fetching and execution.

[0085] The processor 110 may also be provided with a memory for storing instructions and data. In some embodiments, the memory in the processor 110 is a cache memory. This memory can store instructions or data that have just been used or are being recycled by the processor 110. If the processor 110 needs to use the instruction or data again, it can directly call it from the memory. This avoids repeated accesses, reduces the waiting time of the processor 110, and thus improves system efficiency. The processor 110 calls the instructions or data stored in the memory, causing the terminal device 102 to execute the cell handover method performed by the terminal device in the following method embodiment.

[0086] In some embodiments, the processor 110 may include one or more interfaces. The interfaces may include an inter-integrated circuit (I2C) interface, an inter-integrated circuit sound (I2S) interface, a pulse code modulation (PCM) interface, a universal asynchronous receiver / transmitter (UART) interface, a mobile industry processor interface (MIPI), a general-purpose input / output (GPIO) interface, a subscriber identity module (SIM) interface, and / or a universal serial bus (USB) interface.

[0087] The charging management module 140 is configured to receive charging input from a charger, which may be a wireless charger or a wired charger.

[0088] The power management module 141 is used to connect the battery 142, the charging management module 140, and the processor 110. The power management module 141 receives input from the battery 142 and / or the charging management module 140 to provide power to the processor 110, the internal memory 121, the external memory, the display 194, the camera 193, and the wireless communication module 160. In some other embodiments, the power management module 141 can also be set in the processor 110.

[0089] The wireless communication function of the terminal device 102 can be implemented through antenna 1, antenna 2, mobile communication module 150, wireless communication module 160, modem processor and baseband processor.

[0090] Antenna 1 and Antenna 2 are used to transmit and receive electromagnetic wave signals. Each antenna in terminal device 102 can be used to cover a single or multiple communication frequency bands. Different antennas can also be reused to improve antenna utilization. For example, antenna 1 can be reused as a diversity antenna for a wireless local area network. In other embodiments, the antennas can be used in conjunction with a tuning switch.

[0091] The mobile communication module 150 can provide solutions for wireless communications including 2G / 3G / 4G / 5G applied to the terminal device 102. The mobile communication module 150 may include at least one filter, a switch, a power amplifier, a low noise amplifier (LNA), etc. The mobile communication module 150 can receive electromagnetic waves from the antenna 1, and filter, amplify, and process the received electromagnetic waves, and transmit them to the modulation and demodulation processor for demodulation. The mobile communication module 150 can also amplify the signal modulated by the modulation and demodulation processor, and convert it into electromagnetic waves for radiation through the antenna 1. In some embodiments, at least some of the functional modules of the mobile communication module 150 can be set in the processor 110. In some embodiments, at least some of the functional modules of the mobile communication module 150 can be set in the same device as at least some of the modules of the processor 110.

[0092] The modem processor includes a modulator and a demodulator. The modulator modulates the low-frequency baseband signal to be transmitted into a medium- or high-frequency signal. The demodulator demodulates the received electromagnetic wave signal into a low-frequency baseband signal. The demodulator then transmits the demodulated low-frequency baseband signal to the baseband processor for processing. After processing by the baseband processor, the low-frequency baseband signal is passed to the application processor.

[0093] The wireless communication module 160 can provide wireless communication solutions including wireless local area networks (WLAN) (such as Wi-Fi networks), Bluetooth (BT), BLE broadcast, global navigation satellite system (GNSS), frequency modulation (FM), near field communication (NFC), infrared (IR), etc. applied on the terminal device 102. The wireless communication module 160 can be one or more devices integrating at least one communication processing module. The wireless communication module 160 receives electromagnetic waves via the antenna 2, frequency modulates and filters the electromagnetic wave signals, and sends the processed signals to the processor 110. The wireless communication module 160 can also receive the signal to be sent from the processor 110, frequency modulate it, amplify it, and convert it into electromagnetic waves for radiation through the antenna 2.

[0094] In some embodiments, antenna 1 of terminal device 102 is coupled to mobile communication module 150 , and antenna 2 is coupled to wireless communication module 160 , so that terminal device 102 can communicate with the network and other devices through wireless communication technology.

[0095] Terminal device 102 implements display functionality through a GPU, display screen 194, and an application processor. A GPU is a microprocessor for image processing that connects display screen 194 and the application processor. The GPU is used to perform mathematical and geometric calculations for graphics rendering. Processor 110 may include one or more GPUs that execute program instructions to generate or modify display information.

[0096] Display screen 194 is used to display images, videos, etc. Display screen 194 includes a display panel. In some embodiments, terminal device 102 may include one or N display screens 194, where N is a positive integer greater than 1. Display screen 194 may be an outward-folding screen, i.e., a display screen that folds outward.

[0097] The terminal device 102 can implement the shooting function through the ISP, camera 193, video codec, GPU, display screen 194 and application processor. The ISP is used to process the data fed back by the camera 193. The camera 193 is used to capture still images or videos. The camera 193 may include a front camera and a rear camera, the front camera is located in the display area of the screen, and the rear camera is located in the back area of the screen. The digital signal processor is used to process digital signals. In addition to processing digital image signals, it can also process other digital signals. The video codec is used to compress or decompress digital video. The terminal device 102 may support one or more video codecs.

[0098] NPU is a neural-network (NN) computing processor. By drawing on the structure of biological neural networks, such as the transmission mode between neurons in the human brain, it can quickly process input information and can also continuously self-learn.

[0099] The external memory interface 120 can be used to connect an external memory card, such as a Micro SD card, to expand the storage capacity of the terminal device 102. The external memory card communicates with the processor 110 through the external memory interface 120 to implement a data storage function.

[0100] The internal memory 121 can be used to store computer executable program code, which includes instructions. The processor 110 executes various functional applications and data processing of the terminal device 102 by running the instructions stored in the internal memory 121. The internal memory 121 may include a program storage area and a data storage area. Among them, the program storage area can store an operating system, an application required for at least one function (such as a sound playback function), etc. The data storage area can store data (such as audio data) created during the use of the terminal device 102, etc. In addition, the internal memory 121 may include a high-speed random access memory, and may also include a non-volatile memory, such as a flash memory device.

[0101] The terminal device 102 can implement audio functions such as music playback and recording through the audio module 170, the speaker 170A, the receiver 170B, the microphone 170C, the headphone jack 170D, and the application processor.

[0102] The audio module 170 is used to convert digital audio information into analog audio signal output, and is also used to convert analog audio input into digital audio signals. The audio module 170 can also be used to encode and decode audio signals. In some embodiments, the audio module 170 can be provided in the processor 110, or some functional modules of the audio module 170 can be provided in the processor 110.

[0103] Speaker 170A, also known as "horn", is used to convert audio electrical signals into sound signals. Receiver 170B, also known as "earpiece", is used to convert audio electrical signals into sound signals. Microphone 170C, also known as "microphone" or "microphone", is used to convert sound signals into electrical signals. Headphone jack 170D is used to connect wired headphones. Pressure sensor 180A is used to sense pressure signals and convert them into electrical signals. In some embodiments, pressure sensor 180A can be set on display screen 194. Gyroscope sensor 180B can be used to determine the movement posture of terminal device 102. Air pressure sensor 180C is used to measure air pressure. Magnetic sensor 180D includes a Hall sensor. Acceleration sensor 180E can detect the magnitude of acceleration of terminal device 102 in various directions (generally three axes). Distance sensor 180F is used to measure distance. Proximity light sensor 180G can include, for example, a light emitting diode (LED) and a light detector. Ambient light sensor 180L is used to sense the brightness of ambient light. Fingerprint sensor 180H is used to collect fingerprints. The temperature sensor 180J is used to detect the temperature. The touch sensor 180K is also called a "touch panel". The touch sensor 180K can be set on the display screen 194. The touch sensor 180K and the display screen 194 form a touch screen, also called a "touch screen". The touch sensor 180K is used to detect touch operations acting on or near it. The bone conduction sensor 180M can obtain vibration signals. The buttons 190 include a power button, a volume button, etc. The motor 191 can generate vibration prompts. The indicator 192 can be an indicator light, which can be used to indicate the charging status, power changes, messages, missed calls, notifications, etc. The SIM card interface 195 is used to connect a SIM card.

[0104] In addition, an operating system runs on top of the above components. For example, operating systems such as iOS and Android. The operating system of the terminal device 102 can adopt a layered architecture, an event-driven architecture, a micro-kernel architecture, a microservice architecture, or a cloud architecture. The embodiment of the present application uses the Android system with a layered architecture as an example to illustrate the software structure of the terminal device 102. It should be noted that although the embodiment of the present application uses the Android system as an example, its basic principles are also applicable to terminal devices with other operating systems.

[0105] Figure 3 A schematic diagram of the software structure of a terminal device 102 provided in an embodiment of the present application.

[0106] A layered architecture divides software into several layers, each with distinct roles and responsibilities. Layers communicate with each other through software interfaces. In some embodiments, the Android system is divided into four layers: the application layer, the application framework layer, the Android runtime and system libraries, and the kernel layer.

[0107] The application layer can include a series of application packages. Figure 3 As shown, the application package may include applications such as camera, gallery, calendar, call, map, navigation, WLAN, Bluetooth, music, video, short message, etc.

[0108] The application framework layer provides application programming interface (API) and programming framework for the applications in the application layer. The application framework layer includes some predefined functions. Figure 3 As shown, the application framework layer may include a window manager, a content provider, a view system, a phone manager, a resource manager, a notification manager, and the like.

[0109] The window manager is used to manage window programs. The window manager can obtain the display size, determine whether there is a status bar, lock the screen, take screenshots, etc.

[0110] Content providers are used to store and retrieve data and make it accessible to applications. The data may include videos, images, audio, calls made and received, browsing history and bookmarks, phone books, etc.

[0111] The view system includes visual controls, such as those for displaying text and images. The view system is used to build applications. A display interface can consist of one or more views. For example, a display interface containing a text notification icon might include a view for displaying text and a view for displaying images.

[0112] The phone manager is used to provide communication functions for the terminal device 102, such as management of call status (including answering, hanging up, etc.).

[0113] The resource manager provides various resources for applications, such as localized strings, icons, images, layout files, video files, and so on.

[0114] The Notification Manager allows applications to display notifications in the status bar. These messages can be displayed briefly and then disappear automatically, without requiring user interaction. For example, the Notification Manager can be used to notify users of completed downloads and message reminders. The Notification Manager can also display notifications in the system's top status bar as icons or scrolling text, such as notifications from background applications, or as dialog windows on the screen. Examples include displaying text messages in the status bar, emitting alert sounds, vibrating the user's terminal, and flashing indicator lights.

[0115] The Android runtime includes the core library and the virtual machine. The Android runtime is responsible for scheduling and management of the Android system.

[0116] The core library consists of two parts: one is the function that needs to be called by the Java language, and the other is the Android core library.

[0117] The application layer and application framework layer run in a virtual machine. The virtual machine executes Java files in the application layer and application framework layer as binary files. The virtual machine manages object lifecycles, stack management, thread management, security and exception management, and garbage collection.

[0118] The system library can include multiple functional modules, such as surface manager, media library, 3D graphics processing library (such as OpenGL ES), 2D graphics engine (such as SGL), etc.

[0119] The surface manager is used to manage the display subsystem and provide fusion of 2D and 3D layers for multiple applications.

[0120] The media library supports playback and recording of a variety of common audio and video formats, as well as static image files. The media library can support a variety of audio and video encoding formats, such as: MPEG4, H.264, MP3, AAC, AMR, JPG, PNG, etc.

[0121] The 3D graphics processing library is used to implement 3D graphics drawing, image rendering, compositing, and layer processing.

[0122] A 2D graphics engine is a drawing engine for 2D drawings.

[0123] The kernel layer is the layer between hardware and software. The kernel layer includes at least display driver, camera driver, audio driver, and sensor driver.

[0124] Based on the above, a cell switching method provided by an embodiment of the present application is further described in detail below. Figure 4As shown, the cell switching method includes the following steps 401 to 405. Figure 4 The method shown may be performed by the terminal device mentioned above. Alternatively, Figure 4 The execution subject of the method shown can be a chip in the terminal device, which is not limited in the embodiment of this application. For the convenience of description, Figure 4 The following description is made by taking the terminal device as the execution subject of the method as an example.

[0125] 401. During a call, while the terminal device is resident in a first cell, if it detects that the signal strength of the first cell is lower than a first threshold and the signal strength of the second cell is higher than a second threshold, the terminal device sends a first measurement report to the network device, where the first measurement report indicates that the signal strength of the first cell is lower than the first threshold and the signal strength of the second cell is higher than the second threshold. Accordingly, the network device receives the first measurement report sent by the terminal device.

[0126] The first threshold and the second threshold may be configured by a network device, which may be the access network device mentioned above. The network device may be the network device corresponding to the currently resident cell (for example, when the terminal device resides in the first cell, the network device is the network device corresponding to the first cell). The signal strength may be a reference signal received power (RSRP). The unit of the signal strength is dBm. The first measurement report may include the signal strength of the second cell, and / or the signal quality of the second cell, and / or the signal strength of the first cell, and / or the signal quality of the first cell.

[0127] For example, if the first threshold is -60dBm and the second threshold is -50dBm, the terminal device detects that the RSRP of the first cell is -70dBm and the RSRP of the second cell is -30dBm. At this time, the signal strength of the first cell is lower than the first threshold and the signal strength of the second cell is higher than the second threshold. The terminal device sends a first measurement report to the network device.

[0128] In a possible embodiment, if the first cell and the second cell are different systems (for example, the first cell is an NR cell and the second cell is an LTE cell), then the detection that the signal strength of the first cell is lower than the first threshold and the signal strength of the second cell is higher than the second threshold can be a B2 event.

[0129] Optionally, if the first cell and the second cell are in different systems, and the terminal device is in a call and resides in the first cell, if it detects that the signal strength of the second cell is higher than the second threshold, the terminal device sends a first measurement report to the network device. In other words, the B1 event of the second cell can be measured and reported.

[0130] 402. After receiving a first switching instruction sent by a network device to instruct switching to a second cell, the terminal device accesses the second cell.

[0131] The first switching instruction is used to guide the terminal device to switch to the second cell.

[0132] 403. If the terminal device fails to access the second cell, it resides in the first cell.

[0133] The failure to access the second cell may be due to poor signal quality or cell abnormality, etc. This application does not limit the cause of random access failure.

[0134] In a possible embodiment, if the terminal device fails to access the second cell, it resides in the first cell. Specifically, if the terminal device fails to access the second cell and the signal quality of the first cell is higher than the fourth threshold, it resides in the first cell.

[0135] The fourth threshold may be a threshold value pre-set in the terminal device by default, or may be a threshold value pre-set in the terminal device by the network device. The signal quality of the first cell may be a reference signal received quality (RSRQ) or RSRP, etc., and this application does not limit this.

[0136] The triggering reason for triggering the radio link failure process may be: failure of NR cell switching to LTE cell, failure of NR cell switching to NR cell, or failure of LTE cell switching to LTE cell.

[0137] The conditions for determining whether to stay in the first cell may be: the signal quality of the first cell, and / or whether the triggering cause of the radio link failure process is the failure of the NR cell to switch to the LTE cell, and / or whether the terminal device is currently in a call, and / or whether the signal quality of the first cell is higher than the threshold. The following describes several situations respectively:

[0138] Case 1: If access to the second cell fails, the radio link failure process is triggered; if the triggering reason of the radio link failure process is the failure of the NR cell to switch to the LTE cell, and the signal quality of the first cell is higher than the fourth threshold, it resides in the first cell.

[0139] Among them, the RLF process is that when the terminal device detects that the radio link fails and meets the re-establishment conditions, the terminal device initiates the re-establishment process. The RLF process can be referred to the above introduction, and this application will not repeat it here.

[0140] Through the above method, when the triggering reason of the radio link failure process is the failure of the NR cell to switch to the LTE cell, it is ensured that the original NR cell is returned first, thereby avoiding the problem of the voice bearer being unable to be restored.

[0141] Case 2: If the triggering reason for the wireless link failure process of the terminal device is the failure of the NR cell to switch to the LTE cell, and the terminal device is in a call, and the signal quality of the first cell is higher than the fourth threshold, then it will reside in the first cell.

[0142] Case 3: When the triggering reason of the wireless link failure process of the terminal device is not the failure of the NR cell to switch to the LTE cell, based on the signal quality / signal strength of each cell detected, the terminal device resides in the NR cell with the highest signal quality / signal strength.

[0143] The NR cell with the highest signal quality / signal strength may be the third cell, or may be another NR cell other than the third cell. Optionally, based on the signal quality of each detected cell, the NR cell with the highest signal quality may be resided in, or based on the signal strength of each detected cell, the NR cell with the highest signal strength may be resided in, or based on the signal quality and signal strength, the NR cell with the highest signal quality and signal strength may be resided in.

[0144] For example, if the NR cells detected by the terminal device include: cell A, cell B, and cell C. The signal quality of the three NR cells is arranged from high to low as follows: signal quality of cell B > signal quality of cell A > signal quality of cell C. When the triggering cause of the radio link failure process is not the failure of NR cell switching to LTE cell, the terminal device resides in cell B.

[0145] Optionally, when the triggering cause of the wireless link failure process of the terminal device is not the failure of the NR cell to switch the LTE cell, based on the detected signal quality / signal strength of each cell, the NR cell with the highest signal strength is determined from the NR cells with signal quality / signal strength higher than the fifth threshold, and the terminal device resides in the NR cell with the highest signal strength among the NR cells with signal quality higher than the fifth threshold. The fifth threshold can be a threshold pre-set in the terminal device or a threshold pre-configured by the network device.

[0146] For example, if the NR cells detected by the terminal device include: cell A, cell B, and cell C. The signal quality of cell A and cell B is higher than the fifth threshold. The signal strength of cell A is higher than the signal strength of cell B. When the triggering cause of the radio link failure process is not the failure of NR cell handover to LTE cell, the terminal device resides in cell A.

[0147] Optionally, when the triggering cause of the wireless link failure process of the terminal device is not the failure of the NR cell to switch the LTE cell, based on the detected signal strength / signal strength of each cell, the NR cell with the highest signal quality is determined from the NR cells with signal strength / signal strength higher than the sixth threshold, and the terminal device resides in the NR cell with the highest signal quality among the NR cells with signal strength higher than the sixth threshold. The sixth threshold can be a threshold pre-set in the terminal device or a threshold pre-configured by the network device.

[0148] Case 4: If the terminal device is not in a call, it will reside in the NR cell with the highest signal quality / signal strength based on the detected signal quality / signal strength of each cell.

[0149] Among them, based on the signal quality of each cell detected, the NR cell with the highest signal quality is resided. Please refer to the description in the above situation three, and this application will not go into details here.

[0150] To sum up, in a possible embodiment, after the terminal device fails to switch to the second cell, it determines whether the cause of the RLF process is the failure of the NR cell to switch to the LTE cell. If the cause of the RLF process is the failure of the NR cell to switch to the LTE cell, it further determines whether the current terminal device is in a call. If it is in a call, it determines whether the signal quality of the first cell is higher than the fourth threshold; if it is higher than the fourth threshold, it stays in the first cell.

[0151] Alternatively, when the terminal device fails to switch to the second cell, it determines whether the current terminal device is in a call. If it is in a call, it further determines whether the cause of the RLF process is the failure of the NR cell to switch to the LTE cell. If the cause of the RLF process is the failure of the NR cell to switch to the LTE cell, it determines whether the signal quality of the first cell is higher than the fourth threshold; if it is higher than the fourth threshold, it stays in the first cell.

[0152] That is, this application does not limit the order of determining the cause of the RLF process and determining whether the terminal device is in a call. The terminal device can first determine whether the cause of the RLF process is a failure to switch from an NR cell to an LTE cell, and then determine whether the terminal device is in a call; or it can first determine whether the terminal device is in a call, and then determine whether the cause of the RLF process is a failure to switch from an NR cell to an LTE cell.

[0153] 404. When the terminal device resides in the first cell and detects that the signal strength of the third cell meets the measurement and reporting conditions, the terminal device sends a second measurement report to the network device. Accordingly, the network device receives the second measurement report sent by the terminal device.

[0154] The monitoring condition may be a condition for triggering an A2 event, an A3 event, an A4 event, and an A5 event, and the monitoring event may be an A2 event, an A3 event, an A4 event, and an A5 event, which is not limited in this application.

[0155] For example, Figure 5a As shown, Figure 5a The bars 501 and 502 are visual signal strength grids. The more bars in the signal strength grid, the higher the signal strength of the cell the terminal device is currently residing in. The signal strength grid 501 represents the signal strength grid 501 of the terminal device residing in the first cell, and the signal strength grid 502 represents the signal strength grid 502 of the terminal device residing in the third cell. When the terminal device switches from the first cell to the third cell, the signal strength grid displayed by the terminal device changes from signal strength grid 501 to signal strength grid 502.

[0156] In step 404, if the terminal device fails to access the second cell and then camps on the first cell, the following problem arises: the terminal device again detects that the signal strength of the first cell is below the first threshold and the signal strength of the second cell is above the second threshold, and the terminal device sends a first measurement report to the network device. The network device then instructs the terminal device to switch to the second cell. That is, steps 401 to 403 are repeated. To avoid this problem of the terminal device switching back and forth between the first cell and the second cell and ensuring that the terminal device switches to the new NR cell, in one possible embodiment, after failing to access the second cell and camping on the first cell, if the terminal device detects that the signal strength of the second cell is above the second threshold, the terminal device does not report to the network device that the signal strength of the second cell is above the second threshold. Alternatively, after failing to access the second cell and camping on the first cell, if the terminal device detects that the signal strength of the first cell is below the first threshold and the signal strength of the second cell is above the second threshold, the terminal device does not report to the network device that the signal strength of the first cell is below the first threshold and the signal strength of the second cell is above the second threshold.

[0157] The signal strength of the second cell being detected as being higher than the second threshold is reported as a B1 event for the second cell. If the terminal device detects that the signal strength of the second cell is higher than the second threshold, it does not report to the network device that the signal strength of the second cell is higher than the second threshold, thereby suppressing the B1 event for the second cell.

[0158] The measured signal strength of the first cell being lower than the first threshold and the signal strength of the second cell being higher than the second threshold is a second-cell B2 event. If the terminal device detects that the signal strength of the first cell is lower than the first threshold and the signal strength of the second cell is higher than the second threshold, it does not report to the network device that the signal strength of the first cell is lower than the first threshold and the signal strength of the second cell is higher than the second threshold, thus suppressing the B2 event of the second cell.

[0159] Optionally, in addition to suppressing the B1 event of the second cell and / or suppressing the B2 event of the second cell as described above, the B1 event of all cells and / or the B2 event of all cells may also be suppressed. Specifically, in a possible embodiment, after the terminal device fails to access the second cell, when it resides in the first cell, if it detects that the signal strength of the LTE cell is higher than the second threshold, it does not report to the network device that the signal strength of the LTE cell is higher than the second threshold; or, after failing to access the second cell, when it resides in the first cell, if it detects that the signal strength of the first cell is lower than the first threshold, and the signal strength of the LTE cell is higher than the second threshold, it does not report to the network device that the signal strength of the first cell is lower than the first threshold, and the signal strength of the LTE cell is higher than the second threshold.

[0160] Through the above method, after residing in the first cell from the second cell, the B1 event (the signal strength of the second cell is higher than the second threshold) is not reported to the network device, or / and the B2 event (the signal strength of the first cell is lower than the first threshold, and the signal strength of the second cell is higher than the second threshold) is not reported to the network device, so as to avoid the terminal device switching back to the second cell after returning from the second cell to the first cell, thereby achieving the purpose of switching the terminal device to a new cell other than the second cell.

[0161] 405. After receiving the second switching instruction sent by the network device to instruct switching to the third cell, the terminal device accesses the third cell.

[0162] The second switching instruction is used to guide the terminal device to reside in the third cell. The terminal device accesses the third cell through the RRC access process, and the terminal device receives the RRC reconfiguration message sent by the third cell. The configured message configures IMS signaling and voice DRB. After accessing the third cell, RTP / RTCP packets can be exchanged between the terminal device and the third cell, and RTP / RTCP packets can be exchanged between the third cell and the core network, so that RTP / RTCP packets can be exchanged between the terminal device and the core network device.

[0163] In a possible embodiment, the first cell is a NR cell, the second cell is a Long Term Evolution (LTE) cell, and the third cell is a NR cell.

[0164] For example, Figure 5b As shown, Figure 5b The process in the dotted box is an exemplary process. For an introduction to the process in the dotted box, please refer to the above description. Figure 1c This application will not be described in detail here.

[0165] After the handover to LTE cell B fails and the RLF process is triggered, the decision process of whether to choose NR cell A for residence can be found in the above Figure 1c The following is an introduction to the NR cell A: After returning to NR cell A, the A3 event (or A5 event, etc.) is reported to NR cell A, and NR cell A sends a cell switching instruction (second switching instruction) to the terminal device to guide the terminal device to switch to NR cell C. The terminal device accesses NR cell A. The terminal device exchanges RTP / RTCP packets with the core network through NR cell C.

[0166] The above method avoids the problem of failed voice data recovery caused by switching between cells of different standards (different systems), and failed voice bearer recovery after returning to the new cell of the original standard, which leads to dropped calls. For example, after failing to switch from an NR cell to an LTE cell, the voice bearer recovery fails after returning to the new NR cell, resulting in dropped calls.

[0167] Optionally, after the handover fails and the RLF process is triggered, if the reason for the RLF is not: the NR cell fails to switch to the LTE cell, or the terminal device is not in a call, or after searching the NR source cell, the signal quality of NR cell A is lower than the threshold, then the NR cell is selected to reside based on the signal quality / signal strength. In this embodiment, cell D has the highest signal quality / signal strength. After the terminal device selects cell D to reside, the terminal device accesses NR cell D. Since the interaction between cell D and the core network is abnormal, the interaction between the terminal device and the core network is abnormal.

[0168] That is to say, under this embodiment, the NR cell (NR cell D) selected under the dotted line process (if the cause of the RLF is not: the NR cell fails to switch to the LTE cell, or the terminal device is not in a call, or after searching the NR source cell, the signal quality of NR cell A is lower than the threshold) is different from the NR cell (NR cell C) switched under the solid line process (if the cause of the RLF is: the NR cell fails to switch to the LTE cell, and the terminal device is in a call, and after searching the NR source cell, the signal quality of NR cell A is higher than the threshold).

[0169] In a possible embodiment, during a non-call process and when residing in the fourth cell, if it is detected that the signal strength of the fourth cell is lower than the seventh threshold and the signal strength of the fifth cell is higher than the eighth threshold, a third measurement report is sent to the network device, and the third measurement report indicates that the signal strength of the fourth cell is lower than the seventh threshold and the signal strength of the fifth cell is higher than the eighth threshold; after receiving the third switching instruction sent by the network device to indicate switching to the fifth cell, the fifth cell is accessed; if access to the fifth cell fails, the RLF process is triggered and a neighboring cell is selected for residence.

[0170] See Figure 6 , Figure 6 A schematic structural diagram of a cell switching device 600 provided in an embodiment of the present application. Figure 6 The cell switching device shown may be a terminal device, or a device in the terminal device, or a device that can be used in conjunction with the terminal device. Figure 6 The cell switching device shown may include a communication unit 601 and an access unit 602.

[0171] The communication unit 601 is configured to, during a call and while camped on a first cell, send a first measurement report to a network device if it is detected that the signal strength of the first cell is lower than a first threshold and the signal strength of the second cell is higher than a second threshold, where the first measurement report indicates that the signal strength of the first cell is lower than the first threshold and the signal strength of the second cell is higher than the second threshold;

[0172] The access unit 602 is configured to access the second cell after receiving a first handover instruction sent by the network device to instruct handover to the second cell;

[0173] The access unit 602 is further configured to camp on the first cell if access to the second cell fails;

[0174] The communication unit 601 is further configured to, when camped on the first cell, send a second measurement report to the network device if it is detected that the signal strength of the third cell meets the measurement and reporting condition;

[0175] The access unit 602 is further configured to access the third cell after receiving a second handover instruction sent by the network device to instruct handover to the third cell.

[0176] In a possible implementation, the first cell is a New Radio (NR) type cell, the second cell is a Long Term Evolution (LTE) type cell, and the third cell is an NR cell.

[0177] In a possible implementation, the access unit 602 is further configured to camp on the first cell if access to the second cell fails and the signal quality of the first cell is higher than a fourth threshold.

[0178] In one possible implementation, the access unit 602 is further used to trigger the radio link failure process if access to the second cell fails; the access unit 602 is further used to reside in the first cell if the signal quality of the first cell is higher than the fourth threshold and the triggering cause of the radio link failure process is the failure of the NR cell to switch to the LTE cell.

[0179] In one possible implementation, the access unit 602 is further configured to reside in the first cell if the signal quality of the first cell is higher than a fourth threshold and the call is in progress, and the triggering cause of the radio link failure process is the failure of the NR cell to switch to the LTE cell.

[0180] In a possible implementation, the access unit 602 is further configured to reside in the NR cell with the highest signal quality based on the detected signal quality of each cell when the triggering cause of the radio link failure process is not the failure of the NR cell to switch to the LTE cell.

[0181] In a possible implementation, the access unit 602 is further configured to, if not in a call, reside on the NR cell with the highest signal quality based on the detected signal quality of each cell.

[0182] In one possible implementation, the communication unit 601 is further configured to, after failing to access the second cell, when camping on the first cell, not report to the network device that the signal strength of the second cell is higher than the second threshold if the signal strength of the second cell is detected to be higher than the second threshold;

[0183] The communication unit 601 is also used for, after failing to access the second cell, when residing in the first cell, if it is detected that the signal strength of the first cell is lower than the first threshold and the signal strength of the second cell is higher than the second threshold, not reporting to the network device that the signal strength of the first cell is lower than the first threshold and the signal strength of the second cell is higher than the second threshold.

[0184] For the case where the cell switching device can be a chip or a chip system, see Figure 7 Schematic diagram of the chip structure shown. Figure 7 The chip 700 shown includes a processor 701 and an interface 702. Optionally, it may also include a memory 703. The number of processors 701 may be one or more, and the number of interfaces 702 may be multiple.

[0185] For the case where the chip is used to implement the terminal device in the embodiment of the present application:

[0186] The interface 702 is used to receive or output signals;

[0187] The processor 701 is configured to execute data processing operations of the terminal device.

[0188] The above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present application.

[0189] It is understandable that some optional features in the embodiments of the present application may, in certain scenarios, be implemented independently without relying on other features, such as the solution on which they are currently based, to solve corresponding technical problems and achieve corresponding effects. They may also be combined with other features in certain scenarios as needed. Accordingly, the cell switching device provided in the embodiments of the present application may also implement these features or functions accordingly, which will not be described in detail here.

[0190] It should be understood that the processor in the embodiment of the present application can be an integrated circuit chip with signal processing capabilities. In the implementation process, each step of the above method embodiment can be completed by an integrated logic circuit of hardware in the processor or instructions in the form of software. The above processor can be a general-purpose processor, a digital signal processor (DSP), an application specific integrated circuit (ASIC), a field programmable gate array (FPGA) or other programmable logic device, discrete gate or transistor logic device, discrete hardware component.

[0191] It is understood that the memory in the embodiments of the present application may be a volatile memory or a non-volatile memory, or may include both volatile and non-volatile memories. Among them, the non-volatile memory may be a read-only memory (ROM), a programmable read-only memory (PROM), an erasable programmable read-only memory (EPROM), an electrically erasable programmable read-only memory (EEPROM), or a flash memory. The volatile memory may be a random access memory (RAM), which is used as an external cache. By way of example and not limitation, many forms of RAM are available, such as static RAM (SRAM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), double data rate SDRAM (DDR SDRAM), enhanced SDRAM (ESDRAM), synchronous link DRAM (SLDRAM), and direct RAM bus RAM (DR RAM). It should be noted that the memory of the systems and methods described herein is intended to include, but is not limited to, these and any other suitable types of memory.

[0192] The present application also provides a computer-readable storage medium, which stores a computer program. The computer program includes program instructions. When the program instructions are executed on a terminal device, the functions of any of the above method embodiments are implemented.

[0193] The present application also provides a computer program product, which, when executed on a computer, enables the computer to implement the functions of any of the above method embodiments.

[0194] In the above embodiments, all or part of the embodiments may be implemented by software, hardware, firmware, or any combination thereof. When implemented using software, all or part of the embodiments may be implemented in the form of a computer program product. The 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 processes or functions described in the embodiments of the present application are generated. The computer may be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. The computer instructions may be stored in a computer-readable storage medium or transmitted from one computer-readable storage medium to another computer-readable storage medium. For example, the computer instructions may be transmitted from one website, computer, server, or data center to another website, computer, server, or data center via a wired (e.g., coaxial cable, optical fiber, digital subscriber line (DSL)) or wireless (e.g., infrared, wireless, microwave, etc.) method. The computer-readable storage medium may be any available medium that a computer can access or a data storage device such as a server or data center that includes one or more available media integrated therein. The available medium may be a magnetic medium (eg, a floppy disk, a hard disk, a magnetic tape), an optical medium (eg, a high-density digital video disc (DVD)), or a semiconductor medium (eg, a solid state disk (SSD)).

[0195] The above description is merely a specific embodiment of the present application, but the scope of protection of the present application is not limited thereto. Any changes or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in this application should be included in the scope of protection of this application. Therefore, the scope of protection of this application should be based on the scope of protection of the claims.

Claims

1. A cell handover method, characterized in that: The method comprises: During a call, and when camping on a first cell, if it is detected that the signal strength of the first cell is lower than a first threshold and the signal strength of a second cell is higher than a second threshold, a first measurement report is sent to a network device, where the first measurement report indicates that the signal strength of the first cell is lower than the first threshold and the signal strength of the second cell is higher than the second threshold, the first cell is an NR cell, and the second cell is an LTE cell; After receiving a first handover instruction sent by the network device and used to instruct handover to the second cell, access the second cell; If access to the second cell fails, a radio link failure process is triggered; If the signal quality of the first cell is higher than a fourth threshold and the call is in progress, and the triggering cause of the radio link failure process is the failure of the NR cell to switch to the LTE cell, camping on the first cell; When camping on the first cell and in a call, suppressing B1 events of all cells and / or suppressing B2 events of all cells, the B1 events and the B2 events being measurement events for a different system; If it is detected that the signal strength of the third cell meets the measurement and reporting condition, sending a second measurement report to the network device, where the third cell is an NR cell; After receiving the second switching instruction sent by the network device to instruct switching to the third cell, access the third cell.

2. The method according to claim 1, characterized in that When access to the second cell fails, after triggering the radio link failure process, the method further includes: When the triggering cause of the radio link failure process is not the failure of NR cell switching to LTE cell, based on the signal quality of each detected cell, reside in the NR cell with the highest signal quality / signal strength.

3. The method according to claim 2, characterized in that The method further comprises: If not in a call, based on the signal quality of each cell detected, it will reside in the NR cell with the highest signal quality / signal strength.

4. The method according to any one of claims 1 to 3, characterized in that The method further comprises: After failing to access the second cell, when camping on the first cell, if it is detected that the signal strength of the second cell is higher than the second threshold, not reporting to the network device that the signal strength of the first cell is lower than the first threshold; Alternatively, after failing to access the second cell, when residing in the first cell, if it is detected that the signal strength of the first cell is lower than the first threshold and the signal strength of the second cell is higher than the second threshold, the fact that the signal strength of the first cell is lower than the first threshold and the signal strength of the second cell is higher than the second threshold is not reported to the network device.

5. A terminal device comprising one or more memories and one or more processors, characterized in that: The memory is used to store a computer program; the processor is used to call the computer program, so that the terminal device executes the method according to any one of claims 1 to 4.

6. A chip system, applied to a terminal device, characterized in that: The chip system includes at least one processor and an interface, wherein the interface is used to receive instructions and transmit them to the at least one processor; the at least one processor runs the instructions so that the terminal device executes the method according to any one of claims 1 to 4.

7. A computer storage medium, characterized in that include: Computer instructions; when the computer instructions are executed on a terminal device, the terminal device executes the method according to any one of claims 1 to 4.

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