Communication method and related device

Abstract

Disclosed in the present application are a communication method and a related device. The communication method comprises: a terminal device camps on a serving cell to perform a service such as a call and Internet access; when determining that reporting conditions of a preset measurement event are satisfied and that signals of the serving cell and signals of neighboring cells thereof satisfy certain conditions, the terminal device can start a timer T1, and, when the timer T1 times out and the terminal device fails to receive a handover message, trigger an RLF process; according to the RLF process, the terminal device performs cell selection, sends an RRC reestablishment request to a network device corresponding to a cell selected thereby, so as to establish an RRC connection with the network device corresponding to the cell selected thereby, and, on the basis of the RRC connection, continues to perform the service. The method can reduce the service stalling duration caused by failed cell handover, thus improving the communication experience of users during services.

Description

A communication method and related equipment

[0001] This application claims priority to the Chinese patent application filed with the China Patent Office on July 21, 2023, with application number 202310912125.0 and application name “A Communication Method and Related Equipment”, the entire contents of which are incorporated by reference into this application. Technical Field

[0002] The present application relates to the field of terminal technology, and in particular to a communication method and related equipment. Background Art

[0003] In the cell switching process, the network device sends a measurement control message to the terminal device. After receiving the measurement control message, the terminal device measures the "surrounding cells" (for example, adjacent cells) based on the measurement control message, and sends a measurement report to the network device. After receiving the measurement report, the network device makes a judgment on whether the terminal device switches to other cells, and sends a switching message to the terminal device (such as an RRC connection reconfiguration message carrying an indication of switching to other cells). After receiving the switching message, the terminal device performs cell switching based on the switching message. It can be understood that RRC refers to Radio Resource Control (RRC).

[0004] Based on the above content, it can be seen that the cell switching process is controlled by the network equipment, and the terminal equipment only performs measurements, reports and switches based on the instructions issued by the network equipment. In a communication system, such as a New Radio (NR) system or a Long Term Evolution (LTE) system, when the signal of the cell where the terminal equipment is currently resident becomes weak, due to factors such as the rapid attenuation of the signal channel quality, unreasonable configuration of the measurement and reporting threshold, rapid movement of the terminal equipment and obstruction by objects, long duration of measurement or switching preparation, or the terminal equipment's inability to decode the switching message sent by the network equipment, it will lead to a delay in switching to other cells with better signals, causing the services in the current resident cell to be stuck for a long time, affecting the user experience.

[0005] Therefore, how to reduce the service freeze duration in cell switching scenarios is an urgent problem to be solved.

[0006] Summary of the Invention

[0007] Embodiments of the present application provide a communication method and related devices to reduce service interruption duration in cell handover scenarios. In some embodiments, by triggering an RLF process in advance when a cell handover fails or takes too long to successfully switch to another cell, a cell with a better signal can be selected for access, thereby reducing service interruption duration for terminal devices and improving the user's communication experience during services.

[0008] In a first aspect, an embodiment of the present application provides a communication method, characterized in that the method is applied to a terminal device; the method includes: the terminal device resides on a first cell to perform a service; the terminal device determines whether a reporting condition of a preset measurement event is met, and determines whether the signal of the first cell and the signal of the adjacent cell of the first cell meet the preset condition; when the reporting condition of the preset measurement event is met, and the signal of the first cell and the signal of the adjacent cell of the first cell meet the preset condition, the terminal device starts a first timer; when the first timer times out but the terminal device does not receive a switching message, the terminal device triggers a radio link failure RLF process in advance; according to the RLF process, the terminal device performs cell selection and chooses to reside in a second cell; according to the RLF process, the terminal device establishes an RRC connection with the network device corresponding to the second cell through a radio resource control RRC re-establishment process; the terminal device continues to perform the service through the RRC connection. The first cell is the current serving cell of the terminal device; the switching message is used to instruct the terminal device to perform a cell switch.

[0009] In the solution provided in the embodiments of the present application, a terminal device can start a first timer to control the time at which the terminal device triggers the RLF process when the reporting conditions of the preset measurement time are met and the signal of the currently resident cell and the signal of the neighboring cell of the cell meet the preset conditions. This shortens the triggering time of the RLF process, thereby allowing the terminal device to select a cell with a better signal for access as soon as possible, thereby reducing the duration of service freezes during the terminal device's service and improving the user's communication experience in the service. The service may be a call service. If the call service freezes for a long time, it will significantly affect the user experience.

[0010] In some embodiments of the present application, the first cell may be cell B.

[0011] In some embodiments of the present application, the second cell may be cell C. It is understandable that the second cell may also be other cells (eg, other neighboring cells of cell B), and the present application does not impose any specific limitation on this.

[0012] In some embodiments of the present application, the first timer may be timer T1.

[0013] In combination with the first aspect, in one possible implementation, the preset conditions may include: the signal quality of the first cell is less than or equal to a first preset threshold, the signal quality of the second cell is greater than the signal quality of the first cell, and the difference between the signal quality of the second cell and the signal quality of the first cell is greater than or equal to a second preset threshold.

[0014] In the solutions provided in some embodiments of the present application, the second cell may be an adjacent cell of the first cell. When the reporting conditions of the preset measurement event are met, and the signal quality of the first cell is poor, and the signal quality of the second cell is better than the signal quality of the first cell to a certain extent, the terminal device triggers the start of the first timer to shorten the duration of triggering the RLF process. In other cases, the possibility of successful cell switching may be greater or the time consumed may be shorter, and the terminal device may no longer need to consume resources to perform the above operations. This method can be used in different scenarios to achieve access to a cell with a better signal as soon as possible.

[0015] In some embodiments of the present application, the second cell may be one of the one or more neighboring cells of the first cell.

[0016] In some embodiments of the present application, the first preset threshold may be preset threshold 1.

[0017] In some embodiments of the present application, the second preset threshold may be preset threshold 2.

[0018] In conjunction with the first aspect, in one possible implementation, the signal quality of the first cell is less than or equal to a first preset threshold, which may specifically include at least one of the following: the signal-to-noise ratio of the first cell is less than or equal to the first threshold; or the reference signal received power of the first cell is less than or equal to a second threshold; or the reference signal received quality of the first cell is less than or equal to a third threshold. The signal quality of the second cell is greater than the signal quality of the first cell, and the difference between the signal quality of the second cell and the signal quality of the first cell is greater than or equal to the second preset threshold, which may specifically include at least one of the following: the signal-to-noise ratio of the second cell is greater than or equal to the signal-to-noise ratio of the first cell, and the difference between the signal-to-noise ratio of the second cell and the signal-to-noise ratio of the first cell is greater than or equal to a fourth threshold; or the reference signal received power of the second cell is greater than or equal to the reference signal received power of the first cell, and the difference between the reference signal received power of the second cell and the reference signal received power of the first cell is greater than or equal to a fifth threshold; or the reference signal received quality of the second cell is greater than or equal to the reference signal received quality of the first cell, and the difference between the reference signal received quality of the second cell and the reference signal received quality of the first cell is greater than or equal to a sixth threshold.

[0019] In some embodiments of the present application, a terminal device can measure the signal quality of a cell using at least one of parameters such as SNR, RSRP, and RSRQ. In particular, the terminal device can combine different parameters to measure the signal quality of a first cell and a second cell. This approach can improve the accuracy of the terminal device's measurement of the signal quality of the first cell and the second cell.

[0020] In some embodiments of the present application, the first threshold may be threshold_1, the second threshold may be threshold_2, the third threshold may be threshold_3, the fourth threshold may be threshold_4, the fifth threshold may be threshold_5, and the sixth threshold may be threshold_6.

[0021] In combination with the first aspect, in a possible implementation, the method may further include: when a reporting condition of the preset measurement event is met, the terminal device sends at least one preset measurement report, and the preset measurement report corresponds to the preset measurement event. The terminal device triggers the RLF process in advance, including: the duration from the first time the terminal device sends the preset measurement report to the timeout of the first timer is less than the duration from the first time the terminal device sends the preset measurement report to the timeout of timer T310.

[0022] In some embodiments of the present application, the duration defined by the first timer can be set based on the duration defined by timer T310. Timer T310 expiration is one of the reasons for triggering the RLF procedure. This approach can shorten the duration of triggering the RLF procedure, allowing the terminal device to trigger the RLF procedure earlier, thereby allowing the terminal device to access a cell with a better signal as soon as possible and reducing the duration of service interruptions during the terminal device's service.

[0023] With reference to the first aspect, in a possible implementation, the terminal device triggering the RLF process in advance includes: the duration of the first timer is less than the duration of timer T310.

[0024] It can be understood that the duration of the timer mentioned in this application and the duration defined by the timer have the same meaning.

[0025] With reference to the first aspect, in a possible implementation manner, the terminal device triggers the RLF process in advance, including: the duration of the first timer is 300 milliseconds or 500 milliseconds.

[0026] With reference to the first aspect, in a possible implementation, the terminal device triggering the RLF process in advance includes:

[0027] The duration from the first time the terminal device sends the preset measurement report corresponding to the preset measurement event to the timeout of the first timer satisfies at least one of the following: less than the duration from the first time the terminal device sends the preset measurement report to the occurrence of an uplink listen-before-talk LBT failure; less than the duration from the first time the terminal device sends the preset measurement report to the receipt of a random access problem indication from the main cell group media access control MCG MAC; less than the duration from the first time the terminal device sends the preset measurement report to the time the number of retransmissions of the main cell group radio link control MCG RLC reaches the maximum value; less than the duration from the first time the terminal device sends the preset measurement report to the receipt of a backhaul link radio link failure BH RLF indication on the backhaul adaptation protocol BAP entity.

[0028] In some embodiments of the present application, the duration defined by the first timer can be set based on the reason for triggering the RLF procedure. This approach can shorten the duration of triggering the RLF procedure, allowing the terminal device to trigger the RLF procedure in advance, thereby allowing the terminal device to access a cell with a better signal as soon as possible and reducing the duration of service interruptions during the terminal device's service.

[0029] In combination with the first aspect, in a possible implementation method, the moment when the terminal device starts the first timer is earlier than the moment when the terminal device first sends the preset measurement report corresponding to the preset measurement event to the network device corresponding to the first cell, and the interval between the moment when the terminal device starts the first timer and the moment when the terminal device first sends the preset measurement report to the network device corresponding to the first cell is short; or the moment when the terminal device starts the first timer is later than the moment when the terminal device first sends the preset measurement report to the network device corresponding to the first cell, and the interval between the moment when the terminal device starts the first timer and the moment when the terminal device first sends the preset measurement report to the network device corresponding to the first cell is short; or the moment when the terminal device starts the first timer is the same as the moment when the terminal device first sends the preset measurement report to the network device corresponding to the first cell.

[0030] With reference to the first aspect, in a possible implementation, the preset measurement event may be event A3 or event A5.

[0031] With reference to the first aspect, in a possible implementation manner, the second cell is a cell with the strongest signal among one or more neighboring cells of the first cell.

[0032] In a second aspect, some embodiments of the present application provide 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, the memory being used to store computer program code, the computer program code comprising computer instructions, the one or more processors calling the computer instructions to enable the terminal device to execute the method described in the first aspect or any one of the implementations of the first aspect.

[0033] In a third aspect, some embodiments of the present application provide a computer storage medium comprising computer instructions, which, when executed on a terminal device, enable the terminal device to execute the method described in the first aspect or any one of the implementations of the first aspect.

[0034] In a fourth aspect, an embodiment of the present application provides a chip system for use in a terminal device, the chip system comprising at least one processor and an interface, the interface being used to receive instructions and transmit them to the at least one processor; the at least one processor executes the instructions, causing the terminal device to execute the method described in the first aspect or any one of the implementations of the first aspect.

[0035] In some embodiments of the present application, the chip system may be a modem (modulation and demodulation processor), that is, a baseband processor.

[0036] In some other embodiments of the present application, the chip system may include a modem and other modules, such as an AP (Application Processor) or a GPU (Graphics Processing Unit).

[0037] In a fifth aspect, an embodiment of the present application provides a computer program product comprising instructions, which, when executed on a terminal device, enables the terminal device to execute the method described in the first aspect or any one of the implementations of the first aspect.

[0038] It is understood that the terminal device provided in the second aspect, the computer storage medium provided in the third aspect, the chip system provided in the fourth aspect, and the computer program product provided in the fifth aspect are all used to perform the method described in the first aspect or any one of the implementations of the first aspect. Therefore, the beneficial effects that can be achieved can be referenced to the beneficial effects of any possible implementation of the first aspect, and will not be repeated here. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] FIG1 is a schematic diagram of a switching process provided in an embodiment of the present application;

[0040] FIG2 is a schematic diagram of a network architecture provided in an embodiment of the present application;

[0041] FIG3 is a flow chart of a communication method provided in an embodiment of the present application;

[0042] FIG4 is a flow chart of another communication method provided in an embodiment of the present application;

[0043] FIG5 is a schematic diagram of the hardware structure of a terminal device provided in an embodiment of the present application;

[0044] FIG6 is a schematic diagram of the software structure of a terminal device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0045] 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.

[0046] 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.

[0047] 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.

[0048] First, some of the terms and related technologies involved in this application are explained to facilitate understanding by those skilled in the art.

[0049] 1. Cell

[0050] A cell is an area within the wireless coverage of a network device (e.g., a base station). Within this area, terminal devices can reliably communicate with the network device via wireless signals. It can be understood that the coverage area of ​​each network device can be divided into one or more cells, and each cell can correspond to one or more frequencies. It can also be understood that each cell is an area formed by the coverage area of ​​one or more frequencies.

[0051] In some embodiments of the present application, different cells may correspond to the same network device. That is, the network device to which cell A belongs and the network device to which cell B belongs may be the same network device. For example, cell A and cell B may be managed by the same base station. In this case, cell A and cell B may be co-located.

[0052] In some embodiments of the present application, different cells may correspond to different network devices. That is, the network device to which cell A belongs and the network device to which cell B belongs may be different network devices. For example, cell A and cell B may be managed by different base stations. For another example, cell A and cell B may be managed by the same base station, but the radio frequency processing units corresponding to cell A and cell B may be different radio frequency processing units within the same base station.

[0053] A neighboring cell, or adjacent cell, is an area within the wireless coverage of network equipment that is physically adjacent to the current serving cell and transmits signals on the same or different frequencies. In other words, a neighboring cell is a cell that is adjacent to or adjacent to the current serving cell. In layman's terms, a neighboring cell can be understood as a "surrounding cell" of the current serving cell.

[0054] 2. Cell Handover (HO)

[0055] Cell handover is the process of migrating the communication link between a terminal device and its current network device to another network device in mobile communications. In wireless communication systems, when a terminal device moves from one cell to another or approaches another, a cell handover is necessary to maintain uninterrupted communication.

[0056] Cell handover can be intra-site handover or inter-site handover, which is not specifically limited in this application. Intra-site handover means that the source cell and the target cell belong to the same network device (e.g., base station). Inter-site handover means that the source cell and the target cell belong to different network devices (e.g., base stations).

[0057] In this application, the source cell refers to the cell that provides services to the terminal device before the cell handover, and the target cell refers to the cell that provides services to the terminal device after the cell handover. For ease of description, this application refers to the network device corresponding to the source cell as the source network device, and the network device corresponding to the target cell as the target network device. It is understood that the source network device and the target network device can be the same network device or different network devices.

[0058] The following describes the measurement-based cell switching process.

[0059] Step 1: The source network device sends a measurement control message to the terminal device.

[0060] The measurement control message can be an RRC connection reconfiguration message (RRC Connection Reconfiguration) carrying a measConfig information element. The measurement control message is sent to the terminal device in the form of measId. measId is the index of the database measurement configuration entry. Each measId corresponds to two elements: measObjectId and reportConfigId. measObjectId is the measurement object identifier, which corresponds to a measurement object configuration item. reportConfigId is the measurement report identifier, which corresponds to a measurement report configuration item. These two elements are at the beginning of the same measConfig information element. Simply put, the network device compiles several measurement configuration items into a mapping relationship table, and sends the configuration and mapping relationship corresponding to the mapping relationship table to the terminal. When the terminal device subsequently sends a measurement report to the network device, it will carry the corresponding measId so that the network device can correctly parse and process the measurement data.

[0061] Correspondingly, the terminal device can receive the measurement control message sent by the source network device.

[0062] Step 2: The terminal device performs measurement configuration based on the measurement control message and sends a measurement report to the source network device.

[0063] The terminal device measures the "peripheral cells" (including the source cell and the adjacent cells of the source cell) on the specified RAT and frequency based on the measurement configuration items included in the measurement control message sent by the network device, and sends a measurement report corresponding to the measurement event indicated by the measurement control message to the source network device.

[0064] Correspondingly, the source network device may receive the measurement report sent by the terminal device.

[0065] Step 3: The source network device makes a switching decision and prepares for switching.

[0066] After receiving the measurement report sent by the terminal device, the source network device makes a handover decision based on the measurement report and determines the target cell. In other words, the source network device determines the cell to handover to based on the measurement report. After making the handover decision, the source network device can prepare for the handover, i.e., reserve resources (for example, the source network device requests the target network device to prepare the resources required by the terminal device) and generate an RRC connection reconfiguration message.

[0067] Step 4: The source network device sends an RRC connection reconfiguration message to the terminal device.

[0068] After the source network device makes a handover decision and prepares for the handover, it can execute the handover. Specifically, the source network device sends an RRC Connection Reconfiguration message to the terminal device. The RRC Connection Reconfiguration message includes the parameters required for the terminal device to access the target cell. The parameters required for the terminal device to access the target cell may include radio resource configuration such as cell ID, carrier frequency, and target power, as well as physical resource configuration.

[0069] For a long term evolution (LTE) network, the source network device notifies the terminal device of relevant information about the target cell through the mobilityControlInfo information element (IE) included in the RRC connection reconfiguration message.

[0070] For the New Radio (NR) network, the source network device informs the terminal device of the relevant information of the target cell through the reconfigurationWithSync in the spCellConfig included in the RRC connection reconfiguration message.

[0071] Correspondingly, the terminal device can receive the RRC connection reconfiguration message sent by the source network device.

[0072] Step 5: The terminal device switches to the target cell based on the RRC connection reconfiguration message and sends an RRC connection reconfiguration completion message to the target cell.

[0073] After receiving the RRC Connection Reconfiguration message from the source network device, the terminal device terminates the wireless connection with the source network device and begins establishing a new wireless connection with the target network device. During this process, data transmission is interrupted. This process includes steps such as downlink synchronization establishment, timing advance, and data transmission. When the terminal device successfully establishes a wireless connection with the target network device, it sends an RRC Connection Reconfiguration Complete message to the target network device, indicating that the handover process is complete for the terminal device.

[0074] 3. Measurement Report (MR)

[0075] The 3rd Generation Partnership Project (3GPP) specifications propose a set of predefined measurement reporting mechanisms to be performed by terminal devices. These predefined measurement reporting types are called "events." The type of "event" that a terminal device must report is specified by the RRC signaling message sent by the network device (for example, the RRC Connection Reconfiguration message in the first step of the handover procedure described above).

[0076] The following describes in detail the event types of measurement reports.

[0077] (1) Event types for switching within the system

[0078] Event A1: Serving cell quality exceeds an absolute threshold (Serving becomes better than threshold), unit: dBm.

[0079] Event A2: Serving cell quality becomes worse than a threshold (unit: dBm).

[0080] Event A3: The neighboring cell (or neighboring cell, i.e., adjacent cell) is better than the current serving cell by a relative value (Neighbour becomes offset better than SpCell), in dB.

[0081] Event A4: Neighbor cell quality exceeds an absolute threshold (Neighbor becomes better than threshold), unit: dBm.

[0082] Event A5: The serving cell quality is lower than an absolute threshold threshold1, and the neighbor cell quality is higher than an absolute threshold threshold2 (SpCell becomes worse than threshold1 and neighbor becomes better than threshold2), unit: dBm.

[0083] Event A6: The quality of the neighboring cell is higher than that of the secondary cell (SCell) by an absolute threshold (Neighbor becomes offset better than SCell), in dB.

[0084] (2) Event types for inter-system switching

[0085] Event B1: Inter RAT neighbor becomes better than threshold, unit: dBm.

[0086] Event B2: The serving cell falls below an absolute threshold threshold1, and the inter-RAT neighbor cell is better than an absolute threshold threshold2 (PCell becomes worse than threshold1 and inter RAT neighbor becomes better than threshold2), unit: dBm.

[0087] It can be understood that the measurement event corresponding to the measurement report and the event type corresponding to the measurement report mentioned in this application have the same meaning.

[0088] 4. Community selection

[0089] There are two scenarios for cell selection:

[0090] (1) Initial cell selection

[0091] If a terminal device does not store any Evolved Universal Terrestrial Radio Access (E-UTRA) carrier frequency information (for example, when the terminal device is powered on for the first time), it can scan all E-UTRA frequency bands based on its capabilities. Once a suitable cell is found, the terminal device selects that cell for camping. It is important to note that on each carrier frequency, the terminal device only searches for the cell with the best signal quality.

[0092] (2) Cell selection based on stored information

[0093] If the terminal device has previously stored some E-UTRA carrier frequency information and some cell parameter information, it can prioritize searching for these carrier frequencies and cells. Once a suitable cell is found, the terminal device selects it for camping. If no suitable cell is found in the stored information, the terminal device will proceed with the initial cell selection described above.

[0094] It should be noted that the above “finding a suitable cell” means that the cell meets the S criterion and the terminal device is allowed to reside in the cell.

[0095] It is worth noting that during the cell selection process, regardless of whether the terminal device stores carrier frequency information, the terminal device will not select a cell based on carrier frequency priority, but only based on the cell signal quality and S criterion.

[0096] S-qualified means: Srxlev > 0 and Squal > 0. In other words, if a cell meets the S-qualified condition, it must also meet both Srxlev > 0 and Squal > 0. The specific meanings of Srxlev and Squal can be found in relevant technical documentation and are not explained here.

[0097] Based on the above content, it can be known that: cell switching is controlled by the network equipment, and the terminal equipment only performs measurements, reports and switches based on the instructions issued by the network equipment. In the communication system, when the signal of the cell where the terminal equipment is currently resident becomes weak, the measurement report may not be sent to the network equipment due to factors such as the rapid attenuation of the signal channel quality or the unreasonable configuration of the measurement and reporting threshold. The network equipment cannot receive the measurement report and is unaware that the terminal equipment may try to send a measurement report, resulting in a delay in switching to other cells with better signals, causing the services in the current resident cell (i.e., the service cell) to be stuck for a long time. In addition, the rapid movement of the terminal equipment and the obstruction of objects, the long duration of measurement or switching preparation, or the inability of the terminal equipment to decode the switching message sent by the network equipment may result in the inability to switch to other cells with better signals in time, causing the services in the current resident cell to be stuck for a long time.

[0098] Especially in the high-speed rail scenario, due to the high speed of the train and the obstruction of objects such as caves, the signal will frequently decay rapidly to a poor value. At this time, even if the terminal device reports event A3, it may not be able to successfully send the A3 MR (that is, the measurement report with event type A3) to the network device. Therefore, the terminal device may not be able to receive the HO command sent by the network device, resulting in worse and worse signals and eventually radio link failure (Radio Link Failure, RLF). In this case, the terminal device can only resume service (for example, resume calls) after selecting a cell with a better signal through cell selection. It can be understood that in the above process, the service interruption time is long, that is, the freeze time is long, which affects the user experience.

[0099] The following describes the normal process of cell switching and the process of service interruption caused by abnormal cell switching with reference to Figure 1.

[0100] 1. Normal process of cell switching

[0101] As shown in Figure 1, the terminal device resides on cell A and is in service (e.g., making a call, surfing the Internet, etc.). That is, the terminal device is performing services such as making a call, surfing the Internet, etc. based on the wireless connection between it and the network device corresponding to cell A. The network device corresponding to cell A can send a measurement control message to the terminal device. The terminal device can measure the neighboring cells of cell A based on the measurement control message. The neighboring cells of cell A include cell B. At this time, the terminal device is moving from cell A to cell B, the signal of cell A becomes weaker, and the signal of cell B becomes stronger. Based on the measurement results, the terminal device determines that the reporting conditions of event A3 are currently met. The terminal device sends an A3 MR to the network device corresponding to cell A. After receiving the A3 MR, the network device corresponding to cell A makes a handover judgment based on the A3 MR, determines that the target cell is cell B, and prepares for the handover (e.g., the network device corresponding to cell A communicates with the network device corresponding to cell B to determine whether cell B allows the terminal device to access). After the handover preparation is completed, the network device corresponding to cell A sends an RRC connection reconfiguration message to the terminal device. The RRC connection reconfiguration message is used to instruct the terminal device to switch to cell B. The terminal device switches from cell A to cell B based on the parameters in the RRC connection reconfiguration message, and after the handover is complete, it sends an RRC connection reconfiguration complete message to the network device corresponding to cell B. In this case, the terminal device can stay in cell B for services such as calls and Internet access.

[0102] 2. Process of service interruption caused by abnormal cell switching

[0103] As shown in Figure 1, the network device corresponding to cell B can send a measurement control message to the terminal device. Based on this measurement control message, the terminal device can measure cell B and its neighboring cells. Cell B's neighboring cells include cell C. At this time, the terminal device is moving from cell B to cell C, and the signal in cell B is weakening, while the signal in cell C is strengthening. Based on the measurement results, the terminal device determines that the reporting conditions for event A3 are currently met. The terminal device sends an A3 MR to the network device corresponding to cell B. The network device corresponding to cell B cannot successfully receive the A3 MR. The terminal device can send A3 MRs to the network device corresponding to cell B multiple times. It is understandable that if the network device corresponding to cell B continues to fail to successfully receive the A3 MR, the terminal device's received signal will continue to deteriorate, causing lag or even service interruption.

[0104] When the terminal device cannot switch to cell C and meets certain conditions (for details, please refer to the causes of triggering RLF in the 3GPP protocol), the terminal device will experience RLF and perform cell selection, choosing to reside in cell C. The terminal device establishes an RRC connection with the network device corresponding to cell C. In this case, the jam is recovered, that is, the terminal device resumes service. That is to say, in this case, the terminal device can be conducting services such as calls and Internet access based on the wireless connection between it and the network device corresponding to cell C.

[0105] In some embodiments of the present application, the network device corresponding to cell B may receive an A3 MR and send a handover message to the terminal device (such as an RRC connection reconfiguration message carrying a handover indication, which may instruct the terminal device to handover to another cell). The terminal device may not be able to receive the handover message or may not be able to decode the handover message.

[0106] The embodiments of the present application provide a communication method and related equipment. According to the communication method, the terminal device can perform services such as calls and Internet access on the source cell. The terminal device can also start timer T1 when it determines that the reporting conditions of the preset measurement event are met and that the signal of the source cell and the signal of its adjacent cell meet certain conditions, and trigger the RLF process when timer T1 times out and the terminal device does not receive a switching message. According to the RLF process, the terminal device selects a cell and sends an RRC re-establishment request to the network device corresponding to the cell it selects to establish an RRC connection with the network device corresponding to the cell it selects, and continues the above-mentioned service based on the RRC connection. This method can reduce the service freeze duration caused by unsuccessful cell switching and improve the user's communication experience in the service.

[0107] In order to better understand the communication method and related equipment provided in the embodiment of the present application, the network architecture used in the embodiment of the present application is described below.

[0108] The network architecture used in the embodiments of the present application may include at least two cells and at least one terminal device.

[0109] For example, please refer to Figure 2, which is a schematic diagram of a network architecture provided in an embodiment of the present application. As shown in Figure 2, the network architecture may include a terminal device, a cell A belonging to network device _a, a cell B belonging to network device _b, and a cell C belonging to network device _c. As shown in Figure 2, the cell in which the terminal device is currently residing is cell B, and the movement trajectory of the terminal device is from cell A to cell B, and then from cell B to cell C. Among them, cell C is a neighboring cell of cell B (i.e., an adjacent cell). That is to say, cell C is a cell in at least one neighboring cell of cell B. Similarly, cell B is a cell in at least one neighboring cell of cell A.

[0110] It is understandable that the network architecture provided in the embodiments of the present application may also include more cells, and the present application does not impose any restrictions on this.

[0111] In some embodiments of the present application, a network device may correspond to one or more cells. Cell A, cell B, and cell C may belong to the same network device. That is, network device_a, network device_b, and network device_c may be the same network device. In this case, the terminal device performs handover within the network device. Optionally, cell A, cell B, and cell C may belong to different network devices. That is, network device_a, network device_b, and network device_c may not be completely identical. Cell A, cell B, and cell C may belong to different network devices, specifically: at most two of the network devices to which cell A belongs, the network device to which cell B belongs, and the network device to which cell C belongs are identical.

[0112] The technical solutions of the embodiments of the present application can be applied to various communication systems, such as: Global System for Mobile Communication (GSM) system, Code Division Multiple Access (CDMA) system, Wideband Code Division Multiple Access (WCDMA) system, General Packet Radio Service (GPRS), LTE system, LTE Frequency Division Duplex (FDD) system, LTE Time Division Duplex (TDD) system, Universal Mobile Telecommunications System (UMTS) system, Enhanced Data Rate for GSM Evolution (EDGE) system, Worldwide Interoperability for Microwave Access (WiMAX) system. The technical solutions of the embodiments of the present application can also be applied to other communication systems, such as Public Land Mobile Network (PLMN) system, fifth generation (5G) system or communication system after 5G or new radio (NR), etc., and the embodiments of the present application are not limited to this.

[0113] The terminal device in the embodiments of the present application may also be referred to as user equipment (UE), user terminal, mobile station (MS), mobile terminal (MT), etc. The terminal device may be a device that includes wireless transceiver functions and can cooperate with network equipment to provide communication services to users. The terminal device can be a handheld terminal, a laptop computer, a subscriber unit (SU), a cellular phone, a smart phone, a wireless data card, a personal digital assistant (PDA) computer, a tablet computer, a wireless modem (modem), a handheld device (handheld), a laptop computer (Laptop Computer), a cordless phone (Cordless Phone) or a wireless local loop (WLL) station, a machine type communication (MTC) terminal, a wearable device (such as a smart watch, a smart bracelet, a pedometer, etc.), an in-vehicle device (such as a car, a bicycle, an electric car, an airplane, a ship, a train, a high-speed rail, etc.), a virtual reality (VR) device, an augmented reality (AR) device, a wireless terminal in industrial control (Industrial Control), a smart home device (such as a refrigerator, a television, an air conditioner, an electric meter, etc.), an intelligent robot, a workshop device, a wireless terminal in self-driving, a remote medical device (Remote Medical Surgery), wireless terminals in smart grids, wireless terminals in transportation safety, wireless terminals in smart cities, wireless terminals in smart homes, flying equipment (for example, smart robots, drones) or wireless terminals in 5G networks or future communication networks, etc., which are not specifically limited in the embodiments of the present application.

[0114] The network device in the embodiment of the present application can be a device for communicating with a terminal device. For example, the network device can be a base station (Base Transceiver Station, BTS) in a Global System for Mobile Communications (GSM) system or Code Division Multiple Access (CDMA), or a base station (NodeB, NB) in a Wideband Code Division Multiple Access (WCDMA) system, or an evolved base station (eNB or eNodeB) in an LTE system, or a wireless controller in a Cloud Radio Access Network (CRAN) scenario, or the network device can be a relay station, an access point, a vehicle-mounted device, a wearable device, and a network device in a future 5G network or a network after 5G, or a network device in a future evolved PLMN network, etc., for example, a transmission point (TRP or TP) in an NR system, a base station (gNB) in an NR system, one or a group (including multiple antenna panels) of antenna panels of a base station in a 5G system, etc., and the embodiment of the present application is not limited to this.

[0115] Optionally, the base station in the embodiment of the present application may include various forms of base stations, such as: macro base stations, micro base stations (also called small stations), relay stations, access points, next-generation base stations (gNodeB, gNB), transmission points (Transmitting and Receiving Point, TRP), transmission points (Transmitting Point, TP), mobile switching centers, and devices that perform base station functions in device-to-device (D2D), vehicle-to-everything (V2X), and machine-to-machine (M2M) communications, etc. The embodiment of the present application does not specifically limit this.

[0116] The embodiments of the present application do not specifically limit the specific structure of the execution subject of the method provided in the embodiments of the present application; as long as it is capable of communicating according to the method provided in the embodiments of the present application by running a program that records the code of the method provided in the embodiments of the present application, it is sufficient. For example, the execution subject of the method provided in the embodiments of the present application can be a terminal device or a network device, or a functional module in the terminal device or the network device that can call and execute the program.

[0117] Based on the above network architecture, a communication method provided in an embodiment of the present application is introduced below.

[0118] Please refer to Figure 3, which is a flow chart of a communication method provided in an embodiment of the present application. The communication method may include but is not limited to the following steps:

[0119] S101: The terminal device resides in cell B to perform services.

[0120] It can be understood that the current serving cell of the terminal device is cell B. That is, cell B is the source cell. The terminal device can reside in cell B for services such as calls and Internet access.

[0121] In some embodiments of the present application, the terminal device originally resides in cell A, and subsequently resides in cell B through cell selection / cell reselection / HO, etc. (as shown in FIG2 ).

[0122] S102: The terminal device determines whether a reporting condition of a preset measurement event is met, and determines whether a signal of cell B and a signal of a neighboring cell of cell B meet a preset condition. Network device_b is a network device corresponding to cell B.

[0123] It is understandable that when the terminal device resides on cell B for business, the network device corresponding to cell B (i.e., network device_b) can send a measurement control message to the terminal device. The measurement control message may include several measurement configuration items. After receiving the measurement control message, the terminal device can measure cell B and its adjacent cells based on the several measurement configuration items included in the measurement control message to obtain measurement results. The terminal device can determine whether the reporting conditions for the measurement report of a certain event type indicated by the measurement control message are met based on the measurement results. If so, the terminal device sends the corresponding measurement report to network device_b. It is understandable that the relevant descriptions of the measurement control message and the measurement configuration items can refer to the technical documents of the above and relevant standards and will not be repeated here.

[0124] It is understandable that the terminal device can determine whether the reporting conditions of the preset measurement event are met based on the measurement results, and can also determine whether the signal of cell B and the signal of the neighboring area of ​​cell B meet the preset conditions based on the measurement results. If the terminal device determines that the reporting conditions of the preset measurement event are met, and determines that the signal of cell B and the signal of the neighboring area of ​​cell B meet the preset conditions, the terminal device can execute step S103. It is understandable that this application does not limit the order in which the terminal device determines whether the reporting conditions of the preset measurement event are met and the terminal device determines whether the signal of cell B and the signal of the neighboring area of ​​cell B meet the preset conditions. For details, please refer to the following text and will not be explained in detail here.

[0125] In some embodiments of the present application, after the terminal device determines that the reporting conditions for the preset measurement event are met, the terminal device may further determine whether the signal of cell B and the signal of the neighboring cell of cell B meet the preset conditions. In this case, it can be understood that the terminal device will only perform the action of determining whether the signal of cell B and the signal of the neighboring cell of cell B meet the preset conditions when a specific event occurs (a specific event, such as: the terminal device determines that the reporting conditions for the preset measurement event are met). This allows the terminal device to perform the action of determining whether the signal of cell B and the signal of the neighboring cell of cell B meet the preset conditions at an appropriate time, thereby saving power consumption of the terminal device.

[0126] It is understandable that if the terminal device detects that the reporting conditions of the preset measurement event are met, the terminal device can send a preset measurement report to the network device _b.

[0127] In some embodiments of the present application, after the terminal device sends a preset measurement report to the network device _b for the first time, the terminal device can determine whether the signal of cell B and the signal of the neighboring area of ​​cell B meet the preset conditions. In this case, it can be understood that the terminal device will only perform the action of determining whether the signal of cell B and the signal of the neighboring area of ​​cell B meet the preset conditions when a specific event occurs (a specific event such as: the terminal device sends a preset measurement report to the network device _b for the first time). This allows the terminal device to perform the action of determining whether the signal of cell B and the signal of the neighboring area of ​​cell B meet the preset conditions at an appropriate time, which can save the power consumption of the terminal device. When the terminal device determines that the signal of cell B and the signal of the neighboring area of ​​cell B meet the preset conditions, the terminal device executes step S103. When the terminal device determines that the signal of cell B and the signal of the neighboring area of ​​cell B do not meet the preset conditions, the terminal device determines again whether the signal of cell B and the signal of the neighboring area of ​​cell B meet the preset conditions (it can be understood that the terminal device can continuously monitor whether the signal of cell B and the signal of the neighboring area of ​​cell B meet the preset conditions).

[0128] It is understandable that the terminal device can also determine whether the signal of cell B and the signal of the neighboring cell of cell B meet the preset conditions in other situations. Please refer to the following for details and will not be explained in detail here.

[0129] It should be noted that due to the influence of factors such as the location of the terminal device, the signal-to-noise ratio, signal strength, signal quality, etc. of cell B may be different at different times, and the signal-to-noise ratio, signal strength, signal quality, etc. of the neighboring cells of cell B may also be different.

[0130] It is understandable that there is a corresponding relationship between the preset measurement event and the preset measurement report. Specifically, the event type corresponding to the preset measurement report is the preset measurement event.

[0131] In some embodiments of the present application, the preset measurement event may be event A3, and the preset measurement report may be A3 MR.

[0132] In some further embodiments of the present application, the preset measurement event may be event A5, and the preset measurement report may be A5MR.

[0133] In some embodiments of the present application, the reporting condition of event A3 may be: within a period of time (for example, 1 second), the quality of the serving cell is higher than the quality of the neighboring cell by a certain value (for example, 5 decibels).

[0134] It is understandable that the reporting conditions of the preset measurement events can be referred to the relevant technical documents and will not be described in detail here.

[0135] It should be noted that, as long as the signal of cell B and the signal of any neighboring cell of cell B meet the preset conditions, the terminal device can determine that the signal of cell B and the signal of any neighboring cell of cell B meet the preset conditions.

[0136] In some embodiments of the present application, the signal of cell B and the signal of the neighboring cell of cell B meet preset conditions, which may specifically include: the signal quality of cell B is less than or equal to a preset threshold 1, the signal quality of the neighboring cell of cell B is greater than the signal quality of cell B, and the difference between the signal quality of the neighboring cell of cell B and the signal quality of cell B is greater than or equal to a preset threshold 2. In one implementation, when the preset measurement event is an A3 event, the preset threshold 2 may be greater than or equal to the difference threshold between the neighboring cell and the current serving cell that needs to be met when the A3 event meets the reporting conditions.

[0137] In some embodiments of the present application, the signal quality of cell B is less than or equal to a preset threshold 1, which may specifically include any one or more of the following: (1) the SNR of cell B is less than or equal to threshold_1; (2) the RSRP of cell B is less than or equal to threshold_2; (2) the RSRQ of cell B is less than or equal to threshold_3.

[0138] In some embodiments of the present application, the signal quality of the neighboring area of ​​cell B is greater than the signal quality of cell B, and the difference between the signal quality of the neighboring area of ​​cell B and the signal quality of cell B is greater than or equal to a preset threshold 2, which may specifically include any one or more of the following: (1) the SNR of the neighboring area of ​​cell B is greater than the SNR of cell B, and the difference between the SNR of the neighboring area of ​​cell B and the SNR of cell B is not less than a threshold _4; (2) the RSRP of the neighboring area of ​​cell B is greater than the RSRP of cell B, and the difference between the RSRP of the neighboring area of ​​cell B and the RSRP of cell B is not less than a threshold _5; (3) the RSRQ of the neighboring area of ​​cell B is greater than the RSRQ of cell B, and the difference between the RSRQ of the neighboring area of ​​cell B and the RSRQ of cell B is not less than a threshold _6.

[0139] It is understood that threshold_1, threshold_2, threshold_3, threshold_4, threshold_5, and threshold_6 can be set according to actual needs, and this application does not impose any restrictions on this. It is understood that the unit of threshold_1, threshold_2, threshold_3, threshold_4, threshold_5, and threshold_6 can be decibel (dB).

[0140] In some embodiments of the present application, the signal of cell B and the signal of the neighboring cell of cell B meet preset conditions, which may specifically include any one of the following: (1) the SNR of cell B is less than or equal to a1, and the difference between the RSRP of the neighboring cell of cell B and the RSRP of cell B is not less than b1; or, (2) the SNR of cell B is less than or equal to a2, and the difference between the RSRP of the neighboring cell of cell B and the RSRP of cell B is not less than b2.

[0141] It can be understood that a1 is different from a2, and b1 is different from b2. Specifically, a1 can be smaller than a2, and b1 can be smaller than b2. In layman's terms, when the SNR of cell B is relatively poor (such as equal to a1), as long as the RSRP of the neighboring area of ​​cell B is slightly better than the RSRP of cell B (such as the difference between the two is not less than b1), the terminal device can determine that the signal of cell B and the signal of the neighboring area of ​​cell B meet the preset conditions. However, when the SNR of cell B is not particularly poor (such as equal to a2), the RSRP of the neighboring area of ​​cell B is much better than the RSRP of cell B (such as the difference between the two is not less than b2), the terminal device can determine that the signal of cell B and the signal of the neighboring area of ​​cell B meet the preset conditions.

[0142] It is understood that a1, a2, b1 and b2 can be set according to actual needs, and this application does not limit this. It is understood that the unit of a1, a2, b1 and b2 can be dB.

[0143] For example, a1 may be -8dB, b1 may be -3dB, a2 may be -6dB, and b2 may be 6dB.

[0144] In some embodiments of the present application, the signal of cell B and the signal of the neighboring cell of cell B meet preset conditions, which may specifically include any one of the following: (1) the SNR of cell B is less than or equal to a1, and the difference between the RSRP of the neighboring cell of cell B and the RSRP of cell B is not less than b1, and the SNR of the neighboring cell of cell B is greater than the SNR of cell B, and the difference between the SNR of the neighboring cell of cell B and the SNR of cell B is greater than a threshold value _4; (2) the SNR of cell B is less than or equal to a2, and the difference between the RSRP of the neighboring cell of cell B and the RSRP of cell B is not less than b2, and the SNR of the neighboring cell of cell B is greater than the SNR of cell B, and the difference between the SNR of the neighboring cell of cell B and the SNR of cell B is greater than a threshold value _4.

[0145] It can be understood that the difference between the two values ​​mentioned in this application refers to the difference obtained by subtracting the smaller value from the larger value of the two values.

[0146] It can be understood that the full name of SNR in English is SIGNAL NOISE RATIO, which is the signal-to-noise ratio. SNR generally refers to the Signal to Interference plus Noise Ratio (SINR), which refers to the ratio of the strength of the received useful signal to the strength of the received interference signal (noise and interference). The full name of RSRP in English is Reference Signal Receiving Power, which is the reference signal received power. RSRP is a key parameter that can represent the strength of the wireless signal in the LTE network and one of the physical layer measurement requirements. It is the average value of the signal power received on all REs (resource elements) carrying the reference signal in a certain symbol. The full name of RSRQ in English is Reference Singnal Received Quality, which is the reference signal received quality. RSRQ mainly measures the reception quality of the downlink reference signal of a specific cell. RSRQ is defined as N*RSRP / RSSI. Among them, N is the number of resource blocks (RBs) in the LTE carrier received signal strength indicator (Received Signal Strength Indicator, RSSI) measurement bandwidth.

[0147] It should be noted that, if the terminal device fails to successfully obtain the switching message replied by the network side within the preset time after sending the preset measurement report to the network device _b for the first time, the terminal device may send the preset measurement report to the network device _b multiple times.

[0148] S103: The terminal device starts timer T1.

[0149] When the terminal device determines that the signal of cell B and the signal of the neighboring cell of cell B meet the preset conditions, the terminal device starts timer T1.

[0150] It is understood that the duration defined by timer T1 can be set according to actual needs, and this application does not impose specific restrictions on this. For example, the duration defined by timer T1 can be 300 milliseconds (ms). For another example, the duration defined by timer T1 can be 500 ms.

[0151] In some embodiments of the present application, the duration defined by timer T1 may refer to the trigger duration of RLF. RLF triggering causes may include: handover failure caused by wireless interference, cell warnings, equipment problems, terminal problems, neighboring cell mismatch, weak wireless network coverage, cell base station asynchrony, and target cell full load.

[0152] According to the 3GPP protocol, the RLF triggering reasons may specifically include the following: in one possible implementation, the terminal device triggers the RLF process due to the expiration of timer T310; in one possible implementation, the terminal device triggers the RLF process due to the random access problem indication of MCG (Master Cell Group) MAC (Medium Access Control); in one possible implementation, the terminal device triggers the RLF process due to the maximum number of retransmissions of MCG RLC (Radio Link Control); in one possible implementation, the terminal device triggers the RLF process due to an uplink LBT (Listen Before Talk) failure; in one possible implementation, the terminal device triggers the RLF process due to a BH (Backhaul Link) RLF indication received on a BAP (Backhaul Adaptation Protocol) entity, and IAB-MT (Integrated Access and Backhaul-Mobile Termination) triggers the RLF process. It can be understood that the specific meanings of MCG MAC, MCG RLC, LBT, BAP, BH RLF and IAB-MT can be referred to the relevant protocols and will not be elaborated here.

[0153] The terminal device triggering the radio link failure RLF process in advance mentioned in some embodiments of the present application can be understood as, if in the same scenario, the time when the terminal device triggers RLF in this scheme is earlier than the time when RLF is triggered according to the standard protocol without adopting this scheme.

[0154] In some embodiments of the present application, the duration defined by timer T1 may be shorter than the duration defined by timer T310. The duration of timer T310 may be the duration of T310 specified in the standard protocol, or the duration of T310 adjusted in the terminal device. In this way, timer T1 may time out faster than timer T310, allowing the terminal device to trigger the RLF process faster, thereby reducing the duration of service interruption. In some embodiments of the present application, the duration defined by timer T310 is 1 second (s). It can be understood that timer T310 is used to monitor the waiting time for radio link failure. When the UE performs radio link detection, when the number of consecutive downlink out-of-sync indications (out of sync) received is equal to N310, the start of timer T310 is triggered. If, during the duration of T310, the number of consecutive downlink synchronization indications (insync) received is equal to N311, the T310 timer is stopped, indicating that link synchronization has been restored. If timer T310 times out, it is considered that a radio link failure has been detected, and the RRC re-establishment process will be initiated.

[0155] S104: If timer T1 times out but the terminal device has not received the handover message, the terminal device determines to trigger the RLF process. According to the RLF process, the terminal device performs cell selection and chooses to reside in cell C. Cell C is a neighboring cell of cell B.

[0156] If the terminal device does not receive the handover message sent by network device _b within the duration defined by timer T1, that is, timer T1 times out but the terminal device has not received the handover message, the terminal device can again select a cell to camp on, and ultimately choose to camp on cell C. It can be understood that cell C is a neighboring cell of cell B. Specifically, cell C is one of at least one neighboring cell of cell B.

[0157] It is understood that the handover message may include parameters required for the terminal device to access the target cell, such as the cell ID, carrier frequency, target power, and other radio and physical resource configurations. In some embodiments of the present application, the handover message may be an RRC connection reconfiguration message.

[0158] In some embodiments of the present application, if timer T1 expires but the terminal device has not received a handover message, the terminal device triggers an RLF procedure. According to the RLF procedure, the terminal device performs cell selection and selects cell C with a better signal. In some embodiments of the present application, cell C is the cell with the strongest signal among at least one neighboring cell of cell B.

[0159] It can be understood that if the terminal device receives a switching message sent by the network device _b within the duration defined by the timer T1, the terminal device can perform cell switching based on the switching message and can terminate the timer T1.

[0160] S105: According to the RLF process, the terminal device establishes an RRC connection with the network device_c through the RRC re-establishment process. The network device_c is the network device corresponding to the cell C.

[0161] After the terminal device chooses to reside in cell C, it can establish an RRC connection with network device _c. In some embodiments of the present application, the terminal device determines that the RLF condition is met and resides in cell C through cell selection. In this case, the terminal device initiates the RRC re-establishment process. Specifically, the terminal device prepares to send an RRC re-establishment request (RRC Connection Reestablishment Request) to network device _c. Before the terminal device sends the RRC re-establishment request to network device _c, it first needs to perform random access. It is understandable that the RRC re-establishment process and the random access process can be referred to the relevant technical documents and will not be described in detail here.

[0162] S106: The terminal device continues to perform the service through the RRC connection.

[0163] After the terminal device establishes an RRC connection with the network device_c, the service mentioned in step S101 can be continued through the RRC connection.

[0164] Compared with the existing solutions, some embodiments provided in some embodiments of the present application can trigger the RLF process in advance when certain conditions are met (such as: the reporting conditions of the preset measurement event are met, and the signal of the first cell and the signal of the adjacent cell of the first cell meet the preset conditions), thereby shortening the time it takes for the terminal device to trigger cell switching in a scenario where cell switching is required. As a result, the terminal device can switch to other cells with better signals as soon as possible (by selecting cells to change to other cells) when the conditions for cell switching are met. The terminal device will not wait for a long time in the current cell with poor signal (during this period, the service will be stuck) before triggering RLF and switching to other cells due to the failure to receive the switching message sent by the network side. This shortens the time it takes for the terminal device to discover that the current cell signal is poor and switch to other cells, thereby shortening the stuck time of the terminal device during the service process.

[0165] A specific implementation of the above embodiment is described below with reference to FIG4 .

[0166] Please refer to Figure 4, which is a flow chart of another communication method provided in an embodiment of the present application. The communication method may include but is not limited to the following steps:

[0167] S201: The terminal device resides in cell B to perform services.

[0168] It can be understood that the current serving cell of the terminal device is cell B. The terminal device can reside in cell B for services such as calls and Internet access.

[0169] S202: Network device_b sends a measurement control message to the terminal device. Network device_b is the network device corresponding to cell B.

[0170] It is understood that when the terminal device is resident in cell B and performing services, the network device corresponding to cell B (i.e., network device_b) can send a measurement control message to the terminal device. The measurement control message may include several measurement configuration items. It is understood that the relevant description of the measurement control message and the measurement configuration items can be referred to above and related technical documents, and will not be repeated here.

[0171] Correspondingly, the terminal device can receive the measurement control message sent by network device_b.

[0172] S203: As the terminal device moves from cell B to cell C, the signal in cell B rapidly weakens, while the signal in cell C strengthens. Based on the measurement control message, the terminal device measures cell B and its neighboring cells, obtains measurement results, and determines based on the measurement results that the reporting conditions for event A3 are currently met. Neighboring cells of cell B include cell C.

[0173] On the one hand, as the terminal device moves from cell B to cell C, the signal in cell B rapidly weakens, while the signal in cell C strengthens. On the other hand, after receiving the measurement control message sent by network device_b, the terminal device can measure cell B and its neighboring cells based on the measurement control message and obtain measurement results. It is understood that the measurement results may indicate that the signal in cell B is strong and the signal in cell C is weak. Based on the measurement results, the terminal device can determine that the reporting conditions for event A3 are currently met.

[0174] In some embodiments of the present application, when a terminal device moves quickly from cell B to cell C, or when an object blocks the terminal device's movement from cell B to cell C, the signal in cell B will quickly weaken.

[0175] It is understandable that the description of the reporting conditions of event A3 can be found in the above text and related technical documents, and will not be elaborated here.

[0176] S204: The terminal device sends an A3 MR to the network device_b.

[0177] After the terminal device detects that the reporting conditions of event A3 are currently met, it can send an A3 MR to network device _b. In some embodiments, within a preset time after the terminal device sends the A3 MR, the terminal device fails to successfully obtain the handover message replied by network device _b based on the A3 MR, such as:

[0178] In one case, as shown in FIG4 , the network device _b fails to successfully receive the A3 MR sent by the terminal device;

[0179] Or, in another case, the network device_b can successfully receive the A3 MR sent by the terminal device, but the network device_b fails to normally send the switching message to the terminal device (the network device_b may have a fault);

[0180] Or, in another case, the network device_b may successfully receive the A3 MR sent by the terminal device and send a switching message to the terminal device, but the terminal device fails to successfully receive the switching message or cannot decode the switching message.

[0181] In the above-mentioned multiple situations, the terminal device may send A3 MR to the network device_b multiple times.

[0182] S205: The terminal device determines whether the signal of cell B and the signal of the neighboring cell of cell B meet the preset conditions.

[0183] It is understandable that the terminal device can first execute step S203 and then execute step S205, or first execute step S205 and then execute step S203, or execute step S203 and step S205 at the same time. This application does not limit the order in which the terminal device executes step S203 and step S205.

[0184] In some embodiments of the present application, after detecting whether the reporting conditions of event A3 are currently met (in one embodiment, it may be after detecting that the reporting conditions of event A3 are currently met), the terminal device may determine whether the signal of cell B and the signal of the neighboring area of ​​cell B meet the preset conditions. In this case, the interval between the moment when the terminal device detects whether the reporting conditions of event A3 are currently met and the moment when the terminal device determines whether the signal of cell B and the signal of the neighboring area of ​​cell B meet the preset conditions is short. For example, the interval between the moment when the terminal device detects whether the reporting conditions of event A3 are currently met and the moment when the terminal device determines whether the signal of cell B and the signal of the neighboring area of ​​cell B meet the preset conditions is less than the preset duration_1. It is understandable that the preset duration_1 can be set according to actual needs, and this application does not impose any restrictions on this. For example, the preset duration_1 can be 1s.

[0185] In some embodiments of the present application, while detecting whether the reporting conditions of event A3 are currently met, the terminal device can also determine whether the signal of cell B and the signal of the neighboring cell of cell B meet preset conditions.

[0186] In some embodiments of the present application, before detecting whether the reporting conditions of event A3 are currently met, the terminal device may determine whether the signal of cell B and the signal of the neighboring area of ​​cell B meet the preset conditions. In this case, the interval between the moment when the terminal device determines whether the signal of cell B and the signal of the neighboring area of ​​cell B meet the preset conditions and the moment when the terminal device detects whether the reporting conditions of event A3 are currently met is short. For example, the interval between the moment when the terminal device detects whether the reporting conditions of event A3 are currently met and the moment when the terminal device determines whether the signal of cell B and the signal of the neighboring area of ​​cell B meet the preset conditions is less than the preset duration_2. It is understandable that the preset duration_1 can be set according to actual needs, and this application does not impose any restrictions on this. For example, the preset duration_2 can be 1s.

[0187] It is understandable that the terminal device can first execute step S204 and then execute step S205, or first execute step S205 and then execute step S204, or execute step S204 and step S205 at the same time. This application does not limit the order in which the terminal device executes step S204 and step S205.

[0188] In some embodiments of the present application, the terminal device may determine whether the signal of cell B and the signal of the neighboring cell of cell B meet the preset conditions after sending the A3 MR to network device _b for the first time. In this case, the interval between the moment when the terminal device sends the A3 MR to network device _b for the first time and the moment when the terminal device determines whether the signal of cell B and the signal of the neighboring cell of cell B meet the preset conditions is short. For example, the interval between the moment when the terminal device sends the A3 MR to network device _b for the first time and the moment when the terminal device determines whether the signal of cell B and the signal of the neighboring cell of cell B meet the preset conditions is less than the preset duration_3. It is understood that the preset duration_3 can be set according to actual needs, and this application does not impose any restrictions on this. For example, the preset duration_3 can be 1s.

[0189] In some embodiments of the present application, when the terminal device sends the A3 MR to the network device_b for the first time, it can also determine whether the signal of cell B and the signal of the neighboring cell of cell B meet the preset conditions.

[0190] In some embodiments of the present application, after a terminal device determines whether the signal of cell B and the signal of a neighboring cell of cell B meet a preset condition, the terminal device may send an A3 MR to network device_b for the first time. In this case, the interval between the moment the terminal device determines whether the signal of cell B and the signal of a neighboring cell of cell B meet the preset condition and the moment the terminal device first sends an A3 MR to network device_b is short. For example, the interval between the moment the terminal device determines whether the signal of cell B and the signal of a neighboring cell of cell B meet the preset condition and the moment the terminal device first sends an A3 MR to network device_b is less than preset duration_4. It is understood that preset duration_4 can be set according to actual needs and is not limited in this application. For example, preset duration_4 can be 1 second.

[0191] It is understandable that preset duration_1, preset duration_2, preset duration_3 and preset duration_4 can be the same or different, and this application does not impose any restrictions on this.

[0192] It is understandable that the relevant description of the preset conditions can be found above and will not be repeated here.

[0193] S206: The terminal device starts timer T1.

[0194] If the terminal device determines that the signal of cell B and the signal of the neighboring cell of cell B meet the preset conditions, the terminal device starts timer T1. It is understood that the interval between the terminal device executing steps S205 and S206 is short. The description of the short interval duration is provided above and is not further explained here. The description of timer T1 is provided above and is not further explained here.

[0195] It can be understood that since the terminal device executes step S206 only after executing step S205, and this application does not limit the order between the terminal device executing step S205 and step S204, the terminal device can execute step S204 first and then execute step S206, or it can execute step S206 first and then execute step S204, or it can execute step S204 and step S206 at the same time. This application does not limit the order between the terminal device executing step S204 and step S206. It is understandable that, since the interval between the terminal device executing step S203 and step S205 is short, and the interval between the terminal device executing step S204 and step S205 is short, and the terminal device executes step S203 before executing step S204, the terminal device can execute step S204 before executing step S206, or can execute step S206 before executing step S204, or can execute step S204 and step S206 simultaneously. This application does not limit the order in which the terminal device executes step S204 and step S206. It is understandable that, similar to the above, when the terminal device executes step S204 before executing step S206, or executes step S206 before executing step S204, the interval between the terminal device executing step S204 and step S206 is short. The relevant description of the short interval can be found above and will not be elaborated here.

[0196] S207: If the timer T1 times out but the terminal device does not receive the handover message, the terminal device triggers the RLF process. According to the RLF process, the terminal device performs cell selection and chooses to reside in cell C.

[0197] It is understandable that the terminal device may send A3 MR multiple times before the timer T1 expires, in order to receive the switching message sent by the network side according to the A3 MR.

[0198] If the terminal device does not receive the handover message within the duration defined by timer T1 (i.e., timer T1 expires without the terminal device receiving the handover message), the terminal device triggers the RLF procedure. Following the RLF procedure, the terminal device can select a cell. Based on the cell selection rules, the terminal device may choose to reside in cell C, which is a neighboring cell of cell B.

[0199] It should be noted that the signal of cell C is better than the signal of cell B. For example, the signal strength of cell C is greater than the signal strength of cell B. For example, the signal quality of cell C is better than the signal quality of cell B.

[0200] It is understandable that the relevant description of the switching message can be found above and will not be repeated here.

[0201] S208: According to the RLF process, the terminal device establishes an RRC connection with the network device_c through the RRC re-establishment process. The network device_c is the network device corresponding to the cell C.

[0202] After the terminal device determines that the RLF condition has been met and chooses to reside in cell C, it can initiate an RRC re-establishment process (such as sending an RRC re-establishment request) to establish an RRC connection with network device_c. Wherein, network device_c is the network device corresponding to cell C.

[0203] It can be understood that the RRC re-establishment and RRC connection re-establishment mentioned in this application have the same meaning.

[0204] S209: The terminal device continues to perform the service through the RRC connection.

[0205] After the terminal device establishes an RRC connection with the network device_c, the service mentioned in step S201 can be continued based on the RRC connection.

[0206] The following describes the device involved in the embodiments of the present application.

[0207] FIG5 is a schematic diagram of the hardware structure of a terminal device provided in an embodiment of the present application.

[0208] As shown in Figure 5, the structure of the terminal device may include: a processor, an external memory interface, an internal memory, a Universal Serial Bus (USB) interface, a charging management module, a power management module, a battery, antenna 1, antenna 2, a mobile communication module, a wireless communication module, a sensor module, buttons, a motor, an indicator, a camera, a display, and a SIM card slot. The audio module may include a speaker, a receiver, a microphone, and a headphone jack, and the sensor module may include a pressure sensor, a gyroscope sensor, an air pressure sensor, a magnetic sensor, an acceleration sensor, a distance sensor, a proximity light sensor, a fingerprint sensor, a temperature sensor, a touch sensor, an ambient light sensor, and a bone conduction sensor.

[0209] It is understood that the structures illustrated in the embodiments of this application do not constitute specific limitations on the terminal device. In other embodiments, the terminal device 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.

[0210] The processor may include one or more processing units, for example, the processor may include an application processor (AP), a modem processor (also known as a baseband processor), a graphics processor (GPU), an image signal processor (ISP), a controller, a video codec, a digital signal processor (DSP), and / or a neural-network processing unit (NPU). Different processing units may be independent devices or integrated into one or more processors. The processor is the nerve center and command center of the terminal device. The controller can generate operation control signals based on instruction opcodes and timing signals to complete the control of instruction fetching and execution.

[0211] The wireless communication function of the terminal device can be implemented through antenna 1, antenna 2, a mobile communication module, a wireless communication module, and a modem. In some embodiments, antenna 1 of the terminal device is coupled to the mobile communication module, and antenna 2 is coupled to the wireless communication module, so that the terminal device can communicate with the network and other devices through wireless communication technology.

[0212] The operating system of the terminal device can adopt a layered architecture, an event-driven architecture, a micro-kernel architecture, a micro-service architecture, or a cloud architecture. The embodiment of the present application takes the Android system of the layered architecture as an example to exemplify the software structure of the terminal device.

[0213] FIG6 is a schematic diagram of the software structure of a terminal device provided in an embodiment of the present application.

[0214] The software structure of a terminal device adopts a layered architecture, which divides the software into several layers, each with a clear role and division of labor. Layers communicate with each other through software interfaces. Taking the Android system running on an AP as an example, in some embodiments, the Android system is divided into five layers: from top to bottom: the application layer, the application framework layer (Framework), the Android runtime (Android runtime) and system libraries, the hardware abstraction layer (HAL), and the system kernel layer (Kernel).

[0215] The application layer can include a series of application packages. These packages may include apps such as camera, gallery, calendar, call, map, WLAN, Bluetooth, music, video, and short messaging. The application layer may also include the system UI, which is used to display the terminal device interface, such as the signal icon corresponding to the SIM card and the call interface. The application framework layer provides the application programming interface (API) and programming framework for applications in the application layer. The application framework layer includes some predefined functions. For example, the application framework layer may include a window manager, content provider, view system, phone manager, resource manager, notification manager, etc. The phone manager is used to provide call functions for the terminal device, such as call status management (including connecting and ending calls). The phone manager is represented by the telephony in Figure 6. The application framework layer may also include the radio interface layer (RIL). The modem processor (modem) can exchange information with the telephony through the RIL.

[0216] 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.

Claims

1. A communication method, characterized in that: The method is applied to a terminal device; the method comprises: The terminal equipment resides in the first cell to perform services; The terminal device determines whether a reporting condition of a preset measurement event is met, and determines whether a signal of the first cell and a signal of a cell adjacent to the first cell meet a preset condition; the first cell is a current serving cell of the terminal device; When a reporting condition of the preset measurement event is met and a signal of the first cell and a signal of a cell adjacent to the first cell meet the preset condition, the terminal device starts a first timer; When the first timer times out but the terminal device does not receive a switching message, the terminal device triggers a radio link failure RLF process in advance, and the switching message is used to instruct the terminal device to perform a cell switching; According to the RLF process, the terminal device performs cell selection and chooses to reside in the second cell; According to the RLF process, the terminal device establishes an RRC connection with the network device corresponding to the second cell through a radio resource control RRC re-establishment process; The terminal device continues to perform the service through the RRC connection.

2. The method according to claim 1, characterized in that The preset conditions include: the signal quality of the first cell is less than or equal to a first preset threshold, the signal quality of the second cell is greater than the signal quality of the first cell, and the difference between the signal quality of the second cell and the signal quality of the first cell is greater than or equal to a second preset threshold.

3. The method according to claim 2, characterized in that The signal quality of the first cell is less than or equal to a first preset threshold, specifically including at least one of the following: a signal-to-noise ratio of the first cell is less than or equal to a first threshold; or, a reference signal received power of the first cell is less than or equal to a second threshold; or, a reference signal received quality of the first cell is less than or equal to a third threshold; The signal quality of the second cell is greater than the signal quality of the first cell, and the difference between the signal quality of the second cell and the signal quality of the first cell is greater than or equal to a second preset threshold, specifically including at least one of the following: a signal-to-noise ratio of the second cell is greater than or equal to a signal-to-noise ratio of the first cell, and the difference between the signal-to-noise ratio of the second cell and the signal-to-noise ratio of the first cell is greater than or equal to a fourth threshold; or, a reference signal received power of the second cell is greater than or equal to a reference signal received power of the first cell, and the difference between the reference signal received power of the second cell and the reference signal received power of the first cell is greater than or equal to a fifth threshold; or, a reference signal received quality of the second cell is greater than or equal to a reference signal received quality of the first cell, and the difference between the reference signal received quality of the second cell and the reference signal received quality of the first cell is greater than or equal to a sixth threshold.

4. The method according to any one of claims 1 to 3, characterized in that The method further includes: when a reporting condition of the preset measurement event is met, the terminal device sends at least one preset measurement report, the preset measurement report corresponding to the preset measurement event; The terminal device triggering the RLF process in advance includes: the duration from the first time the terminal device sends the preset measurement report to the timeout of the first timer is less than the duration from the first time the terminal device sends the preset measurement report to the timeout of the first timer The timeout duration of the timer T310.

5. The method according to any one of claims 1 to 3, characterized in that The terminal device triggers the RLF process in advance including: the duration of the first timer is less than the duration of timer T310.

6. The method according to any one of claims 1 to 5, characterized in that The terminal device triggers the RLF process in advance including: the duration of the first timer is 300 milliseconds or 500 milliseconds.

7. The method according to any one of claims 1 to 6, characterized in that The terminal device triggering the RLF process in advance includes: The duration from when the terminal device sends a preset measurement report corresponding to the preset measurement event for the first time to when the first timer times out satisfies at least one of the following: is less than the time from when the terminal device sends the preset measurement report for the first time to when an uplink listen-before-talk LBT failure occurs; Less than the duration from the first time the terminal device sends the preset measurement report to the time the terminal device receives the random access problem indication from the primary cell group media access control MCG MAC; is less than the duration from the first time the terminal device sends the preset measurement report to the time when the number of retransmissions of the master cell group radio link control MCG RLC reaches the maximum value; Less than the time from the first time the terminal device sends the preset measurement report to the time the backhaul link radio link failure BH RLF indication is received on the backhaul adaptation protocol BAP entity.

8. The method according to any one of claims 1 to 7, characterized in that The moment when the terminal device starts the first timer is earlier than the moment when the terminal device first sends a preset measurement report corresponding to the preset measurement event to the network device corresponding to the first cell, and the interval between the moment when the terminal device starts the first timer and the moment when the terminal device first sends the preset measurement report to the network device corresponding to the first cell is short; Or the time when the terminal device starts the first timer is later than the time when the terminal device first sends the preset measurement report to the network device corresponding to the first cell, and the time when the terminal device starts the first timer and the time when the terminal device first sends the preset measurement report to the network device corresponding to the first cell are shorter than the time when the terminal device starts the first timer; Or the moment when the terminal device starts the first timer is the same as the moment when the terminal device sends the preset measurement report to the network device corresponding to the first cell for the first time.

9. The method according to any one of claims 1 to 8, characterized in that The preset measurement event is event A3 or event A5.

10. The method according to any one of claims 1 to 9, characterized in that The second cell is a cell with the strongest signal among one or more neighboring cells of the first cell.

11. A terminal device, characterized in that: The terminal device comprises a processor and a memory, wherein the processor calls and executes a computer program stored in the memory, so that the terminal device implements the method according to any one of claims 1 to 10.

12. 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 executes the instructions so that the terminal device executes the method described in any one of claims 1-10.

Images