Call processing method, terminal device and computer-readable storage medium

Abstract

A call processing method, a terminal device and a computer-readable storage medium. When a calling party initiates an IMS-based call, within a time period from a first moment (e.g., the moment when an INVITE request message is sent) to a second moment (e.g., the moment when an UPDATE 200 message is received), if the calling party does not receive an IMS-based voice bearer delivered by a network, the calling party can wait for the bearer within a first time. The calling party can also execute one or more measurements within the first time. If the bearer is not obtained within the first time, and a measurement result within the first time also does not meet a measurement reporting condition, the calling party can disconnect the call by sending a SIP CANCEL message. In this way, the calling party does not need to wait for the bearer for a long period of time, thereby avoiding call abnormalities caused by failing to obtain the bearer after prolonged waiting, and thus shortening the abnormal waiting time.

Description

Call processing methods, terminal devices and computer-readable storage media

[0001] This application claims priority to Chinese Patent Application No. 202411189473.0, filed on August 28, 2024, entitled "Call Processing Method, Terminal Equipment and Computer-Readable Storage Medium", the entire contents of which are incorporated herein by reference. Technical Field

[0002] This application relates to the field of communication technology, specifically to a call processing method, a terminal device, and a computer-readable storage medium. Background Technology

[0003] In the fourth generation (4 th In 4G mobile communication networks, voice services based on the Internet Protocol Multimedia Subsystem (IMS) can be called Long-Term Evolution (LTE) Voice over LTE (VoLTE) services. Compared to voice services prior to 4G networks, VoLTE services can provide high-quality voice and video calls.

[0004] In the fifth generation (5 h In 5G mobile communication networks, voice services based on IMS can be called Voice over NR (VoNR) services. Compared to VoLTE services, VoNR services can provide a higher quality voice service experience and a higher data service experience.

[0005] For terminal devices initiating VoLTE or VoNR calls, reducing abnormal waiting time is currently a hot research topic. Summary of the Invention

[0006] This application provides a call processing method, a terminal device, and a computer-readable storage medium, which can reduce abnormal waiting time.

[0007] In a first aspect, embodiments of this application provide a call processing method, which can be applied to a terminal device. The method may include: when the terminal device initiates an IMS-based call, sending a first message to a network device at a first moment, the first message including an INVITE request message; receiving a second message from the network device at a second moment, the second message including an UPDATE 200 message; during the time period from the first moment to the second moment, the terminal device does not receive a bearer establishment request message from the network device, the bearer establishment request message being used to request the establishment of an IMS-based voice bearer; within the first time period, the terminal device performs one or more measurements, the start time of the first time period being later than or equal to the second moment, and the duration of the first time period being a first preset duration; if the measurement results within the first time period do not meet the measurement report conditions, and the terminal device does not receive a bearer establishment request message within the first time period, sending a third message to the network device, the third message including a SIPCANCEL message, to disconnect the call.

[0008] Among them, IMS-based calls can be VoLTE calls or VoNR calls. For VoLTE calls, the above voice bearer is a quality of service class identifier (QCI) bearer with a value of 1; for VoNR calls, the above voice bearer is a 5G quality of service identifier (5QI) bearer with a value of 1.

[0009] When a terminal device sends an INVITE message to a network device, in practice, the terminal device can send the INVITE message to the called party through the network device. This may involve forwarding through other devices, such as the calling party's IMS server, core network equipment, the called party's IMS server, or the called party's corresponding network equipment. In other words, the source sender of the INVITE message is the calling party, and the final receiver is the called party. Similarly, when a terminal device receives an UPDATE 200 message, in practice, the terminal device can receive the UPDATE 200 message from the called party through a network device. This may involve forwarding through other devices, such as the called party's corresponding network equipment, the called party's IMS server, core network equipment, or the calling party's IMS server. Again, the source sender of the UPDATE 200 message is the called party, and the final receiver is the calling party.

[0010] Implementing the method provided in the first aspect, if the terminal device does not receive a voice bearer from the network during the time period from the first moment (i.e., the moment the INVITE request message is sent) to the second moment (e.g., the moment the UPDATE 200 message is received), measurements are performed during the first moment, and the device waits for the bearer. If the measurement results during the first moment do not meet the measurement report conditions, and the bearer is not received during the first moment, the terminal device sends a SIPCANCEL message to the network device to disconnect the call. In this way, the terminal device does not need to wait for the bearer for a long time, avoiding call anomalies caused by prolonged waiting for the bearer, thereby reducing abnormal waiting time.

[0011] In conjunction with the method provided in the first aspect, in some embodiments, if the measurement results within the first time period do not meet the measurement report conditions, and a bearer establishment request message is received at the third time, the aforementioned voice bearer is established and activated; wherein, the third time is within the first time period, the start time of the first time period is the start time of the first time period, and the end time of the first time period is the third time.

[0012] In other words, if the terminal device receives the bearer from the network in the first time and the measurement results before that time do not meet the measurement report conditions, then the terminal device establishes and activates the bearer from the network so that the terminal device can make VoLTE or VoNR calls based on the bearer.

[0013] In conjunction with the method provided in the first aspect, in some embodiments, the aforementioned bearer establishment request message includes a radio resource control (RRC) connection reconfiguration message, which includes an E-RABSETUPREQUEST message used to request the establishment of the aforementioned voice bearer. Establishing and activating the IMS-based voice bearer may include: establishing the aforementioned voice bearer based on the E-RABSETUPREQUEST message and sending an RRC connection reconfiguration completion message to the network device, the RRC connection reconfiguration completion message indicating that the aforementioned voice bearer has been established; receiving an activation bearer request message from the network device, the activation bearer request message used to request the activation of the aforementioned voice bearer; activating the aforementioned voice bearer based on the activation bearer request message and sending an activation bearer confirmation message to the network device, the activation bearer confirmation message indicating that the aforementioned voice bearer has been activated. When the voice bearer is established and activated, the terminal device can conduct VoLTE or VoNR calls based on the voice bearer.

[0014] In conjunction with the method provided in the first aspect, in some embodiments, after establishing and activating the voice bearer, the terminal device may also receive a fourth message from the network device. This fourth message includes a Ringing180 message, which instructs the terminal device to play a ringtone. Upon receiving the Ringing180 message, the terminal device indicates that resource reservation for both the calling and called parties has been successful and that the voice bearer is available for the aforementioned call.

[0015] In conjunction with the method provided in the first aspect, in some embodiments, after receiving the fourth message from the network device, the terminal device can transmit voice data based on the aforementioned voice bearer. Transmitting voice data can be either the terminal device sending voice data to the called party or the terminal device receiving voice data from the called party; both may occur simultaneously. That is, after establishing and activating the voice bearer and receiving the Ringing180 message, the calling party and the called party can conduct VoLTE or VoNR calls based on the voice bearer.

[0016] In conjunction with the method provided in the first aspect, in some embodiments, if the first measurement result meets the measurement report conditions and no bearer establishment request message is received within the second time period, a measurement report carrying the first measurement result is sent to the network device. The second time period begins at the start of the first time period, ends at the time the first measurement result is obtained, and all measurement results within the second time period do not meet the measurement report conditions. That is, if, within the first time period, the measurement result of a certain measurement meets the measurement report conditions, but no bearer was received from the network before that measurement, then the terminal device reports a measurement report carrying the measurement result to the network device, so that the network device can trigger cell handover or redirection based on the measurement report.

[0017] In conjunction with the method provided in the first aspect, in some embodiments, when the first measurement result meets the measurement report conditions and no bearer establishment request message is received within the second time period, the first measurement result also meets preset conditions before sending a measurement report carrying the first measurement result to the network device; wherein, when the measurement report conditions include reporting the measurement result when the measured value in the measurement result is less than a first threshold value, the preset conditions include reporting the measurement result when the measured value in the measurement result is less than a second threshold value, and the second threshold value is less than the first threshold value; or, when the measurement report conditions include reporting the measurement result when the measured value in the measurement result is greater than a third threshold value, the preset conditions include reporting the measurement result when the measured value in the measurement result is greater than a fourth threshold value, and the fourth threshold value is greater than the third threshold value.

[0018] Understandably, the preset condition is a more stringent condition than the measurement report condition. If the first measurement result meets both the measurement report condition and the preset condition, and no bearer establishment request message is received within the second time period, a measurement report carrying the first measurement result is sent to the network device. By adding a more stringent preset condition than the measurement report condition, cell handover or redirection triggered by unreasonable threshold settings in the measurement report condition can be avoided. It also allows the terminal device more time to wait for the bearer establishment request message before cell handover or redirection, thereby helping to improve call completion rate.

[0019] In conjunction with the method provided in the first aspect, in some embodiments, when the first measurement result meets the measurement report conditions and no bearer establishment request message is received within the second time period, before sending a measurement report carrying the first measurement result to the network device, the first measurement result is less than a first threshold or greater than a third threshold; wherein, when the measurement report conditions include reporting the measurement result when the measured value in the measurement result is less than the first threshold, the first threshold is less than the first threshold; when the measurement report conditions include reporting the measurement result when the measured value in the measurement result is greater than the third threshold, the third threshold is greater than the third threshold.

[0020] Understandably, "less than the first threshold" or "greater than the third threshold" are stricter conditions than the measurement report conditions. A measurement report carrying the first measurement result is sent to the network device if the first measurement result meets the measurement report conditions and is less than the first threshold, and no bearer establishment request message is received within the second time period. Alternatively, a measurement report carrying the first measurement result is sent to the network device if the first measurement result meets the measurement report conditions and is greater than the third threshold, and no bearer establishment request message is received within the second time period. By adding stricter conditions than the measurement report conditions, cell handover or redirection triggered by unreasonable threshold settings in the measurement report conditions can be avoided. It also allows the terminal device more time to wait for the bearer establishment request message before cell handover or redirection, thereby helping to improve call completion rates.

[0021] In conjunction with the method provided in the first aspect, in some embodiments, if the first measurement result is greater than a first threshold and less than a second threshold, the transmission of a measurement report carrying the first measurement result is suppressed, where the second threshold is equal to the first threshold value. Alternatively, if the first measurement result is greater than a fourth threshold and less than a third threshold, the transmission of a measurement report carrying the first measurement result is suppressed, where the fourth threshold is equal to the third threshold value. By adding conditions that are more stringent than the measurement report conditions, cell handover or redirection triggered by unreasonable threshold settings in the measurement report conditions can be avoided. Furthermore, the terminal device can have more time to wait for the bearer establishment request message before cell handover or redirection, thereby helping to improve call completion rate.

[0022] In conjunction with the method provided in the first aspect, in some embodiments, after sending a measurement report carrying the first measurement result to the network device, an indication message is received from the network device, which is used to indicate cell handover or redirection; in response to the indication message, cell handover or redirection is performed. That is, the first measurement result triggers the network device to issue an indication message to indicate cell handover or redirection. During a second time period, one or more measurements are performed, the start time of the second time period is later than or equal to the completion time of the cell handover or redirection, and the duration of the second time period is a second preset duration.

[0023] If the measurement results in the second time period do not meet the measurement report conditions, and if the terminal device does not receive the first bearer establishment request message in the second time period, a third message is sent to disconnect the call.

[0024] If the second measurement result meets the measurement report conditions, and no first bearer establishment request message is received within the third time period, a measurement report carrying the second measurement result is sent. The start time of the third time period is the start time of the second time period, and the end time of the third time period is the time when the second measurement result is obtained. Measurement results within the third time period do not meet the measurement report conditions. The network device sending the first bearer establishment request message may be the same network device as mentioned above, or it may be a different network device. For network devices involved in cell handover or redirection, the network device sending the first bearer establishment request message is a different network device than mentioned above. The receiving end of the third message is the network device that sent the first bearer establishment request message.

[0025] It is understandable that if a terminal device receives an instruction to switch or redirect the cell in the first instance, it will skip waiting for voice transmission in the source cell and wait for voice transmission in the target cell after the cell switch or redirection, thereby helping to improve call completion rate.

[0026] In conjunction with the method provided in the first aspect, in some embodiments, after receiving the second message from the second terminal device at the second moment, a first timer is started, the duration of which is a first preset duration; sending a third message to the network device may be in response to the timer expires. Wherein, the timer expires if all measurement results within the first time period do not meet the measurement report conditions, and if no bearer establishment request message is received within the first time period, then the terminal device can immediately disconnect the call to avoid the terminal device continuing to wait for the bearer establishment request message.

[0027] Optionally, after cell handover or redirection, a second timer is started, with a duration of a second preset duration; a third message is sent, which may be in response to the timeout of the first timer. The timeout of the second timer indicates that all measurement results within the second time period do not meet the measurement report conditions, and no first bearer establishment request message is received within the second time period. In this case, the terminal device can immediately disconnect the call to avoid the terminal device continuing to wait for the first bearer establishment request message.

[0028] In conjunction with the method provided in the first aspect, in some embodiments, after sending a third message to the network device, the aforementioned IMS-based call is automatically initiated, and a first message is sent to the network device. That is, after the call is disconnected, the terminal device automatically triggers a redial mechanism to call the called party again. Redialing can improve the call connection rate to some extent.

[0029] In conjunction with the method provided in the first aspect, in some embodiments, the aforementioned second message further includes a PRACK 200 message or an INVITE 183 message. That is, the second message can be an UPDATE 200 message, a PRACK 200 message, or an INVITE 183 message. For the second message being an INVITE 183 message, the second moment can be the moment when the terminal device receives the INVITE 183 message; for the second message being a PRACK 200 message, the second moment can be the moment when the terminal device receives the PRACK 200 message.

[0030] It should be noted that in the method provided in the first aspect, the threshold values ​​in the measurement report conditions may differ for different reporting methods. For periodically reported measurement reports, the threshold value in the measurement report conditions is the threshold that triggers the network device to decide on cell handover or redirection. For event-triggered measurement report reporting, the threshold value in the measurement report conditions can be the threshold value or offset parameter that triggers each event; the threshold value or offset parameter will differ for different events. In the first time period, the measurement report conditions may be the threshold that triggers the network device to decide on cell handover or redirection; or they may be the threshold value corresponding to at least one event. For example, the measurement report condition corresponding to the first measurement report is the threshold value of event A1, and the measurement report condition corresponding to the second measurement report is the threshold value corresponding to event B1.

[0031] In a second aspect, embodiments of this application provide a terminal device, which includes a processor and an interface circuit. The interface circuit is used to receive signals from other communication devices (e.g., network devices) outside the terminal device and transmit them to the processor, or to send signals from the processor to other communication devices outside the terminal device. The processor, through logic circuits or executing code instructions, is used to implement the method described in the first aspect and any possible implementation of the first aspect.

[0032] Thirdly, embodiments of this application provide a chip system applied to a terminal device. The chip system includes one or more processors, which are used to invoke computer instructions to cause the terminal device to perform the method described in the first aspect and any possible implementation thereof.

[0033] Fourthly, embodiments of this application provide a computer-readable storage medium storing a computer program or instructions that, when executed by a terminal device, implement the method described in the first aspect and any possible implementation thereof.

[0034] Fifthly, embodiments of this application provide a computer program product containing instructions that, when the computer program product is run on a terminal device, cause the terminal device to execute the method described in the first aspect and any possible implementation thereof.

[0035] Understandably, the terminal device provided in the second aspect, the chip system provided in the third aspect, the computer storage medium provided in the fourth aspect, and the computer program product provided in the fifth aspect are all used to execute the method provided in the first aspect of this application. Therefore, the beneficial effects they can achieve can be referred to the beneficial effects in the corresponding methods, and will not be repeated here. Attached Figure Description

[0036] Figure 1 is a schematic diagram of the call process when terminal device A initiates a VoLTE call;

[0037] Figure 2 shows two example interfaces for making a phone call;

[0038] Figure 3 is an example of a terminal device moving between cells;

[0039] Figure 4 is a schematic diagram of the system architecture using an embodiment of this application;

[0040] Figure 5 is a flowchart illustrating a call processing method provided in an embodiment of this application;

[0041] Figure 6 shows several example diagrams based on the embodiments shown in Figure 5;

[0042] Figure 7 is a flowchart illustrating another call processing method provided in an embodiment of this application;

[0043] Figure 8 is an example diagram based on the embodiment shown in Figure 7;

[0044] Figure 9 is a flowchart illustrating another call processing method provided in an embodiment of this application;

[0045] Figure 10 is an example diagram based on the embodiment shown in Figure 9;

[0046] Figure 11 is a schematic diagram of the hardware structure of a terminal device provided in an embodiment of this application;

[0047] Figure 12 is a structural block diagram of a hardware and software combination of a terminal device provided in an embodiment of this application. Detailed Implementation

[0048] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.

[0049] The terms "first," "second," "third," etc., used in the embodiments of this application are to distinguish different objects, rather than to describe a specific order. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion. For example, it may include a series of steps or units, or optionally, steps or units not listed, or other steps or units inherent to these processes, methods, products, or devices. The terms "one embodiment" or "some embodiments," etc., mean that one or more embodiments of this application include a specific feature, structure, or characteristic described in connection with that embodiment. Therefore, the phrases "in one embodiment," "in some embodiments," "in other embodiments," "in still other embodiments," etc., appearing in different parts of the embodiments of this application, do not necessarily refer to the same embodiment, but rather mean "one or more, but not all, embodiments," unless otherwise specifically emphasized.

[0050] Furthermore, "at least one" refers to one or more, while "more than one" refers to two or more. "And / or" describes the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can mean: A alone, A and B simultaneously, or B alone, where A and B can be singular or plural. The character " / " generally indicates that the preceding and following related objects are in an "or" relationship. "At least one of the following" or similar expressions refer to any combination of these items, including any combination of single or plural items. For example, at least one of a, b, and c can mean: a, or b, or c, or a and b, or a and c, or b and c, or a, b, and c, where a, b, and c can be single or multiple.

[0051] The terminology used in the following embodiments of this application is for the purpose of describing particular embodiments only and is not intended to be a limitation of this application.

[0052] I. Measurement Reporting

[0053] In mobile communication networks, measurement reporting refers to the process by which terminal devices report measurement results to network devices, which can then make switching or redirection decisions based on these results.

[0054] The handover process includes a handover decision (based on coverage, capacity, or services, etc.), handover preparation (resource requests and data forwarding occur between the source and target cells), and after handover preparation is complete, the network device issues a handover command, and the terminal device executes the handover from the source cell to the target cell. The source cell can be the serving cell, and the target cell can be a neighboring cell.

[0055] Redirection refers to a network device initiating a new access procedure by indicating target cell information or target network standard through a Radio Resource Control (RRC) Connection Release message. Redirection does not involve a handover preparation process. Redirection can be divided into measurement-based redirection and non-measurement-based redirection. Measurement-based redirection is triggered by measurement results, while non-measurement-based redirection is not triggered by measurement results. The redirection discussed in this application refers to measurement-based redirection.

[0056] The measurement results may include measurements from the serving cell and / or neighboring cells. These measurements may include one or more of the following: reference signal received power (RSRP), reference signal received quality (RSRQ), and signal-to-interference-plus-noise ratio (SINR). The measurement results may be included in a measurement report and sent to the network equipment.

[0057] Terminal devices can send measurement reports to network devices according to reporting methods, which can be divided into periodic reporting and event-triggered reporting. Periodic reporting refers to sending measurement reports to network devices according to a reporting period, such as sending a measurement report every 600 milliseconds (ms) or every 1 second (s). Event-triggered reporting refers to sending measurement reports to network devices when the measurement values ​​of the serving cell and / or neighboring cells meet the triggering conditions in the event. 3G Partner Program (3G) rd The 3GPP (3rd Generation Partnership Project) defines Events A1-A6 (which can be used within a system) and Events B1-B2 (which can be used between systems). The definitions of each Event are as follows:

[0058] Event A1: The serving cell's measurement value exceeds a threshold value. The triggering condition for this event is Ms – Hys > Thresh. Here, Ms represents the serving cell's measurement value; in dBm, it represents the RSRP value; in dB, it represents the RSRQ and SINR values. Hys represents the hysteresis parameter of this event, in dB. Thresh represents the threshold value of this event, with the same unit as Ms; it can be RSRP Thresh (representing the RSRP threshold value of this event), RSRQ Thresh (representing the RSRQ threshold value of this event), or SINR Thresh (representing the SINR threshold value of this event). For example, if the RSRP Thresh of EventA1 is -85dBm and Hys is 1dB, and the RSRP of the serving cell is -89dBm, then -89dBm-1dB < -85dBm, which does not meet the triggering condition, and the terminal device will not report EventA1; if the RSRP of the serving cell is -83dBm, then -83dBm-1dB > -85dBm, which meets the triggering condition, and the terminal device reports EventA1.

[0059] EventA2, the measured value of the serving cell is less than the threshold. The triggering condition for this event is Ms + Hys < Thresh. Here, Ms represents the measured value of the serving cell. When the unit is dBm, it represents the RSRP value; when the unit is dB, it represents the RSRQ and SINR values. Hys represents the hysteresis parameter of this event, with the unit of dB. Thresh represents the threshold of this event, which has the same unit as Ms and can be the RSRP Thresh, or the RSRQ Thresh, or the SINR Thresh. For example, the RSRP Thresh of EventA2 is -80 dBm, and Hys is 3 dB. If the RSRP of the serving cell is -75 dBm, -75 dBm + 3 dB > -80 dBm, which does not meet the triggering condition, then the terminal device does not report EventA2. If the RSRP of the serving cell is -84 dBm, -84 dBm + 3 dB < -80 dBm, which meets the triggering condition, then the terminal device reports EventA2.

[0060] EventA3, the measured value of the neighboring cell is higher than that of the serving cell and higher than a threshold. The triggering condition for this event is Mn + Ofn + Ocn – Hys > Mp + Ofp + Ocp + Off. Here, Mn represents the measured value of the neighboring cell. When the unit is dBm, it represents the RSRP value; when the unit is dB, it represents the RSRQ and SINR values. Ofn represents the specific offset of the neighboring cell. Ocn represents the cell-specific offset of the neighboring cell. If this parameter is not configured, the default value is 0. Hys represents the hysteresis parameter of this event. Mp represents the measured value of the serving cell. Ofp represents the specific offset of the measurement object of the serving cell. Ocp represents the specific cell offset of the serving cell. Off represents the offset parameter of this event. For example, if Off is 3 dB, and Ofn, Ocn, Hys, Ofp, and Ocp are all 0, then once the measured value of the neighboring cell is 3 dB higher than that of the serving cell, the terminal device reports EventA3.

[0061] EventA4, the measured value of the neighboring cell is greater than the threshold. The triggering condition for this event is Mn + Ofn + Ocn – Hys > Thresh. Here, Mn represents the measured value of the neighboring cell. When the unit is dBm, it represents the RSRP value; when the unit is dB, it represents the RSRQ and SINR values. Ofn represents the specific offset of the neighboring cell. Ocn represents the cell-specific offset of the neighboring cell. If this parameter is not configured, the default value is 0. Hys represents the hysteresis parameter of this event. Thresh represents the threshold of this event, which has the same unit as Mn and can be the RSRP Thresh, or the RSRQ Thresh, or the SINR Thresh.

[0062] Event A5, the measured value of the serving cell is lower than a threshold value, and the measured value of the neighboring cell is higher than another threshold value. The triggering condition in this event is Mp + Hys < Thresh1 and Mn + Ofn + Ocn – Hys > Thresh2. Here, Mp represents the measured value of the serving cell; Hys represents the hysteresis parameter of this event; Thresh1 represents a threshold value in this event; Mn represents the measured value of the neighboring cell; Ofn represents the specific offset of the neighboring cell; Ocn represents the cell-specific offset of the neighboring cell; Thresh2 represents another threshold value in this event. Thresh1 and Thresh2 can be RSRP Thresh, or RSRQ Thresh, or SINR Thresh.

[0063] Event A6, the measured value of the neighboring cell is higher than the measured value of the secondary cell and higher than a threshold value. The triggering condition in this event is Mn + Ocn – Hys > Ms + Ocs + Off. Here, Mn represents the measured value of the neighboring cell; Ocn represents the cell-specific offset of the neighboring cell; Hys represents the hysteresis parameter of this event; Ms represents the measured value of the secondary cell; Ocs represents the cell-specific offset of the secondary cell; Off represents the offset parameter of this event.

[0064] Event B1, the measured value of the neighboring cell is greater than the threshold value, and the neighboring cell and the serving cell belong to cells under different systems. For example, the serving cell belongs to a cell under the 5G system, and the neighboring cell belongs to a cell under the LTE system. The triggering condition in this event is Mn + Ofn + Ocn – Hys > Thresh. Here, Mn represents the measured value of the neighboring cell; Ofn represents the specific offset of the neighboring cell; Ocn represents the cell-specific offset of the neighboring cell; Hys represents the hysteresis parameter of this event; Thresh represents the threshold value of this event. For the neighboring cell being a cell under the LTE system, Thresh can be LTERSRP, or LTERSRQ or LTESINR; for the neighboring cell being a cell under the NR system, Thresh can be RSRP Thresh, or RSRQ Thresh, or SINR Thresh.

[0065] EventB2. The measured value of the serving cell is lower than threshold 1, and the measured value of the neighboring cell is higher than threshold 2. The serving cell and the neighboring cell belong to cells under different systems. The triggering condition in this event is Mp + Hys < Thresh1 and Mn + Ofn + Ocn – Hys > Thresh2. Here, Mp represents the measured value of the serving cell; Hys represents the hysteresis parameter of this event; Thresh1 represents a threshold in this event; Mn represents the measured value of the neighboring cell; Ofn represents the specific offset of the neighboring cell; Ocn represents the cell-specific offset of the neighboring cell; Thresh2 represents another threshold in this event. For a serving cell being a cell under the NR system and a neighboring cell being a cell under the LTE system, Thresh1 can be RSRP Thresh, or RSRQ Thresh, or SINR Thresh; Thresh2 can be LTE RSRP, or LTE RSRQ or LTE SINR. For a serving cell being a cell under the LTE system and a neighboring cell being a cell under the NR system, Thresh1 can be LTE RSRP, or LTE RSRQ or LTE SINR; Thresh2 can be RSRP Thresh, or RSRQ Thresh, or SINR Thresh.

[0066] Exemplarily, in NR, the parameters and value ranges in the above several Events can be referred to as shown in Table 1 below.

[0067] Table 1

[0068] For event-triggered reporting, the network device can configure one or more of the above events and the value of the parameters in the events through RRC signaling. For example, the network device configures EventA1 for the terminal device and configures the RSRP Thresh in this event to be -85 dBm.

[0069] The above several events are for illustration and do not constitute a limitation on the embodiments of this application. There may actually be more types of events.

[0070] II. VoLTE Call or VoNR Call

[0071] A VoLTE call means that the terminal device initiates an IMS-based voice service under the 4G network or answers an IMS-based voice service under the 4G network. A VoNR call means that the terminal device initiates an IMS-based voice service under the 5G network or answers an IMS-based voice service under the 5G network. Initiating a VoLTE call or a VoNR call means that the calling terminal device initiates an IMS-based voice service.

[0072] For example, assuming terminal device A is the calling party, base station A serves terminal device A, and terminal device B is the called party, taking the VoLTE call initiated by terminal device A as an example, refer to the call flow diagram shown in Figure 1. The base station, core network equipment, and IMS server serving terminal device B are omitted in the figure. The flow shown in Figure 1 may include, but is not limited to, the following steps:

[0073] 1. Terminal device A sends an INVITE request message to terminal device B. Correspondingly, terminal device B receives the INVITE request message from terminal device A.

[0074] The INVITE request message can be a Session Initiation Protocol (SIP) INVITE request message, for example, it can be represented as IMS_SIP_INVITE->Request. The INVITE request message may include a list of codec information supporting the Session Description Protocol (SDP), and may also indicate support for preprocessing, i.e., resource reservation.

[0075] For example, terminal device A sends an INVITE request message to the calling party's IMS server through base station A. The calling party's IMS server forwards the message to the called party's IMS server, and the called party's IMS server forwards the INVITE request message to the called party, i.e., terminal device B.

[0076] For example, see Figure 2, which shows an example interface for making a phone call. The number display box 201 in Figure 2 is used to display the entered phone number, and the number selection box 202 is used to input the selected number into the number display box 201 in response to a click operation on the number within the box, so that the number display box displays the entered phone number. Figure 2(1) shows an example interface for making a phone call in a single-SIM scenario. Terminal device A receives a click operation on the dial control 203 and, in response to the click operation, sends an INVITE request message. Figure 2(2) shows an example interface for making a phone call in a dual-SIM scenario. Terminal device A receives a click operation on the card 2 control 205 and, in response to the click operation, sends an INVITE request message through card 2. If the terminal device receives a click operation on the card 1 control 204, it sends an INVITE request message through card 1 in response to the click operation.

[0077] 2. Terminal device A establishes an RRC connection with base station A and establishes a service quality class identifier (QCI) = 9 and / or QCI = 5 bearer.

[0078] In LTE networks, QCI=9 is the default bearer, commonly used for services such as web browsing and file transfer. QCI=9 is a non-guaranteed bit rate (non-GBR) bearer, suitable for services insensitive to latency. In other words, QCI=9 is used for data transmission. QCI=5 is a dedicated bearer used for establishing and managing signaling exchanges for voice sessions. It is also a non-GBR bearer, but it ensures timely and reliable signaling transmission. In other words, QCI=5 is used for signaling transmission. For VoLTE-enabled terminal devices, both QCI=9 and QCI=5 bearers will always be present when VoLTE is enabled.

[0079] Step 1 and Step 2 may be executed simultaneously. Figure 1 shows an example of executing Step 1 first and then Step 2. In actual applications, they can be executed simultaneously, or Step 2 can be executed first and then Step 1.

[0080] 3. Terminal device B sends a Trying 100 message to terminal device A. Correspondingly, terminal device A receives the Trying 100 message from terminal device B.

[0081] The Trying 100 message can be represented, for example, as IMS_SIP_INVITE->Trying_100. The Trying 100 message is used in response to an INVITE request message, indicating that the INVITE request message has been received and thus stopping terminal device A from retransmitting the INVITE request message. The Trying 100 message can also be called an INVITE request acknowledgment message and can serve as a temporary response message.

[0082] For example, terminal device B sends a Trying 100 message to the called party's IMS server through a base station. The called party's IMS server forwards the Trying 100 message to the calling party's IMS server, so that the calling party's IMS server can send the Trying 100 message to the calling party, i.e., terminal device A.

[0083] In another implementation, after terminal device A sends an INVITE request message to the calling party's IMS server via a base station, the calling party's IMS server can send a Trying 100 message back to terminal device A, indicating that it has received the INVITE request message and is attempting to contact the called party. The calling party's IMS server then sends an INVITE request message to the called party's IMS server, which in turn sends a Trying 100 message back to the calling party's IMS server, indicating that it has received the INVITE request message and is attempting to contact the called party. Finally, the called party's IMS server sends an INVITE request message to terminal device B, which in turn sends a Trying 100 message back to the called party's IMS server, indicating that it has received the INVITE request message and is processing it.

[0084] 4. Base station A sends an RRC connection reconfiguration message to terminal device A. Correspondingly, terminal device A receives the RRC connection reconfiguration message from base station A. This RRC connection reconfiguration message may include an E-RAB SETUP REQUEST message.

[0085] Based on the E-RAB SETUP REQUEST message issued by the Mobility Management Entity (MME), base station A triggers the establishment of an air interface data radio bearer (DRB) and sends the non-access stratum (NAS) protocol data unit (PDU) from the E-RAB SETUP REQUEST message to terminal device A via an RRC connection reconfiguration message. Optionally, the NASPDU from the E-RAB SETUP REQUEST message is sent to terminal device A via the dedicatedInfoNASList in the RRC connection reconfiguration message.

[0086] The E-RAB SETUP REQUEST message is used to request the establishment of a QCI=1 bearer. In other words, this RRC connection reconfiguration message is also used to request the establishment of a QCI=1 bearer. The QCI=1 bearer is a dedicated bearer, serving as the VoLTE voice channel for transmitting VoLTE voice data. Therefore, for a VoLTE call, a QCI=9 bearer and / or a QCI=5 bearer, as well as a QCI=1 bearer, need to be established so that after terminal device B connects, terminal device A can conduct a VoLTE call with terminal device B.

[0087] 5. Terminal device A sends an RRC connection reconfiguration complete message to base station A. Correspondingly, base station A receives the RRC connection reconfiguration complete message from terminal device A.

[0088] In response to the RRC connection reconfiguration message, terminal device A sends an RRC connection reconfiguration complete message to base station A to indicate that the QCI=1 bearer has been established.

[0089] It is understandable that when the MME sends an E-RAB SETUP REQUEST message to trigger the establishment of a DRB, base station A receives this message and uses the dedicatedInfoNASList in the RRC connection reconfiguration message to carry the NASPDU from the E-RAB SETUP REQUEST message, requesting to establish a QCI=1 bearer with terminal device A. Terminal device A responds to this RRC connection reconfiguration message and establishes a QCI=1 bearer with the MME. The QCI=1 bearer between terminal device A and the MME can also be understood as the QCI=1 bearer between terminal device A and the core network equipment.

[0090] 6. Base station A sends an activation bearer request message to terminal device A. Correspondingly, terminal device A receives the activation bearer request message from base station A.

[0091] When a dedicated bearer is established, the MME can send an Activate Bearer Request message to terminal device A via base station A. This message can be represented, for example, as ACTIVATE DEDICATED EPS BEARER CONTEXT REQUEST. The Activate Bearer Request message is a NAS message used to request the activation of a dedicated bearer for a PDU connection with an existing default bearer, i.e., to activate the bearer with QCI=1.

[0092] Optionally, the Activate Bearer Request message and the RRC Connection Reconfiguration message in step 4 can be sent simultaneously. That is, a request is made to establish and activate the QCI=1 bearer.

[0093] 7. Terminal device A sends an activation bearer confirmation message to base station A. Correspondingly, base station A receives the activation bearer confirmation message from terminal device A.

[0094] In response to the Activate Bearer Request message, terminal device A sends an Activate Bearer Confirmation message to the MME via base station A. This message can be represented, for example, as ACTIVATE DEDICATED EPS BEARER CONTEXT ACCEPT. The Activate Bearer Confirmation message is also a NAS message. The Activate Bearer Confirmation message indicates that the QCI=1 bearer has been activated.

[0095] 8. Terminal device B sends an INVITE 183 message to terminal device A. Correspondingly, terminal device A receives the INVITE 183 message from terminal device B.

[0096] The SIP INVITE 183 message, for example, can be represented as IMS_SIP_INVITE_183, indicating that the called party is responding to the call being processed. The INVITE 183 message is a temporary response message.

[0097] 9. Terminal device A sends a PRACK message to terminal device B. Correspondingly, terminal device B receives the PRACK message from terminal device A.

[0098] The PRACK message can be represented as, for example, IMS_SIP_PRACK. The calling party sends a PRACK message to notify the called party that it has initiated a resource reservation process. Upon receiving an INVITE 183 message, the calling party replies with a PRACK message to the called party.

[0099] 10. Terminal device B sends a PRACK 200 message to terminal device A. Correspondingly, terminal device A receives the PRACK 200 message from terminal device B.

[0100] The PRACK 200 message can be represented as, for example, IMS_SIP_PRACK_200. In response to the PRACK message, the called party sends a PRACK 200 message back to the calling party, instructing the called party to initiate the resource reservation process.

[0101] 11. Terminal device A sends an UPDATE message to terminal device B. Correspondingly, terminal device B receives the UPDATE message from terminal device A.

[0102] An UPDATE message can be represented as, for example, IMS_SIP_UPDATE. The calling party sends an UPDATE message to indicate that the resource reservation has been successful.

[0103] 12. Terminal device B sends an UPDATE 200 message to terminal device A. Correspondingly, terminal device A receives the UPDATE 200 message from terminal device B.

[0104] The UPDATE 200 message can be represented as IMS_SIP_UPDATE_200 in response to IMS_SIP_UPDATE. The called party responds to the UPDATE message by sending an UPDATE 200 message back to the calling party, indicating that the resource reservation was successful.

[0105] Now, the calling party and the called party can conduct VoLTE calls based on the QCI=1 bearer.

[0106] Optionally, after the resources are successfully reserved by both the calling and called parties, terminal device A can receive paging messages from base station A to enable the two parties to communicate.

[0107] 13. Terminal device B sends a Ringing 180 message to terminal device A. Correspondingly, terminal device A receives the Ringing 180 message from terminal device B.

[0108] The Ringing 180 message can be represented as IMS_SIP_INVITE->Ringing 180, indicating that the called party should ring and the calling party should play a ringtone. After the resources are successfully reserved by both the calling and called parties, the called party rings and sends a Ringing 180 message.

[0109] Optionally, after receiving the Ringing 180 message, terminal device A can receive a paging message from base station A so that the two parties can communicate.

[0110] 14. Terminal device B sends an OK 200 message to terminal device A. Correspondingly, terminal device A receives the OK 200 message from terminal device B.

[0111] An OK 200 message can be represented as IMS_SIP_INVITE->OK 200, indicating that the called party has answered the phone, the call has been successfully connected, and a conversation can proceed. After answering the phone, the called party replies with an OK 200 message to the calling party.

[0112] 15. Terminal device A sends an ACK message to terminal device B. Correspondingly, terminal device B receives the ACK message from terminal device A.

[0113] An ACK message can be represented as, for example, IMS_SIP_ACK. An ACK message indicates that the call setup INVITE request process is complete. After receiving an OK 200 message instructing the called party to answer the call, the calling party replies with an ACK message to confirm. Afterward, the calling and called parties enter a call state.

[0114] 16. Terminal device B sends a hang-up request message to terminal device A. Correspondingly, terminal device A receives the hang-up request message from terminal device B.

[0115] The hang-up request message can be represented as IMS_SIP_BYE->Request, indicating that the called party requests to end the call.

[0116] 17. Terminal device A sends a hang-up request confirmation message to terminal device B. Correspondingly, terminal device B receives the hang-up request confirmation message from terminal device A.

[0117] For example, a hang-up request confirmation message can be represented as IMS_SIP_BYE->OK 200 to indicate that the call has ended.

[0118] 18. Base station A sends a deactivate bearer request message to terminal device A. Correspondingly, terminal device A receives the deactivate bearer request message from base station A.

[0119] The deactivation bearer request message can be represented as DEACTIVATE EPS BEARER CONTEXT REQUEST, indicating the release of the QCI=1 bearer. In this case, the QCI=9 bearer can remain to maintain data transmission, and the QCI=5 bearer can remain to maintain signaling transmission.

[0120] 19. Terminal device A sends a deactivation bearer confirmation message to base station A. Correspondingly, base station A receives the deactivation bearer confirmation message from terminal device A.

[0121] The deactivation bearer confirmation message can be represented as DEACTIVATE EPS BEARER CONTEXT ACCEPT, indicating that the QCI=1 bearer has been released. The call ends here, and the call is disconnected.

[0122] The bold lines in Figure 1 represent the SIP signaling interaction between terminal device A and terminal device B. The SIP signaling interaction is forwarded by the base station and the IMS server. The base station and the IMS server serving terminal device B are omitted in the figure.

[0123] In Figure 1, terminal device A establishes a QCI=1 bearer with the core network device after receiving the Trying 100 message and before receiving the INVITE 183 message. In reality, the process of terminal device A establishing a QCI=1 bearer with the core network device can occur at any time between receiving the Trying 100 message and receiving the Ringing 180 message, thus supporting IMS-based voice services. For example, terminal device A can establish a QCI=1 bearer with the core network device after receiving the INVITE 183 message and before sending the PRACK message. That is, Figure 1 uses the example of the network sending a QCI=1 bearer between terminal device A receiving the Trying 100 message and receiving the INVITE 183 message; in reality, the network can send a QCI=1 bearer at any time between terminal device A receiving the Trying 100 message and receiving the Ringing 180 message.

[0124] The network issuing of QCI=1 bearer can be understood as the core network equipment requesting the establishment of QCI=1 bearer through the base station, and requesting the activation of QCI=1 bearer through the base station.

[0125] For cases where steps 4 through 7 are not executed after step 3, terminal device A can execute steps 8 through 12 after step 3. However, in this case, since the QCI=1 bearer is not established and activated, terminal device A will not receive the Ringing 180 message, i.e., it will not execute steps 13 through 19 in Figure 1. In other words, whether the network sends the QCI=1 bearer after terminal device A receives the Trying 100 message and before terminal device A receives the Ringing 180 message does not affect terminal device A's execution of steps 8 through 12.

[0126] Figure 1 shows an example of a VoLTE call initiated by terminal device A. The process of terminal device A sending a VoNR call is similar to that shown in Figure 1, but the core network equipment and bearers involved are different. The core network equipment involved in a VoNR call is the access and mobility management function (AMF). A VoNR call requires the establishment of a 5G quality of service identifier (5QI) = 1 bearer.

[0127] After terminal device A sends an INVITE request message, terminal device A can periodically send measurement reports to base station A (measurement reports are not shown in Figure 1). After the network issues a QCI=1 bearer (for example, after steps 4 to 7 in Figure 1), if the measurement report sent by terminal device A triggers base station A to perform cell handover or redirection, then base station A can instruct terminal device A to perform cell handover through a handover command or instruct terminal device A to initiate an access procedure in the target cell or another network standard through an RRC connection release message.

[0128] During cell handover, the QCI=1 bearer can be migrated from the source cell to the target cell; during redirection, the QCI=1 bearer can be migrated from the source cell to the target cell, or from the source network standard to the target network standard. Before the network issues the bearer (e.g., before step 4 in Figure 1), if terminal device A sends a measurement report to base station A to trigger base station A to perform cell handover or redirection, then base station A will change its planned behavior of sending an E-RAB SETUP REQUEST message via RRC connection reconfiguration message to instruct terminal device A to perform cell handover or redirection, and cancel the original plan to send an E-RAB SETUP REQUEST message via RRC connection reconfiguration message, that is, base station A will not issue the QCI=1 bearer. If the source cell and the target cell belong to different base stations, terminal device A will wait for the QCI=1 bearer from base station A in the source cell. However, base station A cancels the transmission of the QCI=1 bearer, so terminal device A will not receive the QCI=1 bearer from base station A in the source cell. This will cause abnormal VoLTE calls initiated by the calling party, such as no ringtone being played for a long time after the calling party sends the INVITE message, or the calling party being unable to reach the called party.

[0129] For example, see the example diagram shown in Figure 3. Taking the three cells under base station A (cell 1, cell 2 and cell 3) as NR cells and the three cells under base station B (cell 4, cell 5 and cell 6) as LTE cells as an example, cell 1 and cell 4 are neighboring cells. Assume that the physical cell identity (PCI) of cell 1 is 517 and the cell's PCI is 332. Example 1: A terminal device initiates a VoNR call at the edge of cell 1 (i.e., where the NR signal is weak) and periodically reports measurement reports, such as the measurement values ​​of cell 1, to base station A. At this time, the terminal device does not receive the 5QI=1 bearer from the network, and the measurement report does not trigger cell handover. While waiting for the 5QI=1 bearer, the terminal device moves from the edge of cell 1 to cell 4 and continues to report measurement reports, such as the measurement values ​​of cell 1 and cell 4, to base station A. Based on the measurement report, base station A sends an indication message to the terminal device to instruct the terminal device to switch its serving cell from cell 1 to cell 4, and cancels the transmission of the 5QI=1 bearer to the terminal device. As a result, the terminal device cannot receive the E-RAB SETUP REQUEST message from base station A in cell 1, thus causing the call to terminate abnormally.

[0130] Example 2: A terminal device initiates a VoNR call at the edge of cell 1 (i.e., where the NR signal is weak) and periodically reports measurement reports to base station A. Based on a certain measurement report, base station A triggers the terminal device's network mode to redirect from NR to LTE, sending an RRC connection reconfiguration message to the terminal device to redirect it from NR to LTE, and cancels the transmission of the 5QI=1 bearer to the terminal device. Therefore, the terminal device will not receive the 5QI=1 bearer sent by base station A under NR mode. After base station A sends the RRC connection reconfiguration message, it sends a SIPCANCEL 200 message to the terminal device. In response to the SIPCANCEL 200 signaling, the terminal device sends a SIPCANCEL message to base station A to terminate the INVITE request message. This SIPCANCEL message can indicate the cancellation reason, such as 503, insufficient bearer resources. In response to the SIPCANCEL message, base station A sends a SIPINVITE 487 message to the terminal device to indicate cancellation of the INVITE request message. In response to the SIPINVITE 487 message, base station A sends a SIPACK message to the terminal device to indicate confirmation of cancellation of the INVITE request message. Thus, the call ends abnormally.

[0131] In both examples above, the terminal device camps on a weak NR cell and initiates a VoNR call. Before receiving the 5QI=1 bearer from the network, it reports a measurement report, causing the base station to instruct the terminal device to switch from the NR cell to an LTE cell, or to redirect the network standard from NR to LTE. The base station then cancels the transmission of the 5QI=1 bearer, resulting in the terminal device not receiving the 5QI=1 bearer in the NR cell or under the NR standard, thus causing the call to terminate abruptly. Alternatively, the terminal device may camp on a weak LTE cell and initiate a VoLTE call. Before receiving the QCI=1 bearer from the network, it reports a measurement report, causing the base station to instruct the terminal device to switch from the LTE cell to an NR cell, or to redirect the network standard from LTE to NR. The base station then cancels the transmission of the QCI=1 bearer, resulting in the terminal device not receiving the QCI=1 bearer in the LTE cell or under the LTE standard.

[0132] Another reason for abnormal call termination may be that the terminal device is camped on a strong NR cell and initiates a VoNR call. Before receiving the 5QI=1 bearer from the network, it reports a measurement report. Due to an unreasonable threshold setting, the base station, based on the measurement report, instructs the terminal device to switch or redirect from the strong NR cell to the weak LTE cell, or instructs the terminal device to redirect the network type from the strong NR cell to the weak LTE cell, thus canceling the delivery of the 5QI=1 bearer. As a result, the terminal device cannot receive the 5QI=1 bearer in the NR cell or under the NR standard. Another reason for abnormal call termination may be that the terminal device is camped on a strong LTE cell and initiates a VoLTE call. Before receiving the QCI=1 bearer from the network, it reports a measurement report. Due to an unreasonable threshold setting, the base station, based on the measurement report, instructs the terminal device to switch or redirect from the strong LTE cell to the weak NR cell, or instructs the terminal device to redirect the network mode from the strong LTE cell to the weak NR cell, thus canceling the distribution of the QCI=1 bearer. As a result, the terminal device cannot receive the QCI=1 bearer in the LTE cell or under the LTE standard.

[0133] In view of this, embodiments of this application provide a call processing method, a terminal device, and a computer-readable storage medium, which can reduce abnormal waiting time and thereby improve the call completion rate of VoLTE or VoNR calls.

[0134] This application's embodiments can be applied to scenarios where the terminal device is camped in an NR cell or an LTE cell. The terminal device can initiate VoNR calls in an NR cell and VoLTE calls in an LTE cell. This application's embodiments can also be applied to scenarios where the terminal device is camped in a sixth-generation (6G) cell. h In scenarios involving 6G (6G) or future communication system cells, the terminal device can initiate IMS-based voice services in 6G or future communication system cells. In other words, the terminal device in this embodiment is the caller of the IMS voice service, i.e., the terminal device initiating the IMS-based voice service.

[0135] To better understand the embodiments of this application, the system architecture involved in the embodiments of this application will be described first below:

[0136] The embodiments of this application can be applied to wireless communication systems, including at least one or more of the communication systems that have evolved after 5G, such as LTE, 5G, and 6G. Wireless communication systems can also include satellite communication and short-range wireless communication systems. Specifically, the wireless communication systems mentioned in the embodiments of this application include, but are not limited to, the three major application scenarios of 5G / 6G mobile communication systems: enhanced mobile broadband (eMBB), ultra-reliable low latency communication (URLLC), and massive machine-type communication (mMTC), as well as long-range (LoRa) systems or vehicle-to-everything (V2X) systems. A wireless communication system may include one or more network devices and one or more terminal devices.

[0137] The embodiments of this application can be applied to the system architecture shown in Figure 4. The system architecture shown in Figure 4 may include, but is not limited to, terminal device 401a, terminal device 401b, network device 402a, and network device 402b. The number of devices in Figure 4 is for illustrative purposes only and does not constitute a limitation on the embodiments of this application.

[0138] In this context, terminal device 401a is the calling party, and terminal device 401b is the called party. Terminal equipment, also known as user equipment (UE), mobile station (MS), or mobile terminal (MT), refers to devices that provide voice and / or data connectivity to users. Examples include handheld devices with wireless connectivity and in-vehicle devices. Currently, some examples of terminal devices include: mobile phones, tablets, laptops, PDAs, mobile internet devices (MID), wearable devices, virtual reality (VR) devices, augmented reality (AR) devices, wireless terminals in industrial control, self-driving, remote medical surgery, smart grids, transportation safety, smart cities, and smart homes.

[0139] The embodiments of this application do not limit the form of the terminal device. The device used to implement the functions of the terminal device can be the terminal device itself, or it can be a device that supports the terminal device in implementing the functions, such as a chip system. The device can be installed in the terminal device or used in conjunction with the terminal device. In the embodiments of this application, the chip system can be composed of chips, or it can include chips and other discrete components.

[0140] Network device 402a is used to serve terminal device 401a, and network device 402b is used to serve terminal device 401b.

[0141] Network equipment is used to implement functions such as access terminal equipment. It can be a base station, an evolved NodeB (eNodeB), a transmitting and receiving point (TRP), a transmitting point (TP), a next-generation NodeB (gNB), a next-generation base station in a 6G system, a base station in a future mobile communication system, a satellite, an integrated access and backhaul (IAB) node, a mobile switching center, or access network equipment in a non-terrestrial network (NTN) communication system. It can be deployed on high-altitude platforms or satellites. Network equipment can be a macro base station, a micro base station or an indoor station, a relay node or a donor node, or a radio controller in a C-RAN scenario. Network equipment can also act as a base station in device-to-device (D2D) communication, vehicle-to-everything (V2X) communication, drone communication, and machine-to-machine (M2M) communication. Optionally, network equipment can also be a server, wearable device, vehicle or in-vehicle equipment, etc. For example, the access network equipment in vehicle-to-everything (V2X) technology can be a roadside unit (RSU).

[0142] In another possible scenario, multiple network devices collaborate to assist terminal devices in achieving wireless access, with each network device performing a portion of the base station's functions. For example, network devices can be central units (CUs), distributed units (DUs), CU-control plane (CPs), CU-user plane (UPs), or radio units (RUs), etc. CUs and DUs can be set up separately or included in the same network element, such as a baseband unit (BBU). RUs can be included in radio equipment or radio units, such as remote radio units (RRUs), active antenna units (AAUs), or remote radio heads (RRHs). It is understood that network devices can be CU nodes, DU nodes, or devices comprising both CU and DU nodes. Furthermore, CUs can be classified as devices in the access network or as devices in the core network (CN); this is not a limitation.

[0143] In different systems, CU (or CU-CP and CU-UP), DU, or RU may have different names, but those skilled in the art will understand their meaning. For example, in an ORAN system, CU can also be called O-CU (open CU), DU can also be called O-DU, CU-CP can also be called O-CU-CP, CU-UP can also be called O-CU-UP, and RU can also be called O-RU. For ease of description, this application uses CU, CU-CP, CU-UP, DU, and RU as examples. Any of the units among CU (or CU-CP, CU-UP), DU, and RU in this application can be implemented through software modules, hardware modules, or a combination of software and hardware modules.

[0144] In this embodiment, the form of the network device is not limited. The device used to implement the function of the network device can be the network device itself, or it can be a device that supports the network device in implementing the function, such as a chip system. The device can be installed in the network device or used in conjunction with the network device.

[0145] Based on the system architecture shown in Figure 4, the call processing method provided in this application embodiment will be described in detail below.

[0146] Please refer to Figure 5, which is a flowchart illustrating a call processing method provided in an embodiment of this application. Figure 1 takes the case where the terminal device A receives a QCI=1 bearer from the network after receiving the Trying 100 message and before receiving the INVITE 183 message (e.g., steps 4 to 7) as an example. Figure 5 assumes that no QCI=1 bearer or 5QI=1 bearer is received from the network after receiving the Trying 100 message and before receiving the UPDATE 200 message.

[0147] The process shown in Figure 5 may include, but is not limited to, the following steps:

[0148] In step S501, network device 402a sends an UPDATE 200 message to terminal device 401a. Correspondingly, terminal device 401a receives the UPDATE 200 message from the network device.

[0149] Similar to step 12 in Figure 1, the UPDATE 200 message can be represented as, for example, IMS_SIP_UPDATE_200. The called party responds to the UPDATE message by sending an UPDATE 200 message back to the calling party, indicating that the called party's resource reservation was successful. Network device 402a responds to the UPDATE 200 message from the calling party's IMS server by sending an UPDATE 200 message to terminal device 401a. In other words, terminal device 401b sends the UPDATE 200 message to terminal device 401a sequentially through network device 402b, the called party's IMS server, the calling party's IMS server, and network device 402a.

[0150] S502, terminal device 401a responds to the UPDATE 200 message and starts the first timer.

[0151] Optionally, the first timer is a Quality of Service (QoS) timer under the first network standard. The first network standard refers to the network standard used by the subscriber identity module (SIM) card of the terminal device 401a that is currently initiating the voice service. For example, if the terminal device 401a has SIM card 1 and SIM card 2 inserted, SIM card 1 is the SIM card currently initiating the voice service. SIM card 1 supports NR and LTE, but the current network standard used is LTE. The duration of the first timer is the duration for which the terminal device 401a waits for the bearer establishment request message under the first network standard.

[0152] Optionally, the first timer is a QoS timer for the first cell. The first cell is the cell where the terminal device 401a is currently located or the cell to which the current RRC connection is connected. The duration of the first timer is the duration for which the terminal device 401a waits for the bearer establishment request message in the first cell.

[0153] Optionally, the first timer is a QoS timer for the first cell under the first network standard. The duration of the first timer is the duration for which the terminal device 401a waits for a bearer establishment request message in the first cell under the first network standard.

[0154] Upon receiving the UPDATE 200 message, terminal device 401a starts the first timer. The duration of the first timer can be predefined by the protocol, configured by network device 402a, or set by terminal device 401a. For example, the duration of the first timer is 8 seconds (s).

[0155] The duration of the timer is predefined by the protocol. The duration of the QoS timer may vary under different network standards. For example, the duration of the QoS timer under NR may be shorter or longer than that under LTE. The duration of the QoS timer in adjacent cells may also be different.

[0156] Terminal device 401a starts a first timer and monitors in real time whether it receives a bearer establishment request message from network device 402a within the duration of the first timer. Once terminal device 401a receives a bearer establishment request message within the duration of the first timer, it responds by establishing a dedicated voice bearer, i.e., a QCI=1 bearer or a 5QI=1 bearer. After establishing the dedicated voice bearer, steps 13 to 19 in Figure 1 can be executed. Once a bearer establishment request message is received within the duration of the first timer, the first timer expires or terminal device 401a closes the first timer.

[0157] After the terminal device 401a starts the first timer, it can also periodically report measurement reports. The reporting period of the measurement report is generally shorter than the duration of the first timer. Therefore, the terminal device 401a can determine whether a bearer establishment request message has been received and whether the measurement report conditions are met at each reporting time within the duration of the first timer. Determining whether the measurement report conditions are met is step S503.

[0158] The aforementioned bearer establishment request message can be the RRC connection reconfiguration message carrying the E-RABSETUPREQUEST message shown in Figure 1, used to request the establishment of a QCI=1 bearer; or it can be other messages used to request the establishment of a QCI=1 bearer or a 5QI=1 bearer. In other words, the bearer establishment request message is used to request the establishment of an IMS-based voice bearer. Optionally, the bearer establishment request message can be used to request the establishment and activation of an IMS-based voice bearer.

[0159] S503, Terminal device 401a determines whether the measurement report conditions are met.

[0160] In one implementation, the measurement report condition can be a condition that triggers a network device decision to redirect or handover. The conditions for network device decision-to-redirect or cell handover can be configured by RRC signaling, communicated to the terminal device by other signaling, or predefined by the protocol. For example, the RSRP threshold for triggering a cell handover decision by network device 402a is -80dBm. For RSRP measurement values ​​less than -80dBm, network device 402a can instruct the terminal device to perform a cell handover. Assuming the RSRP measurement value of the first cell in the measurement report is -85dBm, which is less than -80dBm, then network device 402a can instruct the terminal device to perform a cell handover. In this example, the RSRP measurement value of the first cell meets the measurement report condition. This method is suitable for scenarios where measurement reports are periodically submitted.

[0161] In another implementation, the measurement reporting conditions can be the trigger conditions from EventA1-EventA6 and EventB1-EventB2 mentioned above. For example, for EventA1, the trigger condition is Ms–Hys>Thresh, meaning that a measurement report can be reported when the measured value of the first cell is greater than a threshold value. The threshold value or offset parameter in the trigger condition can be configured by network device 402a via RRC signaling. For example, configuring EventA1 with RRC signaling and configuring the RSRP Thresh in this event configures the trigger condition for this event. This method is suitable for scenarios where measurement reports are reported based on event triggers.

[0162] For example, taking the network standard of the first cell as NR and the triggering event as EventA2, the RRC signaling configuration for this event is RSRP Thresh as -80dBm and Hys as 3dB. If the terminal device 401a measures the RSRP of the first cell as -75dBm, then -75dBm+3dB>-80dBm, which does not meet the measurement reporting conditions; if the terminal device 401a measures the RSRP of the first cell as -84dBm, then -84dBm+3dB<-80dBm, which meets the measurement reporting conditions.

[0163] Terminal device 401a determines whether the measurement report conditions are met. This can be done by determining whether the measurement value of the first cell meets the measurement report conditions, whether the measurement value of the second cell meets the measurement report conditions, or whether the measurement values ​​of the first cell and the second cell meet the measurement report conditions. The measurement value of the first cell includes one or more of its RSRP, RSRQ, and SINR. The second cell is a neighboring cell of the first cell, and its measurement value includes one or more of its RSRP, RSRQ, and SINR. The network standard of the second cell may be the same as or different from that of the first cell. In other words, terminal device 401a determines whether the measurement values ​​of the first cell and / or the second cell meet the measurement report conditions.

[0164] For example, taking a first timer with a duration of 8 seconds and periodically reporting measurement reports with a reporting period of 1 second as an example, see the example diagrams shown in Figure 6. In Figure 6, within the duration of the first timer, there are 8 opportunities to report measurement reports. Each reporting opportunity may or may not involve reporting a measurement report.

[0165] In Figure 6(1), after the first timer is started, and before or during reporting time #1, if terminal device 401a does not receive a bearer establishment request message and the measurement result corresponding to reporting time #1 does not meet the measurement report conditions, then terminal device 401a will not send the measurement result corresponding to reporting time #1 during reporting time #1. If a bearer establishment request message is received between reporting time #1 and reporting time #2, then terminal device 401a responds to the bearer establishment request message by establishing and activating the IMS-based voice bearer, and then can execute steps 13 to 19 in Figure 1. Furthermore, terminal device 401a can cancel sending the measurement result corresponding to reporting time #2, regardless of whether the measurement result corresponding to reporting time #2 meets the measurement report conditions.

[0166] In Figure 6(2), after the first timer is started, during the period from reporting time #1 to reporting time #7, the terminal device 401a does not receive a bearer establishment request message, and the measurement results corresponding to these reporting times do not meet the measurement report conditions. Therefore, the terminal device 401a does not report a measurement report during this period. Before reporting time #8, the terminal device 401a does not receive a bearer establishment request message, or the terminal device 401a does not receive a bearer establishment request message at reporting time #8, but the measurement results corresponding to reporting time #8 meet the measurement report conditions. Then, the terminal device 401a can send the measurement report corresponding to reporting time #8 to the network device 402a, i.e., execute step S504a. Optionally, after the terminal device 401a sends the measurement report corresponding to reporting time #8 to the network device 402a, the first timer expires or the terminal device 401a closes the first timer.

[0167] In Figure 6(3), after the first timer is started, if the terminal device 401a does not receive a bearer establishment request message within the duration of the first timer, and the measurement results corresponding to the reporting times of these 8 measurement reports do not meet the measurement report conditions, then the terminal device 401a disconnects the call when the first timer expires, i.e., executes step S504b.

[0168] Figure 6 illustrates a periodic measurement report reporting method. For event-triggered measurement report reporting, the reporting method is as follows: when the measurement result meets the triggering conditions, the terminal device reports the measurement report according to the configured reporting frequency and interval. Specifically, for event-triggered measurement report reporting, within the duration of the first timer, at each reporting interval, it is determined whether a bearer establishment request message has been received. If a bearer establishment request message is received, the IMS-based voice bearer is established and activated; otherwise, step S504a is executed.

[0169] S504a, terminal device 401a sends a measurement report to network device 402a. Correspondingly, network device 402a receives the measurement report from terminal device 401a.

[0170] Within the first time period, if the measurement result corresponding to the first reporting time meets the measurement report conditions and no bearer establishment request message is received within the first bearer reception time, the terminal device 401a sends a measurement report to the network device 402a. The start time of the first time period is the start time of the first timer, and the end time of the first time period is the timeout time or the end time of the first timer. The first bearer reception time is the first reporting time, or the time between the first reporting time and the second reporting time, or the time between the start time of the first timer and the first reporting time. The first reporting time is any reporting time within the duration of the first timer; for example, the first reporting time is any of the eight reporting times shown in Figure 6. The second reporting time is the previous reporting time of the first reporting time; for example, if the first reporting time is reporting time #7 among the eight reporting times shown in Figure 6, then the second reporting time is reporting time #6 in Figure 6.

[0171] S504b, in response to the first timer timeout, terminal device 401a disconnects the call.

[0172] When the first timer expires, it means that the measurement results corresponding to all reporting opportunities in the first time do not meet the measurement report conditions and no bearer establishment request message is received (as shown in (3) in Figure 6). At this time, the terminal device 401a can immediately disconnect the call to avoid the terminal device 401a waiting for the bearer establishment request message.

[0173] The termination of a call by terminal device 401a may include: terminal device 401a sending a SIPCANCEL message to network device 402a to end the INVITE request message. The SIPCANCEL message may indicate the reason for cancellation, such as 503, insufficient bearer resources; in response to the SIPCANCEL message, network device 402a sending a SIPINVITE 487 message to terminal device 401a to indicate cancellation of the INVITE request message; in response to the SIPINVITE 487 message, network device 402a sending a SIPACK message to terminal device 401a to indicate confirmation of cancellation of the INVITE request message, thus ending the call.

[0174] After or simultaneously with the call being disconnected, terminal device 401a triggers a redial mechanism. This can be achieved by displaying a dialing interface with the called number shown before the call was disconnected (e.g., the number display box 201 in Figure 2 shows the called number before the disconnection), and sending an INVITE request message in response to a click on the dialing control in the interface. Alternatively, terminal device 401a can obtain the called number before the call was disconnected, automatically send an INVITE request message based on that number, and display a call waiting interface.

[0175] If the measurement results within the duration of the first timer do not meet the measurement report conditions and the bearer establishment request message is not received before the first timer expires, the terminal device 401a disconnects the call and triggers the redial mechanism. Redialing is used to improve the call connection rate.

[0176] Steps S503 and S504b can be understood as follows: if the first timer expires and no bearer establishment request message is received, and the measurement results within the duration of the first timer do not meet the measurement report conditions, then the terminal device 401a disconnects the call to avoid the terminal device 401a continuously waiting for the bearer establishment request message.

[0177] S505, network device 402a sends instruction information to terminal device 401a. Correspondingly, terminal device 401a receives the instruction information from network device 402a. The instruction information instructs terminal device 401a to redirect from a first network standard to a second network standard, or instructs terminal device 401a to handover from a first cell to a second cell.

[0178] Network device 402a may send indication information to terminal device 401a based on the measurement report received in step S504a. Optionally, if the signal is weak under the current network standard, the indication information may instruct terminal device 401a to redirect from the first network standard to the second network standard. For example, if the NR signal is weak, the indication information may instruct terminal device 401a to redirect from NR to LTE. Optionally, if the signal strength of a neighboring cell is higher than that of the current cell, the indication information may instruct terminal device 401a to hand over or redirect from the first cell to the second cell. For example, if the RSRP of the second cell is higher than that of the first cell, the indication information may instruct terminal device 401a to hand over or redirect from the first cell to the second cell.

[0179] Optionally, if the terminal device 401a receives the instruction information in the first time, it can turn off the first timer or disable the first timer.

[0180] S506, terminal device 401a responds to the instruction information to switch or redirect and starts a second timer.

[0181] Regarding the redirection of the instruction information, terminal device 401a responds to the redirection of the instruction information from the first network standard to the second network standard and starts a second timer. The second timer is a QoS timer under the second network standard. The duration of the second timer is the duration for which terminal device 401a waits for a bearer establishment request message under the second network standard.

[0182] In response to the indication information indicating cell handover, terminal device 401a switches from the first cell to the second cell and starts a second timer. The second timer is a QoS timer for the second cell. The duration of the second timer is the duration for which terminal device 401a waits for a bearer establishment request message in the second cell.

[0183] The duration of the second timer may be the same as or different from that of the first timer.

[0184] Optionally, terminal device 401a starts a second timer when completing cell handover or redirection. For cell handover or redirection involving a different network device, such as switching from network device 402a to the network device corresponding to the second cell, during the process, network device 402a can inform the other network device of certain messages. For example, it can inform the other network device of SIP signaling messages received by terminal device 401a, or send an indication message to the other network device that instructs it to issue IMS-based voice bearers to terminal device 401a.

[0185] After starting the second timer, terminal device 401a waits for a bearer establishment request message within the duration of the second timer. In this case, the bearer establishment request message may come from network device 402a or other network devices. For example, if the network device with which terminal device 401a established an RRC connection switches from network device 402a to the network device corresponding to the second cell, terminal device 401a can start the second timer when completing the cell handover or redirection, and wait for a bearer establishment request message from the network device corresponding to the second cell within the duration of the second timer. Figure 5 uses an example of a network device that has not been switched. Within the duration of the second timer, once terminal device 401a receives a bearer establishment request message, it responds to the bearer establishment request message by activating and establishing an IMS-based voice bearer, i.e., a QCI=1 bearer or a 5QI=1 bearer. After establishing the bearer, steps 13 to 19 in Figure 1 can be executed. If terminal device 401a still does not receive a bearer establishment request message when the second timer expires, step S507 is executed.

[0186] Steps S503, S504a, S505, and S506 can be understood as follows: when redirection or cell handover is triggered by reporting a measurement report, the terminal device 401a skips waiting for the bearer establishment request message under the first network standard or the first cell, and waits for the bearer establishment request message in the QoS timer corresponding to another network standard or another cell, which helps to reduce dialing latency and improve call connection rate.

[0187] S507, in response to the second timer timeout, terminal device 401a disconnects the call.

[0188] If the second timer expires and no bearer establishment request message is received, the terminal device 401a disconnects the call to avoid the terminal device 401a waiting indefinitely for the bearer establishment request message.

[0189] The termination of a call by terminal device 401a may include: terminal device 401a sending a SIPCANCEL message to network device 402a to end the INVITE request message. The SIPCANCEL message may indicate the reason for cancellation, such as 503, insufficient bearer resources; in response to the SIPCANCEL message, network device 402a sending a SIPINVITE 487 message to terminal device 401a to indicate cancellation of the INVITE request message; in response to the SIPINVITE 487 message, network device 402a sending a SIPACK message to terminal device 401a to indicate confirmation of cancellation of the INVITE request message, thus ending the call.

[0190] After or simultaneously with a call disconnection, terminal device 401a triggers a redial mechanism. This can be achieved by displaying a dialing interface with the called number from before the call was disconnected, and sending an INVITE request message in response to a click on the dialing controls. Alternatively, terminal device 401a can retrieve the called number from before the call was disconnected, automatically send an INVITE request message based on that number, and display a call waiting interface. Redialing aims to improve call completion rates.

[0191] In the embodiment shown in Figure 5, when redirection or cell handover is triggered by reporting a measurement report, terminal device 401a skips waiting for a bearer establishment request message under the first network standard or the first cell, and instead waits for the bearer establishment request message within the QoS timer corresponding to the other network standard or the second cell. This helps reduce call connection latency and improve call success rate. If no bearer establishment request message is received after the first or second timer expires, the call is disconnected to avoid terminal device 401a continuously waiting for the bearer establishment request message.

[0192] Please refer to Figure 7, which is a flowchart illustrating another call processing method provided in this application embodiment. Figure 1 takes the example of receiving a QCI=1 bearer from the network after receiving the Trying 100 message and before receiving the INVITE 183 message, while Figure 7 assumes that no QCI=1 bearer or 5QI=1 bearer is received from the network after receiving the Trying 100 message and before receiving the UPDATE 200 message.

[0193] The process shown in Figure 7 may include, but is not limited to, the following steps:

[0194] S701, network device 402a sends an UPDATE 200 message to terminal device 401a. Correspondingly, terminal device 401a receives the UPDATE 200 message from the network device.

[0195] S702, terminal device 401a responds to the UPDATE 200 message and starts the first timer.

[0196] S703, Terminal device 401a determines whether the measurement report conditions are met.

[0197] Steps S701 to S703 can be found in the detailed description of steps S501 to S503 in the embodiment shown in Figure 5, and will not be repeated here.

[0198] S704a, terminal device 401a determines whether the preset conditions are met.

[0199] If the measurement result corresponding to a certain reporting time meets the measurement report conditions, the terminal device 401a can further determine whether the measurement report meets the preset conditions.

[0200] In one implementation, the preset conditions include reference conditions that trigger network device decision redirection or cell handover, which differ from the conditions for triggering network device decision redirection or cell handover in step S503. For example, in step S503, the RSRP threshold value for triggering network device 402a to decide on cell handover is -80dBm, while the RSRP threshold value for triggering network device 402a to decide on cell handover in the preset conditions is -90dBm. The threshold value in the preset conditions may not be a threshold value predefined by the protocol, but may be a threshold value set on terminal device 401a. In this example, suppose that in a measurement report corresponding to a certain reporting time, the RSRP measurement value of the first cell is -85dBm, which is less than -80dBm but greater than -90dBm, meeting the measurement report conditions but not the preset conditions. In this case, terminal device 401a will not report the measurement report. If the RSRP measurement value of the first cell is -75dBm, which is greater than both -80dBm and -90dBm, it does not meet either the measurement report conditions or the preset conditions. In this case, terminal device 401a will not report the measurement report. If the RSRP measurement value of the first cell is -95dBm, which is less than both -80dBm and -90dBm, it meets both the measurement report conditions and the preset conditions. In this case, terminal device 401a will report the measurement report.

[0201] In another implementation, the preset conditions include reference threshold values or reference offset parameters corresponding to each event, which are different from the threshold values or offset parameters corresponding to each event in the triggering conditions, and can be reference threshold values or reference offset parameters set on the terminal device 401a. The reference threshold values or reference offset parameters set on the terminal device 401a can be the default reference threshold values or reference offset parameters of the terminal device 401a, that is, the reference threshold values or reference offset parameters corresponding to each event are set in the terminal device 401a at the time of factory shipment; or they can be reference threshold values or reference offset parameters generated in response to operations for modifying or resetting the parameters.

[0202] Exemplarily, taking the network mode of the first cell as NR and the triggering event as EventA2 as an example, the RRC signaling configures the RSRP threshold value in this event to be -80 dBm and Hys to be 3 dB. At this time, the preset condition can be that the RSRP measurement value is greater than the RSRP reference threshold value of -85 dBm, and the triggering condition is Ms + Hys < Thresh (assuming the RSRP Thresh is -80 dBm). For a measurement report corresponding to a certain reporting occasion, if the RSRP measurement value of the first cell is -75 dBm, -75 dBm + 3 dB > -80 dBm, which does not meet the triggering condition, but -75 dBm > -85 dBm, which meets the preset condition, then the terminal device 401a does not report this measurement report; if the RSRP measurement value of the first cell is -90 dBm, -90 dBm + 3 dB < -80 dBm, which meets the triggering condition, but -90 dBm < -85 dBm, which does not meet the preset condition, then the terminal device 401a does not report the measurement report; if the RSRP measurement value of the first cell is -84 dBm, -84 dBm + 3 dB < -80 dBm and -84 dBm > -85 dBm, which meets the triggering condition and meets the preset condition, then the terminal device 401a reports the measurement report.

[0203] From the above two implementation manners, it can be seen that when the measurement report condition includes that the measurement value in the measurement result is less than the first threshold value and the measurement result is reported, the preset condition includes that the measurement value is less than the second threshold value and the measurement result is reported, and the second threshold value is less than the first threshold value. When the measurement report condition includes that the measurement value in the measurement result is greater than the third threshold value and the measurement result is reported, the preset condition includes that the measurement value is greater than the fourth threshold value and the measurement result is reported, and the fourth threshold value is greater than the third threshold value.

[0204] As can be seen from the examples of the two implementation methods above, the preset conditions are more stringent than the measurement report conditions. That is, in this embodiment, the preset conditions are set on the terminal device and are more stringent than the measurement report conditions. Simply judging whether the measurement report conditions are met might trigger the reporting of a measurement report. However, if the threshold settings in the measurement report conditions are unreasonable, the measurement report might trigger the network device to instruct cell handover or redirection, thus canceling the transmission of the bearer establishment request message, leading to call anomalies. By adding more stringent preset conditions based on the judgment of whether the measurement report conditions are met, and only reporting the measurement report when both the measurement report conditions and the preset conditions are met, cell handover or redirection triggered by unreasonable threshold settings in the measurement report conditions can be avoided. At the same time, adding more stringent preset conditions prevents the terminal device from immediately reporting the measurement report when the measurement report conditions are met, allowing the terminal device more time to wait for the bearer establishment request message in the cell before the cell handover or under the current network standard, thereby helping to improve the call completion rate.

[0205] In other words, terminal device 401a will only report a measurement report to network device 402a if both the measurement report conditions and preset conditions are met. If the measurement report conditions are met but the preset conditions are not met, step S704b will be executed.

[0206] Figure 7 shows an example of executing step S703 first and then step S704a. Alternatively, steps S703 and S704a can be executed simultaneously, or step S704a can be executed first and then step S703. If the measurement report conditions are not met, step S704b is executed; if the measurement report conditions are met but the preset conditions are not met, step S704b is executed; if the measurement report conditions are not met but the preset conditions are met, step S704b is executed; if neither the measurement report conditions nor the preset conditions are met, step S704b is executed.

[0207] For example, taking a first timer with a duration of 8 seconds and periodically reporting measurement reports with a reporting period of 1 second as an example, see Figure 8 for an example diagram. In Figure 8, within the duration of the first timer, there are 8 reporting opportunities for measurement reports. Each reporting opportunity may or may not report a measurement report. In Figure 8, after the first timer is started, during the period from reporting opportunity #1 to reporting opportunity #6, if no bearer establishment request message is received, and the measurement results corresponding to reporting opportunities #1 to #5 do not meet the measurement report conditions, then the terminal device 401a will not send the measurement reports corresponding to reporting opportunities #1 to #5; if the measurement report corresponding to reporting opportunity #6 meets both the measurement report conditions and the preset conditions, then the terminal device 401a will send the measurement report corresponding to reporting opportunity #6.

[0208] S704b, in response to the first timer timeout, terminal device 401a disconnects the call.

[0209] Step S704b can be found in the detailed description of step S504b in the embodiment shown in Figure 5, and will not be repeated here.

[0210] S705, terminal device 401a sends a measurement report to network device 402a. Correspondingly, network device 402a receives the measurement report from terminal device 401a.

[0211] S706, network device 402a sends instruction information to terminal device 401a. Correspondingly, terminal device 401a receives the instruction information from network device 402a. The instruction information instructs terminal device 401a to redirect from a first network standard to a second network standard, or instructs terminal device 401a to handover from a first cell to a second cell.

[0212] S707, terminal device 401a responds to the instruction information to switch or redirect and starts a second timer.

[0213] S708, in response to the second timer timeout, terminal device 401a disconnects the call.

[0214] Steps S705 to S708 can be found in the detailed description of steps S504a and S505 to S507 in the embodiment shown in Figure 5, and will not be repeated here.

[0215] In the embodiment shown in Figure 7, a measurement report is submitted when both the measurement report conditions and preset conditions are met. If the measurement report triggers redirection or cell handover, the terminal device 401a skips waiting for a bearer establishment request message under the first network standard or the first cell, and instead waits for the bearer establishment request message within the QoS timer corresponding to the other network standard or the second cell. This helps reduce call connection latency and improve call completion rate. If no bearer establishment request message is received after the first or second timer expires, the call is disconnected to prevent the terminal device 401a from continuously waiting for the bearer establishment request message.

[0216] The difference between Figure 7 and Figure 5 is that the conditions for reporting the measurement report are different. In Figure 5, the measurement report is reported when the conditions for reporting the measurement report are met, while in Figure 7, the measurement report is reported when both the conditions for reporting the measurement report and the preset conditions are met.

[0217] Please refer to Figure 9, which is a flowchart illustrating another call processing method provided in this application embodiment. Figure 1 takes the example of receiving a QCI=1 bearer from the network after receiving the Trying 100 message and before receiving the INVITE 183 message, while Figure 9 assumes that no QCI=1 bearer or 5QI=1 bearer is received from the network after receiving the Trying 100 message and before receiving the UPDATE 200 message.

[0218] The process shown in Figure 9 may include, but is not limited to, the following steps:

[0219] S901, network device 402a sends an UPDATE 200 message to terminal device 401a. Correspondingly, terminal device 401a receives the UPDATE 200 message from the network device.

[0220] S902, terminal device 401a responds to the UPDATE 200 message and starts the first timer.

[0221] Steps S901 and S902 can be found in the detailed description of steps S501 and S502 in the embodiment shown in Figure 5, and will not be repeated here.

[0222] S903, terminal device 401a determines whether the measured value in the measurement report corresponding to the first reporting time is greater than the first threshold and less than the second threshold.

[0223] The first reporting opportunity refers to any reporting opportunity within the duration of the first timer. The measurement report corresponding to the first reporting opportunity refers to the measurement report that the first cell under the first network standard can report at the first reporting opportunity. The first threshold is less than the second threshold, and the specific values ​​of the first and second thresholds can be set by the terminal device 401a. Optionally, the second threshold can be a threshold value in the measurement report conditions.

[0224] In other words, the terminal device 401a determines, in the order of reporting times, whether the measured value corresponding to each reporting time in the first time period is greater than the first threshold and less than the second threshold.

[0225] If the judgment result of step S903 is yes, execute step S904b; if the judgment result of step S903 is less than the first threshold, execute step S904a.

[0226] S904b, when the measurement result corresponding to the first reporting time is greater than the first threshold and less than the second threshold, the terminal device 401a suppresses the transmission of the measurement report, which carries the measurement result corresponding to the first reporting time.

[0227] Suppressing the transmission of measurement reports means not sending the measurement report.

[0228] For example, taking a first timer with a duration of 8 seconds and a periodic reporting cycle of 1 second as an example, see Figure 10. In Figure 10, within the duration of the first timer, there are 8 reporting opportunities for measurement reports. Each reporting opportunity may or may not report a measurement report. For RSRP, assume the first threshold is -90dBm and the second threshold is -80dBm. The RSRP measurement values ​​corresponding to reporting opportunities #1 to #5 are -81dBm, -85dBm, -88dBm, -89dBm, and -100dBm, respectively. The RSRP measurement values ​​corresponding to reporting opportunities #1 to #4 are greater than the first threshold and less than the second threshold. Therefore, the transmission of measurement reports corresponding to reporting opportunities #1 to #4 is suppressed. The measurement report corresponding to reporting opportunity #5 can be transmitted, but whether it is actually transmitted depends on the judgment in step S904a or on the judgment in steps S904a and S905a. In practice, terminal device 401a first determines whether the RSRP measurement value corresponding to reporting time #1 is greater than the first threshold and less than the second threshold. If so, it suppresses the reporting. Otherwise, it determines whether the measurement report corresponding to reporting time #1 meets the measurement report conditions, i.e., it executes step S904a. For RSRP measurement values ​​corresponding to reporting time #1 that are greater than the first threshold and less than the second threshold, it continues to determine whether RSRP measurement values ​​corresponding to reporting time #2 are greater than the first threshold and less than the second threshold. If so, it suppresses the reporting. Otherwise, it determines whether the measurement report corresponding to reporting time #2 meets the measurement report conditions, and so on.

[0229] Without step S903, if terminal device 401a sends an RSRP measurement value of -81dBm to network device 402a during reporting time #1, this RSRP measurement value is less than the threshold value of -80dBm in the measurement report condition. This triggers network device 402a to instruct terminal device 401a to perform cell handover or redirection without sending a bearer establishment request message, thus causing call abnormalities. Furthermore, if the threshold value in the measurement report condition is set unreasonably, it may cause terminal device 401a to handover from a cell with better signal to a cell with worse signal, or from a network type with better signal to a network type with worse signal. Step S903, which determines whether the measurement value is greater than the first threshold and less than the second threshold, is a more stringent condition than the measurement report condition. If the determination result of step S903 is yes, no measurement report is sent, allowing the terminal device to wait for the bearer establishment request message for a little longer in the cell before the cell handover or in the current network type. This can avoid the situation where the threshold value in the measurement report condition is set unreasonably, and help improve the call completion rate.

[0230] The threshold values ​​in the measurement report conditions can be threshold values ​​that trigger network device decision redirection or cell handover, or threshold values ​​or offset parameters of the trigger conditions in EventA1-EventA6 and EventB1-EventB2 mentioned above.

[0231] In step S904a, terminal device 401a determines whether the measurement report conditions are met. Steps S903 and S904a can be executed simultaneously.

[0232] Optionally, S905a, terminal device 401a determines whether the preset conditions are met.

[0233] Steps S904a and S905a can be found in the detailed description of steps S703 and S704a in the embodiment shown in Figure 7, and will not be repeated here.

[0234] In one implementation, steps S903 and S904a are executed. For example, based on the example shown in Figure 10, if the RSRP measurement values ​​corresponding to reporting times #1 to #4 are greater than a first threshold and less than a second threshold, the transmission of measurement reports corresponding to reporting times #1 to #4 is suppressed. If the RSRP measurement value corresponding to reporting time #5 is less than the first threshold, it is further determined whether the RSRP measurement value meets the measurement report conditions. If -100dBm is less than the measurement report threshold value -80dBm, then the terminal device 401a sends the measurement report corresponding to reporting time #5 to the network device 402a.

[0235] In another implementation, steps S903, S904a, and S905a are executed. For example, based on the example shown in Figure 10, if the RSRP measurement values ​​corresponding to reporting times #1 to #4 are greater than a first threshold and less than a second threshold, the transmission of measurement reports corresponding to reporting times #1 to #4 is suppressed. If the RSRP measurement value corresponding to reporting time #5 is less than the first threshold, it is further determined whether the RSRP measurement value meets the measurement report conditions and preset conditions. If -100dBm is less than the measurement report threshold value -80dBm and -100dBm is less than -90dBm in the preset conditions, then the terminal device 401a sends the measurement report corresponding to reporting time #5 to the network device 402a.

[0236] In some embodiments, since the preset conditions and the determination of whether the value is greater than the first threshold and less than the second threshold are generally stricter than the measurement reporting conditions, the terminal device 401a may not execute step S904a. Executing step S904a, on the one hand, conforms to the measurement reporting defined in the protocol; on the other hand, for periodic measurement reporting, it can reduce the number of measurement reports.

[0237] S905b, in response to the first timer timeout, terminal device 401a disconnects the call.

[0238] Step S905b can be found in the detailed description of step S504b in the embodiment shown in Figure 5, and will not be repeated here.

[0239] S906, terminal device 401a sends a measurement report to network device 402a. Correspondingly, network device 402a receives the measurement report from terminal device 401a.

[0240] S907, network device 402a sends instruction information to terminal device 401a. Correspondingly, terminal device 401a receives the instruction information from network device 402a. The instruction information instructs terminal device 401a to redirect from a first network standard to a second network standard, or instructs terminal device 401a to handover from a first cell to a second cell.

[0241] S908, terminal device 401a responds to the instruction information to switch or redirect and starts a second timer.

[0242] S909, in response to the second timer timeout, terminal device 401a disconnects the call.

[0243] Steps S906 to S909 can be found in the detailed description of steps S504a, S505 to S507 in the embodiment shown in Figure 5, and will not be repeated here.

[0244] The embodiment shown in Figure 9 illustrates suppressing the transmission of a measurement report when the measured value is greater than a first threshold and less than a second threshold. This example is based on the measurement report condition that the measured value in the measurement result is less than the first threshold, and the measurement result is reported. Here, the first threshold is less than the first threshold, and the second threshold is equal to the first threshold. For the measurement report condition that the measured value in the measurement result is greater than a third threshold, step S903 can be modified to determine whether the measured value is greater than a fourth threshold and less than the third threshold, where the third threshold is greater than the third threshold and the fourth threshold is equal to the third threshold. When the measured value is greater than the fourth threshold and less than the third threshold, the transmission of the measurement report is suppressed.

[0245] In the embodiment shown in Figure 9, if the measured value is greater than a first threshold but less than a second threshold, the transmission of the measurement report is suppressed. This can, to some extent, avoid the situation where the measurement report threshold value in the measurement report conditions is configured unreasonably, which helps to improve the call connection rate. When the measurement report triggers redirection or cell handover, the terminal device 401a skips waiting for the bearer establishment request message under the first network standard or the first cell, and instead waits for the bearer establishment request message within the QoS timer corresponding to the other network standard or the second cell. This helps to reduce dialing latency and improve the call connection rate. If the bearer establishment request message is not received after the first or second timer expires, the call is disconnected to prevent the terminal device 401a from continuously waiting for the bearer establishment request message.

[0246] In the embodiments shown in Figures 5, 7, and 9, the measurement reporting conditions are exemplified by the RRC signaling configuration. Optionally, the terminal device 401a can determine the actual measurement reporting conditions based on the measurement reporting conditions configured by the RRC signaling to avoid unreasonable threshold values ​​or offset parameters in the RRC signaling configuration. For example, for Event A1, the RSRP threshold value configured by the RRC signaling is -85dBm, and the terminal device 401a can use -85dBm + 3dBm = -82dBm as the threshold value in the actual measurement reporting conditions.

[0247] The embodiments shown in Figures 5, 7, and 9, assuming that terminal device 401a starts a first timer to monitor the bearer establishment request message after receiving the UPDATE 200 message, can actually be sent between the Trying 100 message and the Ringing 180 message. Therefore, terminal device 401a can also start the first timer to monitor the bearer establishment request message after receiving the Trying 100 message. Upon receiving the bearer establishment request message, an IMS-based voice bearer can be established and activated, thus executing steps 8 to 19 in Figure 1. Alternatively, terminal device 401a can also start the first timer to monitor the bearer establishment request message after receiving the INVITE 183 message. Upon receiving the bearer establishment request message, an IMS-based voice bearer can be established and activated, thus executing steps 9 to 19 in Figure 1. Alternatively, terminal device 401a can also start the first timer to monitor the bearer establishment request message after receiving the PRACK 200 message. Upon receiving the bearer establishment request message, an IMS-based voice bearer can be established and activated, thus executing steps 11 to 19 in Figure 1.

[0248] The hardware structure of the terminal device 401a involved in the embodiments of this application is described below:

[0249] Figure 11 shows a hardware structure for a terminal device, which may include: a processor, an audio module, an external memory interface, 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 screen, and a SIM card slot. The audio module may include a speaker, a receiver, a microphone, and a headphone jack. The sensor module may include a pressure sensor, a gyroscope sensor, a barometric pressure sensor, a magnetic sensor, an accelerometer, a proximity sensor, a near-light sensor, a fingerprint sensor, a temperature sensor, a touch sensor, an ambient light sensor, and a bone conduction sensor.

[0250] It is understood that the structures illustrated in the embodiments of this application do not constitute a specific limitation on the terminal. In other embodiments, the terminal device may include more or fewer components than illustrated, or combine some components, or split some components, or have different component arrangements. The illustrated components may be implemented in hardware, software, or a combination of software and hardware.

[0251] The processor may include one or more processing units, such as an application processor (AP), a modem (also known as a baseband processor), a graphics processing unit (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 can be independent devices or integrated into one or more processors. The processor is the nerve center and command center of the terminal. The controller generates operation control signals based on instruction opcodes and timing signals to control instruction fetching and execution.

[0252] The wireless communication function of the terminal device can be implemented through antenna 1, antenna 2, mobile communication module, wireless communication module, and modem, etc. In some embodiments, antenna 1 of the terminal is coupled to the mobile communication module, and antenna 2 is coupled to the wireless communication module, enabling the terminal to communicate with network-side devices and other terminals through wireless communication technology.

[0253] In addition, an operating system runs on top of the aforementioned components. Examples include Apple's iOS operating system, Google's Android open-source operating system, and Microsoft's Windows operating system.

[0254] The operating system of a terminal device can adopt a layered architecture, event-driven architecture, microkernel architecture, microservice architecture, or cloud architecture. This application uses the layered architecture Android system as an example to exemplify the hardware and software structure of the terminal. It should be noted that although this application uses the Android system as an example, its basic principles are equally applicable to terminals based on operating systems such as iOS or Windows.

[0255] Figure 12 is a structural block diagram of the hardware and software integration of a terminal device. The software structure of the terminal device adopts a layered architecture, which divides the software into several layers, each with a clear role and division of labor. The layers communicate with each other through software interfaces. Taking the Android system, which runs on the application processing unit (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 and system libraries, the Hardware Abstraction Layer (HAL), and the kernel layer (Kernel).

[0256] 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 SMS. The application layer may also include the system UI, which displays the terminal's interface, such as the signal icon corresponding to the SIM card or the call interface. The application framework layer provides application programming interfaces (APIs) and a programming framework for the applications in the application layer. The application framework layer includes some predefined functions. For example, it may include a window manager, content provider, view system, phone manager, resource manager, and notification manager. The phone manager provides the terminal's call functionality, such as call status management (including call connection and disconnection). The phone manager is represented by "telephony" in Figure 12. The application framework layer may also include the RIL (Radio Interface Layer), through which the modem can interact with "telephony." The system library may include multiple functional modules. Examples include: surface manager, media libraries, 3D graphics processing libraries (e.g., OpenGL ES), and 2D graphics engines (e.g., SGL). The Hardware Algorithm (HAL) can include display HAL, camera HAL, audio HAL, sensor HAL, etc. The kernel layer is the layer between the hardware and software layers. The kernel layer includes display drivers, camera drivers, audio drivers, sensor drivers, etc.

[0257] The hardware structure of a terminal device may include a modem and an antenna. The modem may include a NAS (Non-Access Stratum) layer, an RRC (Radio Resource Control) layer, a Packet Data Convergence Protocol (PDCP) layer, a Radio Link Control (RLC) layer, a Medium Access Control (MAC) layer, and a Physical (PHY) layer. Each of these layers can be a software module. The modem can interact with the base station via the antenna.

[0258] In this method embodiment, the modem generates a measurement report and sends it to the network device. In this embodiment, the terminal device sending the measurement report to the network device can be done via the modem. The measurement report can be transmitted in the order of RRC layer > PDCP layer > RCL layer > MAC layer > PHY layer, and then sent to the base station by the PHY layer. In this embodiment, the terminal device receiving messages can be done via the modem. The messages can be transmitted to the RRC layer in the order of PHY layer > MAC layer > RCL layer > PDCP layer > RRC layer, and then processed by the RRC layer.

[0259] Furthermore, some embodiments of this application provide a terminal device, including: one or more processors and a memory; the memory is used to store computer program code, the computer program code including computer instructions, and when one or more processors execute the computer instructions, the terminal performs the above-described paging message processing method.

[0260] Some embodiments of this application provide a chip system applied to a terminal device. The chip system includes at least one processor and an interface for receiving instructions and transmitting them to the at least one processor. The at least one processor executes instructions to cause the terminal to perform the paging message processing method described above. The chip system may be a modem or a system-on-a-chip (SoC) including a modem, and the above method may be implemented by a modem.

[0261] This application also provides a computer-readable storage medium storing instructions that, when executed on a processor, enable the implementation of the method flow described in the above method embodiments.

[0262] This application also provides a computer program product, which, when run on a processor, enables the implementation of the method flow described in the above method embodiments.

[0263] It should be noted that, for the sake of simplicity, the foregoing method embodiments are all described as a series of actions. However, those skilled in the art should understand that this application is not limited to the described order of actions, as some operations can be performed in other orders or simultaneously according to this application. Furthermore, those skilled in the art should also understand that the embodiments described in the specification are preferred embodiments, and the actions and modules involved are not necessarily essential to this application.

[0264] The descriptions of the various embodiments provided in this application can be referenced mutually. Each embodiment has its own emphasis, and parts not described in detail in a certain embodiment can be referred to the relevant descriptions of other embodiments. For the sake of convenience and brevity, for example, the functions and operations of the various devices and equipment provided in the embodiments of this application can be referred to the relevant descriptions of the method embodiments of this application. The method embodiments and the device embodiments can also be referenced, combined or cited from each other.

[0265] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application.

Claims

1. A call processing method, characterized in that, The method is applied to a terminal device, and the method includes: When the terminal device initiates an IMS-based call, it sends a first message to the network device at the first moment, the first message including an INVITE request message; At a second time point, a second message is received from the network device, the second message including an UPDATE 200 message; wherein, during the time period from the first time point to the second time point, the terminal device did not receive a bearer establishment request message from the network device; the bearer establishment request message is used to request the establishment of an IMS-based voice bearer; One or more measurements are performed within a first time period, the start time of the first time period is later than or equal to the second time period, and the duration of the first time period is a first preset duration. If the measurement results within the first time period do not meet the measurement report conditions, and if the terminal device does not receive the bearer establishment request message within the first time period, the terminal device sends a third message to the network device, the third message including a SIPCANCEL message.

2. The method as described in claim 1, characterized in that, The method further includes: If the measurement results within the first time period do not meet the measurement report conditions, and the bearer establishment request message is received at the third time period, an IMS-based voice bearer is established and activated. Wherein, the third moment is within the first time period, the start time of the first time period is the start time of the first time period, and the end time of the first time period is the third moment.

3. The method as described in claim 2, characterized in that, The bearer establishment request message includes an RRC connection reconfiguration message, which includes an E-RABSETUPREQUEST message. The E-RABSETUPREQUEST message is used to request the establishment of the voice bearer. The establishment and activation of the IMS-based voice bearer includes: Based on the E-RABSETUPREQUEST message, an IMS-based voice bearer is established, and an RRC connection reconfiguration complete message is sent to the network device, indicating that the voice bearer has been established. Receive an activation bearer request message from the network device, the activation bearer request message being used to request the activation of the voice bearer; The voice bearer is activated based on the activation bearer request message, and an activation bearer confirmation message is sent to the network device, the activation bearer confirmation message indicating that the voice bearer has been activated.

4. The method as described in claim 2, characterized in that, After establishing and activating the IMS-based voice bearer, the process also includes: A fourth message is received from the network device, the fourth message including a Ringing180 message, the Ringing180 message instructing the terminal device to play a ringtone.

5. The method as described in claim 4, characterized in that, After receiving the fourth message from the network device, the method further includes: Based on the aforementioned voice bearer, voice data is transmitted.

6. The method according to any one of claims 1-5, characterized in that, The voice bearer is either a QCI=1 bearer or a 5QI=1 bearer.

7. The method as described in claim 1, characterized in that, The method further includes: If the first measurement result meets the measurement report conditions and no bearer establishment request message is received within the second time period, a measurement report carrying the first measurement result is sent to the network device. The start time of the second time period is the start time of the first time period, and the end time of the second time period is the time when the first measurement result is obtained; the measurement results within the second time period do not meet the measurement report conditions.

8. The method as described in claim 7, characterized in that, If the first measurement result meets the measurement report conditions and no bearer establishment request message is received within the second time period, before sending a measurement report carrying the first measurement result to the network device, the method further includes: The first measurement result meets the preset conditions; Wherein, if the measurement report conditions include reporting the measurement result when the measured value in the measurement result is less than a first threshold, the preset conditions include reporting the measurement result when the measured value in the measurement result is less than a second threshold, wherein the second threshold is less than the first threshold; or, if the measurement report conditions include reporting the measurement result when the measured value in the measurement result is greater than a third threshold, the preset conditions include reporting the measurement result when the measured value in the measurement result is greater than a fourth threshold, wherein the fourth threshold is greater than the third threshold.

9. The method as described in claim 7, characterized in that, If the first measurement result meets the measurement report conditions and no bearer establishment request message is received within the second time period, before sending a measurement report carrying the first measurement result to the network device, the method further includes: The first measurement result is less than the first threshold or greater than the third threshold; Wherein, when the measurement report conditions include a measurement value in the measurement result being less than a first threshold value, and the measurement result is reported, the first threshold value is less than the first threshold value; when the measurement report conditions include a measurement value in the measurement result being greater than a third threshold value, and the measurement result is reported, the third threshold value is greater than the third threshold value.

10. The method as described in claim 9, characterized in that, The method further includes: If the first measurement result is greater than the first threshold and less than the second threshold, the transmission of the measurement report is suppressed, where the second threshold is equal to the first threshold value. Alternatively, if the first measurement result is greater than a fourth threshold and less than a third threshold, the transmission of the measurement report is suppressed, where the fourth threshold is equal to the third threshold value.

11. The method according to any one of claims 7-10, characterized in that, After sending a measurement report carrying the first measurement result to the network device, the method further includes: Receive indication information from the network device, the indication information being used to indicate cell handover or redirection; In response to the indicated information, perform cell handover or redirection; During the second time period, one or more measurements are performed; the start time of the second time period is later than or equal to the completion time of cell handover or redirection, and the duration of the second time period is a second preset duration. If the measurement results within the second time period do not meet the measurement report conditions, and the terminal device does not receive the first bearer establishment request message within the second time period, then the third message is sent; or, If the second measurement result meets the measurement report conditions and no first bearer establishment request message is received within the third time period, a measurement report carrying the second measurement result is sent; wherein, the start time of the third time period is the start time of the second time period, and the end time of the third time period is the time when the second measurement result is obtained; and the measurement results within the third time period do not meet the measurement report conditions.

12. The method as described in claim 1, characterized in that, After receiving the second message from the second terminal device at the second moment, the process also includes: Start the first timer, the duration of which is the first preset duration; Sending a third message to the network device includes: In response to the expiration of the first timer, a third message is sent to the network device.

13. The method as described in claim 1, characterized in that, After sending the third message to the network device, the process also includes: The IMS-based call is automatically initiated, and the first message is sent to the network device.

14. The method as described in claim 1, characterized in that, The second message also includes a PRACK 200 message or an INVITE 183 message.

15. A terminal device, characterized in that, The device includes a processor and an interface circuit. The interface circuit is used to receive signals from other communication devices outside the terminal device and transmit them to the processor, or to send signals from the processor to other communication devices outside the terminal device. The processor is used to implement the method as described in any one of claims 1-14 through logic circuits or execution code instructions.

16. A chip system, characterized in that, Includes a processor, which, when executing instructions, performs the method as described in any one of claims 1 to 14.

17. A computer-readable storage medium, characterized in that, The storage medium stores a computer program or instructions, which, when executed by a terminal device, implement the method as described in any one of claims 1-14.

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