Data transmission method and terminal equipment

Abstract

The invention provides a data transmission method and terminal equipment, which are beneficial to realizing information synchronization of a session state between the terminal equipment and a network, thereby avoiding the problem that an SIM card of the terminal equipment cannot perform a call service. The method is applied to a first terminal device, the first terminal device is provided with a first SIM card and a second SIM card, the first SIM card registers a first network, and the second SIM card registers a second network. The method comprises the following steps: receiving a first call from a second terminal device; establishing a first call with a second terminal device; receiving a second call from a third terminal device in the process of the first call; upon receiving the first event from the base station, transmitting a cancellation message to reject the second call; sending a first measurement report to the base station after receiving an acknowledgement message of the cancel message; a first switching instruction from the base station is received, the second SIM card is registered in a third network, and the network types of the third network and the second network are different.

Description

Data transmission method and terminal equipment

[0001] This application claims priority to the Chinese patent application filed with the State Intellectual Property Office of China on December 15, 2022, with application number 202211620134.4 and application name “Data Transmission Method and Terminal Equipment”, the entire contents of which are incorporated by reference into this application. Technical Field

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

[0003] With the rapid development of wireless communication technology, people are increasingly relying on wireless terminals. To provide users with a better service experience, the market currently includes terminal devices that support dual SIM dual standby (DSDS). These terminal devices include terminal devices that support dual SIM dual standby single call (hereinafter referred to as DSDS) and terminal devices that support dual SIM dual active (DSDA) (hereinafter referred to as DSDS). Both terminal devices that support DSDS and DSDA can be equipped with two independent subscriber identity modules (SIMs). For terminal devices that support DSDS, although both SIM cards can be in standby mode simultaneously, they cannot make voice calls or use data to access the Internet at the same time. For terminal devices that support DSDS, both SIM cards can be in standby mode and make voice calls simultaneously (for example, while one SIM card is in a call, the other SIM card can receive calls).

[0004] Taking SIM card 1 and SIM card 2 as an example, for a dual-SIM dual-pass terminal device that only supports dual-SIM registration on the fifth-generation mobile communication technology (5G) network, if SIM card 1 is in a call and SIM card 2 has an incoming call, if SIM card 1 and / or SIM card 2 switches from the 5G network to the fourth-generation mobile communication technology (4G) network, the terminal device will fall back from dual-SIM dual-pass to dual-SIM single-pass. When the terminal device is in dual-SIM single-pass mode, since SIM card 1 is in a call, SIM card 2 cannot use data services, cannot make calls, and cannot be called. As a result, the terminal device will actively hang up the call from SIM card 2.

[0005] However, the terminal device hangs up the call of SIM card 2 locally, and does not synchronize the call hang-up message to the network device. This will cause the session status of SIM card 2's card slot and the network device to be out of sync. The network device will think that SIM card 2 is still in the call service, resulting in SIM card 2 being unable to make or receive calls subsequently.

[0006] Summary of the Invention

[0007] The present application provides a data transmission method and terminal device, which are conducive to achieving information synchronization of the session status of the terminal device and the network, thereby avoiding the problem that the SIM card of the terminal device cannot perform call services.

[0008] In a first aspect, the present application provides a data transmission method, applied to a first terminal device, the first terminal device being provided with a first SIM card and a second SIM card, the first SIM card being registered with a first network, and the second SIM card being registered with a second network. The method comprises: the first terminal device receiving a first call from a second terminal device; in response to a user answering the first call on the first terminal device, establishing a first call between the first terminal device and the second terminal device; during the first call, the first terminal device receiving a second call from a third terminal device, the first call and the second call being to numbers of the first SIM card and the second SIM card, respectively; after receiving a first event from a base station, the first terminal device sending a cancellation message to reject the second call, where the second call was not answered at the time of receiving the first event; after receiving a confirmation message of the cancellation message, the first terminal device sending a first measurement report to the base station, where after receiving the first event and before sending the first measurement report, the first terminal device meets measurement report reporting conditions for the first event; and the first terminal device receiving a first handover instruction from the base station and registering the second SIM card to a third network, where the third network is of a different network standard than the second network.

[0009] In this application, the first terminal device has the dual-SIM dual-communication function when the first SIM card is registered with the first network and the second SIM card is registered with the second network. When at least one of the first SIM card and the second SIM card is registered with a network different from the first network and the second network, the first terminal device no longer has the dual-SIM dual-communication function.

[0010] For example, the first network is a 5G network and the second network is a 5G network. When the first terminal device switches the network of the second SIM card and registers the 4G network, the first terminal device no longer has the dual-card dual-pass function.

[0011] For example, a first terminal device establishes a first call with a second terminal device through a first SIM card, and the first terminal device receives a second call from a third terminal device through a second SIM card. In this scenario, if the first terminal device receives a first event, the first terminal device obtains a first measurement report based on the first event. If the first terminal device meets the measurement report reporting conditions for the first event, it needs to report the measurement report of the first event to the base station. Since the base station instructs the first terminal device to perform network switching after receiving the measurement report of the first event, after the network switching, the first terminal device no longer meets the requirements of registering the first SIM card on the first network and registering the second SIM card on the second network. In this way, the first terminal device no longer has the dual-SIM dual-communication function. Therefore, the first terminal device will reject the second call to the second SIM card. However, since the first terminal device no longer has the dual-SIM dual-communication function, the cancellation message used to reject the second call cannot be sent to the network side. The network side cannot synchronize the session status of the second SIM card and will consider the second SIM card to be still in an occupied state, thereby causing the first terminal device to be unable to make or receive calls through the second SIM card.

[0012] Based on the technical solution of the present application, the first terminal device can delay (suppress) the reporting of the first measurement report when the measurement report reporting conditions of the first event are met. That is to say, the first terminal device first sends a cancellation message for rejecting the second call to the base station without performing network switching, that is, when it still has the dual-card dual-pass function. At this time, the cancellation message for rejecting the second call can be sent normally. After receiving the confirmation message for the cancellation message, the first terminal device determines that the network side has synchronized the session status of the second SIM card. After this, the first terminal device can send the first measurement report to the base station, and then register the second SIM card with the 4G network based on the first switching instruction of the base station. This is conducive to realizing the information synchronization of the session status of the terminal device and the network side, thereby avoiding the problem that the SIM card of the terminal device cannot perform call services.

[0013] In combination with the first aspect, in certain implementations of the first aspect, after the first terminal device receives a second call from the third terminal device, when answering the second call, the method also includes: in response to the user's operation of answering the second call on the first terminal device, a second call is established between the first terminal device and the third terminal device, and the first call is retained; after receiving a second event from the base station, the first terminal device sends a hang-up message to end the first call; after receiving a confirmation message of the hang-up message, the first terminal device sends a second measurement report to the base station, and after receiving the second event and before sending the second measurement report, the first terminal device meets the measurement report reporting conditions of the second event; the first terminal device receives a second switching instruction from the base station and registers the second SIM card to the third network.

[0014] In the present application, exemplarily, a first terminal device establishes a first call with a second terminal device through a first SIM card, and the first terminal device receives a second call from a third terminal device through a second SIM card, answers the second call, and establishes a second call with the third terminal device. After the first terminal device answers the second call, the first call between the first terminal device and the second terminal device is retained. In this scenario, if the first terminal device receives a second event, the first terminal device obtains a second measurement report based on the second event. If the first terminal device meets the measurement report reporting conditions of the second event, it needs to report the measurement report of the second event to the base station.

[0015] Based on the technical solution of the present application, the first terminal device can delay (suppress) the reporting of the second measurement report when the measurement report reporting conditions of the second event are met. That is to say, the first terminal device first sends a hang-up message for ending the first call to the base station when no network switching is performed, that is, when it still has the dual-card dual-pass function. At this time, the hang-up message for ending the first call can be sent normally. After receiving the confirmation message for the hang-up message, the first terminal device determines that the network side has synchronized the session status of the first SIM card. After this, the first terminal device can send a second measurement report to the base station, and then register the second SIM card with the 4G network based on the second switching instruction of the base station. This is conducive to realizing the information synchronization of the session status of the terminal device and the network side, thereby avoiding the problem that the SIM card of the terminal device cannot perform call services.

[0016] In combination with the first aspect, in certain implementations of the first aspect, if the first network and the second network are 5G networks, the first terminal device has a dual-SIM dual-pass function; if one of the first network and the second network is a 5G network and the other is a 4G network, the first terminal device has a dual-SIM single-pass function.

[0017] In combination with the first aspect, in certain implementations of the first aspect, before the first terminal device sends a cancellation message, the method includes: the first terminal device determines that the first SIM card and the second SIM card are SIM cards registered for the 5G network, and the first SIM card and the second SIM card are both in an occupied state, and the occupied state includes a call state or an incoming call state.

[0018] In this application, the first terminal device can determine whether the first SIM card and the second SIM card meet the preset conditions when sending the cancellation message. The preset conditions include at least: the first SIM card and the second SIM card are SIM cards registered for the 5G network, and the first SIM card and the second SIM card are both in an occupied state.

[0019] In combination with the first aspect, in certain implementations of the first aspect, the first event is a B1 event / B2 event; after receiving the first event from the base station, the method also includes: the first terminal device measures the signal quality of the first cell based on the B1 event / B2 event, and the first cell and the service cell of the first terminal device belong to different communication systems; the first terminal device obtains a first measurement report based on the signal quality of the first cell.

[0020] In the present application, the first cell and the service cell of the first terminal device belong to different communication systems, that is, the first cell is a heterosystem cell of the service cell of the first terminal device. Optionally, the first cell is a heterosystem cell adjacent to the service cell of the first terminal device, which is called a heterosystem neighboring cell. Among them, the neighboring cell is determined by the operator according to the coverage area of ​​the base station and the requirements of inter-zone switching. Two cells with overlapping coverage and a switching relationship can be called neighboring cells. The communication system of the heterosystem neighboring cell is different from that of the service cell, and the communication system includes 4G, 5G, etc. For example, the service cell of the first terminal device is a 5G cell, and the first cell is a 4G cell. The B1 event / B2 event is used to indicate the measurement of the signal quality of the heterosystem neighboring cell of the first terminal device. The first measurement report is a measurement report of the B1 event / B2 event, including the signal quality of the heterosystem neighboring cell of the first terminal device.

[0021] In combination with the first aspect, in certain implementations of the first aspect, before receiving the first event from the base station, the method also includes: the first terminal device receives a third event from the base station, the third event is used to indicate the measurement of the signal quality of the service cell of the first terminal device; if the signal quality of the service cell of the first terminal device is lower than the threshold value, the first terminal device sends a third measurement report to the base station, and the third measurement report includes the signal quality of the service cell of the first terminal device.

[0022] In a second aspect, the present application provides a data transmission method, applied to a first terminal device, wherein the first terminal device is provided with a first SIM card and a second SIM card, wherein the first SIM card is registered with a first network, and the second SIM card is registered with a second network. The method comprises: the first terminal device receives a first event from a base station; after receiving the first event from the base station, the first terminal device determines whether the first SIM card and the second SIM card meet preset conditions, wherein the preset conditions at least include: the first network and the second network are 5G networks, and the first SIM card and the second SIM card are in an occupied state, wherein the occupied state includes a call state or an incoming call state; if the first SIM card and the second SIM card meet the preset conditions, the first terminal device sends a termination message to reject the incoming call of the second SIM card, or hangs up the call of the first SIM card; after receiving a confirmation message of the termination message, the first terminal device sends a first measurement report to the base station, wherein after receiving the first event and before sending the first measurement report, the first terminal device meets the measurement report reporting conditions of the first event; the first terminal device receives a third handover instruction from the base station and registers the second SIM card with a third network, wherein the third network has a different network standard from the second network.

[0023] In this application, the first terminal device has the dual-SIM dual-communication function when the first SIM card is registered with the first network and the second SIM card is registered with the second network. When at least one of the first SIM card and the second SIM card is registered with a network different from the first network and the second network, the first terminal device no longer has the dual-SIM dual-communication function.

[0024] For example, the first network is a 5G network and the second network is a 5G network. When the first terminal device switches the network of the second SIM card and registers the 4G network, the first terminal device no longer has the dual-card dual-pass function.

[0025] In the technical solution of the present application, before sending the termination message, the first terminal device determines whether the first SIM card and the second SIM card meet the preset conditions. If the preset conditions are met, the network switching needs to be delayed; if not, the network switching does not need to be delayed.

[0026] In one possible scenario, the first terminal device communicates with other terminal devices through the first SIM card. During the call, the first terminal device receives an incoming call from the other terminal device through the second SIM card. If the first terminal device receives the first event at this time, the first terminal device first sends a termination message to the network side to reject the incoming call from the second SIM card, wherein the termination message can be a CANCEL message in the Session Initiation Protocol (SIP) signaling, which is used to terminate an unestablished session. After receiving the confirmation message of the termination message from the network side, the first terminal device reports the first measurement report to the base station, and the first measurement report is a measurement report of the first event. Afterwards, the first terminal device can register the second SIM card with the third network based on the third switching instruction of the base station.

[0027] In another possible scenario, the first terminal device is talking to another terminal device through the first SIM card. During the call, the first terminal device receives an incoming call from the other terminal device through the second SIM card, and the first terminal device answers the incoming call from the second SIM card in response to the user operation, and keeps the call through the first SIM card. If the first terminal device receives the first event at this time, the first terminal device first sends a termination message to the network side for hanging up the call of the first SIM card, wherein the termination message can be a hang-up (BYE) message in the SIP signaling, which is used to terminate an established session. After receiving the confirmation message of the termination message from the network side, the first terminal device reports the first measurement report to the base station, and the first measurement report is a measurement report of the first event. Afterwards, the first terminal device can register the second SIM card with the third network based on the third switching instruction of the base station.

[0028] The technical solution based on the present application is conducive to achieving information synchronization of the session status of the terminal device and the network side, thereby avoiding the problem that the SIM card of the terminal device cannot perform call services.

[0029] In a third aspect, the present application provides a data transmission method, applied to a base station, the method comprising:

[0030] The base station sends a first event to a first terminal device, wherein the first terminal device is provided with a first SIM card and a second SIM card, the first SIM card is registered with a first network, the second SIM card is registered with a second network, the first terminal device is conducting a first call with the second terminal device, and the first terminal device is receiving a second call from a third terminal device; the base station sends a cancellation message, which is used to reject the second call; the base station receives a confirmation message of the cancellation message; after sending the confirmation message of the cancellation message to the first terminal device, the base station receives a first measurement report from the first terminal device; the base station sends a first switching instruction to the first terminal device, the first switching instruction instructing the first terminal device to register the second SIM card to a third network, and the network standard of the third network is different from that of the second network.

[0031] In this application, the base station can send a cancellation message for rejecting the second call before instructing the first terminal device to switch networks, and receive a confirmation message of the cancellation message. This helps the network side synchronize the session status of the SIM card of the first terminal device, thereby avoiding the problem of the SIM card of the first terminal device being unable to perform call services.

[0032] In a fourth aspect, the present application provides a data transmission method, applied to a communication system including a first terminal device and a base station, wherein the first terminal device is provided with a first SIM card and a second SIM card, the first SIM card being registered with a 5G network, and the second SIM card being registered with a 5G network. The method comprises: the first terminal device receiving a first call from a second terminal device; in response to a user answering the first call on the first terminal device, establishing a first call between the first terminal device and the second terminal device; during the first call, the first terminal device receiving a second call from a third terminal device, the first call and the second call being to numbers of the first SIM card and the second SIM card, respectively; the base station sending a first event to the first terminal device; after receiving the first event, the first terminal device sending a cancellation message to reject the second call; upon receiving the first event, the second call was not answered; after receiving a confirmation message of the cancellation message, the first terminal device sending a first measurement report to the base station, wherein after receiving the first event and before sending the first measurement report, the first terminal device meets the measurement report reporting conditions of the first event; and after receiving the first measurement report, the base station sending a fourth switching instruction to the first terminal device, the fourth switching instruction instructing the first terminal device to register the second SIM card with a 4G network.

[0033] In the fourth aspect, taking the first network as a 5G network, the second network as a 5G network, and the third network as a 4G network in the first and third aspects as an example, the beneficial effects achieved by the feasible embodiments corresponding to the fourth aspect are similar to those described in the first and third aspects, and will not be repeated here.

[0034] In a fifth aspect, the present application provides a terminal device, which may also be referred to as a terminal, user equipment (UE), mobile station (MS), mobile terminal (MT), etc. The terminal device may be a mobile phone, a personal computer (PC), a smart TV, a wearable device, a tablet computer (Pad), a computer with wireless transceiver function, a virtual reality (VR) terminal device, an augmented reality (AR) terminal device, a wireless terminal in industrial control, a wireless terminal in self-driving, a wireless terminal in remote medical surgery, a wireless terminal in a smart grid, a wireless terminal in transportation safety, a wireless terminal in a smart city, a wireless terminal in a smart home, etc.

[0035] The terminal device includes: a processor and a memory; the memory stores computer-executable instructions; the processor executes the computer-executable instructions stored in the memory, so that the terminal device executes the method of the first aspect or the second aspect.

[0036] In a sixth aspect, the present application provides a computer-readable storage medium storing a computer program, which, when executed by a processor, implements the method of the first or second aspect.

[0037] In a seventh aspect, the present application provides a computer program product, which includes a computer program. When the computer program is run, it enables the computer to execute the method of the first aspect or the second aspect.

[0038] In an eighth aspect, the present application provides a chip, the chip including a processor, the processor being used to call a computer program in a memory to execute the method described in the first aspect or the second aspect.

[0039] It should be understood that the fifth to eighth aspects of the present application correspond to the technical solutions of the first or second aspect of the present application, and the beneficial effects achieved by each aspect and the corresponding feasible implementation methods are similar and will not be repeated here. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] FIG1 is a schematic structural diagram of a terminal device applicable to an embodiment of the present application;

[0041] FIG2 is a schematic diagram of a communication scenario provided in an embodiment of the present application;

[0042] FIG3 is a flow chart of a calling method provided in an embodiment of the present application;

[0043] FIG4 is a schematic flow chart of a data transmission method provided in an embodiment of the present application;

[0044] 5A to 5C are schematic diagrams of network switching provided by an embodiment of the present application;

[0045] FIG6 is a schematic flow chart of another data transmission method provided in an embodiment of the present application;

[0046] FIG7 is a schematic diagram of a call interface of a terminal device with 5G dual-SIM dual-pass function provided in an embodiment of the present application;

[0047] FIG8 is a schematic flowchart of another data transmission method provided in an embodiment of the present application. DETAILED DESCRIPTION

[0048] The technical solution in this application will be described below with reference to the accompanying drawings.

[0049] To facilitate a clear description of the technical solutions of the embodiments of the present application, the following briefly introduces some of the terms and technologies involved in the embodiments of the present application:

[0050] 1. In the embodiments of this application, words such as "first" and "second" are used to distinguish identical or similar items with substantially the same functions and effects, and do not limit their order of precedence. Those skilled in the art will understand that words such as "first" and "second" do not limit the quantity or execution order, and that words such as "first" and "second" do not necessarily mean different.

[0051] 2. Throughout this application, words such as "exemplarily" or "for example" are used to indicate examples, illustrations, or descriptions. Any embodiment or design described in this application as "exemplary" or "for example" should not be construed as preferred or advantageous over other embodiments or designs. Rather, the use of words such as "exemplarily" or "for example" is intended to present the relevant concepts in a concrete manner.

[0052] 3. "At least one" means one or more, and "more" means two or more. "And / or" describes the association relationship of associated objects, indicating that three relationships may exist. For example, A and / or B can mean: A exists alone, A and B exist at the same time, and B exists alone, where A and B can be singular or plural. The character " / " generally indicates that the previous and next associated objects are in an "or" relationship. "At least one of the following items" or similar expressions refers to any combination of these items, including any combination of single or plural items. For example, at least one of a, b 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, c can be single or plural.

[0053] 4. The mobility management of wireless communication systems is usually achieved through the terminal device reporting measurement reports, and the base station decides whether to perform network switching (for example, switching from a 5G cell to a 4G cell) based on the measurement reports. The terminal device can have multiple measurement indicators to measure the signal quality of the serving cell and / or the neighboring cell of the heterogeneous system. Among them, the multiple measurement indicators include reference signal receiving power (RSRP), reference signal receiving quality (RSRQ), and signal to interference plus noise ratio (SINR).

[0054] Ideally, the base station allows the terminal device to report the signal quality of the current serving cell and adjacent cells (including neighboring cells of different systems) and trigger handover through unilateral measurement. However, in actual applications, unnecessary ping-pong handovers can cause overload. To avoid this, the 3rd Generation Partnership Project (3GPP) specification 38.331 defines a set of predefined measurement reporting mechanisms performed by terminal devices. The types of these measurement reports are called "events", such as A1 events, A2 events, B1 events, B2 events, etc. The type of event that the terminal device needs to report is specified by the radio resource control (RRC) message sent by the base station, such as the RRC connection reconfiguration message.

[0055] It should be noted that the "at..." in the embodiments of the present application can be the instant when a certain situation occurs, or it can be a period of time after the situation occurs, and the embodiments of the present application do not specifically limit this. In addition, the display interface provided in the embodiments of the present application is only an example, and the display interface can also include more or less content.

[0056] Figure 1 is a schematic diagram of the structure of a terminal device applicable to an embodiment of the present application. As shown in Figure 1, the terminal device 100 may include: a processor 110, an external memory interface 120, an internal memory 121, a USB interface 130, a charging management module 140, a power management module 141, a battery 142, an antenna 1, an antenna 2, a mobile communication module 150, a wireless communication module 160, an audio module 170, a speaker 170A, a receiver 170B, a microphone 170C, an earphone interface 170D, a sensor module 180, a button 190, a motor 191, an indicator 192, a camera 193, a display 194, and a SIM card interface 195, etc.

[0057] It should be understood that the structure illustrated in this embodiment does not constitute a specific limitation on the terminal device 100. In other embodiments of the present application, the terminal device 100 may include more or fewer components than shown, or may combine or separate certain components, or arrange the components differently. The illustrated components may be implemented in hardware, software, or a combination of software and hardware.

[0058] The processor 110 may include one or more processing units. For example, the processor 110 may include an application processor (AP), a modem processor, a graphics processing unit (GPU), an image signal processor (ISP), a controller, a video codec, a digital signal processor (DSP), a baseband processor, a display processing unit (DPU), and / or a neural-network processing unit (NPU). The different processing units may be independent devices or integrated into one or more processors. In some embodiments, the terminal device 100 may also include one or more processors 110. The processor may serve as the nerve center and command center of the terminal device 100. The processor may generate operation control signals based on instruction opcodes and timing signals to control instruction fetching and execution. The processor 110 may also include a memory for storing instructions and data. In some embodiments, the memory in the processor 110 is a cache memory. This memory may store instructions or data used or recycled by the processor 110. If the processor 110 needs to use the instruction or data again, it can directly call it from the memory. This avoids repeated accesses, reduces the waiting time of the processor 110 , and thus improves the efficiency of the terminal device 100 .

[0059] In some embodiments, the processor 110 may include one or more interfaces. The interfaces may include an inter-integrated circuit (I2C) interface, an inter-integrated circuit sound (I2S) interface, a pulse code modulation (PCM) interface, a universal asynchronous receiver / transmitter (UART) interface, a mobile industry processor interface (MIPI), a general-purpose input / output (GPIO) interface, a subscriber identity module (SIM) interface, and / or a USB interface. The USB interface 130 is an interface that complies with USB standards and may be a Mini USB interface, a Micro USB interface, a USB Type C interface, or the like. The USB interface 130 may be used to connect a charger to charge the terminal device 100, or to transmit data between the terminal device 100 and peripheral devices. It may also be used to connect headphones to play audio through the headphones.

[0060] It is understood that the interface connection relationship between the modules illustrated in the embodiments of the present application is for illustrative purposes only and does not constitute a structural limitation on the terminal device 100. In other embodiments of the present application, the terminal device 100 may also adopt different interface connection methods from the above embodiments, or a combination of multiple interface connection methods.

[0061] The wireless communication functionality of terminal device 100 can be implemented using antenna 1, antenna 2, mobile communication module 150, wireless communication module 160, a modem processor, and a baseband processor. Antenna 1 and antenna 2 are used to transmit and receive electromagnetic wave signals. Each antenna in terminal device 100 can be used to cover a single or multiple communication frequency bands. Different antennas can also be reused to improve antenna utilization. For example, antenna 1 can be reused as a diversity antenna for a wireless local area network. In other embodiments, the antennas can be used in conjunction with a tuning switch.

[0062] The mobile communication module 150 can provide solutions for wireless communications including 2G / 3G / 4G / 5G applied to the terminal device 100. The mobile communication module 150 may include at least one filter, a switch, a power amplifier, a low noise amplifier, etc. The mobile communication module 150 can receive electromagnetic waves from the antenna 1, and filter, amplify, and process the received electromagnetic waves, and transmit them to the modulation and demodulation processor for demodulation. The mobile communication module 150 can also amplify the signal modulated by the modulation and demodulation processor, and convert it into electromagnetic waves for radiation through the antenna 1. In some embodiments, at least some of the functional modules of the mobile communication module 150 can be set in the processor 110. In some embodiments, at least some of the functional modules of the mobile communication module 150 can be set in the same device as at least some of the modules of the processor 110.

[0063] The modem processor may include a modulator and a demodulator. The modulator is used to modulate the low-frequency baseband signal to be transmitted into a medium-high frequency signal. The demodulator is used to demodulate the received electromagnetic wave signal into a low-frequency baseband signal. The demodulator then transmits the demodulated low-frequency baseband signal to the baseband processor for processing. After being processed by the baseband processor, the low-frequency baseband signal is passed to the application processor. The application processor outputs a sound signal through an audio device (not limited to the speaker 170A, the receiver 170B, etc.) or displays an image or video through the display screen 194. In some embodiments, the modem processor may be an independent device. In other embodiments, the modem processor may be independent of the processor 110 and be set in the same device as the mobile communication module 150 or other functional modules.

[0064] The wireless communication module 160 can provide wireless communication solutions including wireless local area networks (WLAN), Bluetooth, global navigation satellite system (GNSS), frequency modulation (FM), NFC, infrared technology (IR), etc. applied to the terminal device 100. The wireless communication module 160 can be one or more devices integrating at least one communication processing module. The wireless communication module 160 receives electromagnetic waves via the antenna 2, frequency modulates and filters the electromagnetic wave signals, and sends the processed signals to the processor 110. The wireless communication module 160 can also receive the signal to be transmitted from the processor 110, frequency modulate it, amplify it, and convert it into electromagnetic waves for radiation through the antenna 2.

[0065] In some embodiments, the antenna 1 of the terminal device 100 is coupled to the mobile communication module 150, and the antenna 2 is coupled to the wireless communication module 160, so that the terminal device 100 can communicate with the network and other devices through wireless communication technology. The wireless communication technology may include GSM, GPRS, CDMA, WCDMA, TD-SCDMA, LTE, GNSS, WLAN, NFC, FM, and / or IR technology. The above-mentioned GNSS may include a global positioning system (GPS), a global navigation satellite system (GLONASS), a Beidou navigation satellite system (BDS), a quasi-zenith satellite system (QZSS) and / or a satellite-based augmentation system (SBAS).

[0066] The terminal device 100 can implement display functions through a GPU, a display screen 194, and an application processor. The application processor may include an NPU and / or a DPU. The GPU is a microprocessor for image processing, which is connected to the display screen 194 and the application processor. The GPU is used to perform mathematical and geometric calculations for graphics rendering. The processor 110 may include one or more GPUs, which execute instructions to generate or change display information. The NPU is a neural network (NN) computing processor that quickly processes input information by drawing on the structure of biological neural networks, such as the transmission pattern between neurons in the human brain, and can also continuously self-learn. The NPU can realize applications such as intelligent cognition of the terminal device 100, such as image recognition, face recognition, voice recognition, text understanding, etc. The DPU is also called a display sub-system (DSS). The DPU is used to adjust the color of the display screen 194. The DPU can adjust the color of the display screen through a three-dimensional (3D) color lookup table (LUT). The DPU can also perform image scaling, noise reduction, contrast enhancement, backlight brightness management, HDR processing, and display parameter Gamma adjustment.

[0067] Display screen 194 is used to display images, videos, etc. Display screen 194 includes a display panel. The display panel can be a liquid crystal display (LCD), an organic light-emitting diode (OLED), an active-matrix organic light-emitting diode (AMOLED), a flexible light-emitting diode (FLED), a MiniLED, a MicroLED, a Micro-oLed, or a quantum dot light-emitting diode (QLED). In some embodiments, terminal device 100 may include one or N display screens 194, where N is a positive integer greater than 1.

[0068] The terminal device 100 can implement the shooting function through an ISP, one or more cameras 193, a video codec, a GPU, one or more display screens 194, and an application processor.

[0069] The external memory interface 120 can be used to connect an external memory card, such as a Micro SD card, to expand the storage capacity of the terminal device 100. The external memory card communicates with the processor 110 via the external memory interface 120 to implement data storage functions. For example, data files such as music, photos, and videos can be stored on the external memory card.

[0070] The internal memory 121 can be used to store one or more computer programs, each of which includes instructions. The processor 110 can execute the instructions stored in the internal memory 121, thereby enabling the terminal device 100 to perform various functional applications and data processing. The internal memory 121 may include a program storage area and a data storage area. The program storage area may store an operating system; the program storage area may also store one or more applications (such as a gallery, contacts, etc.). The data storage area may store data created during the use of the terminal device 100 (such as photos, contacts, etc.). In addition, the internal memory 121 may include a high-speed random access memory and may also include a non-volatile memory, such as at least one disk storage device, a flash memory device, a universal flash storage (UFS), etc. In some embodiments, the processor 110 can execute the instructions stored in the internal memory 121 and / or the instructions stored in the memory provided in the processor 110, thereby enabling the terminal device 100 to perform various functional applications and data processing.

[0071] The terminal device 100 can implement audio functions through the audio module 170, speaker 170A, receiver 170B, microphone 170C, headphone jack 170D, and application processor. For example, music playback and recording. The audio module 170 is used to convert digital audio information into analog audio signal output, and also to convert analog audio input into digital audio signals. The audio module 170 can also be used to encode and decode audio signals. In some embodiments, the audio module 170 can be provided in the processor 110, or some functional modules of the audio module 170 can be provided in the processor 110. The speaker 170A, also known as the "speaker", is used to convert audio electrical signals into sound signals. The terminal device 100 can listen to music or listen to hands-free calls through the speaker 170A. The receiver 170B, also known as the "earpiece", is used to convert audio electrical signals into sound signals. When the terminal device 100 receives a call or voice message, the voice can be heard by holding the receiver 170B close to the human ear. Microphone 170C, also known as "microphone" or "microphone", is used to convert sound signals into electrical signals. When making a call or sending a voice message, the user can speak by putting their mouth close to the microphone 170C to input the sound signal into the microphone 170C. The terminal device 100 can be provided with at least one microphone 170C. In other embodiments, the terminal device 100 can be provided with two microphones 170C, which can not only collect sound signals but also realize noise reduction function. In other embodiments, the terminal device 100 can also be provided with three, four or more microphones 170C to realize sound signal collection, noise reduction, sound source identification, directional recording function, etc. The headphone jack 170D is used to connect wired headphones. The headphone jack 170D can be a USB interface 130, or a 3.5mm open mobile terminal platform (OMTP) standard interface, or a cellular telecommunications industry association of the USA (CTIA) standard interface.

[0072] The sensor module 180 may include a pressure sensor 180A, a gyroscope sensor 180B, an air pressure sensor 180C, a magnetic sensor 180D, an acceleration sensor 180E, a distance sensor 180F, a proximity light sensor 180G, a fingerprint sensor 180H, a temperature sensor 180J, a touch sensor 180K, an ambient light sensor 180L, a bone conduction sensor 180M, and the like.

[0073] In addition, on top of the above components, an operating system runs in the terminal device, such as the iOS operating system, the Android operating system, the Windows operating system, etc. Applications can be installed and run on the operating system. In other embodiments, there can be multiple operating systems running in the terminal device.

[0074] It should be understood that the hardware modules included in the terminal device shown in Figure 1 are merely illustrative and do not limit the specific structure of the terminal device. In fact, the terminal device provided in the embodiments of the present application may also include other hardware modules that interact with the hardware modules illustrated in the figure, and these are not specifically limited here. For example, the terminal device may also include a flashlight, a micro-projector, etc. For another example, if the terminal device is a PC, it may also include components such as a keyboard and a mouse.

[0075] The terminal device involved in the embodiments of the present application may be a device with wireless transceiver functions, which can be deployed on land, including indoors or outdoors, handheld or vehicle-mounted; can also be deployed on the water (such as a ship, etc.); can also be deployed in the air (for example, on an airplane, a balloon, and a satellite, etc.). The terminal device may be a user equipment (UE), an access terminal, a terminal unit, a subscriber unit, a terminal station, a mobile station (MS), a mobile station, a remote station, a remote terminal, a mobile device, a wireless communication device, a terminal agent, or a terminal device in a 5G network or a future evolved public land mobile network (PLMN). The access terminal may be a cellular phone, a cordless phone, a Session Initiation Protocol (SIP) phone, a wireless local loop (WLL) station, a personal digital assistant (PDA), a handheld device with wireless communication capabilities, a computing device or other processing device connected to a wireless modem, a vehicle-mounted device or a wearable device, a virtual reality (VR) terminal device, an augmented reality (AR) terminal device, a wireless terminal in industrial control, a wireless terminal in self-driving, a wireless terminal in remote medical, a wireless terminal in smart grid, a wireless terminal in transportation safety, a wireless terminal in smart city, a wireless terminal in smart home, etc. The terminal may be mobile or fixed. The embodiments of the present application do not limit the specific type and structure of the terminal.

[0076] It should be understood that in the embodiments of the present application, the terminal device may be a device for implementing a terminal device function, or a device capable of supporting the terminal device in implementing the function, such as a chip system, which may be installed in the terminal. In the embodiments of the present application, the chip system may be composed of a chip, or may include a chip and other discrete devices.

[0077] The terminal device in the embodiments of the present application may also be referred to as: user equipment (UE), mobile station (MS), mobile terminal (MT), access terminal, user unit, user station, mobile station, mobile station, remote station, remote terminal, mobile device, user terminal, terminal, wireless communication equipment, user agent or user device, etc.

[0078] The network devices involved in the embodiments of the present application include base stations deployed in the radio access network (RAN), core network devices deployed in the 5G core network, and IP multimedia subsystem (IMS) devices deployed in the IMS network. Base stations include, but are not limited to, the next generation node B (gNB) in the 5G system.

[0079] The 5G core network is primarily responsible for user access control, mobility management, session management, user security authentication, billing, and other services. The 5G core network consists of multiple functional units and can be divided into two functional entities: the 5G control plane and the 5G data plane.

[0080] The 5G control plane includes the access and mobility management function (AMF) and the session management function (SMF). The AMF is responsible for user access management, security authentication, and mobility management. The SMF is responsible for interacting with the separate 5G data plane, creating, updating, and deleting protocol data unit (PDU) sessions, and managing the session environment with the PDU.

[0081] The 5G data plane consists of the user plane function (UPF) and the data network. The UPF is responsible for interacting with the data network, managing user plane data transmission, traffic statistics, and secure eavesdropping. The data network can provide the UPF with massive and diverse data.

[0082] In the embodiments of the present application, the network elements in the 5G core network are collectively referred to as core network devices.

[0083] The IMS network includes at least one of an access-session border controller (A-SBC), a proxy-call session control function (P-CSCF), an interrogating-call session control function (I-CSCF), a serving-call session control function (S-CSCF), or a multimedia telephony service application server (MMTEL AS).

[0084] In the embodiment of the present application, the network elements related to processing call services in the IMS network are collectively referred to as IMS devices.

[0085] It should be understood that in the embodiments of the present application, the network device can be a device for implementing the network device function, or it can be a device that can support the network device to implement the function, such as a chip system, which can be installed in the network device. It is understood that all or part of the functions of the network device in the present application can also be implemented by software functions running on hardware, or by virtualization functions instantiated on a platform (such as a cloud platform).

[0086] It should also be understood that the network devices and terminal devices in the embodiments of the present application can be deployed on land, including indoors or outdoors, handheld or vehicle-mounted; or deployed on the water; or deployed in the air on aircraft, balloons, and satellites. The embodiments of the present application do not limit the application scenarios of the network devices and terminal devices.

[0087] The technical solutions of the embodiments of the present application can be applied to various communication systems, such as the fifth generation (5G) system or future evolved communication systems, vehicle-to-X V2X, where V2X may include vehicle to network (V2N), vehicle to vehicle (V2V), vehicle to infrastructure (V2I), vehicle to pedestrian (V2P), etc., long-term evolution of vehicle communication technology (LTE-V), Internet of Vehicles, machine type communication (MTC), Internet of Things (IoT), long-term evolution of machine communication technology (LTE-M), machine to machine (M2M), device to device (D2D), etc.

[0088] Figure 2 is a schematic diagram of a communication scenario provided by an embodiment of the present application. The communication scenario shown in Figure 2 shows terminal device A, terminal device B, and terminal device C. Terminal device A is installed with SIM card 1 and SIM card 2, supporting dual-SIM dual-standby mode. Terminal device B and terminal device C can be installed with one or more SIM cards, which is not limited in this embodiment of the present application.

[0089] Among them, terminal device A supports dual-SIM dual-standby mode, including supporting dual-SIM single pass or dual-SIM dual pass.

[0090] Optionally, if terminal device A supports dual 5G dual-SIM dual-pass, then when SIM card 1 is registered with the 5G network and SIM card 2 is registered with the 5G network, terminal device A has the dual-SIM dual-pass function; if at least one SIM card among SIM card 1 and SIM card 2 is not registered with the 5G network, terminal device A does not have the dual-SIM dual-pass function.

[0091] Optionally, if terminal device A supports dual 5G+4G dual-SIM dual-pass, then when any one of SIM card 1 and SIM card 2 is registered to the 5G network and the other is registered to the 4G network or the 5G network, terminal device A has the dual-SIM dual-pass function; when SIM card 1 and SIM card 2 are both registered to the 4G network, terminal device A does not have the dual-SIM dual-pass function.

[0092] The embodiment of the present application is introduced by taking as an example that the terminal device A has the dual-SIM dual-pass function when SIM card 1 is registered with the 5G network and SIM card 2 is registered with the 5G network, and the terminal device A has the dual-SIM single-pass function when at least one of SIM card 1 and SIM card 2 is registered with the 4G network.

[0093] As shown in a in Figure 2, SIM card 1 of terminal device A is registered for the 5G network, and SIM card 2 is registered for the 4G network. In this case, terminal device A has the function of dual-SIM single-call. Therefore, when terminal device A is making a voice over new radio (VoNR) call with terminal device B through SIM card 1, SIM card 2 is temporarily unavailable. If terminal device C calls SIM card 2 of terminal device A at this time, terminal device A cannot receive the call from terminal device C, and terminal device A cannot communicate with terminal device C. The reason for the above problem is that for terminal device A that supports dual-SIM single-call, the two SIM cards share a set of radio frequency resources. When SIM card 1 is in a call state, SIM card 1 will occupy all radio frequency resources, and SIM card 2 has no radio frequency resources available, so it can only be temporarily disconnected and cannot make or receive calls.

[0094] As shown in Figure 2(b), SIM card 1 of terminal device A is registered to the 5G network, and SIM card 2 is registered to the 5G network. In this case, terminal device A has dual-SIM dual-communication functionality. Therefore, if terminal device A is conducting a VoNR call with terminal device B using SIM card 1, and terminal device C calls terminal device A's SIM card 2 at the same time, terminal device A can receive the incoming call from terminal device C through SIM card 2, and terminal devices A and C can communicate normally.

[0095] Taking terminal device A in Figure 2 as an example, which has dual-SIM dual-talk functionality, in one possible scenario, terminal device A is conducting a VoNR call with terminal device B via SIM card 1, when terminal device A receives an incoming call from terminal device C via SIM card 2. If terminal device A switches SIM card 1 and / or SIM card 2 from the 5G network to the 4G network based on the base station's instructions, terminal device A will fall back from dual-SIM dual-talk to dual-SIM single-talk.

[0096] When terminal device A has the dual-SIM single-call function, since SIM card 1 is in a call, SIM card 2 cannot use data services, cannot make calls or be called, and terminal device A will actively hang up the call from SIM card 2.

[0097] However, since SIM card 1 is occupying radio frequency resources for a call, terminal device A only hangs up the call on SIM card 2 locally, and the message of hanging up the call on SIM card 2 cannot be sent to the IMS device. In this way, the session status of terminal device A and the IMS device are out of sync, and the IMS device will think that SIM card 2 is still in the call service, which will cause SIM card 2 to be unable to make or receive calls subsequently.

[0098] Figure 3 is a schematic flow diagram of a call method 300 provided in an embodiment of the present application. As shown in Figure 3, method 300 describes the call flow and hang-up process of a SIP session. In conjunction with Figure 2, method 300 is interactively executed by terminal device A, terminal device B, terminal device C, and network devices shown in Figure 2. The network devices include base stations, core network devices, and IMS devices (not shown in Figure 3). SIP messages are transmitted between terminal device A and terminal device B / terminal device C via the base stations, core network devices, and IMS devices.

[0099] Terminal device A is provided with SIM card 1 and SIM card 2. SIM card 1 is registered with the first network, and SIM card 2 is registered with the second network. In this embodiment of the application, the first network is a 5G network, and the second network is a 5G network. For example, terminal device A has the dual-SIM dual-communication function.

[0100] Method 300 includes S301 to S324, and the specific steps are as follows:

[0101] S301: Terminal device B sends a first INVITE message to terminal device A via a network device. The first INVITE message is used to request to start a session. Correspondingly, terminal device A receives the first INVITE message.

[0102] S302: Terminal device A sends a first 100Trying message to terminal device B via the network device. The first 100Trying message is used to indicate that the first INVITE message has been received and to stop retransmitting the INVITE message. Accordingly, terminal device B receives the first 100Trying message.

[0103] S303: Terminal device A sends a first 183 (session_progress) message to terminal device B via the network device. The first 183 message is used to indicate that the call is in progress. Accordingly, terminal device B receives the first 183 message.

[0104] S304: Terminal device B sends a first PRACK message to terminal device A via the network device. The first PRACK message is used to ensure reliable transmission of temporary messages (including messages 101 to 199, such as the first message 183 described above). If the first PRACK message is not received, the temporary message will be retransmitted. Accordingly, terminal device A receives the first PRACK message.

[0105] At step S305, terminal device A sends a first 200OK message to terminal device B via the network device. This first 200OK message is a response to the first INVITE message. The messages transmitted from step S301 to step S304 carry Session Description Protocol (SDP) content. For example, the first INVITE message includes information such as the caller and callee addresses, the call subject, and the call priority. Terminal device A sends the first 200OK message, indicating that the SDP content exchange is complete. Accordingly, terminal device B receives the first 200OK message.

[0106] S306: Terminal device B sends a first UPDATA message to terminal device A via the network device. The first UPDATA message is used to update the media stream state. Correspondingly, terminal device A receives the first UPDATA message.

[0107] S307, terminal device A sends a second 200OK message to terminal device B via the network device. The second 200OK message is a response to the first UPDATA message, indicating that the media stream status has been updated. Correspondingly, terminal device B receives the first 200OK message.

[0108] S308: Terminal device A sends a first 180 (Ringing) message to terminal device B via the network device. The first 180 message is used to indicate that the called party has been ringing. Correspondingly, terminal device B receives the first 180 message.

[0109] S309: Terminal device A sends a third 200OK message to terminal device B via the network device. The third 200OK message indicates that the called party (terminal device A) has answered the call. Accordingly, terminal device B receives the third 200OK message.

[0110] S310: Terminal device B sends an ACK message to terminal device A via a network device. The first ACK message is used to indicate that the session has been established. Accordingly, terminal device A receives the first ACK message.

[0111] The above S301 to S310 describe a complete conversation process by taking the example of terminal device B making a call to the SIM card 1 of terminal device A and terminal device A answering the call. After S310, call data can be transmitted between terminal device A and terminal device B.

[0112] While terminal device B is talking to terminal device A through SIM card 1, terminal device C makes a call to SIM card 2 of terminal device A. The process (S311 to S318) of terminal device C calling terminal device A is similar to the process (S301 to S308) of terminal device B calling terminal device A, and will not be repeated here.

[0113] When SIM card 1 is in a call state and SIM card 2 is in an incoming call state, terminal device A can hang up the call of SIM card 1 and answer the incoming call of SIM card 2, or reject the incoming call of SIM card 2 in response to user operation.

[0114] The following S319 to S322 describe the process of hanging up SIM card 1 and connecting SIM card 2, and S323 to S324 describe the process of rejecting SIM card 2.

[0115] S319: Terminal device A sends a first BYE message to terminal device B via the network device. The first BYE message is used to terminate an established call. Correspondingly, terminal device B receives the first BYE message.

[0116] In this step, terminal device A sends a first BYE message to terminal device B in response to the user hanging up the call on SIM card 1.

[0117] S320 , terminal device B sends a sixth 200OK message to terminal device A through the network device. The sixth 200OK message is a response to the first BYE message, indicating that the first BYE message has been received.

[0118] S321, terminal device A sends a seventh 200OK message to terminal device C via the network device, the seventh 200OK message indicating that the called party (terminal device A) has answered the call. Accordingly, terminal device C receives the seventh 200OK message.

[0119] In this step, terminal device A sends a seventh 200 OK message to terminal device C in response to the user answering the incoming call of SIM card 2 .

[0120] S322: Terminal device C sends a second ACK message to terminal device A via the network device. The second ACK message is used to indicate that the session has been established. Accordingly, terminal device A receives the second ACK message.

[0121] S323: Terminal device A sends a first CANCEL message to terminal device C via the network device. The first CANCEL message is used to terminate a session that has not yet been established. Accordingly, terminal device C receives the first CANCEL message.

[0122] S324 , terminal device C sends an eighth 200OK message to terminal device A through the network device. The eighth 200OK message is a response to the first CANCEL message, indicating that the session establishment has been canceled.

[0123] In the above S323 to S324, terminal device A may send a first CANCEL message to the network device to reject the incoming call from terminal device C to SIM card 2 of terminal device A. Accordingly, the network device may receive the first CANCEL message and send an eighth 200OK message to terminal device A to confirm that the session establishment has been canceled.

[0124] However, if SIM card 1 is in a call state and SIM card 2 is in an incoming call state, terminal device A switches SIM card 1 and / or SIM card 2 from the 5G network to the 4G network, then terminal device A no longer has the dual-SIM dual-communication function, so terminal device A will actively hang up the incoming call of SIM card 2. At this time, the CANCEL message of terminal device A hanging up the incoming call of SIM card 2 cannot be sent to the network device, and the network device cannot synchronize the session status of SIM card 2.

[0125] It should be understood that in method 300, the first INVITE message and the second INVITE message are of the same type but are not the same message. Similarly, the first 100Trying message and the second 100Trying message are of the same type but are not the same message; the first 183 message and the second 183 message are of the same type but are not the same message; the first PRACK message and the second PRACK message are of the same type but are not the same message; the first 200OK to the eighth 200OK are of the same type but are not the same message; the first UPDATE message and the second UPDATE message are of the same type but are not the same message; the first 180 message and the second 180 message are of the same type but are not the same message; and the first ACK message and the second ACK message are of the same type but are not the same message.

[0126] Figure 4 is a schematic flow chart of a data transmission method 400 provided in an embodiment of the present application. Method 400 is applied to a communication system including a first terminal device, a second terminal device, a third terminal device, and a base station. The first terminal device is provided with a first SIM card and a second SIM card, with the first SIM card registered to a first network and the second SIM card registered to a second network.

[0127] 3 and 6 , method 400 illustrates a process in which the first terminal device switches networks when the first terminal device receives an incoming call from a third terminal device during a call with a second terminal device. For details, see S401 to S409 .

[0128] In this embodiment of the present application, when a first SIM card is registered with a first network and a second SIM card is registered with a second network, the first terminal device has dual-SIM dual-communication functionality. The first network and the second network can be the same or different. This embodiment of the present application uses the example of the first terminal device having dual-SIM dual-communication functionality when the first network and the second network are the same.

[0129] It should be understood that the first network and the second network are the same, which means that the communication systems are the same, and the communication systems include 5G, 4G, etc. For example, the first network and the second network are both 5G networks.

[0130] It should be understood that different operators may use the same or different network standards for the same communication system. For example, the 4G network standard of the first operator is time division long term evolution (TDD-LTE), and the 4G network standard of the second operator is time division long term evolution and frequency division long term evolution (TDD-LTE&FDD-LTE). For another example, the 5G network standard of the first operator and the second operator is the globally unified standard 5G new radio (NR).

[0131] Method 400 includes S401 to S409, and the specific steps are as follows:

[0132] S401: A second terminal device sends a first call to a first terminal device. Correspondingly, the first terminal device receives the first call.

[0133] Exemplarily, the first terminal device may be terminal device A shown in FIG2(b) or terminal device A in FIG3 , the first SIM card may be SIM card 1 of terminal device A, and the second SIM card may be SIM card 2 of terminal device A. The first network and the second network are 5G networks. Exemplarily, the second terminal device may be terminal device B shown in FIG2(b) or terminal device B in FIG3 .

[0134] For example, when the first SIM card and the second SIM card of the first terminal device are registered on a 5G network, the first terminal device has a dual-SIM dual-pass function.

[0135] In conjunction with the description of method 300 above, the first terminal device and the second terminal device can communicate via a base station, a core network device, and an IMS device. The first call can be the first INVITE message in S301. After receiving the first call, the first terminal device can interactively execute S302 to S308 with the second terminal device.

[0136] S402: In response to the user answering the first call on the first terminal device, a first call is established between the first terminal device and the second terminal device.

[0137] In conjunction with the description of method 300 above, the first terminal device begins ringing after S307 and indicates to the second terminal device that the called party has ringed through S308. After ringing, the first terminal device responds to the user's operation to answer the incoming call from the second terminal device and interacts with the second terminal device to perform S309 and S310, thereby establishing the first call.

[0138] S403: During the first call, the third terminal device sends a second call to the first terminal device. Correspondingly, the first terminal device receives the second call, and the first call and the second call are to the numbers of the first SIM card and the second SIM card, respectively.

[0139] In conjunction with the example in S401, the first terminal device has a dual-SIM dual-call function. Therefore, the first terminal device can receive a second call from a third terminal device during a call with the second terminal device. For example, the third terminal device can be terminal device C shown in FIG2(b) or terminal device C in FIG3.

[0140] In conjunction with the description of method 300 above, the first terminal device and the third terminal device can communicate via a base station, a core network device, and an IMS device. The second call can be the second INVITE message in S311. After receiving the second call, the first terminal device can interact with the third terminal device to execute S312 to S318.

[0141] In a possible scenario, the second terminal device may call the number of the first SIM card or the second SIM card of the first terminal device, and the third terminal device may also call the number of the first SIM card or the second SIM card of the first terminal device.

[0142] For example, the second terminal device calls the number of the first SIM card of the first terminal device. If the third terminal device calls the first SIM card of the first terminal device, the third terminal device cannot successfully call the first terminal device, and the third terminal device will prompt the user that the call is in progress; if the third terminal device calls the second SIM card of the first terminal device, the third terminal device can successfully call the first terminal device.

[0143] In the embodiment of the present application, an example is given in which the second terminal device calls the number of the first SIM card of the first terminal device, and the third terminal device calls the number of the second SIM card of the first terminal device.

[0144] Here, calling the number of the SIM card means calling the phone number corresponding to the SIM card.

[0145] S404: The base station sends a first event to the first terminal device. Correspondingly, the first terminal device receives the first event.

[0146] The first event is an inter-system measurement event, which is used to instruct the first terminal device to measure the signal quality of an inter-system cell adjacent to the serving cell of the first terminal device. The inter-system cell and the serving cell of the first terminal device belong to different communication systems. For example, the serving cell of the first terminal device is a 5G cell, and the inter-system cell is a 4G cell. In this embodiment of the application, the inter-system cell adjacent to the serving cell of the first terminal device may be referred to as an inter-system neighboring cell.

[0147] It should be understood that the first terminal device may be in a mobile environment. During the movement of the first terminal device, there may be a situation where the base station instructs the first terminal device to perform network switching.

[0148] In conjunction with the example in S401, Figures 5A to 5C are schematic diagrams of network switching provided in embodiments of the present application. For example, if the first SIM card is a SIM card of a first operator and the second SIM card is a SIM card of a second operator, the first SIM card is registered with the first operator's network, and the second SIM card is registered with the second operator's network. The first operator and the second operator may be the same or different. This embodiment of the present application is described using the example of different first and second operators.

[0149] As shown in Figure 5A, the first terminal device 501 is in the overlapping area of ​​the 5G cell of the first operator and the 5G cell of the second operator. The first SIM card and the second SIM card of the first terminal device 501 are registered with the 5G network. The first terminal device 501 can make or be called through the first SIM card, and the first terminal device 501 can also make or be called through the second SIM card. For example, at time T1, the first terminal device 501 establishes a first call with the second terminal device 502 through the first SIM card. The second SIM card is in an unoccupied state and can normally receive calls from other terminal devices. As the first terminal device 501 moves, the position of the first terminal device 501 is constantly changing.

[0150] As shown in Figure 5B, at time T2, the first terminal device 501 moves to the edge of the second operator's 5G cell, which is in the overlapping area of ​​the second operator's 5G cell and the second operator's 4G cell. At this time, the first terminal device 501 is making a first call with the second terminal device 502 through the first SIM card, and receives a second call from the third terminal device 503 through the second SIM card.

[0151] As shown in Figure 5C, after the first terminal device 501 moves to the overlapping area of ​​the second operator's 5G cell and the second operator's 4G cell, the base station can send a first event to the first terminal device 501, instructing the first terminal device 501 to perform inter-system measurement to measure the signal quality of the second operator's 4G cell adjacent to the second operator's 5G cell. For example, at time T3 after receiving the first event, the first terminal device 501 rejects the second call of the third terminal device 503 and switches the second SIM card from the second operator's 5G network to the second operator's 4G network based on the instruction of the base station. After the second SIM card switches from the second operator's 5G network to the second operator's 4G network, the first SIM card is still the SIM card registered with the first operator's 5G network, and the second SIM card becomes the SIM card registered with the second operator's 4G network. In this case, the first terminal device 501 no longer has the dual-card dual-pass function.

[0152] It should be understood that after the first terminal device 501 receives the first event, the second call has not been answered. When the first terminal device 501 no longer has the dual-SIM dual-communication function, the first terminal device 501 cannot connect the second call and will actively hang up the second call.

[0153] Optionally, the first event is a B1 event. After receiving the B1 event, the first terminal device measures the signal quality of the heterosystem neighboring cell of the first terminal device's service cell based on the B1 event, and determines whether the measurement report reporting conditions of the B1 event are met. Wherein, determining whether the measurement report reporting conditions of the B1 event are met includes: if the signal quality of the heterosystem neighboring cell of the current service cell of the first terminal device is higher than a first threshold value, the first terminal device needs to report the measurement report of the B1 event to the base station; if the signal quality of the heterosystem neighboring cell of the current service cell of the first terminal device is lower than the first threshold value, the first terminal device does not report the measurement report of the B1 event to the base station.

[0154] Optionally, the first event is a B2 event. After receiving the B1 event, the first terminal device measures the signal quality of the service cell of the first terminal device and the signal and quality of the heterosystem neighboring cell of the service cell based on the B2 event, and determines whether the measurement report reporting conditions of the B2 event are met. Wherein, the determination of whether the measurement report reporting conditions of the B2 event are met includes: if the signal quality of the current service cell of the first terminal device is lower than the second threshold value, and the signal quality of the heterosystem neighboring cell of the current service cell of the first terminal device is higher than the third threshold value, the first terminal device needs to report the measurement report of the B2 event to the base station; if the signal quality of the current service cell of the first terminal device is higher than the second threshold value, and / or the signal quality of the heterosystem neighboring cell of the current service cell of the first terminal device is lower than the third threshold value, the first terminal device does not report the measurement report of the B2 event to the base station.

[0155] Optionally, the base station may send the B1 event / B2 event through an RRC message. Optionally, the RRC message may carry a threshold value of the B1 event / B2 event.

[0156] The measurement report of the B1 event / B2 event includes the signal quality of the heterogeneous system neighboring cell of the first terminal device, for example, RSRP, RSRQ, and SINR. Optionally, the measurement report also includes at least one of the following: physical cell identity (PCI) of the heterogeneous system neighboring cell, downlink frequency, uplink frequency, downlink bandwidth, uplink bandwidth, cell identity (CI), tracking area code (TAC), frequency band indication, mobile country code (MCC), mobile network code (MNC), or number of MNC digits.

[0157] In conjunction with the description of Figure 6, in an optional embodiment, when the first terminal device determines that it is necessary to report a measurement report of the B1 event / B2 event to the base station, the first terminal device can execute S602 to determine whether the first SIM card and the second SIM card meet the preset conditions. The preset conditions include at least: the first network registered by the first SIM card and the second network registered by the second SIM card are 5G networks, and the first SIM card and the second SIM card are in an occupied state, and the occupied state includes a call state or an incoming call state. In the example of the embodiment of the present application, the first SIM card is registered with the 5G network, the second SIM card is registered with the 5G network, and the first terminal device is making a first call with the second terminal device through the first SIM card, and the first terminal device is receiving a second call from the third terminal device through the second SIM card. Therefore, the first SIM card is in a call state and the second SIM card is in an incoming call state, which meets the preset conditions.

[0158] For example, the first terminal device can determine the status of the first SIM card and the second SIM card by checking the usage flags of the first SIM card and the second SIM card. For example, if the usage flags of the first SIM card and the second SIM card are both "1", it means that both the first SIM card and the second SIM card have services in progress (or are occupied), where "services in progress" include being in a call, making a call, and receiving a call. For another example, if the usage flag of the first SIM card is "0", it means that the first SIM card is in an idle state.

[0159] The first SIM card and the second SIM card do not meet the preset conditions, including:

[0160] Case 1: The first and / or second SIM cards are not registered for the 5G network. For example, the first SIM card is registered for the 5G network, and the second SIM card is registered for the 4G network. In this case, the first terminal device does not have dual-SIM dual-connection functionality, but only dual-SIM single-connection functionality. Therefore, when the first SIM card is in a call, the second SIM card cannot receive calls from other terminal devices.

[0161] Case 2: The first SIM card and the second SIM card are SIM cards registered for the 5G network, but at least one of the first SIM card and the second SIM card is in an idle state. For example, the first SIM card is in a call state and the second SIM card is in an idle state. In this case, the first terminal device has the dual-card dual-communication function, but since no other terminal device calls the second SIM card, there is no problem of hanging up the call of the second SIM card, and there is no problem of not being able to notify the IMS device of the call of the second SIM card.

[0162] Case 3: The first SIM card and / or the second SIM card are not SIM cards registered with the 5G network, and at least one of the first SIM card and the second SIM card is in an idle state. Case 3 is a combination of Case 1 and Case 2 and will not be further described here.

[0163] If the first terminal device determines that the preset conditions are met, it indicates that the dual-SIM dual-pass mode supported by the first terminal device is dual 5G dual-SIM dual-pass. After at least one SIM card in the first terminal device switches to register on the 4G network, the first terminal device no longer has the dual-SIM dual-pass function. Therefore, the first terminal device needs to execute S407 after S405 and S406 to switch networks. In this way, when the first terminal device has the dual-SIM dual-pass function, a message rejecting the second call to the second SIM card can be sent to the network side, thereby achieving the purpose of synchronizing the session status of the second SIM card on the network side.

[0164] Optionally, before the base station sends the first event to the first terminal device, the base station sends a third event to the first terminal device, where the third event is used to indicate measuring the signal quality of the serving cell of the first terminal device. The first terminal device reports the third measurement report to the base station when a measurement report reporting condition for the third event is met.

[0165] Exemplarily, the third event includes an A2 event, and the third measurement report is a measurement report of the A2 event. After receiving the A2 event, the first terminal device measures the signal quality of the current service cell of the first terminal device, and determines whether the measurement report reporting conditions of the A2 event are met. Wherein, determining whether the measurement report reporting conditions of the A2 event are met includes: if the signal quality of the current service cell of the first terminal device is lower than the fourth threshold value, the first terminal device needs to report the measurement report of the A2 event to the base station; if the signal quality of the current service cell of the first terminal device is higher than the fourth threshold value, the first terminal device does not report the measurement report of the A2 event to the base station.

[0166] Optionally, before the base station sends the A2 event to the first terminal device, the base station sends the A1 event to the first terminal device. After receiving the A1 event, the first terminal device measures the signal quality of the current service cell of the first terminal device and determines whether the measurement report reporting conditions of the A1 event are met. If the signal quality of the current service cell of the first terminal device is higher than the fifth threshold value, the first terminal device needs to report the measurement report of the A1 event to the base station. After receiving the measurement report of the A1 event, the base station stops the hetero-frequency / hetero-system measurement; if the signal quality of the current service cell of the first terminal device is lower than the fifth threshold value, the first terminal device does not report the measurement report of the A1 event to the base station. If the base station does not receive the measurement report of the A1 event, it sends the A2 event to the first terminal device to instruct the first terminal device to continue measuring whether the signal quality of the current service cell is lower than the fourth threshold value.

[0167] S405: The first terminal device sends a cancellation message to the base station to reject the second call. Correspondingly, the base station receives the cancellation message.

[0168] 6 , in an optional embodiment, if the first SIM card and the second SIM card meet preset conditions, the first terminal device sends a cancellation message to the base station to reject the second call, i.e., executes S603 in method 600. The second call is a call from the third terminal device to the second SIM card of the first terminal device.

[0169] In combination with the description of the above method 300, the cancellation message in this step can be the first CANCEL in S323, which is used to terminate a session that has not yet been established. In the embodiment of the present application, it is to reject the second call of the third terminal device.

[0170] In this step, after receiving the first event, the first terminal device sends a cancellation message to the base station when it has dual-SIM dual-communication functionality, so the cancellation message can be sent to the base station normally. It should be understood that after receiving the cancellation message, the base station sends the cancellation message to the IMS device via the core network device, so that the IMS device synchronizes the session state of the second SIM card to an unoccupied state. Subsequently, when another terminal device calls the number of the second SIM card of the first terminal device, the first terminal device can normally receive the call through the second SIM card. Alternatively, the first terminal device can normally make calls to other terminal devices through the second SIM card.

[0171] S406: The base station sends a confirmation message of the cancellation message to the first terminal device. Correspondingly, the first terminal device receives the confirmation message of the cancellation message.

[0172] In combination with the description of the above method 300, the confirmation message of the cancellation message in this step can be the eighth 200OK message in S324, indicating that the establishment of the session has been canceled. In the embodiment of the present application, the establishment of the session between the first terminal device and the third terminal device has been canceled.

[0173] In this step, after receiving the confirmation message of the cancellation message transparently transmitted from the IMS device through the core network device, the base station sends the confirmation message of the cancellation message to the first terminal device.

[0174] S407: The first terminal device sends a first measurement report to the base station. Correspondingly, the base station receives the first measurement report.

[0175] In this step, the first measurement report is a measurement report for the first event. Combined with the description in S404, after receiving the first event, the first terminal device measures the signal quality of the heterogeneous system neighboring cell of the first terminal device's current serving cell, and reports the first measurement report to the base station if the measurement report reporting conditions for the first event are met.

[0176] It should be noted that the first terminal device sends the first measurement report to the base station after receiving the confirmation message of the cancellation message (i.e., S407 is executed after S406). In combination with the description in method 600, S407 can be executed after receiving the confirmation message of the cancellation message in S604 and before registering the second SIM card with the 4G network.

[0177] S408: The base station sends a first handover instruction to the first terminal device, where the first handover instruction is used to instruct the first terminal device to register the second SIM card with a third network, where the third network is of a different standard than the second network. Accordingly, the first terminal device receives the first handover instruction.

[0178] In this step, after receiving the first measurement report reported by the first terminal device, the base station sends a first switching instruction to the first terminal device. Exemplarily, the network standard of the second network is the 5G NR standard, and the third network is the 4G TDD-LTE standard.

[0179] S409: The first terminal device registers the second SIM card with the third network.

[0180] In this step, the first terminal device registers the second SIM card to the third network. The third network is different from the first network. It can be understood that the communication systems of the third network and the first network are different. For example, the first network is a 5G network and the third network is a 4G network.

[0181] In combination with the description in method 600, this step may be performed after S603, that is, corresponding to registering the second SIM card with the 4G network in S604.

[0182] After this step, the first SIM card of the first terminal device is registered with the first network, and the second SIM card is registered with the third network, and the first network and the third network are different. In the case where the first network and the second network are different, the first terminal device no longer has the dual-SIM dual-pass function, but has the dual-SIM single-pass function.

[0183] Based on the technical solution of the present application, in a case where the first SIM card of the two SIM cards of a first terminal device is in a call and the second SIM card is receiving an incoming call, if the first terminal device receives a first event from the base station, the first terminal device first sends a message to the base station indicating that the incoming call is rejected. After receiving a confirmation message from the network side regarding the message indicating that the incoming call is rejected, the first terminal device then sends a first measurement report to the base station, and then performs network switching based on the instruction of the base station. After the network switching, the first terminal device falls back from dual-SIM dual-pass to dual-SIM single-pass. Therefore, when the first terminal device sends the message indicating that the incoming call is rejected, it still has the dual-SIM dual-pass function, and the message indicating that the incoming call is rejected can be sent to the network side, so that the network side can synchronize the session state of the second SIM card to an unoccupied state, which is conducive to avoiding the problem that the second SIM card is subsequently unable to make calls or receive calls.

[0184] Optionally, the method 400 further includes: after the call of the first SIM card is hung up, in response to a user operation, the first terminal device makes a call with the second terminal device through the second SIM card.

[0185] In an embodiment of the present application, the first terminal device can, in response to a user operation, initiate a call with another terminal device without re-registering with the network. The user operation can be a call placement operation, where the first terminal device can place a call to the second terminal device via the second SIM card after the first SIM card is disconnected. The user operation can also be a call answering operation, where the first terminal device can answer a call from the second terminal device via the second SIM card after the first SIM card is disconnected.

[0186] Figure 6 is a schematic flow chart of another data transmission method 600 provided in an embodiment of the present application. The steps of method 600 are performed by a first terminal device, and the first terminal device is provided with a first SIM card and a second SIM card. If the first terminal device only supports dual 5G dual-card dual-pass, then when the first SIM card and the second SIM card are registered with the 5G network, the first terminal device has the dual-card dual-pass function, otherwise the first terminal device does not have the dual-card dual-pass function. For example, when the first terminal device has the dual-card dual-pass function, the first terminal device can talk with other terminal devices through the first SIM card. During the call, the first terminal device receives an incoming call from the other terminal device through the second SIM card, and the incoming call has not been connected at this time.

[0187] Optionally, in conjunction with S401 to S409 in FIG4 , method 600 illustrates the internal judgment logic for switching network modes after receiving a B1 event / B2 event in a scenario where the first terminal device is making a call through the first SIM card and receiving an incoming call through the second SIM card. It should be noted that method 600 is not dependent on the method of FIG4 . For ease of understanding, this embodiment only exemplarily combines method 600 with the method illustrated in FIG4 . Method 600 can be executed independently. Method 600 includes S601 to S606, and the specific steps are as follows:

[0188] S601, determine whether the B1 event / B2 event sent by the base station is received. If so, execute S602; if not, end this process.

[0189] The B1 event / B2 event can refer to the description of S404 and will not be repeated here.

[0190] S602: Determine whether the first and second SIM cards meet preset conditions. The preset conditions include at least: the first and second SIM cards are registered with the 5G network, and the first and second SIM cards are in an occupied state, including a call state or an incoming call state. If so, execute S603 and S604, with S603 executed before S604. If not, execute S605 and S606, with S605 executed before S606.

[0191] S603: Send a cancel message to the base station to reject the incoming call from the second SIM card.

[0192] It should be understood that at this time, the first SIM card and the second SIM card of the first terminal device are still registered with the 5G network, and the first terminal device still has the dual-SIM dual-communication function. Therefore, the first terminal device can normally send the hang-up message to the network side. The network side includes the base station, the core network equipment, and the IMS equipment. After receiving the hang-up message, the base station can send the hang-up message to the IMS equipment via the core network equipment, so that the IMS equipment can synchronize the session state of the second SIM card.

[0193] S604: After receiving the confirmation message of the cancellation message, register the second SIM card to the 4G network. After the first terminal device registers the second SIM card to the 4G network, the first terminal device no longer has the dual-SIM dual-communication function.

[0194] S605: Register the second SIM card to the 4G network. After the first terminal device registers the second SIM card to the 4G network, the first terminal device no longer has the dual-SIM dual-communication function.

[0195] S606: Send a cancel message to the base station to reject the incoming call from the second SIM card. It should be understood that at this time, the first SIM card of the first terminal device is registered with the 5G network, and the second SIM card is registered with the 4G network. The first terminal device no longer has the dual-SIM dual-communication function. Therefore, the first terminal device cannot send a hang-up message to the network side and only hangs up the incoming call from the second SIM card locally.

[0196] In an embodiment of the present application, after receiving a B1 event / B2 event, the first terminal device determines whether the first SIM card and the second SIM card meet preset conditions if the measurement report reporting conditions for the B1 event / B2 event are met. If the preset conditions are met, the first terminal device delays reporting the measurement report for the B1 event / B2 event, first sends a hang-up message to the network side to reject the incoming call from the second SIM card, and after receiving a confirmation message from the network side regarding the hang-up message, reports the measurement report for the B1 event / B2 event, and then registers the second SIM card with the 4G network to implement network switching. This helps to improve the success rate of sending hang-up messages, achieves synchronization of the session status of the SIM card between the first terminal device and the network side, and thus avoids the problem of the SIM card of the first terminal device being unable to perform call services.

[0197] Taking terminal device A shown in b of Figure 2 as an example, which has 5G dual-SIM dual-pass functionality, in one possible scenario, terminal device A is conducting a VoNR call with terminal device B via SIM card 1, when terminal device A receives an incoming call from terminal device C via SIM card 2. In response to a user operation, terminal device A answers the call from terminal device C and holds the call with terminal device B. Holding the call with terminal device B means temporarily suspending the call without hanging up. After the call between terminal device A and terminal device C ends, terminal device A can resume the call with terminal device B.

[0198] Figure 7 is a schematic diagram of a call interface of a terminal device with 5G dual-SIM dual-pass function provided in an embodiment of the present application.

[0199] As shown in a in Figure 7, terminal device A is making a VoNR call with terminal device B through SIM card 1, and terminal device A displays the call interface with terminal device B.

[0200] During the process of terminal device A talking to terminal device B through SIM card 1, SIM card 2 of terminal device A receives an incoming call from terminal device C and displays the incoming call interface.

[0201] Figure 7 (b) shows a possible incoming call interface, which includes controls 01 and 02. Control 01 is used to end the call with terminal device B via SIM card 1 and answer the call from terminal device C via SIM card 2. Control 02 is used to reject the call from SIM card 2. Control 03 is used to answer the call from SIM card 2 and hold the call from SIM card 1.

[0202] Figure 7 c is another possible incoming call interface, which includes controls 04 and 05. In one possible design, control 04 is used to answer the incoming call from SIM card 2 and hold the incoming call from SIM card 1, and control 05 is used to hang up the incoming call from SIM card 2. In another possible design, control 04 is used to answer the incoming call from SIM card 2 and hang up the incoming call from SIM card 1.

[0203] For example, if the user selects control 03 or control 04, and control 04 is used to answer the incoming call from SIM card 2 and place the incoming call from SIM card 1, as shown in d of Figure 7, after the user answers the incoming call from terminal device C on terminal device A, terminal device A conducts a VoNR call with terminal device C through SIM card 2, and terminal device A displays the call interface with terminal device C. At this point, the call between terminal device A and terminal device B is placed on hold and is not hung up. The user can subsequently switch back to the call with terminal device B on terminal device A after hanging up the call with SIM card 2.

[0204] However, while terminal device A is communicating with terminal device C through SIM card 2 and maintaining a call with terminal device B, if terminal device A switches SIM card 2 from the 5G network to the 4G network, terminal device A no longer has the dual-SIM dual-communication function. In this case, terminal device A cannot meet the needs of simultaneous calls with two SIM cards and can hang up the call with terminal device B through SIM card 1 and continue the call with terminal device C through SIM card 2. However, after terminal device A switches SIM card 2 from the 5G network to the 4G network, the message that terminal device A hung up the call with SIM card 1 cannot be synchronized to the network side. Therefore, terminal device A cannot subsequently make calls or receive calls through SIM card 1.

[0205] To address the above issues, Figure 8 is a schematic flowchart of another data transmission method 800 provided in an embodiment of the present application. Method 800 is applied to a communication system including a first terminal device, a second terminal device, a third terminal device, and a base station. The first terminal device is provided with a first SIM card and a second SIM card, with the first SIM card registered to a first network and the second SIM card registered to a second network.

[0206] 3 and 7 , method 800 illustrates a process in which the first terminal device switches networks in a scenario where the first terminal device retains a call with the second terminal device and conducts a call with a third terminal device. For a detailed description, see S801 to S810 .

[0207] In this embodiment of the present application, when a first SIM card is registered with a first network and a second SIM card is registered with a second network, the first terminal device has dual-SIM dual-communication functionality. The first network and the second network can be the same or different. This embodiment of the present application uses the example of the first terminal device having dual-SIM dual-communication functionality when the first network and the second network are the same.

[0208] In this embodiment of the present application, the first terminal device may correspond to terminal device A as shown in FIG2(b). When the first network is a 5G network and the second network is a 5G network, the first terminal device has a dual-SIM dual-pass function. When at least one of the first network and the second network is a 4G network, the first terminal device does not have a dual-SIM dual-pass function. The second terminal device may correspond to terminal device B as shown in FIG2, and the third terminal device may correspond to terminal device C as shown in FIG2(b).

[0209] The method 800 includes steps S801 to S810, and the specific steps are as follows:

[0210] S801: A second terminal device sends a first call to a first terminal device. Correspondingly, the first terminal device receives the first call from the second terminal device.

[0211] In conjunction with the description of method 300 above, the first terminal device and the second terminal device can communicate via a base station, a core network device, and an IMS device. The first call can be the first INVITE message in S301. After receiving the first call, the first terminal device can interactively execute S302 to S308 with the second terminal device.

[0212] S802: In response to the user answering the first call on the first terminal device, a first call is established between the first terminal device and the second terminal device.

[0213] In conjunction with the description of method 300 above, the first terminal device begins ringing after S307 and indicates to the second terminal device that the called party has ringed through S308. After ringing, the first terminal device responds to the user's operation to answer the incoming call from the second terminal device and interacts with the second terminal device to perform S309 and S310, thereby establishing the first call.

[0214] S803: During the first call, the third terminal device sends a second call to the first terminal device. Accordingly, the first terminal device receives the second call. The first call and the second call are placed to the numbers of the first SIM card and the second SIM card, respectively. This embodiment of the application uses an example in which the first call is placed to the number of the first SIM card and the second call is placed to the number of the second SIM card.

[0215] In conjunction with the description of method 300 above, the first terminal device and the third terminal device can communicate via a base station, a core network device, and an IMS device. The second call can be the second INVITE message in S311. After receiving the second call, the first terminal device can interact with the third terminal device to execute S312 to S318.

[0216] The above descriptions of S801 to S803 are similar to those of S501 to S503 and are not repeated here.

[0217] S804: In response to the user answering the second call on the first terminal device, a second call is established between the first terminal device and the second terminal device, and the first call is retained.

[0218] In conjunction with the description of method 300 above, the first terminal device begins ringing after S317 and indicates to the third terminal device that the called party has ringed through S318. After ringing, the first terminal device, in response to a user operation, answers the call from the third terminal device and interacts with the third terminal device to perform S321 and S322, thereby establishing a second call.

[0219] Among them, the first call is retained, which means that the first terminal device temporarily suspends the first call but does not hang up (as shown in d in Figure 7), and the conversation path between the first terminal device and the second terminal device still exists, and the user can switch between the first call and the second call.

[0220] S805. The base station sends a second event to the first terminal device. Correspondingly, the first terminal device receives the second event.

[0221] For example, the second event is a B1 event / B2 event. The explanation of the B1 event / B2 event can refer to the description of S404 and will not be repeated here.

[0222] S806: The first terminal device sends a hang-up message to the base station to end the first call. Accordingly, the base station receives the hang-up message.

[0223] In this step, after receiving the second event, the first terminal device sends a hang-up message to the base station when it has the dual-SIM dual-communication function, so the hang-up message can be sent to the network side normally.

[0224] In combination with the description of the above method 300, the hang-up message may be the first BYE message in S319.

[0225] It should be understood that after receiving the hang-up message, the base station sends the hang-up message to the IMS device via the core network device, so that the IMS device synchronizes the session state of the first SIM card to an unoccupied state. Subsequently, when another terminal device calls the number of the first SIM card of the first terminal device, the first terminal device can normally receive the incoming call through the first SIM card. Alternatively, the first terminal device can normally make calls to other terminal devices through the first SIM card.

[0226] S807: The base station sends a confirmation message of the hang-up message to the first terminal device. Correspondingly, the first terminal device receives the confirmation message of the hang-up message.

[0227] In combination with the description of the above method 300, the confirmation message of the hang-up message may be the sixth 200 OK in S320.

[0228] In this step, after receiving a confirmation message of the hang-up message transparently transmitted from the IMS device via the core network device, the base station sends a confirmation message of the hang-up message to the first terminal device. After receiving the confirmation message of the hang-up message, the first terminal device can determine that the network side has synchronized the session state of the first SIM card.

[0229] S808: The first terminal device sends a second measurement report to the base station. Correspondingly, the base station receives the second measurement report.

[0230] It should be understood that the second measurement report is a measurement report for the second event. After receiving the second event, the first terminal device measures the signal quality of the heterosystem neighboring cell of the first terminal device. When the measurement report reporting conditions of the second event are met, the first terminal device sends a second measurement report to the base station. Exemplarily, the second event is a B1 event, and the measurement report reporting conditions of the second event are met, including: the signal quality of the heterosystem neighboring cell of the current serving cell of the first terminal device is higher than the first threshold value.

[0231] S809: The base station sends a second handover instruction to the first terminal device, where the second handover instruction is used to instruct the first terminal device to register the second SIM card with a third network, where the third network is of a different standard than the second network. Accordingly, the first terminal device receives the second handover instruction.

[0232] In this step, after receiving the second measurement report reported by the first terminal device, the base station sends a second switching instruction to the first terminal device. Exemplarily, the network standard of the second network is the 5G NR standard, and the third network is the 4G TDD-LTE standard.

[0233] S810: The first terminal device registers the second SIM card with the third network.

[0234] In this step, the first terminal device registers the second SIM card to the third network. The third network is different from the first network. It can be understood that the communication systems of the third network and the first network are different. For example, the first network is a 5G network and the third network is a 4G network.

[0235] Based on the technical solution of the present application, when the first call of the first SIM card of the first terminal device is retained and the second call is being made through the second SIM card, if the first terminal device receives a second event from the base station, the first terminal device first sends a message to the base station to instruct the first call of the first SIM card to be hung up. After receiving a confirmation message from the network side regarding the message for instructing the hang up of the first call, the first terminal device sends a second measurement report to the base station, and then performs network switching based on the instruction of the base station. After the network switching, the first terminal device falls back from dual-SIM dual-communication to dual-SIM single-communication. Therefore, when the first terminal device sends the message for instructing the hang up of the first call, it still has the dual-SIM dual-communication function, and the message for instructing the hang up of the first call can be sent to the network side, so that the network side can synchronize the session state of the first SIM card to an unoccupied state, which is conducive to avoiding the problem that the first SIM card is unable to make calls or be called later.

[0236] An embodiment of the present application provides a terminal device, which includes: a processor and a memory; the memory stores computer-executable instructions; the processor executes the computer-executable instructions stored in the memory, so that the terminal device executes the above method.

[0237] The present embodiment provides a chip. The chip includes a processor configured to invoke a computer program stored in a memory to execute the technical solution of the above embodiment. The implementation principles and technical effects are similar to those of the above-mentioned related embodiments and will not be further described here.

[0238] The embodiments of the present application also provide a computer-readable storage medium. The computer-readable storage medium stores a computer program. When the computer program is executed by a processor, the above-mentioned method is implemented. The methods described in the above embodiments can be implemented in whole or in part by software, hardware, firmware, or any combination thereof. If implemented in software, the functions can be stored as one or more instructions or codes on a computer-readable medium or transmitted on a computer-readable medium. Computer-readable media can include computer storage media and communication media, and can also include any medium that can transfer a computer program from one place to another. The storage medium can be any target medium that can be accessed by a computer.

[0239] In one possible implementation, a computer-readable medium may include random access memory (RAM), read-only memory (ROM), compact disc read-only memory (CD-ROM) or other optical disk storage, magnetic disk storage or other magnetic storage devices, or any other medium designed to carry or store the desired program code in the form of instructions or data structures and accessible by a computer. Furthermore, any connection is appropriately referred to as a computer-readable medium. For example, if software is transmitted from a website, server or other remote source using a coaxial cable, fiber optic cable, twisted pair, digital subscriber line (DSL) or wireless technologies such as infrared, radio and microwave, then the coaxial cable, fiber optic cable, twisted pair, DSL or wireless technologies such as infrared, radio and microwave are included in the definition of medium. Disk and disc, as used herein, include optical discs, laser discs, optical discs, digital versatile discs (DVDs), floppy disks and Blu-ray discs, where disks typically reproduce data magnetically, while optical discs reproduce data optically using lasers. Combinations of the above should also be included within the scope of computer-readable media.

[0240] An embodiment of the present application provides a computer program product, which includes a computer program. When the computer program is executed, the computer executes the above method.

[0241] The present application embodiment is described with reference to the flow chart and / or block diagram of the method, device (system) and computer program product according to the embodiment of the present application.It should be understood that each flow process and / or box in the flow chart and / or block diagram and the combination of the flow process and / or box in the flow chart and / or block diagram can be realized by computer program instructions.These computer program instructions can be provided to the processing unit of general-purpose computer, special-purpose computer, embedded processing machine or other programmable device to produce a machine, so that the instruction executed by the processing unit of computer or other programmable data processing device produces the device for realizing the function specified in one flow chart flow or multiple flows and / or one block or multiple blocks of block diagram.

[0242] The above specific implementation methods further illustrate the purpose, technical solutions and beneficial effects of this application in detail. It should be understood that the above are only specific implementation methods of this application and are not intended to limit the scope of protection of this application. Any modifications, equivalent replacements, improvements, etc. made on the basis of the technical solutions of this application should be included in the scope of protection of this application.

Claims

1. A data transmission method, characterized in that: Applied to a first terminal device, the first terminal device is provided with a first subscriber identification module (SIM) card and a second SIM card, the first SIM card is registered with a first network, and the second SIM card is registered with a second network; the method includes: The first terminal device receives a first call from a second terminal device; In response to the user answering the first call on the first terminal device, establishing a first call between the first terminal device and the second terminal device; During the first call, the first terminal device receives a second call from a third terminal device, where the first call and the second call are to the numbers of the first SIM card and the second SIM card respectively; After receiving the first event from the base station, the first terminal device sends a cancellation message to reject the second call; when receiving the first event, the second call is not answered; After receiving a confirmation message of the cancellation message, the first terminal device sends a first measurement report to the base station; after receiving the first event and before sending the first measurement report, the first terminal device meets a measurement report reporting condition of the first event; The first terminal device receives a first switching instruction from the base station and registers the second SIM card with a third network, where the third network has a different network standard from the second network.

2. The method according to claim 1, characterized in that After the first terminal device receives a second call from a third terminal device, when answering the second call, the method further includes: In response to the user answering the second call on the first terminal device, a second call is established between the first terminal device and the third terminal device, and the first call is retained; After receiving the second event from the base station, the first terminal device sends a hang-up message to end the first call; After receiving a confirmation message of the hang-up message, the first terminal device sends a second measurement report to the base station; after receiving the second event and before sending the second measurement report, the first terminal device meets the measurement report reporting condition of the second event; The first terminal device receives the second switching instruction from the base station and registers the second SIM card with the third network.

3. The method according to claim 1 or 2, characterized in that If the first network and the second network are fifth-generation mobile communication technology 5G networks, the first terminal device has a dual-SIM dual-pass function; If one of the first network and the second network is the 5G network and the other is the fourth generation mobile communication technology 4G network, the first terminal device has the dual-SIM single-pass function.

4. The method according to claim 3, characterized in that Before the first terminal device sends a cancellation message, the method includes: The first terminal device determines that the first SIM card and the second SIM card are SIM cards registered with the 5G network, and the first SIM card and the second SIM card are both in an occupied state, where the occupied state includes a call state or an incoming call state.

5. The method according to any one of claims 1 to 4, characterized in that The first event is event B1 / event B2; After receiving the first event from the base station, the method further includes: The first terminal device measures the signal quality of the first cell based on the B1 event / B2 event, and the first cell The service cell of the first terminal device and the service cell of the first terminal device belong to different communication systems; The first terminal device obtains the first measurement report according to the signal quality of the first cell.

6. The method according to any one of claims 1 to 5, characterized in that Before receiving the first event from the base station, the method further includes: The first terminal device receives a third event from the base station, where the third event is used to indicate measuring a signal quality of a serving cell of the first terminal device; If the signal quality of the serving cell of the first terminal device is lower than a threshold value, the first terminal device sends a third measurement report to the base station, where the third measurement report includes the signal quality of the serving cell of the first terminal device.

7. A data transmission method, characterized in that: Applied to a first terminal device, the first terminal device is provided with a first subscriber identification module (SIM) card and a second SIM card, the first SIM card is registered with a first network, and the second SIM card is registered with a second network; the method includes: The first terminal device receives a first event from a base station; After receiving the first event from the base station, the first terminal device determines whether the first SIM card and the second SIM card meet preset conditions; wherein the preset conditions at least include: the first network and the second network are fifth-generation mobile communication technology 5G networks, and the first SIM card and the second SIM card are in an occupied state, and the occupied state includes a call state or an incoming call state; When the first SIM card and the second SIM card meet the preset condition, the first terminal device sends a termination message to reject the incoming call of the second SIM card, or hangs up the call of the first SIM card; After receiving a confirmation message of the termination message, the first terminal device sends a first measurement report to the base station; after receiving the first event and before sending the first measurement report, the first terminal device meets the measurement report reporting condition of the first event; The first terminal device receives a third switching instruction from the base station and registers the second SIM card with a third network, where the third network has a different network standard from the second network.

8. A data transmission method, characterized in that: Applied to a base station, the method includes: The base station sends a first event to a first terminal device; wherein the first terminal device is provided with a first subscriber identification module (SIM) card and a second SIM card, the first SIM card is registered with a first network, the second SIM card is registered with a second network, the first terminal device is conducting a first call with a second terminal device, and the first terminal device is receiving a second call from a third terminal device; The base station sends a cancellation message, where the cancellation message is used to reject the second call; The base station receives a confirmation message of the cancellation message; After sending a confirmation message of the cancellation message to the first terminal device, the base station receives a first measurement report from the first terminal device; The base station sends a first switching instruction to the first terminal device, where the first switching instruction instructs the first terminal device to register the second SIM card with a third network, where the third network has a different network standard from the second network.

9. A data transmission method, characterized in that: Applied to a communication system including a first terminal device and a base station, the first terminal device is provided with a first subscriber identification module (SIM) card and a second SIM card, the first SIM card is registered with a fifth-generation mobile communication technology 5G network, and the second SIM card is registered with the 5G network; the method includes: The first terminal device receives a first call from a second terminal device; In response to the user answering the first call on the first terminal device, the first terminal device and the Establishing a first call between the second terminal device; During the first call, the first terminal device receives a second call from a third terminal device, where the first call and the second call are to the numbers of the first SIM card and the second SIM card respectively; The base station sends a first event to the first terminal device; After receiving the first event, the first terminal device sends a cancellation message to reject the second call; when receiving the first event, the second call is not answered; After receiving a confirmation message of the cancellation message, the first terminal device sends a first measurement report to the base station, and after receiving the first event and before sending the first measurement report, the first terminal device meets a measurement report reporting condition of the first event; After receiving the first measurement report, the base station sends a fourth switching instruction to the first terminal device, where the fourth switching instruction instructs the first terminal device to register the second SIM card with a fourth generation mobile communication technology 4G network.

10. A terminal device, characterized in that: For carrying out the method according to any one of claims 1 to 7.

11. A computer-readable storage medium, characterized in that Used to store a computer program, which, when running on a computer, causes the computer to perform the method according to any one of claims 1 to 7.

12. A computer program product, characterized in that The invention comprises a computer program which, when being executed, causes a computer to execute the method according to any one of claims 1 to 7.

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