A call method and terminal

Abstract

The application provides a call method and a terminal, and relates to the technical field of communication. In the call process of a first terminal and a second terminal, when the signal quality of a second communication network is higher than that of a first communication network, and second configuration parameters of a first bearer channel corresponding to the second communication network are invalid or do not exist, the first terminal keeps connection with the first communication network through a first network device, avoids switching of the first terminal to the second communication network, and prevents call drop.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of communication, and particularly relates to a call method and a terminal. BACKGROUND

[0002] In the process of gradually constructing a 5th generation (5G) standalone (SA) network by a mobile communication operator, there is still a problem of imperfect SA function of the 5G network. For example, in a call process and a call process of a terminal device in an SA mode, a terminal call exception problem is caused due to network failure or terminal itself. SUMMARY

[0003] Embodiments of the present application provide a call method and a terminal, which are used for solving a call drop problem existing in a call process of a first terminal and a second terminal.

[0004] To achieve the above object, embodiments of the present application adopt the following technical solutions:

[0005] In a first aspect, a call method is provided, and the call method comprises the following steps:

[0006] The first terminal establishes a call connection with the second terminal by using a first configuration parameter of a first bearer channel corresponding to the first communication network; and in the call process of the first terminal and the second terminal, the first terminal keeps the connection with the first communication network through the first network device in a case that signal quality of a second communication network is higher than signal quality of the first communication network, and a second configuration parameter of the first bearer channel corresponding to the second communication network is invalid or does not exist.

[0007] The second configuration parameter of the first bearer channel corresponding to the second communication network being invalid comprises that the first target configuration parameter of the first bearer channel comprises the second configuration parameter of the first bearer channel corresponding to the second communication network and the second configuration parameter is invalid.

[0008] The second configuration parameter of the first bearer channel corresponding to the second communication network not existing comprises that the first target configuration parameter of the first bearer channel does not comprise the second configuration parameter of the first bearer channel corresponding to the second communication network.

[0009] In conclusion, by using the scheme of the present application, in the process of the call between the first terminal and the second terminal, when the signal quality of the second communication network is higher than that of the first communication network, and the second configuration parameter of the first bearer channel corresponding to the second communication network is invalid or does not exist, the first terminal keeps the connection with the first communication network through the first network device, avoids switching to the second communication network, and prevents call drop.

[0010] In an implementation form of the first aspect, the first terminal keeps the connection with the first communication network through the first network device, including: the first terminal refrains from reporting a measurement report event to the first network device, and keeps the connection with the first communication network through the first network device; the measurement report event is used to indicate that the signal quality of the second communication network is higher than that of the first communication network.

[0011] Alternatively, the first terminal reports the measurement report event to the first network device; after receiving the switching / re-directing indication message from the first network device, the first terminal ignores the switching / re-directing indication message, and keeps the connection with the first communication network through the first network device; the switching / re-directing indication message is used to indicate that the first terminal switches / re-directs to the second communication network.

[0012] Optionally, the first terminal ignores the switching / re-directing indication message, which means that the first terminal does not respond to the switching / re-directing indication message; or the first terminal does not comply with the switching / re-directing indication message.

[0013] In this way, by refraining from reporting the measurement report event to the first network device, or by ignoring the switching / re-directing indication message, the first terminal avoids switching to the second communication network, and prevents call drop.

[0014] In an implementation form of the first aspect, before the first terminal calls the second terminal for the call, the call method further includes: the first terminal sends a first release request to the first network device, to request deleting the first target configuration parameter of the first bearer channel; the first terminal sends a first request to the first network device, to request obtaining the second target configuration parameter of the first bearer channel.

[0015] If the first terminal does not obtain the second target configuration parameter of the first bearer channel, in the process of the call between the first terminal and the second terminal, when the signal quality of the second communication network is higher than that of the first communication network, and the second configuration parameter of the first bearer channel corresponding to the second communication network is invalid or does not exist, the first terminal keeps the connection with the first communication network through the first network device.

[0016] In this way, before the first terminal initiates a call to the second terminal, the first terminal can attempt to acquire the second target configuration parameter of the first bearer channel, and can ensure that the call between the first terminal and the second terminal is normal with a high probability; if the first terminal fails to acquire the second target configuration parameter of the first bearer channel, the first terminal keeps connected to the first communication network through the first network device during the call between the first terminal and the second terminal, avoids switching to the second communication network, and prevents call drop.

[0017] In an implementation form of the first aspect, if the first terminal acquires the second target configuration parameter of the first bearer channel, the call method further includes that the second target configuration parameter of the first bearer channel includes a third configuration parameter of the first bearer channel corresponding to the first communication network, and the first terminal establishes a call connection with the second terminal by using the third configuration parameter of the first bearer channel corresponding to the first communication network.

[0018] In the call between the first terminal and the second terminal, if the signal quality of the second communication network is higher than that of the first communication network, and the fourth configuration parameter of the first bearer channel corresponding to the second communication network is invalid or does not exist, the first terminal keeps connected to the first communication network through the first network device.

[0019] In the call between the first terminal and the second terminal, if the signal quality of the second communication network is higher than that of the first communication network, and the fourth configuration parameter of the first bearer channel corresponding to the second communication network is invalid or does not exist, the first terminal keeps connected to the first communication network through the first network device.

[0020] The fourth configuration parameter of the first bearer channel corresponding to the second communication network does not exist includes that the second target configuration parameter of the first bearer channel does not include the mapped fourth configuration parameter of the first bearer channel corresponding to the second communication network.

[0021] In this way, in the case that the first terminal acquires the second target configuration parameter of the first bearer channel, but the fourth configuration parameter of the first bearer channel corresponding to the second communication network is invalid or does not exist, the first terminal keeps connected to the first communication network through the first network device during the call between the first terminal and the second terminal, avoids switching to the second communication network, and prevents call drop.

[0022] In an implementation form of the first aspect, if the first terminal fails to acquire the second target configuration parameter of the first bearer channel, the first terminal keeps sending the first request to the first network device; or the first terminal sends the first request to the first network device, and has not received a first acceptance message sent by the first network device and including the second target configuration parameter of the first bearer channel before the first terminal initiates a call to the second terminal.

[0023] In an implementation of the first aspect, the call method further includes: after the call between the first terminal and the second terminal ends, the first terminal re-establishes a connection with the first communication network through the first network device and re-establishes configuration parameters of the first bearer channel.

[0024] In this way, when the first terminal and the second terminal have a call next time, it is highly likely that the call will be normal.

[0025] In an implementation of the first aspect, the first communication network is a 5G network, and the second communication network is a long-term evolution LTE network; before the first terminal calls the second terminal, the calling method further includes: if the first terminal does not enable the new radio interface voice bearer VoNR function, the first terminal enables the VoNR function and sends a network capability message to the first communication network; the network capability message is used to indicate that the first terminal supports the VoNR function; the first terminal uses VoNR technology to call the second terminal.

[0026] In this way, when the first terminal initiates a call to the second terminal, the call can be guaranteed to be successful.

[0027] In an implementation of the first aspect, the first terminal uses the first configuration parameters of the first bearer channel corresponding to the first communication network to establish a call connection with the second terminal, including: the first terminal uses the first configuration parameters of the first bearer channel corresponding to the first communication network, and establishes a call connection with the second terminal when the VoNR function is turned on.

[0028] In an implementation manner of the first aspect, the first indication message is a PDU session modification command.

[0029] In an implementation of the first aspect, the first bearer channel is an Internet Protocol Multimedia Subsystem IMS default bearer channel, and the first target configuration parameters of the first bearer channel include: an access point name APN, a data network name DNN, a PDU session ID, an evolved packet system EPS bearer identity, a 5G service quality identifier, and one or more of an LTE service quality identifier.

[0030] In an implementation of the first aspect, the networking mode of the first network device is independent networking SA.

[0031] In a second aspect, a call method includes: a first terminal connecting to a first network device through a first communication network; the first terminal receiving a first indication message sent by the first network device; wherein the first indication message includes first target configuration parameters of a first bearer channel, and the first bearer channel is used for transmitting signaling between the first terminal and a second terminal during a call or a conversation; the first target configuration parameters of the first bearer channel include first configuration parameters of the first bearer channel corresponding to the first communication network, and second configuration parameters of the first bearer channel corresponding to a second communication network.

[0032] In a case where the second configuration parameters of the first bearer channel corresponding to the second communication network exist and are valid, the first terminal establishes a call connection with the second terminal using the first configuration parameters of the first bearer channel corresponding to the first communication network.

[0033] The first terminal receives a second indication message sent by the first network device; wherein the second indication message includes configuration parameters of a second bearer channel, and the second bearer channel is used for transmitting multimedia data between the first terminal and the second terminal during the conversation.

[0034] In a case where, during the conversation between the first terminal and the second terminal, the signal quality of the second communication network is higher than that of the first communication network, and the sixth configuration parameters of the second bearer channel corresponding to the second communication network are invalid or do not exist, the first terminal maintains a communication connection with the first communication network through the first network device.

[0035] The sixth configuration parameters of the second bearer channel corresponding to the second communication network being invalid include: the configuration parameters of the second bearer channel include fifth configuration parameters of the second bearer channel corresponding to the first communication network, and the sixth configuration parameters of the second bearer channel corresponding to the second communication network, and the sixth configuration parameters of the second bearer channel corresponding to the second communication network are invalid.

[0036] The sixth configuration parameters of the second bearer channel corresponding to the second communication network not existing include: the configuration parameters of the second bearer channel include the fifth configuration parameters of the second bearer channel corresponding to the first communication network, and do not include the sixth configuration parameters of the second bearer channel corresponding to the second communication network.

[0037] In summary, by using the scheme of the present application, in a case where, during the conversation between the first terminal and the second terminal, the signal quality of the second communication network is higher than that of the first communication network, and the sixth configuration parameters of the second bearer channel corresponding to the second communication network are invalid or do not exist, the first terminal maintains a communication connection with the first communication network through the first network device, thereby avoiding switching to the second communication network and preventing call drop.

[0038] In an implementation form of the second aspect, the first terminal maintaining the connection with the first communication network via the first network device comprises: the first terminal refraining from reporting a measurement report event to the first network device, and maintaining the connection with the first communication network via the first network device; the measurement report event is used to indicate that the signal quality of the second communication network is higher than the signal quality of the first communication network.

[0039] Alternatively, the first terminal reports the measurement report event to the first network device; after receiving the handover / re-direction indication message from the first network device, the first terminal ignores the handover / re-direction indication message, and maintains the connection with the first communication network via the first network device; the handover / re-direction indication message is used to instruct the first terminal to handover / re-direct to the second communication network.

[0040] In this way, by refraining from reporting the measurement report event to the first network device, or by ignoring the handover / re-direction indication message, the first terminal avoids handover to the second communication network, and call drop is prevented.

[0041] In an implementation form of the second aspect, the call method further comprises: after the call between the first terminal and the second terminal ends, the first terminal re-establishes the connection with the first communication network via the first network device, and re-establishes the configuration parameters of the first bearer channel.

[0042] In this way, when the first terminal and the second terminal call next time, the call can be ensured to be normal with high probability.

[0043] In a third aspect, a call method is provided, which comprises: a first terminal connects to a first network device via a first communication network; the first terminal receives a first indication message sent by the first network device; wherein the first indication message comprises first target configuration parameters of a first bearer channel, and the first bearer channel is used to transmit signaling between the first terminal and a second terminal during a call or a conversation.

[0044] In a case where second configuration parameters of the first bearer channel corresponding to the second communication network are invalid or do not exist, before the first terminal calls the second terminal for a conversation, the first terminal obtains the second target configuration parameters of the first bearer channel; wherein the first bearer channel is used to transmit signaling between the first terminal and the second terminal during a call or a conversation.

[0045] The second configuration parameters of the first bearer channel corresponding to the second communication network being invalid comprises: the first target configuration parameters of the first bearer channel comprise first configuration parameters of the first bearer channel corresponding to the first communication network, and mapped second configuration parameters of the first bearer channel corresponding to the second communication network, and the second configuration parameters of the first bearer channel corresponding to the second communication network are invalid.

[0046] The second configuration parameter of the first bearer channel corresponding to the second communication network does not exist, including: the first target configuration parameter of the first bearer channel includes the first configuration parameter of the first bearer channel corresponding to the first communication network, but does not include the second configuration parameter of the first bearer channel corresponding to the second communication network.

[0047] During a call between the first terminal and the second terminal, if the signal quality of the second communication network is higher than the signal quality of the first communication network and the fourth configuration parameter of the first bearer channel corresponding to the second communication network is valid, the first terminal establishes a communication connection with the second communication network through the second network device.

[0048] Among them, the fourth configuration parameter of the first bearer channel corresponding to the second communication network is valid and includes: the second target configuration parameter of the first bearer channel includes the third configuration parameter of the first bearer channel corresponding to the first communication network, and the fourth configuration parameter of the first bearer channel corresponding to the mapped second communication network, and the fourth configuration parameter of the first bearer channel corresponding to the second communication network is valid.

[0049] In summary, by adopting the solution of the present application, before the first terminal calls the second terminal for a call, the first terminal can re-acquire the second target configuration parameters of the first bearer channel; during the call between the first terminal and the second terminal, if the signal quality of the second communication network is higher than the signal quality of the first communication network, and the fourth configuration parameters of the first bearer channel corresponding to the second communication network are valid, the first terminal establishes a communication connection with the second communication network through the second network device, that is, the first terminal switches to the second communication network, and the call can also be normal.

[0050] In a fourth aspect, a terminal is provided, the terminal having the function of implementing any of the call methods described in the first aspect, or the function of implementing any of the call methods described in the second aspect, or the function of implementing any of the call methods described in the third aspect. The function may be implemented by hardware or by hardware executing corresponding software. The hardware or software includes one or more modules corresponding to the above-mentioned functions.

[0051] In the fifth aspect, a terminal is provided, comprising: a processor and a memory; the memory is used to store computer-executable instructions, and when the terminal is running, the processor executes the computer-executable instructions stored in the memory to enable the terminal to execute a call method as described in any one of the first aspects above; or execute a call method as described in any one of the second aspects above, or execute a call method as described in any one of the third aspects above.

[0052] In a sixth aspect, a terminal is provided, comprising: a processor; the processor is configured to read instructions in a memory, and execute the call method according to any one of the first aspect or the call method according to any one of the second aspect or the call method according to any one of the third aspect after reading the instructions in the memory.

[0053] In a seventh aspect, a chip system is provided, applied to a terminal, the chip system comprising a processor and an interface, the interface configured to receive instructions and transmit the instructions to the at least one processor; the at least one processor executes the instructions to make the terminal execute the call method according to any one of the first aspect or the call method according to any one of the second aspect or the call method according to any one of the third aspect.

[0054] Optionally, the processor can be a Modem and / or an application processor (AP).

[0055] In an eighth aspect, a computer readable storage medium is provided, the computer readable storage medium storing instructions, when the instructions are executed on a computer, the computer can execute the call method according to any one of the first aspect or the call method according to any one of the second aspect or the call method according to any one of the third aspect.

[0056] In a ninth aspect, a computer program product is provided, comprising instructions, when the instructions are executed on a computer, the computer can execute the call method according to any one of the first aspect or the call method according to any one of the second aspect or the call method according to any one of the third aspect.

[0057] The technical effects brought by any one of the fourth aspect to the ninth aspect can refer to the technical effects brought by different design manners of the first aspect to the third aspect, which will not be described here. BRIEF DESCRIPTION OF DRAWINGS

[0058] Figure 1 A structural schematic diagram of a communication system provided by an embodiment of the present application is provided;

[0059] Figure 2 A flowchart of a call abnormal scenario provided by an embodiment of the present application is provided Figure 1 ;

[0060] Figure 3 A flowchart of a call abnormal scenario provided by an embodiment of the present application is provided Figure 2 ;

[0061] Figure 4 A schematic diagram of an interface for an abnormal call scenario provided in an embodiment of the present application;

[0062] Figure 5 A flowchart of an abnormal call scenario provided in an embodiment of the present application Figure 3 ;

[0063] Figure 6 A flowchart of a call method provided in an embodiment of the present application Figure 1 ;

[0064] Figure 7 A flowchart of a call method provided in an embodiment of the present application Figure 2 ;

[0065] Figure 8 A flowchart of a call method provided in an embodiment of the present application Figure 3 ;

[0066] Figure 9 A flowchart of a call method provided in an embodiment of the present application Figure 4 ;

[0067] Figure 10 A flowchart of a call method provided in an embodiment of the present application Figure 5 ;

[0068] Figure 11 A flowchart of a call method provided in an embodiment of the present application Figure 6 ;

[0069] Figure 12 A flowchart of a call method provided in an embodiment of the present application Figure 7 ;

[0070] Figure 13 A flowchart of an abnormal call scenario provided in an embodiment of the present application Figure 4 ;

[0071] Figure 14 A flowchart of an abnormal call scenario provided in an embodiment of the present application Figure 5 ;

[0072] Figure 15 A flowchart of a call method provided in an embodiment of the present application Figure 8 ;

[0073] Figure 16 A schematic diagram of the hardware structure of a terminal provided in an embodiment of the present application;

[0074] Figure 17 A schematic diagram of a software framework of a terminal provided in an embodiment of the present application;

[0075] Figure 18 A schematic structural diagram of a chip system provided in an embodiment of the present application. DETAILED DESCRIPTION

[0076] In the description of the embodiments of the present application, unless otherwise specified, “ / ” means or, for example, A / B can mean A or B; “and / or” in this article is merely a way to describe the association relationship of associated objects, indicating that three relationships can exist, for example, A and / or B can mean: A exists alone, A and B exist at the same time, and B exists alone.

[0077] The terms "first" and "second" below are used for descriptive purposes only and should not be understood to indicate or imply relative importance or implicitly specify the number of the technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of the embodiments of this application, unless otherwise specified, "plurality" means two or more.

[0078] In the embodiments of this application, words such as "exemplary" or "for example" are used to indicate examples, illustrations, or descriptions. Any embodiment or design described as "exemplary" or "for example" in the embodiments of this application should not be interpreted as being preferred or advantageous over other embodiments or designs. Rather, the use of words such as "exemplary" or "for example" is intended to present the relevant concepts in a concrete manner.

[0079] The technical solutions of the embodiments of the present application can be applied to various communication systems, such as wireless fidelity (Wi-Fi) systems, vehicle to everything (V2X) communication systems, device-to-device (D2D) communication systems, Internet of Vehicles communication systems, 4th generation (4G) mobile communication systems (such as long term evolution (LTE) systems), worldwide interoperability for microwave access (WiMAX) communication systems, 5G communication systems (such as new radio (NR) systems), and future communication systems (such as sixth generation (6G) mobile communication systems).

[0080] For example, Figure 1As shown, it is a structural diagram of a communication system provided in an embodiment of the present application, which communication system includes a first terminal 10, a second terminal 20, a first access network device 30, a second access network device 40, a core network device 50 and an Internet Protocol (IP) multimedia subsystem (IMS) device 60.

[0081] It should be noted that IMS is a new form of multimedia service that can meet customers' needs for newer and more diverse multimedia services. IMS is considered to be the core technology of the next-generation communication network, which can achieve the integration of mobile networks and fixed networks. The Session Initialization Protocol (SIP) is used in IMS, so that IP-based voice transmission (Voice over Internet Protocol, VoIP) can be implemented in LTE or NR. Among them, VoIP is called Long Term Evolution Voice Bearer (VoLTE) in LTE and Voice over NR (VoNR) in NR.

[0082] VoLTE refers to the use of the evolved packet system (EPS) to carry call data during a call. When a first terminal 10 calls a second terminal 20 via VoLTE, the first terminal 10 requests that the control plane signaling (IMS signaling) and user plane data (IMS traffic) involved in the call between the first terminal 10 and the second terminal 20 be packaged into IP packets and transmitted through EPS and IMS. In this case, both the service data and voice data involved in the call between the first terminal 10 and the second terminal 20 are transmitted in the form of IP packets.

[0083] VoNR refers to the use of the 5G system (5GS) to carry call data during a call. When a first terminal 10 calls a second terminal 20 via VoNR, the first terminal 10 packages the control plane signaling (IMS signaling) and user plane data (IMS traffic) involved in the call between the first terminal 10 and the second terminal 20 into IP packets and transmits them through 5GS and IMS. In this case, both the service data and voice data involved in the call between the first terminal 10 and the second terminal 20 are transmitted in the form of IP packets.

[0084] In some embodiments, the first access network device 30 is a network layer of a first communication network, and the second access network device 40 is a network layer of a second communication network. The first access network device 30 and the second access network device 40 are devices with wireless transceiving functions or chips (systems) or components or assemblies provided in the devices. The first access network device 30 and the second access network device 40 include, but are not limited to, an access point (AP) (such as a home gateway, a router, a server, a switch, a bridge, etc.) in a Wi-Fi system, an evolved Node B (eNB), a radio network controller (RNC), a Node B (NB), a base station controller (BSC), a base transceiver station (BTS), a home base station (for example, a home evolved Node B or a home Node B (HNB)), a baseband unit (BBU), a wireless relay node, a wireless backhaul node, a transmission and reception point (TRP or TP), and the like. It can also be a 5G (such as a gNB or a transmission point (TRP or TP) in NR), one or a group (including multiple antenna panels) of antenna panels of a base station in a 5G system, or a network node (such as a baseband unit (BBU) or a distributed unit (DU), a road side unit (RSU) with base station functions, etc.) constituting a gNB or a transmission point.

[0085] In some embodiments, the first access network device 30 can be a gNB of a 5G network, and the second access network device 40 can be an eNB of an LTE network. On this basis, the first communication network can be a 5G network, and the second communication network can be an LTE network.

[0086] Of course, the first access network device 30 can also be an eNB of an LTE network, and the second access network device 40 can also be a gNB of a 5G network. The embodiments of the present application do not limit this, and the subsequent embodiments are exemplarily described by taking the first access network device 30 as a gNB of a 5G network and the second access network device 40 as an eNB of an LTE network.

[0087] In an embodiment of the present application, the first terminal 10 and the second terminal 20 in the above-mentioned communication system can receive signals from the first communication network or the second communication network at their current locations. Taking the first terminal 10 as an example, illustratively, when the current location of the first terminal 10 is the cell corresponding to the first communication network (i.e., 5G network), the first terminal 10 can access the first communication network through the first access network device 30, and communicate with the second terminal 20 through the first communication network (such as performing voice or data services). When the first terminal 10 moves from its current location to the cell corresponding to the second communication network (i.e., LTE network), the first terminal 10 can access the second communication network through the second access network device 40, and communicate with the second terminal 20 through the second communication network.

[0088] It is understandable that when the first terminal 10 chooses to access the first communication network through the first access network device 30, the core network device 50 is a 5G core network. When the first terminal 10 chooses to access the second communication network through the second access network device 40, the core network device 50 is an LTE core network.

[0089] In some embodiments, the first access device 30 , the second access device 40 , the core network device 50 , and the IMS device 60 may also be collectively referred to as a network (NW).

[0090] The first terminal 10 can initiate an audio or video call request (or call request) to the second terminal 20. For example, the first terminal 10 that initiates the call request can be called the calling terminal, and the second terminal 20 that receives the call request can be called the called terminal. After the second terminal 20 receives the call request, a call can be established between the first terminal 10 and the second terminal 20. That is, multimedia data such as voice and video can be transmitted between the first terminal 10 and the second terminal 20, thereby providing multimedia services such as voice and video to users at both ends. During the call and conversation process, the international mobile subscriber identification number (IMSI) can be used as an identity between the first terminal 10 and the second terminal 20.

[0091] It should be noted that in the embodiment of the present application, the voice scheme involved when the first terminal 10 initiates a call includes but is not limited to: VoNR, VoLTE, a voice scheme based on a circuit switched network (circuit switched, CS) domain, VoWi-Fi, or non-3GPP (Non-3GPP inter working function, N3IWF), etc. The subsequent embodiments will describe the technical solutions of the embodiments of the present application in detail using VoNR and VoLTE as examples, and will not be repeated here.

[0092] The following combination Figure 1 The communication system shown in the figure is used as an example to illustrate the call method provided in the embodiment of the present application. The call method is applied in a terminal, which can be the first terminal in the above communication system or the second terminal in the above communication system.

[0093] Normally, the terminal will choose to establish a connection with a communication network with a strong network signal strength or high signal quality; or, establish a connection with a more advanced communication network (for example, the LTE network is better than the 3G network and the 2G network, and the 5G network is better than the LTE network). In a communication network (2G, 3G, LTE or 5G), whether the terminal switches the communication network is determined by the terminal's measurement report. For example, the terminal can periodically measure the signal quality of the serving cell and the neighboring cell through a variety of measurement methods, and report the measurement event (or B event) to the network. Then, the network instructs the first terminal to switch / redirect to other communication networks based on the B event reported by the first terminal.

[0094] Taking the example of a terminal switching from a 5G network to an LTE network, illustratively, in order to ensure service continuity when the terminal switches from a 5G network to an LTE network, when the terminal establishes a connection with the 5G network, it will establish the configuration parameters of the IMS bearer channel required for communication on the 5G network, and map the configuration parameters of the IMS bearer channel required for communication on the LTE network. When the terminal switches from a 5G network to an LTE network, or the terminal is in flight mode / powered on / plugging in and out of a card, etc., the network will send a PDU session modification command to the terminal. The PDU session modification command will carry the configuration parameters of the IMS bearer channel, which include the configuration parameters of the IMS bearer channel corresponding to the established 5G network and the configuration parameters of the IMS bearer channel corresponding to the mapped LTE network.

[0095] For example, when the configuration parameters of the IMS bearer channel corresponding to the LTE network in the PDU session modification command are abnormal, the configuration parameters of the IMS bearer channel corresponding to the LTE network mapped by the terminal by default are invalid or non-existent. In this case, when the terminal is always connected to the 5G network, the terminal's call will not be affected. When the terminal switches from the 5G network to the LTE network, the terminal's call will be abnormal because the configuration parameters of the IMS bearer channel corresponding to the LTE network are invalid or non-existent.

[0096] In some embodiments, after a terminal receives a PDU session modification command sent from the network, if the terminal detects that the configuration parameters of the IMS bearer channel corresponding to the LTE network in the PDU session modification command are abnormal, the terminal will send a PDU session modification request to the network to request modification of the configuration parameters of the IMS bearer channel corresponding to the LTE network. Since the network has not modified the configuration parameters of the IMS bearer channel corresponding to the LTE network, after the terminal switches from the 5G network to the LTE network, the configuration parameters of the IMS bearer channel corresponding to the LTE network will be invalid or non-existent, resulting in abnormal calls on the terminal.

[0097] It should be noted that in this embodiment of the present application, if the terminal detects that the configuration parameters of the IMS bearer channel corresponding to the 5G network are abnormal, the terminal sends a PDU session modification request to the network. Since the terminal is currently resident on the 5G network, the network will modify the configuration parameters of the IMS bearer channel corresponding to the 5G network. However, since the terminal is currently resident on the 5G network, the network will not modify the configuration parameters of the IMS bearer channel corresponding to the LTE network.

[0098] In some embodiments, the terminal may set a timer. When the timer expires, the terminal determines that the network has not modified the configuration parameters of the IMS bearer channel corresponding to the LTE network. In other embodiments, when the network has not modified the configuration parameters of the IMS bearer channel corresponding to the LTE network, the network may send a notification message to the terminal to inform the terminal that the network has not modified the configuration parameters of the IMS bearer channel corresponding to the LTE network.

[0099] For example, the present application embodiment is combined with Figure 2 As shown in the figure, an example is given of why call abnormalities occur after the terminal switches from a 5G network to an LTE network.

[0100] S1. The first terminal sends a registration request to the 5G network.

[0101] The registration request is used to indicate that the first terminal requests to register on the 5G network, and the registration request may be, for example, a registration request.

[0102] In some embodiments, the registration request sent by the first terminal to the network carries configuration parameters for a bearer channel established by the first terminal. The bearer channel is established between the first terminal and a public data network (PDN). Bearer channels include default bearer channels and dedicated bearer channels; default bearer channels include internet default bearer channels and IMS default bearer channels.

[0103] Specifically, the Internet default bearer channel is used to transmit data during the first terminal's Internet access process, the IMS default bearer channel is used to transmit control signaling during calls and conversations, and the dedicated bearer channel is used to transmit multimedia data (such as voice data or video data) during conversations.

[0104] Exemplarily, the configuration parameters of the bearer channel established by the first terminal may include: access point name (APN), data network name (DNN), PDU session ID (PSI), EPS bearer identity (EBI), 5G quality of service (QoS) identifier (5G QoS identifier, 5QI), and LTE QoS identifier (QoS class identifier, QCI).

[0105] Among them, PSI represents the PDU session ID of the 5G network, EBI represents the EPS ID of the LTE network, 5QI represents the quality level of the 5G network, and QCI represents the quality level of the LTE network.

[0106] It should be noted that the above are merely some examples of configuration parameters of the bearer channel and do not constitute a limitation of the present application.

[0107] In addition, in the embodiments of the present application, "mapping" refers to a one-to-one correspondence, that is, the configuration parameters of the IMS bearer channel corresponding to the 5G network correspond one-to-one with the configuration parameters of the IMS bearer channel corresponding to the LTE network. For example, PSI corresponds to EBI, and 5QI corresponds to QCI.

[0108] S2. The 5G network sends a registration acceptance message to the first terminal.

[0109] The registration accept message is used to instruct the 5G network to accept the request of the first terminal to register on the 5G network. Exemplarily, the registration accept message may be, for example, registration accept.

[0110] S3. The 5G network sends a PDU session modification command to the first terminal; it carries the configuration parameters of the IMS bearer channel, including the configuration parameters of the IMS bearer channel corresponding to the 5G network and the configuration parameters of the IMS bearer channel corresponding to the mapped LTE network.

[0111] Exemplarily, the PDU session modification command may be, for example, a PDU session modification command.

[0112] S4. Perform semantic / syntactic detection on the configuration parameters of the IMS bearer channel to determine that the configuration parameters of the IMS bearer channel corresponding to the LTE network are abnormal.

[0113] It is understandable that if the first terminal determines that the configuration parameters of the IMS bearer channel corresponding to the LTE network are abnormal, the first terminal defaults that the configuration parameters of the IMS bearer channel corresponding to the LTE network are invalid or do not exist.

[0114] S5. The first terminal sends a PDU session modification completion message to the 5G network.

[0115] Exemplarily, the PDU session modification completion message may be, for example, PDU session modification complete.

[0116] S6. The first terminal sends a PDU session modification request to the 5G network, requesting to modify the configuration parameters of the IMS bearer channel corresponding to the LTE network.

[0117] Exemplarily, the PDU session modification request may be, for example, a PDU session modification request, which carries a cause value #85 “invalid mapped EPS bearer identity” (ie, the mapped EPS bearer identity is invalid).

[0118] S7. The 5G network does not modify the configuration parameters of the IMS bearer channel corresponding to the LTE network.

[0119] S8. The first terminal and the second terminal establish a call connection on the 5G network.

[0120] S9. After the first terminal switches to the LTE network, the call is abnormal.

[0121] In an embodiment of the present application, since the 5G network does not modify the configuration parameters of the IMS bearer channel corresponding to the LTE network after receiving the PDU session modification request sent by the first terminal, after the first terminal switches from the 5G network to the LTE network, the call will be abnormal because the first terminal defaults to the configuration parameters of the IMS bearer channel corresponding to the LTE network being invalid or non-existent.

[0122] Combine Figure 2 As shown, in this embodiment of the present application, if the first terminal determines that the IMS bearer channel corresponding to the LTE network is invalid or does not exist, the first terminal will send a PDU session modification request to the 5G network, and carry the cause value #85 "invalid mapped EPS bearer identity". Exemplarily, in this embodiment of the present application, when the following three situations exist, the terminal will send a "PDU session modification request, #85 "invalid mapped EPS bearer identity" to the network.

[0123] Case 1: Due to a network failure, the bearer channel configuration parameters sent by the network to the terminal do not comply with the specifications; or the bearer channel configuration parameters lack necessary elements. Exemplarily, the bearer channel configuration parameters do not include protocol configuration options (PCO) or extended protocol configuration options (ePCO).

[0124] Case 2: Due to a network failure, the mapping relationship between the bearer channel corresponding to the 5G network and the bearer channel corresponding to the LTE network in the bearer channel configuration parameters sent by the network to the terminal is incorrect; or, the bearer channel corresponding to the LTE network is incorrect.

[0125] Case 3: Due to reasons of the terminal itself, a detection error occurs when the terminal performs semantic / syntactic detection on the configuration parameters of the bearer channel sent by the network.

[0126] When any of the preceding three situations occurs, the terminal determines that the bearer channel corresponding to the LTE network is invalid or does not exist and sends a "PDU session modification request, #85 "invalid mapped EPS bearer identity"" message to the network. Because the network receives the "PDU session modification request, #85 "invalid mapped EPS bearer identity" message sent by the terminal, it does not modify the configuration parameters of the bearer channel corresponding to the LTE network. Therefore, when the terminal switches from the 5G network to the LTE network, the bearer channel corresponding to the LTE network is invalid or does not exist, resulting in a network anomaly.

[0127] In some embodiments, after receiving the "PDU session modification request, #85 "invalid mapped EPS bearer identity" sent by the terminal, the network refuses to modify the configuration parameters of the bearer channel corresponding to the LTE network. In other embodiments, after receiving the "PDU session modification request, #85 "invalid mapped EPS bearer identity" sent by the terminal, the network does not respond to the "PDU session modification request, #85 "invalid mapped EPS bearer identity".

[0128] It should be noted that the configuration parameters of the above-mentioned bearer channel can be understood as the configuration parameters of the internet default bearer channel, the configuration parameters of the IMS default bearer channel, and the configuration parameters of the IMS dedicated bearer channel.

[0129] Combine Figure 2 As shown, the following takes the case where the first terminal switches from a 5G network to an LTE network as an example to list scenarios where the call between the first terminal and the second terminal is abnormal.

[0130] Scenario 1: The configuration parameters of the default internet bearer channel corresponding to the LTE network are invalid or do not exist, and the configuration parameters of the default IMS bearer channel corresponding to the LTE network are invalid or do not exist.

[0131] For example, the embodiments of the present application are combined with Figure 3 As shown, the above scenario 1 is illustrated as an example.

[0132] S10, the first terminal establishes a 5G communication connection with the core network device through the first access network device.

[0133] For example, the first terminal can establish a communication connection with the core network device through a registration process. For an example of the registration process, reference can be made to the above embodiment, which will not be described in detail here.

[0134] S11, the core network device sends a PDU session modification command to the first terminal through the first access network device, carrying configuration parameters of the internet default bearer channel, including configuration parameters of the internet default bearer channel corresponding to the 5G network and configuration parameters of the internet default bearer channel corresponding to the mapped LTE network.

[0135] For example, the PDU session modification command can be represented as: PDU session modification command, PSI#1map EBI#5.

[0136] S12, the first terminal performs semantic / syntax detection on the configuration parameters of the internet default bearer channel, and determines that the configuration parameters of the internet default bearer channel corresponding to the LTE network are abnormal.

[0137] It can be understood that if the configuration parameters of the internet default bearer channel corresponding to the LTE network are abnormal, the first terminal determines that the configuration parameters of the internet default bearer channel corresponding to the LTE network are invalid or do not exist.

[0138] S13, the first terminal sends a PDU session modification complete message to the core network device through the first access network device.

[0139] For example, the PDU session modification complete message can be: PDU session modification complete.

[0140] S14, the first terminal sends a PDU session modification request to the core network device through the first access network device, for requesting to modify the configuration parameters of the internet default bearer channel corresponding to the LTE network.

[0141] For example, the PDU session modification request can be PDU session modification request, and the PDU session modification request carries a reason value #85 “invalid mapped EPS bearer identity”.

[0142] S15, the core network device does not modify the configuration parameter of the internet default bearer channel corresponding to the LTE network.

[0143] It can be understood that, since the core network device does not modify the configuration parameter of the internet default bearer channel corresponding to the LTE network, when the first terminal is switched from the 5G network to the LTE network, the first terminal will experience abnormal phenomena such as lagging, delay, etc. when accessing the Internet, due to the need to re-establish the internet default bearer channel corresponding to the LTE network between the first terminal and the PDN. For example, the first terminal lags for several seconds when accessing the Internet.

[0144] S16, the core network device sends a PDU session modification command to the first terminal through the first access network device, carrying the configuration parameter of the IMS default bearer channel; including the configuration parameter of the IMS default bearer channel corresponding to the 5G network, and the mapped configuration parameter of the IMS default bearer channel corresponding to the LTE network.

[0145] Exemplarily, the PDU session modification command can be represented as, for example, PDU session modification command, PSI#2map EBI#6.

[0146] S17, the first terminal performs semantic / syntax detection on the configuration parameter of the IMS default bearer channel, and determines that the configuration parameter of the IMS default bearer channel corresponding to the LTE network is abnormal.

[0147] It can be understood that, if the configuration parameter of the IMS default bearer channel corresponding to the LTE network is abnormal, the terminal determines that the configuration parameter of the IMS default bearer channel corresponding to the LTE network is invalid or does not exist.

[0148] S18, the first terminal sends a PDU session modification complete message to the core network device through the first access network device.

[0149] Exemplarily, the PDU session modification complete message can be, for example, PDU session modification complete.

[0150] S19, the first terminal sends a PDU session modification request to the core network device through the first access network device, for requesting to modify the configuration parameter of the IMS default bearer channel corresponding to the LTE network.

[0151] Exemplarily, the PDU session modification request can be, for example, PDU session modification request, and the PDU session modification request carries a reason value #85 “invalid mapped EPS bearer identity”.

[0152] S20, the core network device does not modify the configuration parameters of the IMS default bearer channel corresponding to the LTE network.

[0153] It can be understood that, since the core network device does not modify the configuration parameters of the IMS default bearer channel corresponding to the LTE network, if the first terminal is handed over from the 5G network to the LTE network during the call between the first terminal and the second terminal, the call between the first terminal and the second terminal will be abnormal, such as call drop, due to the invalid or non-existent configuration parameters of the IMS bearer channel corresponding to the LTE network.

[0154] S21, the first terminal sends an invitation message to the second terminal through the network to initiate a call.

[0155] The invitation message is used to indicate that the first terminal requests to call the second terminal. For example, the invitation message can be an invite message.

[0156] In some embodiments, an application for a call can be installed on the first terminal. For example, a "phone application" is installed on the first terminal. On this basis, the first terminal can dial a voice or video call to call the second terminal in response to the user's operation of selecting the phone number of the contact corresponding to the second terminal in the "phone application". For example, as shown in (a) of Figure 4 (a) of FIG. 1 shows a call interface schematic diagram of the first terminal calling the second terminal. In combination with (a) of Figure 4 When the first terminal calls the second terminal, the first terminal can send an invitation message to the second terminal through the network. For example, as shown in (a) of Figure 3 (a) of FIG. 1, the first terminal sends an invitation message to the second terminal through the first access network device, the core network device and the IMS device.

[0157] For example, after the second terminal receives the invitation message sent by the first terminal, the second terminal sends a 100 trying message to the first terminal. The 100 trying message is used to indicate that the second terminal has received the invitation message from the first terminal. For example, the 100 trying message can be 100 trying.

[0158] S22, the first access network device judges whether the VoNR function of the first terminal is turned on.

[0159] In some embodiments, during the process that the first terminal calls the second terminal, the first access network device judges whether the first terminal is enabled with the VoNR function. Illustratively, if the first terminal is not enabled with the VoNR function, the first access network device instructs the first terminal to switch to the LTE network, i.e., S25 is performed. After the first terminal is switched from the 5G network to the LTE network, the configuration parameters of the IMS corresponding to the LTE network are invalid or do not exist, thus causing the call failure of the first terminal. Wherein, the call failure refers to that the first terminal fails to successfully call the second terminal.

[0160] Illustratively, if the first terminal is enabled with the VoNR function, the first terminal can continue to call the second terminal, i.e., S23 is continued to be performed.

[0161] S23, the second terminal sends a 183 session progress message to the first terminal through the network.

[0162] Wherein, the 183 session progress message is used to indicate the progress information of the established session. Illustratively, the 183 session progress message can be, for example, 183session progress.

[0163] During the process that the first terminal communicates with the second terminal, the first terminal can periodically measure the signal quality of the surrounding cells by using various measurement technologies. If the first terminal detects that the signal quality of the LTE network is higher than that of the 5G network, the first terminal sends a measurement report event (such as B event) to the first access network device.

[0164] S24, the first terminal sends the B event to the first access network device.

[0165] Wherein, the B event is used to indicate that the signal quality of the LTE network is higher than that of the 5G network.

[0166] S25, the first access network device sends a switching / re-directing indication message to the first terminal, which is used to instruct the first terminal to switch / re-direct to the LTE network.

[0167] Illustratively, the switching / re-directing indication message can be, for example, a radio resource control (RRC) connection release. Alternatively, the switching / re-directing indication message can also be a redirection message. The embodiments of the present application do not make any limitation in this regard.

[0168] S26, the first terminal performs an attachment process, and the communication is dropped.

[0169] As Figure 3As shown, when the first terminal receives a handover / redirection indication message sent by the first access network device, the first terminal switches to the LTE network. Thus, during a call between the first terminal and the second terminal, if the first terminal switches to the LTE network, the call between the first terminal and the second terminal will be dropped because the configuration parameters of the IMS default bearer channel corresponding to the LTE network are invalid or non-existent.

[0170] In addition, in the above scenario 1, since the internet default bearer channel corresponding to the LTE network is invalid or does not exist, and the IMS default bearer channel corresponding to the LTE network is invalid or does not exist, the first terminal will re-execute the attach process after switching to the LTE network. The attach process is used to indicate the registration process when the first terminal reconnects to the LTE network. For examples of the attach process, please refer to the relevant technology and will not be repeated here.

[0171] For example, Figure 4 As shown in (b), during a call between a first terminal and a second terminal, if the first terminal switches to an LTE network, Figure 4 As shown in (c), the network identifier of the first terminal changes from 5G to 4G, and the call between the first terminal and the second terminal ends.

[0172] Scenario 2: The configuration parameters of the IMS default bearer channel on the LTE network are invalid or do not exist.

[0173] For example, the embodiments of the present application are combined with Figure 5 As shown, the above scenario 2 is illustrated as an example.

[0174] It should be noted that the difference between Scenario 2 and Scenario 1 is that in Scenario 2, the configuration parameters of the default internet bearer channel corresponding to the LTE network in the PDU session modification command sent by the core network device to the first terminal are normal. That is, the first terminal performs semantic / syntactic detection on the configuration parameters of the default internet bearer channel and determines that the configuration parameters of the default internet bearer channel corresponding to the LTE network are normal, that is, the configuration parameters of the default internet bearer channel corresponding to the LTE network exist and are valid.

[0175] It is understandable that, combined with the above scenario 1 and Figure 3 As shown, in scenario 2, the embodiment of the present application can determine that the configuration parameters of the internet default bearer channel corresponding to the LTE network are normal by executing S10-S13, that is, the internet default bearer channel corresponding to the LTE network exists and is valid. The specific implementation method can refer to the above embodiment and will not be repeated here.

[0176] S30. The core network device sends a PDU session modification command to the first terminal through the first access network device, carrying the configuration parameters of the IMS default bearer channel; including the configuration parameters of the IMS default bearer channel corresponding to the 5G network, and the configuration parameters of the IMS default bearer channel corresponding to the mapped LTE network.

[0177] S31. The first terminal performs semantic / syntactic detection on configuration parameters of the IMS default bearer channel and determines that the configuration parameters of the IMS default bearer channel corresponding to the LTE network are abnormal.

[0178] S32. The first terminal sends a PDU session modification completion message to the core network device through the first access network device.

[0179] S33. The first terminal sends a PDU session modification request to the core network device through the first access network device, requesting to modify the configuration parameters of the IMS default bearer channel corresponding to the LTE network.

[0180] S34. The core network device does not modify the configuration parameters of the IMS default bearer channel corresponding to the LTE network.

[0181] S35. The first terminal sends an invitation message to the second terminal through the network to initiate a call.

[0182] S36. The first access network device determines whether the VoNR function is enabled on the first terminal.

[0183] S37. The second terminal sends a 183 session progress message to the first terminal through the network.

[0184] S38. The first terminal sends event B to the first access network device.

[0185] The B event is used to indicate that the signal quality of the LTE network is higher than the signal quality of the 5G network.

[0186] S39. The first access network device sends a switching / redirection indication message to the first terminal, to instruct the first terminal to switch / redirect to the LTE network.

[0187] It should be noted that, for the example description of the specific implementation process of the above S30-S39, reference can be made to the example description of the specific implementation process of S16-S26 in the above scenario 1, which will not be repeated here.

[0188] S40: The first terminal executes a tracking area update procedure.

[0189] like Figure 5As shown, when the first terminal receives a handover / redirection indication message sent by the first access network device, the first terminal can switch to the LTE network through the tracking area update (TAU) process. In this way, during a call between the first terminal and the second terminal, if the first terminal switches to the LTE network, the call between the first terminal and the second terminal will be dropped because the configuration parameters of the IMS default bearer channel corresponding to the LTE network are invalid or do not exist.

[0190] S41. The first terminal sends a BYE message to the core network device through the second access network device, and the call is dropped.

[0191] For example, Figure 5 As shown, the first terminal sends a call BYE message to the core network device via the second access network device. The BYE message carries the cause value "cancel with media beare loss," indicating an abnormal call between the first and second terminals. After receiving the BYE message, the core network device terminates the call between the first and second terminals, effectively dropping the call.

[0192] The embodiment of the present application provides a call method that can solve the call drop problem in the above scenario 1-scenario 2. Taking the above terminal as the first terminal and the first terminal switching from the 5G network to the LTE network as an example, the call method provided by the embodiment of the present application is exemplified. For example, Figure 6 As shown, the calling method may include the following steps.

[0193] S201. A first terminal establishes a communication connection to a core network device through a first access network device.

[0194] Exemplarily, in S201, the first access network device and the core network device may be referred to as a first network device. That is, the first terminal may establish a 5G communication connection with the first network device through the first communication network (ie, a 5G network).

[0195] S202. The core network device sends a first indication message to the first terminal through the first access network device, carrying the first target configuration parameters of the first bearer channel, including the first configuration parameters of the first bearer channel corresponding to the first communication network, and the second configuration parameters of the first bearer channel corresponding to the mapped second communication network.

[0196] For example, the first indication message can be the PDU session modification command in the above-mentioned scenarios 1 and 2, the first bearer channel can be the above-mentioned IMS default bearer channel, and the first target configuration parameter of the first bearer channel can be the configuration parameter of the IMS default bearer channel carried in the above-mentioned PDU session modification command. Correspondingly, the first configuration parameter of the first bearer channel of the first communication network can be the configuration parameter (such as PSI) of the IMS default bearer channel of the above-mentioned 5G network, and the second configuration parameter of the first bearer channel of the second communication network can be the configuration parameter (such as EBI) of the IMS default bearer channel of the above-mentioned LTE network.

[0197] S203, the first terminal determines that the second configuration parameter of the first bearer channel of the second communication network is invalid or does not exist according to the first target configuration parameter of the first bearer channel.

[0198] For example, the first terminal performs semantic / syntax detection on the first target configuration parameter of the first bearer channel, and determines that the second configuration parameter of the first bearer channel of the second communication network is invalid or does not exist if the second configuration parameter of the first bearer channel of the second communication network is abnormal.

[0199] S204, the first terminal sends a PDU session modification completion message to the core network device through the first access network device.

[0200] S205, the first terminal sends a PDU session modification request to the core network device through the first access network device, for requesting to modify the second configuration parameter of the first bearer channel of the second communication network.

[0201] S206, the core network device does not modify the second configuration parameter of the first bearer channel of the second communication network.

[0202] It should be noted that for the example of S204-S205, the example of S18-S20 in the above-mentioned scenario 1 can be referred to, and details are not repeated here.

[0203] S207, the first terminal initiates a call to the second terminal to establish a call connection.

[0204] For example, the first terminal can send an invitation message to the second terminal to invite the second terminal to call. Then, the second terminal sends a 100 attempt message and a 183 session progress message to the first terminal, and after the second terminal accepts the invitation message of the first terminal, the first terminal establishes a call connection with the second terminal.

[0205] In some embodiments, the first terminal can use the first configuration parameter of the first bearer channel of the first communication network to establish a call connection with the second terminal.

[0206] S208, the first terminal detects that the signal quality of the second communication network is higher than the signal quality of the first communication network.

[0207] For example, the first terminal can periodically detect the communication quality of the communication network of the surrounding serving cell in multiple measurement manners.

[0208] S209, in the case that the signal quality of the second communication network is higher than the signal quality of the first communication network, and the second configuration parameter of the first bearer channel corresponding to the second communication network is invalid or does not exist, the first terminal maintains the communication connection with the first communication network.

[0209] In some embodiments, when the configuration parameter of the first bearer channel includes the first configuration parameter of the first bearer channel corresponding to the first communication network, and the second configuration parameter of the first bearer channel corresponding to the second communication network is mapped, the first terminal determines that the second configuration parameter of the first bearer channel corresponding to the second communication network is invalid.

[0210] In some other embodiments, when the configuration parameter of the first bearer channel includes the first configuration parameter of the first bearer channel corresponding to the first communication network, and does not include the second configuration parameter of the first bearer channel corresponding to the second communication network, the first terminal determines that the second configuration parameter of the first bearer channel corresponding to the second communication network does not exist.

[0211] In the related art, if the first terminal detects that the signal quality of the LTE network is higher than the signal quality of the 5G network, the first terminal will switch to the LTE network. In the process of the call between the first terminal and the second terminal, if the first terminal switches to the LTE network, the call between the first terminal and the second terminal will be dropped due to the invalidity or nonexistence of the configuration parameter of the IMS default bearer channel corresponding to the LTE network.

[0212] In summary, by using the scheme of the embodiments of the present application, in the process of the call between the first terminal and the second terminal, in the case that the signal quality of the second communication network is higher than the signal quality of the first communication network, and the second configuration parameter of the first bearer channel corresponding to the second communication network is invalid or does not exist, the first terminal maintains the connection with the first communication network through the first network device, avoids switching to the second communication network, and prevents the call drop between the first terminal and the second terminal.

[0213] In some embodiments of the present application, as shown in Figure 7 the first terminal maintaining the communication connection with the first communication network through the first network device includes the following steps.

[0214] S2091, the first terminal suppresses reporting the B event to the first access network device.

[0215] The B event is used to indicate that the signal quality of the second communication network is higher than the signal quality of the first communication network.

[0216] It can be understood that, in the prior art, after the first terminal reports the B event to the first access network device, the first access network device sends a handover / redirection instruction message to the first terminal to instruct the first terminal to handover / redirection to the second communication network.

[0217] In this embodiment, since the first terminal suppresses reporting the B event to the first access network device, i.e., the first terminal does not inform the first access network device that the signal quality of the second communication network is higher than the signal quality of the first communication network, the first access network device does not send a handover / redirection instruction message to the first terminal, thereby avoiding the first terminal handover / redirection to the second communication network and preventing the first terminal from dropping the call with the second terminal.

[0218] In some embodiments of the present application, as shown in Figure 8 the first terminal maintains a communication connection with the first communication network through the first network device, including the following steps.

[0219] S209a, the first terminal reports the B event to the first access network device.

[0220] S209b, the first access network device sends a handover / redirection instruction message to the first terminal to instruct handover to the second communication network.

[0221] S209c, the first terminal does not comply with the handover / redirection instruction message sent by the first access network device.

[0222] For example, the first terminal not complying with the handover / redirection instruction message sent by the first access network device means that the first terminal does not respond to the handover / redirection instruction message sent by the first access network device, or the first terminal responds to the handover / redirection instruction message sent by the first access network device, but the first terminal does not handover / redirection to the second communication network, i.e., the first terminal ignores the handover / redirection instruction message sent by the first access network device.

[0223] In this way, after the first terminal receives the handover / redirection instruction message sent by the first access network device, the first terminal does not comply with the handover / redirection instruction message sent by the first access network device, thereby avoiding the first terminal handover / redirection to the second communication network and preventing the first terminal from dropping the call with the second terminal.

[0224] In some embodiments, as shown in Figure 9 before the first terminal calls the second terminal for a call, the call method can further include the following steps.

[0225] S210. The first terminal sends a first release request to the core network device through the first access network device, requesting the core network device to delete the first target configuration parameter of the first bearer channel.

[0226] Exemplarily, after receiving the first release request, the core network device may use the second target configuration parameters of the first bearer channel to overwrite the first target configuration parameters of the first bearer channel.

[0227] S211. The core network device deletes the first target configuration parameter of the first bearer channel.

[0228] S212. The first terminal sends a first request to the core network device through the first access network device, requesting to obtain the second target configuration parameters of the first bearer channel; including the third configuration parameters of the first bearer channel corresponding to the first communication network, and the fourth configuration parameters of the first bearer channel corresponding to the mapped second communication network.

[0229] S213. The core network device sends a first acceptance message to the first terminal to notify the first terminal that the first request is received; the message does not include the second target configuration parameters of the first bearer channel.

[0230] Exemplarily, after the first terminal receives the first acceptance message, the first terminal deletes the first target configuration parameters of the first bearer channel; or, after the first terminal receives the first acceptance message, the first terminal uses the second target configuration parameters of the first bearer channel to overwrite the first target configuration parameters of the first bearer channel.

[0231] It is understandable that in S213, the core network device sends a first acceptance message to the first terminal, informing the first terminal that the first request has been received, but does not configure the second target configuration parameters of the first bearer channel for the first terminal. Therefore, in this case, the first terminal does not obtain the second target configuration parameters of the first bearer channel.

[0232] In some embodiments, the first terminal's failure to obtain the third configuration parameter of the first bearer channel may include: the first terminal refraining from sending the first request to the core network device; or the first terminal sending the first request to the core network device, but the first terminal not receiving the first acceptance message sent by the core network device. Exemplarily, the first terminal sending the first request to the core network device but not receiving the first acceptance request sent by the core network device within a preset time period; or the first terminal sending the first request to the core network device but not receiving the first acceptance request sent by the core network device before the first terminal initiates a call to the second terminal.

[0233] For example, Figure 9As shown, in a case where the first terminal does not acquire the second target configuration parameter of the first bearer channel, the first terminal can continue to perform S207 to S208. The specific implementation process can refer to the above-mentioned embodiments, which will not be described here one by one.

[0234] S209A, in a case where the first terminal does not acquire the second target configuration parameter of the first bearer channel, the signal quality of the second communication network is higher than that of the first communication network, and the second configuration parameter of the first bearer channel corresponding to the second communication network is invalid or does not exist, the first terminal maintains the connection with the first communication network through the first network device.

[0235] In the embodiments of the present application, before the first terminal communicates with the second terminal, the first terminal can attempt to reacquire the configuration parameter of the first bearer channel from the core network device, that is, reacquire the second target configuration parameter of the first bearer channel. In a case where the first terminal does not acquire the second target configuration parameter of the first bearer channel, during the communication between the first terminal and the second terminal, in a case where the signal quality of the second communication network is higher than that of the first communication network, and the second configuration parameter of the first bearer channel corresponding to the second communication network is invalid or does not exist, the first terminal maintains the connection with the first communication network through the first network device, avoids switching to the second communication network, and prevents the communication between the first terminal and the second terminal from being dropped.

[0236] S214, in a case where the first terminal does not acquire the second target configuration parameter of the first bearer channel, the first terminal can initiate initial registration to the core network device to reestablish the configuration parameter of the first bearer channel.

[0237] For example, the first terminal can initiate initial registration to the core network device in a non-service state (such as a flight mode). Alternatively, the first terminal initiates initial registration to the core network device in an off-screen state.

[0238] In this way, the next communication between the first terminal and the second terminal can be ensured to be normal with a high probability.

[0239] In some embodiments of the present application, as shown, Figure 10 As shown, before the first terminal calls the second terminal for communication, the communication method can further include the following steps.

[0240] S210, the first terminal sends a first release request to the core network device through the first access network device, for requesting the core network device to delete the first target configuration parameter of the first bearer channel.

[0241] S211, the core network device deletes the first target configuration parameter of the first bearer channel.

[0242] S212. The first terminal sends a first request to the core network device through the first access network device, requesting to obtain the second target configuration parameters of the first bearer channel; including the third configuration parameters of the first bearer channel corresponding to the first communication network, and the fourth configuration parameters of the first bearer channel corresponding to the mapped second communication network.

[0243] S213a. The core network device sends a second acceptance message to the first terminal, which is used to notify the first terminal that the first request is received; the second acceptance message includes a second target configuration parameter of the first bearer channel.

[0244] It is understandable that in S213a, the core network device sends a second acceptance message to the first terminal, informing the first terminal of the receipt of the first request and configuring the second target configuration parameters of the first bearer channel for the first terminal. Therefore, in this case, the first terminal obtains the second target configuration parameters of the first bearer channel. S215: The first terminal determines, based on the second target configuration parameters of the first bearer channel, that the fourth configuration parameters of the first bearer channel corresponding to the second communication network are invalid or do not exist.

[0245] S216. The first terminal sends a PDU session modification completion message to the core network device.

[0246] S217. The first terminal sends a PDU session modification request to the core network device, requesting to modify the fourth configuration parameter of the first bearer channel corresponding to the second communication network.

[0247] S218. The core network device does not modify the fourth configuration parameter of the first bearer channel corresponding to the second communication network.

[0248] For example, Figure 10 As shown, if the first terminal obtains the second target configuration parameters of the first bearer channel, but the fourth configuration parameters of the first bearer channel corresponding to the second communication network are invalid or do not exist, the first terminal may continue to execute S207 to S208. The specific implementation process can be referred to the above embodiment and will not be repeated here.

[0249] S209B. If the first terminal obtains the second target configuration parameter of the first bearer channel, and the signal quality of the second communication network is higher than the signal quality of the first communication network, and the fourth configuration parameter of the first bearer channel corresponding to the second communication network is invalid or does not exist, the first terminal maintains connection with the first communication network through the first network device.

[0250] In an embodiment of the present application, before a first terminal and a second terminal communicate with each other, the first terminal may attempt to re-acquire the configuration parameters of the first bearer channel from the core network device, that is, re-acquire the second target configuration parameters of the first bearer channel. If the first terminal obtains the second target configuration parameters of the first bearer channel, during a call between the first terminal and the second terminal, if the signal quality of the second communication network is higher than the signal quality of the first communication network, and the fourth configuration parameter of the first bearer channel corresponding to the second communication network is invalid or does not exist, the first terminal maintains a connection with the first communication network through the first network device, avoids switching to the second communication network, and prevents the call between the first terminal and the second terminal from being dropped.

[0251] S214A. When the first terminal obtains the second target configuration parameters of the first bearer channel, but the fourth configuration parameters of the first bearer channel corresponding to the second communication network are invalid or do not exist, the first terminal can initiate an initial registration to the core network device to re-establish the configuration parameters of the first bearer channel.

[0252] In this way, it is possible to ensure with a high probability that the next call between the first terminal and the second terminal will be normal.

[0253] In some embodiments of the present application, Figure 10 ,like Figure 11 As shown, the calling method may further include the following steps. Figure 11 In the illustrated embodiment, the first terminal determines that the second configuration parameters of the first bearer channel corresponding to the second communication network are invalid or do not exist by executing steps S201 to S206. Furthermore, the first terminal obtains the second target configuration parameters of the first bearer channel from the core network device by executing steps S210 to S213a.

[0254] S215a: The first terminal determines, based on the second target configuration parameter of the first bearer channel, that the fourth configuration parameter of the first bearer channel corresponding to the second communication network exists and is valid.

[0255] It is understandable that, in S215a, after performing semantic / syntactic detection on the second target configuration parameter of the first bearer channel, the first terminal determines that the fourth configuration parameter of the first bearer channel corresponding to the second communication network is normal.

[0256] S216. The first terminal sends a PDU session modification completion message to the core network device through the first access network device.

[0257] For example, Figure 11 As shown, when the first terminal obtains the second target configuration parameter of the first bearer channel, the first terminal may continue to execute S207 to S208. The specific implementation process can refer to the above embodiment and will not be repeated here.

[0258] S219, if the first terminal acquires the second target configuration parameter of the first bearer channel, the signal quality of the second communication network is higher than that of the first communication network, and the fourth configuration parameter of the first bearer channel corresponding to the second communication network exists and is valid, establishing a communication connection of the second communication network.

[0259] In this embodiment, since the first terminal acquires the second target configuration parameter of the first bearer channel, and determines that the fourth configuration parameter of the first bearer channel corresponding to the second communication network is normal, i.e., the fourth configuration parameter of the first bearer channel corresponding to the second communication network exists and is valid, after performing voice / syntax detection on the second target configuration parameter of the first bearer channel, the first terminal can establish a communication connection with the second communication network through the second network device in the case that the signal quality of the second communication network is higher than that of the first communication network. In this way, even if the first terminal switches / redirects to the second communication network during the call, the call can be ensured to be normal.

[0260] In some embodiments, as shown in Figure 12 Before the first terminal calls the second terminal, the call method can further include the following steps. It should be noted that in the embodiment shown in Figure 12 In the embodiment shown in

[0261] S220, the first terminal determines whether the VoNR function is enabled.

[0262] In some embodiments, if the first terminal does not enable the VoNR function, the first terminal continues to perform S221; if the first terminal enables the VoNR function, the first terminal continues to perform S223.

[0263] S221, the first terminal enables the VoNR function.

[0264] S222, the first terminal sends a network capability message to the core network device through the first access network device, indicating that the first terminal supports the VoNR function.

[0265] S223, the first terminal initiates a call to the second terminal using the first configuration parameter of the first bearer channel corresponding to the first communication network.

[0266] In some embodiments, if the first communication network is a 5G network, after the first terminal enables the VoNR function, when the first terminal performs the TAU process, the first terminal can trigger the core network device to query the capability of the first terminal (i.e., trigger the core network device to query whether the first terminal supports the VoNR function). Then, the core network device sends a capability query message to the first terminal, instructing the first terminal to query whether it supports the VoNR function.

[0267] After the first terminal receives the capability query message sent by the core network device, in response to the capability query message, the first terminal sends a network capability message to the core network device through the first access network device.

[0268] In the related art, if the first terminal does not enable the VoNR function, the first terminal will switch to the LTE network and initiate a call to the second terminal using the VoLTE technology. After the first terminal switches to the LTE network, the configuration parameters of the bearer channel corresponding to the LTE network are invalid or do not exist, so the first terminal will fail to call.

[0269] By using the scheme of the embodiments of the present application, if the first terminal does not enable the VoNR function, the first terminal first enables the VoNR function and then sends a network capability message to the core network device to inform the core network device that the first terminal supports the VoNR function. Since the first terminal enables the VoNR function, the first terminal can avoid switching to the LTE network, and the call of the first terminal can be ensured to be successful.

[0270] In combination with Figure 2 As shown in FIG. 5, taking the case that the first terminal switches from the 5G network to the LTE network as an example, the scenario of abnormal communication between the first terminal and the second terminal is further listed.

[0271] Scenario 3: The configuration parameters of the IMS dedicated bearer channel of the LTE network are invalid or do not exist. It should be noted that in scenario 3, after the first terminal establishes a connection with the 5G communication network, the first terminal determines that the configuration parameters of the IMS default bearer channel corresponding to the LTE network exist and are valid.

[0272] By way of example, the embodiments of the present application in combination with Figure 13 As shown in FIG. 5, scenario 3 is exemplarily illustrated.

[0273] S50, the first terminal establishes a 5G communication connection with the core network device through the first access network device.

[0274] S51, the first terminal sends an invitation message to the second terminal through the network to initiate a call.

[0275] S52, the second terminal sends a 183 session progress message to the first terminal through the network.

[0276] It should be noted that for the illustration of S50-S52, reference can be made to the illustration of S10, S21 and S23 in the above embodiments, which will not be repeated here.

[0277] S53, the core network device sends a PDU session modification command to the first terminal through the first access network device, carrying configuration parameters of the IMS dedicated bearer channel; including configuration parameters of the IMS dedicated bearer channel corresponding to the 5G network, and configuration parameters of the IMS dedicated bearer channel corresponding to the mapped LTE network.

[0278] For example, the PDU session modification command can be expressed as: PDU session modification command, PSI#2map EBI#7, 5QI / QCI=1.

[0279] S54, the first terminal performs semantic / syntax detection on the configuration parameters of the IMS dedicated bearer channel, and determines that the configuration parameters of the IMS dedicated bearer channel corresponding to the LTE network are abnormal.

[0280] S55, the first terminal sends a PDU session modification complete message to the core network device through the first access network device.

[0281] S56, the first terminal sends a PDU session modification request to the core network device through the first access network device, for requesting to modify the configuration parameters of the IMS dedicated bearer channel corresponding to the LTE network.

[0282] S57, the core network device does not modify the configuration parameters of the IMS dedicated bearer channel corresponding to the LTE network.

[0283] S58, the first terminal reports a B event to the first access network device.

[0284] S59, the first access network device sends a handover / redirection indication message to the first terminal, indicating to switch to the LTE network.

[0285] S60, the first terminal performs a tracking area update process and switches to the LTE network.

[0286] S61a, the first terminal uses the IMS default bearer channel corresponding to the LTE network to communicate with the second terminal.

[0287] It can be understood that since the IMS default bearer channel is used to transmit signaling in the process of calling and communication, when the first terminal uses the IMS default bearer channel corresponding to the LTE network to communicate with the second terminal, it is highly likely to cause the communication to be silent. Wherein, the communication being silent means that the first terminal and the second terminal cannot hear each other's voice in the process of communication.

[0288] S61b, the first terminal does not use the IMS default bearer channel corresponding to the LTE network to communicate with the second terminal.

[0289] S62, the first terminal sends a BYE message to the core network device through the second access network device when the timer expires, and the communication is dropped.

[0290] For example, in the case that the first terminal does not use the IMS default bearer channel corresponding to the LTE network to communicate with the second terminal, the first terminal can start a timer using a quality of service (QoS) technology, and when the timer expires, the first terminal sends a communication BYE message to the core network device through the second access network device; wherein the BYE message carries a reason value "cancel with media beare loss", and the BYE message is used to indicate that the communication between the first terminal and the second terminal is abnormal. Then, the core network device receives the BYE message and ends the communication between the first terminal and the second terminal, i.e. the call is dropped.

[0291] It should be noted that the above scenarios 1-3 list scenarios in which the first terminal switches from the 5G network to the LTE network, and due to the invalid or non-existent configuration parameters of the bearer channel corresponding to the LTE network, the communication is abnormal. The following lists scenarios in which the first terminal switches from the LTE network to the 5G network, and due to the invalid or non-existent configuration parameters of the bearer channel corresponding to the 5G network, the communication is abnormal.

[0292] Scenario 4: The configuration parameters of the IMS dedicated bearer channel of the 5G network are invalid or do not exist.

[0293] For example, the embodiments of the present application combine Figure 14 As shown in the above scenario 4.

[0294] S70, the first terminal establishes a communication connection of the LTE network with the core network device through the second access network device.

[0295] For example, the first terminal can establish a communication connection of the LTE network with the core network device through an attach process. For an example of the attach process, please refer to the above embodiments, which will not be described in detail here.

[0296] S71, the first terminal sends an invitation message to the second terminal through the network to initiate communication.

[0297] For example, the first terminal can send an invitation message to the second terminal through the second access network device, the core network device and the IMS device.

[0298] S72, the second terminal sends a 183 session progress message to the first terminal through the network.

[0299] S73. The core network device sends a request to activate the IMS dedicated bearer channel to the first terminal through the second access network device, carrying the configuration parameters of the IMS dedicated bearer channel corresponding to the LTE network, but not carrying the configuration parameters of the IMS dedicated bearer channel corresponding to the 5G network.

[0300] Exemplarily, the request for activating the IMS dedicated bearer channel may be expressed as: EBI=7, QCI=1, without PCO or ePCO.

[0301] In some embodiments, since PCO or ePCO is not configured in the request for activating the IMS dedicated bearer channel, that is, the configuration parameters of 5QI=1 corresponding to the 5G network are not configured, after the first terminal receives the request for activating the IMS dedicated bearer channel sent by the core network device, the configuration parameters of the IMS dedicated bearer channel corresponding to the 5G network will be marked as "EBI#7markas non-transferable".

[0302] S74. The first terminal sends a message of consent to activate the IMS dedicated bearer channel to the core network device through the second access network device.

[0303] S75. The first terminal reports event B to the second access network device.

[0304] Exemplarily, the B event is used to indicate that the signal quality of the 5G network is higher than the signal quality of the 4G network.

[0305] S76. The second access network device sends a switching / redirection indication message to the first terminal, instructing it to switch to the 5G network.

[0306] For example, Figure 14 As shown, after the first terminal receives the handover / redirection indication message sent by the second access network device, the first terminal accesses the 5G network. That is, the first terminal establishes a 5G communication connection with the core network device through the first access network device. In this way, during a call between the first terminal and the second terminal, if the first terminal switches to the 5G network, the call between the first terminal and the second terminal will be dropped because the configuration parameters of the IMS dedicated bearer channel corresponding to the 5G network are invalid or do not exist.

[0307] S77. The first terminal sends a BYE message to the core network device through the first access network device, and the call is dropped.

[0308] For example, Figure 14As shown, the first terminal sends a BYE message to the core network device through the first access network device; wherein the BYE message carries a reason value "cancel with media beare loss", and the BYE message is used to indicate that the call between the first terminal and the second terminal is abnormal. Then, the core network device ends the call between the first terminal and the second terminal after receiving the BYE message, that is, the call between the first terminal and the second terminal is dropped.

[0309] The embodiment of the present application also provides a call method, which can solve the problem of call silence or call drop in the above-mentioned scenarios 3-4. Taking the above-mentioned terminal as the first terminal and the first terminal being switched from the 5G network to the LTE network as an example, the call method provided by the embodiment of the present application is exemplarily described. For example, as shown in the figure, Figure 15 The call method can include the following steps.

[0310] S301, the first terminal establishes a communication connection of a first communication network to a core network device through a first access network device.

[0311] S302, the first terminal initiates a call to the second terminal to establish a call connection.

[0312] Exemplarily, the first terminal can send an invitation message to the second terminal to invite the second terminal to call. Then, the second terminal sends a 100 attempt message and a 183 session progress message to the first terminal, and after the second terminal accepts the invitation message of the first terminal, the first terminal and the second terminal establish a call connection.

[0313] S303, the core network device sends a second indication message to the first terminal through the first access network device, carrying configuration parameters of a second bearer channel; including fifth configuration parameters of a second bearer channel corresponding to the first communication network, and sixth configuration parameters of a second bearer channel corresponding to the second communication network.

[0314] Exemplarily, the second indication message can be the PDU session modification command in the above-mentioned scenario 3; or the request for activating the IMS dedicated bearer in the scenario 4. The first bearer channel can be the IMS dedicated bearer channel described above, and the configuration parameters of the first bearer channel can be the configuration parameters of the IMS dedicated bearer channel carried in the PDU session modification command described above; or the configuration parameters of the IMS dedicated bearer channel carried in the request for activating the IMS dedicated bearer.

[0315] S304, the first terminal determines that the sixth configuration parameters of the second bearer channel corresponding to the second communication network are invalid or do not exist according to the configuration parameters of the second bearer channel.

[0316] For example, the first terminal performs semantic / syntax detection on the configuration parameters of the first bearer channel. If the sixth configuration parameter of the second bearer channel corresponding to the second communication network is abnormal, the first terminal determines that the sixth configuration parameter of the second bearer channel corresponding to the second communication network is invalid or does not exist.

[0317] S305, the first terminal sends a PDU session modification complete message to the core network device through the first access network device.

[0318] S306, the first terminal sends a PDU session modification request to the core network device through the first access network device, for requesting to modify the sixth configuration parameter of the second bearer channel corresponding to the second communication network.

[0319] S307, the core network device does not modify the sixth configuration parameter of the second bearer channel corresponding to the second communication network.

[0320] S308, the first terminal detects that the signal quality of the second communication network is higher than that of the first communication network.

[0321] S309, in the case that the signal quality of the second communication network is higher than that of the first communication network, and the sixth configuration parameter of the second bearer channel corresponding to the second communication network is invalid or does not exist, the communication connection with the first communication network is maintained.

[0322] It can be understood that in the related art, if the first terminal detects that the signal quality of the LTE network is higher than that of the 5G network, the first terminal will switch to the LTE network. In some embodiments, the first terminal can use the IMS default bearer channel to communicate with the second terminal. Since the IMS default bearer channel is used to transmit the signaling of the first terminal and the second terminal in the process of calling or communication, in this case, it is highly likely to cause the communication between the first terminal and the second terminal to be silent. In other embodiments, during the communication between the first terminal and the second terminal, when the first terminal switches to the LTE network, since the IMS dedicated bearer channel corresponding to the LTE network is invalid or does not exist, the communication between the first terminal and the second terminal is dropped.

[0323] In summary, by using the scheme of the embodiments of the present application, in the case that the signal quality of the second communication network is higher than that of the first communication network, and the sixth configuration parameter of the second bearer channel corresponding to the second communication network is invalid or does not exist, the communication connection with the first communication network is maintained, avoiding switching to the second communication network, and preventing the communication between the first terminal and the second terminal from being dropped or silent.

[0324] It should be noted that in the above description, the first terminal is a terminal in a 5G network, and the second terminal is a terminal in an LTE network. Figure 15In the illustrated embodiment, for an example of the first terminal maintaining the communication connection of the first communication network, reference may be made to the example of S2091 or S209a-S209c in the above embodiment, which will not be repeated here.

[0325] In addition, after the call between the first terminal and the second terminal ends, the first terminal can initiate an initial registration to the core network device through the first access network device to re-establish the configuration parameters of the second bearer channel. The specific implementation process can refer to the examples of S214 or S214A in the above embodiments, and will not be repeated here.

[0326] The above embodiment of the present application is described by taking the example of the first terminal switching from the 5G network to the LTE network. Among them, the specific implementation method of the first terminal switching from the LTE network to the 5G network is similar to the above embodiment, and the examples of the above embodiment can be referred to, and no further details are given here.

[0327] In addition, the above embodiments of the present application are described using the first terminal as the calling end. Of course, the second terminal as the called end has the same technical problem as the first terminal, and the above technical solution can also be used to solve the technical problem. The specific implementation process can refer to the above embodiments and will not be repeated here.

[0328] It should be noted that the contents recorded in each embodiment of the present application can explain and illustrate the technical solutions in other embodiments of the present application, and the technical features recorded in each embodiment can also be applied in other embodiments and combined with the technical features in other embodiments to form a new solution. The present application only lists several embodiments for illustration, and does not mean that the present application is strictly limited to this.

[0329] An embodiment of the present application provides a terminal, which may be the first terminal or the second terminal described above. The terminal may include: a memory and one or more processors; the memory stores computer program code, which includes computer instructions. When the computer instructions are executed by the processor, the electronic device performs the functions or steps performed in the first terminal described above. The structure of this terminal may refer to the structure of terminal 100 described below.

[0330] like Figure 16As shown, it is a structural diagram of a terminal 100 provided in an embodiment of the present application. The terminal 100 can be the above-mentioned first terminal 10 or the second terminal 20. Among them, the terminal 100 is a terminal that accesses the above-mentioned communication system and has wireless transceiver functions, or a chip (system) or other parts or components that can be set in the terminal. The terminal 100 can also be called a user device, access terminal, user unit, user station, mobile station, mobile station, remote station, remote terminal, mobile device, user terminal, terminal, wireless communication device, user agent or user device. The terminal 100 in the embodiment of the present application can be a mobile phone, tablet computer, smart watch, desktop, laptop, handheld computer, notebook computer, vehicle-mounted device, ultra-mobile personal computer (UMPC), netbook, as well as cellular phone, personal digital assistant (PDA), augmented reality (AR)\virtual reality (VR) device, etc. The embodiment of the present application does not impose any special restrictions on the specific form of the terminal 100.

[0331] like Figure 16 As shown, the terminal 100 may include: a processor 110, an external memory interface 120, an internal memory 121, a universal serial bus (USB) interface 130, a charging management module 140, a power management module 141, a battery 142, an antenna 1, an antenna 2, a mobile communication module 150, a wireless communication module 160, an audio module 170, a speaker 170A, a receiver 170B, a microphone 170C, an earphone interface 170D, a sensor module 180, a positioning module 181, a button 190, a motor 191, an indicator 192, a camera 193, a display screen 194, and a subscriber identification module (SIM) card interface 195, etc.

[0332] It should be understood that the structure illustrated in this embodiment does not constitute a specific limitation on terminal 100. In other embodiments, terminal 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.

[0333] The processor 110 may include one or more processing units. For example, the processor 110 may include an application processor (AP), a modem processor (Modem), a graphics processing unit (GPU), an image signal processor (ISP), a controller, a memory, a video codec, a digital signal processor (DSP), a baseband processor, and / or a neural-network processing unit (NPU). The different processing units may be independent devices or integrated into one or more processors.

[0334] The controller may be the nerve center and command center of the terminal 100. The controller may generate an operation control signal according to the instruction operation code and the timing signal to complete the control of fetching and executing instructions.

[0335] Processor 110 may also include a memory for storing instructions and data. In some embodiments, the memory in processor 110 is a cache memory. This memory can store instructions or data that have just been used or are being recycled by processor 110. If processor 110 needs to use the same instruction or data again, it can directly access the memory. This avoids duplicate accesses, reduces processor 110 latency, and thus improves system efficiency.

[0336] In some embodiments, the processor 110 may include one or more interfaces. It should be understood that the interface connection relationships between the modules illustrated in this embodiment are merely illustrative and do not constitute a structural limitation on the terminal 100. In other embodiments, the terminal 100 may also adopt different interface connection methods from those in the above embodiments, or a combination of multiple interface connection methods.

[0337] The charging management module 140 is used to receive charging input from a charger. The charger can be a wireless charger or a wired charger. While charging the battery 142, the charging management module 140 can also power the electronic device through the power management module 141.

[0338] The power management module 141 is used to connect the battery 142, the charging management module 140, and the processor 110. The power management module 141 receives input from the battery 142 and / or the charging management module 140 to provide power to the processor 110, the internal memory 121, the external memory, the display 194, the camera 193, and the wireless communication module 160.

[0339] The wireless communication function of the terminal 100 can be implemented through the antenna 1, the antenna 2, the mobile communication module 150, the wireless communication module 160, the modem processor and the baseband processor.

[0340] Terminal 100 implements display functions through a GPU, display screen 194, and an application processor. The GPU is a microprocessor for image processing that connects display screen 194 and the application processor. The GPU is used to perform mathematical and geometric calculations for graphics rendering. Processor 110 may include one or more GPUs that execute program instructions to generate or modify display information.

[0341] 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 Mini-LED, a Micro-OLED, a quantum dot light-emitting diode (QLED), etc.

[0342] The terminal 100 can realize the shooting function through the ISP, camera 193, video codec, GPU, display screen 194 and application processor.

[0343] The ISP processes data fed back by camera 193. For example, when taking a photo, the shutter is opened, and light is transmitted through the lens to the camera's photosensitive element. The light signal is converted into an electrical signal, which is then passed to the ISP for processing and converted into a visible image. The ISP can also perform algorithmic optimization on image noise, brightness, and color. It can also optimize parameters such as exposure and color temperature of the captured scene. In some embodiments, the ISP can be located within camera 193.

[0344] The camera 193 is used to capture still images or videos. An object projects an optical image through a lens to a photosensitive element. The photosensitive element can be a charge coupled device (CCD) or a complementary metal-oxide-semiconductor (CMOS) phototransistor. The photosensitive element converts the optical signal into an electrical signal, which is then passed to an ISP to convert into a digital image signal. The ISP outputs the digital image signal to a DSP for processing. The DSP converts the digital image signal into a standard RGB, YUV, or the like format image signal.

[0345] The digital signal processor is used to process digital signals, in addition to processing digital image signals, it can also process other digital signals. For example, when the electronic device selects a frequency point, the digital signal processor is used to perform Fourier transform on the frequency point energy, etc.

[0346] The video codec is used to compress or decompress digital videos. The terminal 100 can support one or more video codecs. In this way, the electronic device can play or record videos in multiple encoding formats, such as moving picture experts group (MPEG) 1, MPEG 2, MPEG 3, MPEG 4, etc.

[0347] The NPU is a neural-network (NN) computing processor, which is inspired by the structure of biological neural networks, such as the transmission mode between human brain neurons, and can quickly process input information and continuously self-learn. Through the NPU, the electronic device can realize intelligent cognition and other applications, such as image recognition, face recognition, speech recognition, text understanding, etc.

[0348] The terminal 100 can realize audio functions through the audio module 170, the speaker 170A, the receiver 170B, the microphone 170C, the earphone interface 170D, and the application processor, etc. For example, music playing, recording, etc.

[0349] The audio module 170 is used to convert digital audio information into analog audio signals, and is also used to convert analog audio input into digital audio signals. The audio module 170 can also be used to encode and decode audio signals. The speaker 170A, also known as a “loudspeaker”, is used to convert audio electrical signals into sound signals. The receiver 170B, also known as a “earpiece”, is used to convert audio electrical signals into sound signals. The microphone 170C, also known as a “microphone”, “sound transducer”, is used to convert sound signals into electrical signals. The earphone interface 170D is used to connect a wired earphone.

[0350] 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 electronic device. The external memory card communicates with the processor 110 via the external memory interface 120 to implement data storage functions. For example, audio, video, and other files can be stored on the external memory card.

[0351] The internal memory 121 can be used to store computer executable program code, which includes instructions. The processor 110 executes various functional applications and data processing of the electronic device by running the instructions stored in the internal memory 121. For example, in an embodiment of the present application, the processor 110 can execute instructions stored in the internal memory 121, and the internal memory 121 can include a program storage area and a data storage area.

[0352] The program storage area may store an operating system, at least one application required for a function (such as a sound playback function, an image playback function, etc.), etc. The data storage area may store data created during the use of the electronic device (such as audio data, a phone book, etc.), 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.

[0353] Exemplarily, the processor 110 may execute computer-executable program code stored in the internal memory 121, wherein the executable program code includes instructions. By executing the instructions, the processor 110 executes various functional applications and data processing of the terminal. For example, in an embodiment of the present application, the AP in the processor 110 executes the instructions stored in the internal memory, executes the corresponding steps, and sends a message to the network side via the modem.

[0354] Buttons 190 include a power button and volume buttons. Motor 191 can be used for incoming call vibration alerts and touch vibration feedback. Indicator 192 can be an indicator light that can be used to indicate charging status, power level changes, messages, missed calls, notifications, etc.

[0355] The SIM card interface 195 is used to connect a SIM card. The SIM card can be connected to or disconnected from the electronic device by inserting it into or removing it from the SIM card interface 195. The electronic device can support 1 or N SIM card interfaces, where N is a positive integer greater than 1. The SIM card interface 195 can support Nano SIM cards, Micro SIM cards, SIM cards, and the like. Multiple cards can be inserted into the same SIM card interface 195 at the same time. The types of the multiple cards can be the same or different. The SIM card interface 195 can also be compatible with different types of SIM cards. The SIM card interface 195 can also be compatible with external memory cards. The terminal 100 interacts with the network through the SIM card to implement functions such as calls and data communications. In some embodiments, the terminal 100 uses an eSIM card, i.e., an embedded SIM card. The eSIM card can be embedded in the terminal 100 and cannot be separated from the terminal 100.

[0356] In addition, on top of the above components, the terminal 100 also runs an operating system, such as an iOS operating system, an Android operating system, etc. Application programs can be installed and run on the operating system.

[0357] The software system of the terminal 100 may adopt a layered architecture, an event-driven architecture, a micro-kernel architecture, a micro-service architecture or a cloud architecture, etc. In the embodiment of the present application, the Android system with a layered architecture is used as an example to exemplify the software structure of the terminal 100 .

[0358] Figure 17 It is a software structure block diagram of the terminal in an embodiment of the present application.

[0359] A layered architecture divides software into several layers, each with distinct roles and responsibilities. Layers communicate with each other through software interfaces. In some embodiments, the Android system is divided into five layers: from top to bottom: the application layer, the application framework layer, the Android runtime and system libraries, and the kernel layer.

[0360] The application layer can include a series of application packages.

[0361] like Figure 17 As shown, the application package may include applications such as phone, mailbox, calendar, camera, etc. The application layer may also include system UI (system UI), which is used to display the terminal interface, such as displaying the signal icon corresponding to the SIM card, displaying the call interface, etc. For example, the system UI can be used to display Figure 4 (a) Figure 4 (b) and Figure 4 The interface shown in (c).

[0362] The application framework layer provides an application programming interface (API) and programming framework for the applications in the application layer. The application framework layer includes some predefined functions.

[0363] like Figure 17 As shown, the application framework layer can include a window manager, an input manager, an activity manager, a resource manager, a phone manager, etc. Among them, the window manager is used to manage window programs. The window manager can obtain the display size, determine whether there is a status bar, lock the screen, take screenshots, etc. The input manager is used to manage the programs of the input devices. For example, the input system can determine input operations such as mouse clicks, keyboard input operations, and touch slides. The activity manager is used to manage the life cycle of each application and the navigation back function. It is responsible for creating the Android main thread and maintaining the life cycle of each application. The resource manager provides various resources for the application, such as localized strings, icons, pictures, layout files, video files, etc.

[0364] The phone manager is used to provide terminal call functions, such as call status management (including answering, hanging up, etc.). The application framework layer HIA may include a radio interface layer (RIL), through which the modem can exchange information with the phone manager.

[0365] The application framework layer also includes a Modem processing module. In the embodiment of the present application, the Modem processing module is used to execute the various steps executed by the first terminal in the above embodiment, such as executing Figure 2 S4 shown, Figure 3 S12 and S17 in Figure 5 S31 in Figure 6 S203 and S208 in Figure 8 S209c in Figure 10 S215 in Figure 11 S215a in Figure 12 S220 and S221 in Figure 13 S54, S61a and S61b in Figure 15 S304 and S308 in.

[0366] In addition, the Modem processing module is also used to send messages to the network (such as access network equipment, core network equipment and IMS equipment) through the Modem.

[0367] The Android runtime includes the core library and the virtual machine. The Android runtime is responsible for scheduling and management of the Android system.

[0368] The core library consists of two parts: one is the function that Java voice needs to call, and the other is the Android core library.

[0369] The application layer and application framework layer run in a virtual machine. The virtual machine executes Java files in the application layer and application framework layer as binary files. The virtual machine manages object lifecycles, stack management, thread management, security and exception management, and garbage collection.

[0370] The system library can include multiple functional modules. For example, the function library, media library, and input processing library provide macros, type definitions, string manipulation functions, mathematical calculation functions, and input / output functions used in C language. The media library supports playback and recording of various common audio and video formats, as well as static image files. The media library supports a variety of audio and video encoding formats, such as MPEG4, H.264, MP3, AAC, AMR, JPG, and PNG. The input processing library is a library for processing input devices, enabling mouse, keyboard, and touch input processing.

[0371] The kernel layer is the layer between hardware and software. The kernel layer includes at least display drivers, Bluetooth drivers, Wi-Fi drivers, and camera drivers.

[0372] In the embodiment of the present application, the modem in the terminal can report messages sent by the network side (such as PDU session modification commands, switching / redirection indication messages, etc.) to the AP. Correspondingly, the modem processing module in the terminal can also send messages to the network side (such as PDU session modification completion messages, B events, etc.).

[0373] The present application also provides a chip system. Figure 18 As shown, the chip system 1100 includes at least one processor 1101 and at least one interface circuit 1102. The processor 1101 can be Figure 16 The processor 110 is shown. The interface circuit 1102 may be, for example, an interface circuit between the processor 110 and an external memory; or an interface circuit between the processor and the internal memory 121.

[0374] The processor 1101 and the interface circuit 1102 can be connected by wire. For example, the interface circuit 1102 can be used to receive signals from other devices (for example, the memory of the mobile phone 100). For another example, the interface circuit 1102 can be used to send signals to other devices (for example, the processor 1101). For example, the interface circuit 1102 can read the instructions stored in the memory and send the instructions to the processor 1101. When the instructions are executed by the processor 1101, the terminal can perform various steps performed by the first terminal in the above embodiments. Of course, the chip system can also include other discrete devices, and the embodiments of the present application do not make specific limitations.

[0375] The embodiments of the present application also provide a computer readable storage medium, which includes computer instructions, when the computer instructions run on a terminal, make the terminal execute various functions or steps performed by the first terminal in the above method embodiments.

[0376] The embodiments of the present application also provide a computer program product, when the computer program product runs on a computer, make the computer execute various functions or steps performed by the first terminal in the above method embodiments.

[0377] Through the description of the above embodiments, those skilled in the art can clearly understand that, for the convenience and brevity of description, only the above-mentioned division of functional modules is taken as an example, and in actual application, the above-mentioned functions can be completed by different functional modules according to needs, that is, the internal structure of the device is divided into different functional modules to complete all or part of the functions described above.

[0378] In several embodiments provided in the present application, it should be understood that the disclosed devices and methods can be implemented in other ways. For example, the device embodiments described above are only schematic, for example, the division of the modules or units is only a logical function division, and actual implementation can have another division manner, for example, a plurality of units or components can be combined or integrated into another device, or some features can be ignored or not executed. In addition, the coupling or direct coupling or communication connection between the units shown or discussed can be indirect coupling or communication connection through some interfaces, devices or units, and can be electrical, mechanical or other forms.

[0379] The units described as separate components can or can not be physically separated, and the components shown as units can be one physical unit or multiple physical units, that is, can be located in one place, or can be distributed to multiple different places. Some or all of the units can be selected according to actual needs to achieve the purpose of the embodiments of the present application.

[0380] In addition, the functional units in the various embodiments of the present application may be integrated into a single processing unit, or each unit may exist physically separately, or two or more units may be integrated into a single unit. The aforementioned integrated units may be implemented in the form of hardware or software functional units.

[0381] If the integrated unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a readable storage medium. Based on this understanding, the technical solution of the embodiment of the present application is essentially or the part that contributes to the prior art or all or part of the technical solution can be embodied in the form of a software product, which is stored in a storage medium and includes several instructions for enabling a device (which can be a single-chip microcomputer, chip, etc.) or a processor (processor) to execute all or part of the steps of the method described in each embodiment of the present application. The aforementioned storage medium includes: various media that can store program codes, such as a USB flash drive, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk or an optical disk.

[0382] The above content is only a specific embodiment of this application, but the scope of protection of this application is not limited to this. Any changes or replacements within the technical scope disclosed in this application should be included in the scope of protection of this application. Therefore, the scope of protection of this application should be based on the scope of protection of the claims.

Claims

1. A calling method, characterized in that: The calling method includes: The first terminal is connected to the first network device via the first communication network; The first terminal receives a first indication message sent from the first network device; wherein the first indication message includes a first target configuration parameter of a first bearer channel, and the first bearer channel is used to transmit signaling between the first terminal and the second terminal during a call or conversation; The first target configuration parameters of the first bearer channel include first configuration parameters of the first bearer channel corresponding to the first communication network, and the first terminal uses the first configuration parameters of the first bearer channel corresponding to the first communication network to establish a call connection with the second terminal; During a call between the first terminal and the second terminal, if the signal quality of the second communication network is higher than the signal quality of the first communication network and the second configuration parameter of the first bearer channel corresponding to the second communication network is invalid or does not exist, the first terminal maintains the connection with the first communication network through the first network device; The second configuration parameter of the first bearer channel corresponding to the second communication network being invalid includes: the first target configuration parameter of the first bearer channel includes the mapped second configuration parameter of the first bearer channel corresponding to the second communication network and the second configuration parameter is invalid; The second configuration parameter of the first bearer channel corresponding to the second communication network does not exist includes: the first target configuration parameter of the first bearer channel does not include the mapped second configuration parameter of the first bearer channel corresponding to the second communication network.

2. The communication method according to claim 1, wherein: The first terminal maintaining a connection with the first communication network through the first network device includes: The first terminal suppresses reporting of the measurement event to the first network device and maintains connection with the first communication network through the first network device; the measurement event is used to indicate that the signal quality of the second communication network is higher than the signal quality of the first communication network; or The first terminal reports the measurement event to the first network device; the first terminal receives a switching / redirection indication message from the first network device; the switching / redirection indication message is used to instruct the first terminal to switch / redirect to the second communication network; the first terminal ignores the switching / redirection indication message and maintains a connection with the first communication network through the first network device.

3. The communication method according to claim 1 or 2, characterized in that: Before the first terminal calls the second terminal for a call, the call method further includes: The first terminal sends a first release request to the first network device; the first release request is used to delete a first target configuration parameter of the first bearer channel; The first terminal sends a first request to the first network device; the first request is used to request to obtain a second target configuration parameter of the first bearer channel; Wherein, when the signal quality of the second communication network is higher than the signal quality of the first communication network, and the second configuration parameter of the first bearer channel corresponding to the second communication network is invalid or does not exist, the first terminal maintains a connection with the first communication network through the first network device, including: If the first terminal fails to obtain the second target configuration parameters of the first bearer channel, during a call between the first terminal and the second terminal, when the signal quality of the second communication network is higher than the signal quality of the first communication network, and the second configuration parameters of the first bearer channel corresponding to the second communication network are invalid or do not exist, the first terminal maintains a connection with the first communication network through the first network device.

4. The communication method according to claim 3, wherein: If the first terminal obtains the second target configuration parameter of the first bearer channel, the call method further includes: The second target configuration parameter of the first bearer channel includes the third configuration parameter of the first bearer channel corresponding to the first communication network, and the first terminal uses the third configuration parameter of the first bearer channel corresponding to the first communication network to establish a call connection with the second terminal; During a call between the first terminal and the second terminal, when the signal quality of the second communication network is higher than the signal quality of the first communication network, and the fourth configuration parameter of the first bearer channel corresponding to the second communication network is invalid or does not exist, the first terminal maintains the connection with the first communication network through the first network device; The second target configuration parameter of the first bearer channel corresponding to the second communication network being invalid includes: the second target configuration parameter of the first bearer channel including the mapped fourth configuration parameter of the first bearer channel corresponding to the second communication network and the fourth configuration parameter is invalid; The configuration parameter of the first bearer channel corresponding to the second communication network does not exist includes: the second target configuration parameter of the first bearer channel does not include the mapped fourth configuration parameter of the first bearer channel corresponding to the second communication network.

5. The communication method according to claim 4, characterized in that: If the first terminal fails to obtain the second target configuration parameter of the first bearer channel, the method includes: The first terminal refrains from sending the first request to the first network device; or The first terminal sends the first request to the first network device, and before the first terminal initiates a call to the second terminal, does not receive a first acceptance message sent from the first network device; the first acceptance message includes the second target configuration parameter of the first bearer channel.

6. The communication method according to any one of claims 1, 2, 4 or 5, characterized in that: The calling method further includes: After the call between the first terminal and the second terminal ends, the first terminal re-establishes a connection with the first communication network through the first network device and re-establishes the configuration parameters of the first bearer channel.

7. The communication method according to any one of claims 1, 2, 4 or 5, characterized in that: The first communication network is a 5G network, and the second communication network is a Long Term Evolution (LTE) network; Before the first terminal calls the second terminal, the calling method further includes: If the first terminal does not enable the new radio interface voice bearer VoNR function, the first terminal enables the VoNR function and sends a network capability message to the first communication network; the network capability message is used to indicate that the first terminal supports the VoNR function; The first terminal uses VoNR technology to call the second terminal.

8. The communication method according to claim 7, characterized in that: The first terminal uses the first configuration parameter of the first bearer channel corresponding to the first communication network to establish a call connection with the second terminal, including: The first terminal uses the first configuration parameters of the first bearer channel corresponding to the first communication network to establish a call connection with the second terminal when the VoNR function is turned on.

9. The communication method according to any one of claims 1, 2, 4, 5 or 8, characterized in that: The first indication message is a PDU session modification command.

10. The communication method according to any one of claims 1, 2, 4, 5 or 8, characterized in that: The first bearer channel is the Internet Protocol Multimedia Subsystem IMS default bearer channel, and the first target configuration parameters of the first bearer channel include: access point name APN, data network name DNN, PDU session ID, evolved packet system EPS bearer identity, 5G service quality identifier, and one or more of LTE service quality identifier.

11. The communication method according to any one of claims 1, 2, 4, 5 or 8, characterized in that: The networking mode of the first network device is independent networking SA.

12. A communication method, characterized in that: The calling method includes: The first terminal is connected to the first network device via the first communication network; The first terminal receives a first indication message sent from the first network device; wherein the first indication message includes a first target configuration parameter of a first bearer channel, and the first bearer channel is used to transmit signaling between the first terminal and the second terminal during a call or conversation; the first target configuration parameter of the first bearer channel includes a first configuration parameter of the first bearer channel corresponding to the first communication network, and a second configuration parameter of the first bearer channel corresponding to the mapped second communication network; When the second configuration parameters of the first bearer channel corresponding to the second communication network are valid, the first terminal uses the first configuration parameters of the first bearer channel corresponding to the first communication network to establish a call connection with the second terminal; The first terminal receives a second indication message sent from the first network device; wherein the second indication message includes configuration parameters of a second bearer channel, and the second bearer channel is used to transmit multimedia data during a call between the first terminal and the second terminal; During a call between the first terminal and the second terminal, when the signal quality of the second communication network is higher than the signal quality of the first communication network and the sixth configuration parameter of the second bearer channel corresponding to the second communication network is invalid or does not exist, the first terminal maintains a communication connection with the first communication network through the first network device; The invalid sixth configuration parameter of the second bearer channel corresponding to the second communication network includes: the configuration parameter of the second bearer channel includes the fifth configuration parameter of the second bearer channel corresponding to the first communication network and the mapped sixth configuration parameter of the second bearer channel corresponding to the second communication network, and the sixth configuration parameter of the second bearer channel corresponding to the second communication network is invalid; The sixth configuration parameter of the second bearer channel corresponding to the second communication network does not exist, including: the configuration parameters of the second bearer channel include the fifth configuration parameter of the second bearer channel corresponding to the first communication network, but do not include the sixth configuration parameter of the second bearer channel corresponding to the mapped second communication network.

13. The communication method according to claim 12, wherein: The first terminal maintaining a connection with the first communication network through the first network device includes: The first terminal suppresses reporting of the measurement event to the first network device and maintains connection with the first communication network through the first network device; the measurement event is used to indicate that the signal quality of the second communication network is higher than the signal quality of the first communication network; or The first terminal reports the measurement event to the first network device; the first terminal receives a switching / redirection indication message from the first network device; the switching / redirection indication message is used to instruct the first terminal to switch / redirect to the second communication network; the first terminal ignores the switching / redirection indication message and maintains a connection with the first communication network through the first network device.

14. The communication method according to claim 12 or 13, characterized in that: The calling method further includes: After the call between the first terminal and the second terminal ends, the first terminal re-establishes a connection with the first communication network through the first network device and re-establishes configuration parameters of the second bearer channel.

15. The communication method according to any one of claims 12 or 13, characterized in that: The second indication message is a PDU session modification command.

16. A communication method, characterized in that: The calling method includes: The first terminal is connected to the first network device via the first communication network; The first terminal receives a first indication message sent from the first network device; wherein the first indication message includes a first target configuration parameter of a first bearer channel, and the first bearer channel is used to transmit signaling between the first terminal and the second terminal during a call or conversation; When the second configuration parameters of the first bearer channel corresponding to the second communication network are invalid or do not exist, before the first terminal calls the second terminal for a call, the first terminal obtains the second target configuration parameters of the first bearer channel; wherein the first bearer channel is used to transmit signaling between the first terminal and the second terminal during the call or conversation; The second configuration parameter of the first bearer channel corresponding to the second communication network is invalid, which includes: the first target configuration parameter of the first bearer channel includes the first configuration parameter of the first bearer channel corresponding to the first communication network and the mapped second configuration parameter of the first bearer channel corresponding to the second communication network, and the second configuration parameter of the first bearer channel corresponding to the second communication network is invalid; The second configuration parameter of the first bearer channel corresponding to the second communication network does not exist, including: the first target configuration parameter of the first bearer channel includes the first configuration parameter of the first bearer channel corresponding to the first communication network, but does not include the second configuration parameter of the first bearer channel corresponding to the second communication network; The second target configuration parameter of the first bearer channel includes the third configuration parameter of the first bearer channel corresponding to the first communication network, and the first terminal uses the third configuration parameter of the first bearer channel corresponding to the first communication network to establish a call connection with the second terminal; During a call between the first terminal and the second terminal, if the signal quality of the second communication network is higher than the signal quality of the first communication network, and the fourth configuration parameter of the first bearer channel corresponding to the second communication network is valid, the first terminal establishes a communication connection with the second communication network through the second network device; Among them, the fourth configuration parameter of the first bearer channel corresponding to the second communication network is valid, which includes: the second target configuration parameter of the first bearer channel includes the mapped fourth configuration parameter of the first bearer channel corresponding to the second communication network, and the fourth configuration parameter of the first bearer channel corresponding to the second communication network is valid.

17. A terminal, characterized in that: The terminal includes: a memory and one or more processors; The memory stores computer program code, which includes computer instructions; when the computer instructions are executed by the processor, the terminal executes the call method as described in any one of claims 1 to 11; or executes the call method as described in any one of claims 12 to 15; or executes the call method as described in claim 16.

18. A chip system, characterized in that: Applied to a terminal, the chip system includes: at least one processor and an interface, the interface being used to receive instructions and transmit them to the at least one processor; the at least one processor executes the instructions so that the terminal executes the call method described in any one of claims 1-11; or executes the call method described in any one of claims 12-15; or executes the call method described in claim 16.

19. A computer-readable storage medium, characterized in that The method comprises computer instructions, which, when executed on a terminal, cause the terminal to execute the calling method according to any one of claims 1 to 11; or execute the calling method according to any one of claims 12 to 15; or execute the calling method according to claim 16.

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