Voice call method, device, computer-readable storage medium and chip system

Abstract

A method and device for improving the quality of voice calls in EPSFB scenarios are applied to the field of communications, specifically a voice call method, device, computer-readable storage medium and chip system. The method provides an optimization solution for refreshing the resource reservation status, which can solve the problem of silent calls, dropped calls or dropped calls after silence between the calling terminal and the called terminal due to signaling disorder in EPSFB scenarios, effectively improve the success rate of call status refresh in the current scenario, and ensure the normal voice of the terminal in abnormal scenarios.

Description

[0001] This application is a divisional application, the parent case is an invention patent application with application number 202380013243.6, application date May 12, 2023, and invention name “Voice call method, device, computer-readable storage medium and chip system”, as well as claiming priority to a Chinese patent application filed with the State Intellectual Property Office of China on March 3, 2023, with application number 202310252491.8 and application name “Voice call method, device, computer-readable storage medium and chip system”, all contents of which are incorporated by reference in this application. Technical Field

[0002] The present application relates to the field of communications, and in particular, to a communication method, device, computer-readable storage medium, and chip system. Background Art

[0003] Wireless cellular communication network technology has entered the 5G era, and the fifth-generation system (5GS) has begun to provide new radio (NR) access technology. However, some areas do not have time-limited 5G network coverage, and some users are unwilling to use 5G and will turn off the 5G function on their terminal devices, which will cause the terminal devices to fall back from the 5G network to the 4G network. In the process of initiating a phone call between two terminal devices, if the called party falls back from 5G to 4G, it will affect the time to establish the voice bearer, which may cause no sound or automatic hang-up after the call is connected. Summary of the invention

[0004] In view of this, the present application provides a communication method, device, computer-readable storage medium and chip system, which can effectively improve the success rate of call status refresh of terminal equipment during the EPSFB process, avoid the problems of silence on both ends, dropped calls or dropped calls after silence when an abnormality occurs, thereby improving the user experience of the terminal equipment.

[0005] In a first aspect, a communication method is provided, including: a second terminal device receives a first call initiated by a first terminal device; based on the first call, the second terminal device sends a first signaling to the first terminal device, the first signaling includes 200OK and a=curr:qos local sendrecv, and the first signaling is sent before the second terminal device receives the second signaling, the second signaling includes QCI=1; after the second terminal device connects the first call, the second terminal device receives the voice sent by the first terminal device.

[0006] In one implementation, the method further includes: before the second terminal device sends the first signaling to the first terminal device, receiving an UPDATE signaling sent by the first terminal device based on the first call; the first signaling is sent to the first terminal device in response to the UPDATE signaling.

[0007] In one implementation, after receiving the call initiated by the first terminal device and before receiving the first signaling, the second terminal device performs EPS fallback.

[0008] In one implementation, the first signaling is received after the second terminal device completes EPS fallback.

[0009] In one implementation, the method further includes: receiving a first switching instruction before the network standard of the second terminal device is configured as the second network standard; the network standard of the second terminal device is configured as the second network standard in response to the first switching instruction.

[0010] In one implementation, the method further includes: before the second terminal device receives the first switching instruction, in response to the first call initiated by the first terminal device, sending a 100Trying signaling to the first terminal device; the first switching instruction is received based on the 100Trying signaling.

[0011] In a second aspect, a communication method is provided, including: a second terminal device receives a second call initiated by a first terminal device; at a first moment, the second terminal device sends a third signaling to the first terminal device, the third signaling includes 200OK and a=curr:qos local sendrecv, and the third signaling is sent after the second terminal device receives a fourth signaling, and the fourth signaling includes QCI=1; starting from the first moment, after a first time length, after the second terminal device receives the fourth signaling, the second terminal device sends a first 180Ringing signaling to the first terminal device; after the second terminal device rejects the second call, the second terminal device receives the third call initiated by the first terminal device; at a second moment, the second terminal device sends a fifth signaling to the first terminal device, the fifth signaling includes 200OK and a=curr:qos local none, and the fifth signaling is sent before the second terminal device receives a sixth signaling, and the sixth signaling includes QCI=1; starting from the second moment, after a second time length, after the second terminal device receives the sixth signaling, the second terminal device sends a second 180Ringing signaling to the first terminal device, based on the fifth signaling including a=curr:qos local none, the second duration is greater than the first duration; after the second terminal device connects to the third call, the second terminal device receives the voice sent by the first terminal device.

[0012] In one implementation, after the second terminal device sends the fourth signaling to the first terminal device, the method further includes: the second terminal device starts timing, and the second 180Ringing signaling is sent based on the timing duration being greater than the preset duration.

[0013] According to a third aspect, a communication method is provided, including: when a first terminal device initiates a fourth call to a second terminal device, the first terminal device sends a first INVITE signaling to the second terminal device; after receiving the 180Ringing signaling, based on the fourth call, the first terminal device receives a seventh signaling, the seventh signaling including 200OK and a=curr:qos localnone; at a third moment, the fourth call is connected; based on the fourth call being connected, at a fourth moment, the first terminal device sends a second INVITE signaling to the second terminal device, the first INVITE signaling and the second INVITE signaling including the same SIP CallID, the second INVITE signaling including a=sendrecv, and between the third moment and the fourth moment, the first terminal device does not receive the voice sent by the second terminal device; based on the second INVITE signaling, the first terminal device receives a third signaling sent by the second terminal device, the third signaling including 200OK and a=sendrecv; after the first terminal device receives the third signaling, the first terminal device receives the voice sent by the second terminal device.

[0014] In one implementation, before the first terminal device sends the second INVITE signaling to the second terminal device, it also includes: based on the fourth call being connected, the first terminal device sends a third INVITE signaling to the second terminal device, the third INVITE signaling includes a=sendonly information, and the first INVITE signaling and the third INVITE signaling include the same SIP Call ID; based on the third INVITE signaling, the first terminal device receives a fourth signaling sent by the second terminal device, the fourth signaling includes 200OK and a=recvonly.

[0015] In a fourth aspect, a communication method is provided, including: when the second terminal device receives the fourth call initiated by the first terminal device, the second terminal device receives the first INVITE signaling sent by the first terminal device; based on the fourth call, the second terminal device sends a seventh signaling to the first terminal device, and the seventh signaling includes 200OK and a=curr:qos local none; at a third moment, the fourth call is connected; based on the fourth call being connected, at a fifth moment, the second terminal device receives the second INVITE signaling sent by the first terminal device, the first INVITE signaling and the second INVITE signaling include the same SIP Call ID, the second INVITE signaling includes a=sendrecv, and between the third moment and the fifth moment, the second terminal device does not receive the voice sent by the first terminal device; in response to the second INVITE signaling, the second terminal device sends a third signaling to the first terminal device, the third signaling includes 200OK and a=sendrecv; after the second terminal device sends the third signaling, the second terminal device receives the voice sent by the first terminal device.

[0016] In one implementation, before the second terminal device receives the second INVITE signaling sent by the first terminal device, it also includes: based on the fourth call being connected, the second terminal device receives the third INVITE signaling sent by the first terminal device, the third INVITE signaling includes a=sendonly information, and the first INVITE signaling and the third INVITE signaling include the same SIP Call ID; in response to the third INVITE signaling, the second terminal device sends a fourth signaling to the first terminal device, the fourth signaling includes 200OK and a=recvonly.

[0017] In a fifth aspect, a communication device is provided, which includes a processor, an antenna and a memory, the memory is used to store instructions, and the processor is used to execute the instructions stored in the memory to control the antenna to receive or send signals, so that any of the above methods is executed.

[0018] In a sixth aspect, a computer-readable storage medium is provided, which stores a computer-executable program. When the computer-executable program is called by a computer, the computer executes any one of the above methods.

[0019] In a seventh aspect, a chip system is provided, comprising a processor, the processor being configured to execute a computer executable program so that a device equipped with the chip system executes any of the above methods. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is an example diagram of an application scenario of an embodiment of the present application;

[0021] Figure 2 It is a signaling interaction diagram of a voice call in a 5G network in a communication method according to an embodiment of the present application;

[0022] Figure 3 is another signaling interaction diagram of a voice call in an EPSFB scenario of the communication method according to an embodiment of the present application;

[0023] Figure 4 It is a schematic flow chart of a terminal device switching from 5G to 4G voice call in a communication method in an embodiment of the present application;

[0024] Figure 5 is another signaling interaction diagram of a voice call in an EPSFB scenario of the communication method according to an embodiment of the present application;

[0025] Figure 6 is another signaling interaction diagram of a voice call in an EPSFB scenario of the communication method according to an embodiment of the present application;

[0026] Figure 7 is a schematic flow chart of a communication method according to an embodiment of the present application;

[0027] Figure 8 is another signaling interaction diagram of a voice call in an EPSFB scenario of the communication method according to an embodiment of the present application;

[0028] Fig. 9 is another schematic flow chart of a communication method according to an embodiment of the present application;

[0029] Fig.10 is another signaling interaction diagram of a voice call in an EPSFB scenario of the communication method according to an embodiment of the present application;

[0030] Fig.11 is another signaling interaction diagram of a voice call in an EPSFB scenario of the communication method according to an embodiment of the present application;

[0031] Fig.12 is another schematic flow chart of a communication method according to an embodiment of the present application;

[0032] Fig.13 It is a schematic diagram of the composition of an electronic device provided in an embodiment of the present application;

[0033] Fig.14 It is a software architecture block diagram of an electronic device provided in an embodiment of the present application;

[0034] Fig.15 is a schematic block diagram of a communication device provided in an embodiment of the present application;

[0035] Fig.16is a schematic block diagram of another communication device provided in an embodiment of the present application;

[0036] Fig.17 It is a possible schematic structural diagram of a terminal device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0037] The technical solutions in the embodiments of the present application will be described below in conjunction with the accompanying drawings. When the following description refers to the drawings, unless otherwise indicated, the same numbers in different drawings represent the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the present disclosure. Instead, they are merely examples of devices and methods consistent with some aspects of the present disclosure as detailed in the attached claims.

[0038] The terms used in the embodiments of the present application are only for the purpose of describing specific embodiments and are not intended to limit the present disclosure. The singular forms of "a", "said" and "the" used in the present disclosure and the appended claims are also intended to include plural forms unless the context clearly indicates other meanings. "Multiple" can be understood as "at least two"; "multiple" can be understood as "at least two". It should also be understood that the term "and / or" used herein refers to and includes any or all possible combinations of one or more associated listed items.

[0039] It should be understood that although the terms first, second, third, etc. may be used in the present disclosure to describe various information, such information should not be limited to these terms. These terms are only used to distinguish the same type of information from each other. For example, without departing from the scope of the present disclosure, the first information may also be referred to as the second information, and similarly, the second information may also be referred to as the first information. Depending on the context, the word "if" as used herein may be interpreted as "at the time of" or "when" or "in response to determining".

[0040] The technical solution of the embodiment of the present application can be applied to various communication systems, such as: long term evolution (LTE) system, universal mobile telecommunication system (UMTS), worldwide interoperability for microwave access (WiMAX) communication system, fifth generation (5G) system or new radio (NR) and future mobile communication system, vehicle-to-X V2X, where V2X can include vehicle to network (V2N), vehicle to vehicle (V2V), vehicle to infrastructure (V2I), vehicle to pedestrian (V2P), etc., long term evolution technology of vehicle communication (LTE-V), Internet of Vehicles, machine type communication (MTC), Internet of Things (IoT), long term evolution technology of machine communication (LTE-M), machine to machine (LTE-M), etc. Machine, M2M) etc.

[0041] The terminal device of the embodiment of the present application may also be referred to as: user equipment (UE), mobile station (MS), mobile terminal (MT), access terminal, user unit, user station, mobile station, mobile station, remote station, remote terminal, mobile device, user terminal, terminal, wireless communication device, user agent or user device, etc. The terminal device may be a device that provides voice / data connectivity to a user, for example, a handheld device with wireless connection function, a vehicle-mounted device, etc. At present, some examples of terminals are: mobile phones, tablet computers, laptop computers, PDAs, mobile internet devices (MID), wearable devices, virtual reality (VR) devices, augmented reality (AR) devices, wireless terminals in industrial control, wireless terminals equipped with cloud games, wireless terminals in self-driving, wireless terminals in remote medical surgery, wireless terminals in smart grids, wireless terminals in transportation safety, wireless terminals in smart cities, wireless terminals in smart homes, cellular phones, cordless phones, session initiation protocol (SIP) phones, wireless local loop (WLL) stations, personal digital assistants (PDAs), handheld devices with wireless communication functions, computing devices or other processing devices connected to wireless modems, vehicle-mounted devices, wearable devices, terminal devices in 5G networks or future evolved public land mobile communication networks (public land mobile communication networks) Mobile network, PLMN) and the like, but the embodiments of the present application are not limited to this.

[0042] The network referred to in the embodiments of the present application is a general term for the core network and access network equipment responsible for processing voice services, including Internet Protocol (IP) multimedia subsystem (IMS) network and other networks. The IMS network includes the IMS domain core network and the Evolved Packet Core (EPC). The IMS domain core network includes: serving-call session control function (S-CSCF), interrogating-call session control function (I-CSCF), proxy-call session control function (P-CSCF) session border controller (SBC), and several dedicated servers, such as multimedia telephony application server (MMTel AS). Among them, I-CSCF can be combined with S-CSCF, which can be referred to as "I / S-CSCF". SBC and P-CSCF can be combined, which can be referred to as "SBC / P-CSCF". The EPC may include a packet data network gateway (PGW), a serving gateway (SGW) and a mobile management entity (MME). The PGW and SGW may be combined and referred to as "SGW / PGW".

[0043] The above network elements are all corresponding network elements in the IMS network in the prior art. They will not be described in detail here, but only briefly explained. For example: S-CSCF can be used for user registration, authentication control, session routing and service triggering control, and maintain session status information. I-CSCF can be used for the assignment and query of S-CSCF registered by the user. P-CSCF can be used for signaling and message proxy. SBC can provide secure access and media processing. MMTel AS provides basic multimedia telephone services and supplementary services. MME is the core equipment of the EPC network. SGW can be used for the connection between the IMS core network and the wireless network, and PGW can be used for the connection between the IMS core network and the IP network.

[0044] The radio access network (RAN) device is an access device that the terminal device accesses to the mobile communication system by wireless means, which may be a base station NodeB, an evolved base station (eNB), a next generation NodeB (gNB) in a 5G mobile communication system, a transmission point, a base station in a future mobile communication system or an access node in a Wi-Fi system, one or more antenna panels of a base station in a 5G system, or a network node constituting a gNB or a transmission point, such as a baseband unit (BBU), or a distributed unit (DU). The embodiments of the present application do not limit the specific technology and specific device form adopted by the radio access network device. In some deployments, the gNB may include a centralized unit (CU) and a DU, and the CU and the DU respectively implement part of the functions of the gNB. For example, the CU is responsible for processing non-real-time protocols and services, and implementing the functions of the radio resource control (RRC) and the packet data convergence protocol (PDCP) layer. DU is responsible for processing physical layer protocols and real-time services, and implementing the functions of the radio link control (RLC) layer, the media access control (MAC) layer, and the physical (PHY) layer. The gNB may also include an active antenna unit (AAU). The AAU implements some physical layer processing functions, radio frequency processing, and related functions of the active antenna. Since the information of the RRC layer will eventually become the information of the PHY layer, or be converted from the information of the PHY layer, therefore, under this architecture, high-level signaling, such as RRC layer signaling, can also be considered to be sent by the DU, or, sent by the DU+AAU. It should be noted that the network device may be a device including one or more of a CU node, a DU node, and an AAU node. In addition, the CU can be used as a network device in an access network or as a network device in a core network (CN), and this application does not limit this.

[0045] The wireless access network equipment and the terminal equipment can be deployed on land, including indoors or outdoors, handheld or vehicle-mounted; they can also be deployed on the water surface; they can also be deployed on aircraft, balloons and satellites in the air. The embodiments of the present application do not limit the application scenarios of the wireless access network equipment and the terminal equipment. The wireless access network equipment and the terminal equipment, as well as the terminal equipment and the terminal equipment, can communicate through the licensed spectrum (licensed spectrum), or through the unlicensed spectrum (unlicensed spectrum), or through the licensed spectrum and the unlicensed spectrum at the same time. The wireless access network equipment and the terminal equipment, as well as the terminal equipment and the terminal equipment, can communicate through the spectrum below 6 gigahertz (GHz), or through the spectrum above 6G, or use the spectrum below 6G and the spectrum above 6G at the same time. The embodiments of the present application do not limit the spectrum resources used between the wireless access network equipment and the terminal equipment.

[0046] In an embodiment of the present application, a terminal device or a network device includes a hardware layer, an operating system layer running on the hardware layer, and an application layer running on the operating system layer. The hardware layer includes hardware such as a central processing unit (CPU), a memory management unit (MMU), and a memory (also called main memory). The operating system can be any one or more computer operating systems that implement business processing through a process, such as a Linux operating system, a Unix operating system, an Android operating system, an iOS operating system, or a Windows operating system. The application layer includes applications such as a browser, an address book, a word processing software, and an instant messaging software. In addition, the specific structure of the execution subject of the method provided in the embodiment of the present application is specifically limited, as long as it can communicate according to the method provided in the embodiment of the present application by running a program that records the code of the method provided in the embodiment of the present application, for example, the execution subject of the method provided in the embodiment of the present application can be a terminal device or a network device, or a functional module in a terminal device or a network device that can call a program and execute the program.

[0047] In addition, various aspects or features of the present application can be implemented as methods, devices or products using standard programming and / or engineering techniques. The term "product" used in this application covers computer programs that can be accessed from any computer-readable device, carrier or medium. For example, computer-readable media may include, but are not limited to: magnetic storage devices (e.g., hard disks, floppy disks or tapes, etc.), optical disks (e.g., compact discs (CDs), digital versatile discs (DVDs), etc.), smart cards and flash memory devices (e.g., erasable programmable read-only memory (EPROM), cards, sticks or key drives, etc.). In addition, the various storage media described herein may represent one or more devices and / or other machine-readable media for storing information. The term "machine-readable medium" may include, but is not limited to, wireless channels and various other media capable of storing, containing and / or carrying instructions and / or data.

[0048] It should be noted that the explanation of the terms and definitions of signaling and terminology in this application can also refer to the explanations in the third generation partnership project (3GPP) standard protocol, such as 24.229, RFC3261 and RFC3262. The uppercase and lowercase letters and spaces of the signaling in this application are only examples, and the specific provisions in the standard protocol shall prevail.

[0049] Reference Figure 1 , which is an example diagram of an application scenario of an embodiment of the present application. Figure 1 The process of user A using the first terminal device 140 and user B using the second terminal device 150 for a call is illustrated. During the call, the second terminal device 150 falls back from the 5G network to the 4G network, which ultimately causes the call to be silent, dropped, or silent and then dropped. The first terminal device 140 is configured with a first SIM card, and the second terminal device 150 is configured with a second SIM card. The first SIM card corresponds to the first phone number, and the second SIM card corresponds to the second phone number. The operator of the first SIM card is different from the operator of the second SIM card, but in other cases, the operator of the first SIM card and the operator of the second SIM card may also be the same, and the embodiment of the present application does not limit the operator of the SIM card.

[0050] Exemplarily, the first terminal device 140 is connected to the first radio access network device 110 wirelessly. The first radio access network device 110 refers to a base station that the first terminal device 140 accesses when a certain condition is met, rather than a specific base station. The first radio access network device 110 may be a gNB base station, an eNB base station, or other base stations that the first terminal device 140 should access under certain conditions. Specifically, when the network in which the second terminal device 150 is located switches from 5G to 4G, the first radio access network device 110 may not be switched, or it may be switched to meet specific network requirements. For simplicity and ease of understanding, the specific information of the base station accessed by the first terminal device 140 and the switching process are described in detail in the following sections. Figure 1 It is not shown in the figure, but the first radio access network device 110 is used as an example.

[0051] Exemplarily, the second terminal device 150 is connected to the second wireless access network device 120 and the exemplary 5G core network device 102 in a wireless manner, or the second terminal device 150 is connected to the third wireless access network device 130 and the exemplary 4G core network device 101 in a wireless manner. The first wireless access network device 110 interacts with the exemplary 5G core network device 102 or the exemplary 4G core network device 101. The second wireless access network device 120 and the third wireless access network device 130 can be gNB base stations, eNB base stations, or other base stations that the second terminal device 150 should access under certain conditions, depending on the network situation where the second terminal device 150 resides. Specifically, when the network where the second terminal device 150 resides switches from 5G to 4G, the second terminal device 150 switches from interacting with the second wireless access network device 120 to interacting with the third wireless access network device 130. In combination Figure 1 , the network accessed by the second wireless access network device 120 is a 5G network, and the network accessed by the third wireless access network device 130 is a 4G network. When the second terminal device 150 is connected to the second wireless access network device 120 and the exemplary 5G core network device 102 by wireless means, the 5G core network accessed by the second terminal device 150 is the first core network. When the second terminal device 150 is connected to the third wireless access network device 130 and the exemplary 4G core network device 101 by wireless means, the 4G core network accessed by the second terminal device 150 is the second core network.

[0052] For the sake of simplicity and ease of understanding, the specific information of the base station accessed by the second terminal device 150 and the switching process are as follows: Figure 1 The first wireless access network device 110 is not shown in the figure, but is exemplarily represented by the second wireless access network device 120 and the third wireless access network device 130. For simplicity and ease of understanding, the interaction between the first wireless access network device 110 and the exemplary 5G core network device 102 or the exemplary 4G core network device 101 is shown in FIG. Figure 1 The signaling transmission interaction process, voice bearer establishment process, etc. involved above are not limited to the interaction between the terminal device and the base station device, and the interaction between the base station devices, but should also include other network devices in the mobile communication system. For the sake of simplicity and ease of understanding, Figure 1 Not drawn in.

[0053] It should be noted that the core network device and the wireless access network device can be independent and different physical devices, or the functions of the core network device and the logical functions of the wireless access network device can be integrated on the same physical device, or the functions of some core network devices and some wireless access network devices can be integrated on one physical device. The terminal device can be fixed or movable. The first terminal device 140 and the second terminal device 150 can interact with the wireless access network device and the core network device as user equipment. The wireless access network device includes but is not limited to 2G wireless access network, 3G wireless access network, 4G wireless access network, and 5G wireless access network. The core network device includes but is not limited to 2G core network, 3G core network, 4G core network, and 5G core network.

[0054] It should be noted that Figure 1 The communication system architecture in the embodiment of the present application is for illustration only. The above description does not constitute a limitation on the call test system architecture diagram of the embodiment of the present application. The mobile communication system applied in the embodiment of the present application includes but is not limited to the following: Figure 1 The signaling transmission interaction process, the voice bearer establishment process and other processes involved in the embodiments of the present application are not limited to the interaction between the terminal device and the wireless access network device, but should also include other network devices in the mobile communication system, such as the core network device. Figure 2-Figure 11 The first wireless access network device 110, the second wireless access network device 120, and the third wireless access network device 130 include, but are not limited to, a 4G long term evolution (4G-Long Term Evolution, 4G-LET) base station or a 5G new air interface (5G-New Radio, 5G-NR) base station. The embodiments of the present application do not limit the number and supplier of core network devices, wireless access network devices, and terminal devices included in the mobile communication system. The wireless access network device can be Figure 1 The first wireless access network device 110, the second wireless access network device 120, and the third wireless access network device 130 may also refer to devices in the access network device. The interaction between the first wireless access network device 110, the second wireless access network device 120, or the third wireless access network device 130 is not limited to the interaction between the calling side wireless access network device, the core network device and the called side wireless access network device, the core network device, but should be the entire interaction process between the calling side network and the called side network. Figure 1 Part or all of the information exchanged between the terminal device and the core network device or access network device may be carried in existing messages, channels, signals or signaling, or may be newly defined messages, channels, signals or signaling, without any specific limitation.

[0055] exist Figure 1 In the scenario shown, user A uses the first terminal device 140, user B uses the second terminal device 150, user A's phone number is the first phone number, and user B's phone number is the second phone number. The first SIM card corresponds to the first phone number, and the second SIM card corresponds to the second phone number. Figure 1 As shown, user A uses the first terminal device 140 to dial the phone number of user B. At this time, the first terminal device 140 and the second terminal device 150 are both resident in the 5G network. It should be noted that in the embodiment of the present application, the resident network refers to the network that the terminal device is currently registered based on the SIM card.

[0056] During the dialing process, before the second terminal device 150 enters the ringing state or starts ringing, the network where the second terminal device 150 resides falls back from 5G to 4G. Exemplarily, after the first terminal device 140 dials, the second terminal device 150 falls back to the 4G network because the currently residing 5G network supports IMS registration (IMS registration) locally but does not support 5G voice service (Voiceover NR). Alternatively, the second terminal device 150 supports the 5G network, but the user turns off the 5G voice call function. After the first terminal device 140 dials, the network where the second terminal device 150 resides will also fall back from the 5G network to the 4G network. Optionally, when the second terminal device 150 receives a voice call from user A on a 5G network that does not support the telephone voice service function, or when user B receives a call from user A on a 5G network that supports the telephone voice service function using a second terminal device 150 that does not support the 5G voice call function, the network of the second terminal device 150 falls back from the 5G network to the 4G network. In this case, the 4G network carries the voice service of the second terminal device 150. When the voice call ends, the second terminal device 150 returns to the 5G network. This process is called the evolved packet system (EPS) fallback (EPS Fallback, EPSFB) process. The evolved packet system fallback process can also be called EPSFallback, EPSFB, EPSFallback, EPS fallback, EPS fallback, etc.

[0057] Combination Figure 1During a 4G voice call, in order to prevent the problem of silence, call drop or call drop after silence due to the failure to establish a voice bearer after answering the call, the terminal device will negotiate resource reservation with the network in advance during the call establishment process, that is, complete the establishment of the voice bearer before user B can feel the ringing, and synchronize the voice bearer status between the first terminal device 140 and the second terminal device 150 through the resource reservation negotiation process. When the voice bearer status of both parties is ready and enters the state where voice packets can be sent and received, the first terminal device 140 sends 180Ringing signaling to the second terminal device 150, and the call status of the second terminal device 150 is updated to the ringing state, and the second terminal device 150 starts ringing.

[0058] It should be noted that the phrases "the voice bearer has been established", "the voice bearer is established" and the like in this application mean "the voice bearer has been established". The ringing state in this application refers to the state in which when there is an incoming call and the user has not answered the call, the called party's terminal device rings to remind the user of the incoming call. The ringing tone at the beginning of the ringing includes: vibration, color ringback tone, beep, personalized music, songs, recordings, videos, etc., which are not limited here. When the called party's terminal device is ringing, the calling terminal device can display information such as "the other party is ringing" to prompt the calling party user that the called party's terminal device has started ringing.

[0059] Because the second terminal device 150 falls back from the 5G network to the 4G network, the second terminal device 150 completes the establishment of the voice bearer later than normal after receiving the call from the first terminal device 140. When the voice bearer of the first terminal device 140 is established, the voice bearer of the second terminal device 150 has not yet been established. The second terminal device 150 will send a signaling to the first terminal device 140 indicating that the voice bearer of the second terminal device 150 has not been established, and will also send a signaling for instructing the first terminal device 140 to play a ringback tone. After the first terminal device 140 receives the signaling for instructing the first terminal device 140 to play the ringback tone, the first terminal device 140 starts to play the ringback tone, and the second terminal device 150 starts to ring after sending the signaling for instructing the first terminal device 140 to play the ringback tone. After the second terminal device 150 starts to ring, user B answers the call, and the call between the first terminal device 140 and the second terminal device 150 is connected. If, due to network compatibility issues, some core network operators fail to refresh the resource reservation status normally during the voice bearer establishment process, the voice bearer of the terminal device is normal, but the core network where the terminal device or another terminal device in conversation with it resides is not synchronized in the state of sending and receiving voice packets, or there is a synchronization abnormality. Under normal circumstances, if the voice bearer of a terminal device of a certain party has not been established due to problems on the terminal side or the network side, the called terminal will not enter the ringing state to prevent the problem of silence after answering, dropped calls, or dropped calls after silence. However, some abnormal signaling disorder may cause the problem that the voice bearer of the terminal device has been established but the network side is still abnormal, resulting in silence after the call is connected, dropped calls, or dropped calls after silence, which seriously affects the user experience. For example, in the above scenario, if the network side receives the signaling for instructing the first terminal device 140 to play the ringback tone, and then receives the signaling of the second terminal device 150 that the voice bearer has not been established, it will cause the problem of silence after answering the call, dropped calls, or dropped calls after silence.

[0060] refer to Figure 2 As shown, Figure 2 The following is a signaling interaction diagram for describing a voice call in a 5G network according to an embodiment of the present application. Figure 1 As shown, the communication method described in the embodiment of the present application is applied to Figure 1 and Figure 2 The first terminal device 140, the second terminal device 150, the first radio access network device 110 and the second radio access network device 120 are shown.

[0061] Optionally, in some embodiments, during the process of the first terminal device 140 making a call to the second terminal device 150, no EPSFB process occurs, the first terminal device 140 can establish a session with the second terminal device 150 normally, and the user can answer the call normally. Figure 2 As shown, the steps are as follows:

[0062] Step S201: The first terminal device 140 sends an INVITE signaling to the second terminal device 150.

[0063] It should be noted that, combined with Figure 1 In the scenario shown, when user A dials user B's number on the first terminal device 140 , the first terminal device 140 initiates a call to the second terminal device 150 .

[0064] Optionally, when user A dials the number of user B on the first terminal device 140 , the first terminal device 140 sends an INVITE signaling to the second terminal device 150 .

[0065] Optionally, in response to user A dialing the number of user B on the first terminal device 140 , the first terminal device 140 sends an INVITE signaling to the second terminal device 150 .

[0066] The INVITE signaling may be first request information, and the INVITE signaling may indicate that the first terminal device 140 has initiated a call to the second terminal device 150 .

[0067] Optionally, the first terminal device 140 can send an INVITE signaling to the first wireless access network device 110. After receiving the INVITE signaling, the first wireless access network device 110 sends the INVITE signaling received from the first terminal device 140 to the second wireless access network device 120. After the second wireless access network device 120 receives the INVITE signaling, the second wireless access network device 120 sends the INVITE signaling received from the first wireless access network device 110 to the second terminal device 150.

[0068] The embodiment of the present application does not limit the timing when the first terminal device sends the first request information. For example, the first terminal device sends the first request information when the calling user initiates a voice call.

[0069] Optionally, after receiving the INVITE signaling, the second terminal device 150 can confirm that the first terminal device 140 supports resource reservation based on the information contained in the INVITE signaling that the first terminal device 140 supports resource reservation. It should be noted that the support field in the INVITE signaling carries a precondition tag, and the precondition tag indicates that the first terminal device 140 supports resource reservation. After receiving the INVITE signaling, the second terminal device 150 can also determine whether it supports resource reservation. After confirming that the second terminal device 150 supports resource reservation, the second terminal device 150 can also confirm its own call status. When the terminal state CALL_STATE of the current second terminal device 150 is the IN_CALL state in a call and the radio access technology (RAT) of the network where the second terminal device 150 resides is NR, it indicates that the second terminal device 150 is in a call process and the call is received under the 5G network.

[0070] Step S202: The second terminal device 150 sends a 100Trying signaling to the first terminal device 140.

[0071] The 100Trying signaling may be the first response information, and the 100Trying signaling may indicate that the second terminal device 150 responds to the INVITE signaling sent by the first terminal device 140 to the second terminal device 150 .

[0072] Optionally, the second terminal device 150 may send a 100Trying signaling to the second radio access network device 120. After receiving the 100Trying signaling, the second radio access network device 120 sends the 100Trying signaling received from the second terminal device 150 to the first radio access network device 110. After the first radio access network device 110 receives the 100Trying signaling, the first radio access network device 110 sends the 100Trying signaling received from the second radio access network device 120 to the first terminal device 140.

[0073] Step S203: The second radio access network device 120 sends a voice dedicated bearer establishment instruction to the second terminal device 150.

[0074] The dedicated bearer establishment instruction for voice includes QCI=1. The dedicated bearer establishment instruction for voice may be expressed as an Activate dedicated EPS bearer context request. The dedicated bearer establishment instruction for voice may be a second voice bearer establishment instruction, which may instruct the second terminal device 150 to establish a second voice bearer, and the second voice bearer indicates that the voice resources of the second terminal device 150 have been reserved. The second voice bearer may be a logical path for transmitting voice.

[0075] Optionally, step S203 is performed after the second radio access network device 120 receives the 100Trying signaling. After the second radio access network device 120 receives the 100Trying signaling, the second radio access network device 120 sends a voice dedicated bearer establishment instruction to the second terminal device 150. After the second radio access network device 120 sends the voice dedicated bearer establishment instruction to the second terminal device 150, the second radio access network device 120 instructs the second terminal device 150 to establish a second voice bearer.

[0076] The embodiment of the present application does not limit the specific state of voice resource reservation for the second voice bearer. In the embodiment of the present application, the establishment of the second voice bearer by the terminal device can be understood as the resource reservation state being in a normal state, that is, the terminal device is in a state where voice packets can be sent and received. The embodiment of the present application does not limit the specific time when the second wireless access network device 120 sends a voice dedicated bearer establishment instruction to the second terminal device 150, that is, step S203 can occur at other times after the second wireless access network device 120 in step S202 receives the 100Trying signaling. The specific implementation can refer to the 3GPP standard protocol and other related protocols.

[0077] Step S204 : The first radio access network device 110 sends a voice dedicated bearer establishment instruction to the first terminal device 140 .

[0078] The dedicated bearer establishment instruction for voice includes QCI=1. The dedicated bearer establishment instruction for voice may be expressed as an Activate dedicated EPS bearer context request. The dedicated bearer establishment instruction for voice may be a first voice bearer establishment instruction, which may instruct the first terminal device 140 to establish a first voice bearer, wherein the first voice bearer indicates that the voice resources of the first terminal device 140 have been reserved. The first voice bearer may be a logical path for transmitting voice.

[0079] Optionally, step S204 is performed after the first radio access network device 110 receives the 100Trying signaling. After the first radio access network device 110 receives the 100Trying signaling, the first radio access network device 110 sends a voice dedicated bearer establishment instruction to the first terminal device 140. After the first radio access network device 110 sends a voice dedicated bearer establishment instruction to the first terminal device 140, the first radio access network device 110 instructs the first terminal device 140 to establish a first voice bearer.

[0080] The embodiment of the present application does not limit the specific state of voice resource reservation for the first voice bearer. In the embodiment of the present application, the establishment of the first voice bearer by the terminal device can be understood as the resource reservation state being in a normal state, that is, the terminal device is in a state where voice packets can be sent and received. The embodiment of the present application does not limit the specific time when the first wireless access network device 110 sends a voice dedicated bearer establishment instruction to the first terminal device 140, that is, step S204 can occur at other times after the first wireless access network device 110 in step S202 receives the 100Trying signaling. The specific implementation can refer to the 3GPP standard protocol and other related protocols.

[0081] Step S205 : The second terminal device 150 sends a 183 Session Progress signaling to the first terminal device 140 .

[0082] 183 Session Progress signaling may be first session progress information, including the first handshake information in a three-way handshake (including the first handshake, the second handshake and the third handshake) between the second terminal device and the first terminal device. 183 Session Progress signaling may indicate that the second terminal device 150 negotiates the voice coding with the first terminal device 140.

[0083] Optionally, after the second terminal device 150 sends the 100Trying signaling to the second radio access network device 120, the second terminal device 150 sends the 183Session Progress signaling to the second radio access network device 120, and after the second radio access network device 120 receives the 183Session Progress signaling. The second radio access network device 120 sends the 183Session Progress signaling received from the second terminal device 150 to the first radio access network device 110. After the first radio access network device 110 receives the 183Session Progress signaling, the first radio access network device 110 sends the 183Session Progress signaling received from the second radio access network device 120 to the first terminal device 140.

[0084] Step S206 : The first terminal device 140 sends a PRACK signaling to the second terminal device 150 .

[0085] The PRACK signaling may be first confirmation information, and the first confirmation information includes the second handshake information in the three-way handshake. The PRACK signaling may indicate that the first terminal device 140 confirms that the 183 Session Progress signaling sent by the second terminal device 150 has been received.

[0086] Optionally, after the first terminal device 140 receives the 183Session Progress signaling, the first terminal device 140 sends a PRACK signaling to the first radio access network device 110. After the first radio access network device 110 receives the PRACK signaling, the first radio access network device 110 sends the PRACK signaling received from the first terminal device 140 to the second radio access network device 120. After the second radio access network device 120 receives the PRACK signaling, the second radio access network device 120 sends the PRACK signaling received from the first radio access network device 110 to the second terminal device 150.

[0087] Step S207 : The second terminal device 150 sends a 200 OK (PRACK) signaling to the first terminal device 140 .

[0088] It should be noted that the signaling sent at this time is actually a 200OK signaling for replying to the PRACK signaling. In the embodiment of the present application, in order to facilitate expression and distinguish different 200OK signalings, the signaling to be replied is marked with brackets after the 200OK signaling for replying to different signalings for distinction. The 200OK signaling for replying to the PRACK signaling is written as 200OK (PRACK) signaling here, but the writing here is only for example, and the specific expression of the actual sent signaling shall be subject to the 3GPP standard protocol. Other 200OK signaling with double brackets in this application can also refer to this explanation.

[0089] The 200OK (PRACK) signaling may be the first 200OK signaling, and the 200OK (PRACK) signaling may be the first response information, and the first response information includes the third handshake information in the three-way handshake. The 200OK (PRACK) signaling may indicate that the second terminal device 150 confirms that the PRACK signaling sent by the first terminal device 140 has been received.

[0090] Optionally, after the second terminal device 150 receives the PRACK signaling, the second terminal device 150 sends a 200OK (PRACK) signaling to the second radio access network device 120. After the second radio access network device 120 receives the 200OK (PRACK) signaling, the second radio access network device 120 sends the 200OK (PRACK) signaling received from the second terminal device 150 to the first radio access network device 110. After the first radio access network device 110 receives the 200OK (PRACK) signaling, the first radio access network device 110 sends the 200OK (PRACK) signaling received from the second radio access network device 120 to the first terminal device 140.

[0091] Step S208 : The first terminal device 140 sends an UPDATE signaling to the second terminal device 150 .

[0092] The UPDATE signaling may be first update information, and the UPDATE signaling may indicate that the first terminal device 140 has established the first voice bearer, that is, the first voice bearer has completed establishment or the first voice bearer has been established.

[0093] Optionally, after the first terminal device 140 receives the 200OK (PRACK) signaling, the first terminal device 140 checks whether it has established the first voice bearer, that is, the first voice bearer has been established or the first voice bearer has been established. After the first terminal device 140 confirms that it has received the voice dedicated bearer establishment instruction issued by the first radio access network device 110 in step S203, and has completed the establishment of the first voice bearer according to the voice dedicated bearer establishment instruction, it sends an UPDATE signaling to the first radio access network device 110, and the UPDATE signaling includes information indicating that the first terminal device 140 has established the first voice bearer. After the first radio access network device 110 receives the UPDATE signaling, it sends the UPDATE signaling to the second radio access network device 120. After the second radio access network device 120 receives the UPDATE signaling, it sends the UPDATE signaling to the second terminal device 150.

[0094] After step S208, if the second terminal device 150 has not completed the establishment of the second voice bearer, the second terminal device 150 responds to the UPDATE signaling and returns a signaling indicating that the second voice bearer has not been established to the first terminal device 140. In some embodiments, the information indicating that the second voice bearer has not been established is carried in the 200OK (UPDATE) signaling and sent to the first terminal device 140. After step S208, if the second terminal device 150 has completed the establishment of the second voice bearer, the 200OK (UPDATE) signaling may carry information indicating that the second voice bearer has been established.

[0095] For example, in combination Figure 2 As shown, the situation where the second terminal device 150 has completed the establishment of the second voice bearer after step S208 is described:

[0096] Step S209 : The second terminal device 150 sends a 200 OK (UPDATE) signaling to the first terminal device 140 .

[0097] The 200 OK (UPDATE) signaling may be a second 200 OK signaling. The 200 OK (UPDATE) signaling may indicate that the second terminal device 150 confirms that the UPDATE signaling sent by the first terminal device 140 has been received.

[0098] It should be noted that the signaling sent at this time is actually a 200OK signaling for replying to the UPDATE signaling. In the embodiment of the present application, in order to facilitate expression and distinguish different 200OK signaling, the signaling to which it replies is marked in brackets after the 200OK signaling for replying to different signalings for distinction. Here, the 200OK signaling for replying to the UPDATE signaling is written as 200OK (UPDATE) signaling, but the writing here is only for example, and the specific expression of the actual sent signaling shall be subject to the 3GPP standard protocol. Other 200OK (UPDATE) signaling in this application can also refer to this explanation.

[0099] Optionally, after receiving the UPDATE signaling, the second terminal device 150 checks the voice bearer status of the second terminal device 150. Since the second terminal device 150 confirms that it has received the voice dedicated bearer establishment instruction issued by the second radio access network device 120, and the second voice bearer is established, the 200OK (UPDATE) signaling sent by the second terminal device 150 to the second radio access network device 120 contains a = curr: qos local sendrecv information, and the a = curr: qos local sendrecv information is the syntax of the SDP protocol. Optionally, the 200OK (UPDATE) signaling can indicate that the voice bearer resources of the second terminal device 150 have been configured or the second voice bearer has been established. Optionally, the 200OK (UPDATE) signaling can indicate that the second terminal device 150 is in a state where voice packets can be sent and received. After the second radio access network device 120 receives the 200OK (UPDATE) signaling containing the information a=curr:qos local sendrecv from the second terminal device 150, the 200OK (UPDATE) signaling is sent to the first radio access network device 110. Based on the fact that the first radio access network device 110 has received the 200OK (UPDATE) signaling containing the information a=curr:qos local sendrecv, the first radio access network device 110 determines that the current called terminal device, i.e., the second terminal device 150, is in a state where voice packets can be sent and received. The first radio access network device 110 is in an on state, i.e., a state where voice packets can be forwarded normally. After the first radio access network device 110 receives the 200OK (UPDATE) signaling containing the information a=curr:qos local sendrecv, the 200OK (UPDATE) signaling is sent to the first terminal device 140.

[0100] Step S210 : The second terminal device 150 sends a 180Ringing signaling to the first terminal device 140 .

[0101] The 180Ringing signaling may be the first ringing information, and the 180Ringing signaling may indicate that the second terminal device 150 has established the second voice bearer and is ready to make a call.

[0102] Optionally, after the second terminal device 150 sends the 180Ringing signaling, the call state of the second terminal device 150 is updated to the ringing state, and the second terminal device 150 starts ringing. The ringing state refers to the state in which when there is an incoming call, the user has not answered the call, and the called party terminal device rings to remind the user of the incoming call; the ringing tone when the ringing starts includes: vibration, color ringback tone, beep, personalized music, song, recording, video, etc., which are not limited here. After the second wireless access network device 120 receives the 180Ringing signaling, the second wireless access network device 120 sends the 180Ringing signaling to the first wireless access network device 110. After the first wireless access network device 110 receives the 180Ringing signaling, the first wireless access network device 110 determines that the current called terminal, i.e., the second terminal device 150, is in a state where voice packets can be sent and received, and the first wireless access network device 110 is set to a connected state, i.e., a state where voice packets can be forwarded normally, and sends the 180Ringing signaling to the first terminal device 140. After the first terminal device 140 receives the 180Ringing signaling, the call state of the first terminal device 140 is updated to a ringback tone state, and the first terminal device 140 starts to play the ringback tone. The ringback tone state refers to the state where, when the call is successful but the called user does not answer the call, the calling party terminal device sends a ringback tone to remind the user that the called user has not answered the call; the ringback tone includes: vibration, color ringback tone, beep, personalized music, song, recording, video, etc., which are not limited here.

[0103] Step S211 : the second terminal device 150 sends a 200 OK (INVITE) signaling to the first terminal device 140 .

[0104] It should be noted that, combined with Figure 1 In the scenario shown, after the second terminal device 150 starts ringing, user B answers the call on the second terminal device 150 .

[0105] Optionally, when user B answers the call on the second terminal device 150 , the second terminal device 150 sends a 200 OK (INVITE) signaling to the first terminal device 140 .

[0106] Optionally, in response to user B answering the call on the second terminal device 150 , the second terminal device 150 sends a 200 OK (INVITE) signaling to the first terminal device 140 .

[0107] The 200 OK (INVITE) signaling may be the third 200 OK signaling, and the 200 OK (INVITE) signaling may indicate that the second terminal device 150 responds to the first terminal device 140 that it is ready to send and receive voice packets.

[0108] Optionally, after the second terminal device 150 starts ringing, user B answers the call, and the second terminal device 150 sends a 200 OK (INVITE) signaling to the second radio access network device 120. The second radio access network device 120 sends the 200 OK (INVITE) signaling received from the second terminal device 150 to the first radio access network device 110. After the first radio access network device 110 receives the 200 OK (INVITE) signaling, the first radio access network device 110 sends the 200 OK (INVITE) signaling received from the second radio access network device 120 to the first terminal device 140. After the first terminal device 140 receives the 200 OK (INVITE) signaling, the first terminal device 140 displays that the call is connected. Specifically, the first terminal device 140 can display user prompts such as: "Phone call in progress", "Call in progress", "Calling in progress", "Connected" to the user. In general, a call time prompt can also be added, such as "00:01", "00:02", "00:03", etc.

[0109] It should be noted that the first terminal device 140 displays that the call is connected at a time point that may be in step S211: after the first terminal device 140 receives the 200OK (INVITE) signaling, and in step S212: before the first terminal device 140 sends an ACK signaling to the second terminal device 150; or in step S212: after the first terminal device 140 sends an ACK signaling to the second terminal device 150. This embodiment of the present application does not limit this time point.

[0110] Step S212: The first terminal device 140 sends an ACK signaling to the second terminal device 150.

[0111] The ACK signaling may be second confirmation information, and the ACK signaling may indicate that the first terminal device 140 confirms to the second terminal device 150 that it has received the 200 OK (INVITE) signaling sent by the second terminal device 150 to the first terminal device 140 .

[0112] Optionally, after the first terminal device 140 receives the 200OK (INVITE) signaling, the first terminal device 140 sends an ACK signaling to the first radio access network device 110. The first radio access network device 110 sends the ACK signaling received from the first terminal device 140 to the second radio access network device 120. After the second radio access network device 120 receives the ACK signaling, the second radio access network device 120 sends the received ACK signaling to the second terminal device 150.

[0113] Step S213 : the second terminal device 150 sends a first voice packet to the first terminal device 140 .

[0114] The first voice packet may be IMS RTP SN and Payload. The first voice packet may be voice data.

[0115] Optionally, after the second terminal device sends the 200OK (INVITE) signaling, the second terminal device 150 sends the first voice packet to the second radio access network device 120. The second radio access network device 120 sends the first voice packet received from the second terminal device 150 to the first radio access network device 110. After the first radio access network device 110 receives the first voice packet, it sends the first voice packet to the first terminal device 140, and after the first terminal device 140 receives the first voice packet, it plays the voice.

[0116] It should be noted that the embodiment of the present application does not limit the timing of the second terminal device 150 sending the first voice packet to the first wireless access network device 110. For example, after the second terminal device sends the 200OK (INVITE) signaling, the second terminal device 150 sends the first voice packet to the first wireless access network device 110; or, after the second terminal device receives the ACK signaling, the second terminal device 150 sends the first voice packet to the first wireless access network device 110.

[0117] Step S214 : the first terminal device 140 sends a second voice packet to the second terminal device 150 .

[0118] The second voice packet may be IMS RTP SN and Payload. The second voice packet may be voice data.

[0119] Optionally, after the first terminal device 140 sends the ACK signaling, or after the first terminal device 140 receives the 200OK (INVITE) signaling, the first terminal device 140 sends the second voice packet to the first radio access network device 110. After the first radio access network device 110 receives the second voice packet, the second voice packet is sent to the second radio access network device 120. After the second radio access network device 120 receives the second voice packet, the second voice packet is sent to the second terminal device 150, and after the second terminal device 150 receives the second voice packet, the voice is played.

[0120] It should be noted that the embodiment of the present application does not limit the timing of the first terminal device 140 sending the second voice packet to the first wireless access network device 110. Steps S214 and S215 have no mutual trigger relationship and sequence, and the order of the two can be interchanged. During a call, the voice packets exchanged between the calling terminal device and the called terminal device are not limited to the first voice packet and the second voice packet. The embodiment of the present application will not be repeated, and the first voice packet and the second voice packet are only used as an example to represent the interaction process of the user voice packets between the calling and called terminal devices during the call.

[0121] Therefore, in a possible normal 5G call scenario, users can make voice calls normally.

[0122] refer to Figure 3 As shown, Figure 3 This is a diagram for describing a normal voice call signaling interaction in an EPSFB scenario according to an embodiment of the present application. Figure 1 As shown, the communication method described in the embodiment of the present application is applied to Figure 1 and Figure 3 The first terminal device 140, the second terminal device 150, the first wireless access network device 110, the second wireless access network device 120 and the third wireless access network device 130 are shown. Figure 1 , the first terminal device 140 and the second terminal device 150 are wirelessly connected to the first wireless access network device 110 and the second wireless access network device 120 or the third wireless access network device 130. The first wireless access network device 110 and the second wireless access network device 120 or the third wireless access network device 130 are wirelessly or wiredly connected to the corresponding core network devices and other network devices, which are not shown in the figure.

[0123] Optionally, in some embodiments, during the process of the first terminal device 140 making a call to the second terminal device 150, even if the EPSFB process occurs, there is no disorder in the signaling interaction, the first terminal device 140 can establish a session with the second terminal device 150 normally, and the user can answer the call normally. Figure 3 As shown, the steps are as follows:

[0124] Step S301: The first terminal device 140 sends an INVITE signaling to the second terminal device 150.

[0125] It should be noted that, combined with Figure 1 In the scenario shown, when user A dials user B's number on the first terminal device 140 , the first terminal device 140 initiates a call to the second terminal device 150 .

[0126] Optionally, when user A dials the number of user B on the first terminal device 140 , the first terminal device 140 sends an INVITE signaling to the second terminal device 150 .

[0127] Optionally, in response to user A dialing the number of user B on the first terminal device 140 , the first terminal device 140 sends an INVITE signaling to the second terminal device 150 .

[0128] The INVITE signaling may be first request information, and the INVITE signaling may indicate that the first terminal device 140 has initiated a call to the second terminal device 150 .

[0129] The INVITE signaling may be the first INVITE signaling, and the INVITE signaling may be signaling including invite.

[0130] Optionally, the first terminal device 140 may send an INVITE signaling to the first wireless access network device 110. After receiving the INVITE signaling, the first wireless access network device 110 sends the INVITE signaling received from the first terminal device 140 to the second wireless access network device 120. After the second wireless access network device 120 receives the INVITE signaling, the second wireless access network device 120 sends the INVITE signaling received from the first wireless access network device 110 to the second terminal device 150.

[0131] The embodiment of the present application does not limit the timing when the first terminal device sends the first request information. For example, the first terminal device sends the first request information when the calling user initiates a voice call.

[0132] Optionally, after receiving the INVITE signaling, the second terminal device 150 can confirm that the first terminal device 140 supports resource reservation based on the information contained in the INVITE signaling that the first terminal device 140 supports resource reservation. It should be noted that the support field in the INVITE signaling carries a precondition tag, and the precondition tag indicates that the first terminal device 140 supports resource reservation. After receiving the INVITE signaling, the second terminal device 150 can also determine whether it supports resource reservation. After confirming that the second terminal device 150 supports resource reservation, the second terminal device 150 can also confirm its own call status. When the terminal state CALL_STATE of the current second terminal device 150 is the IN_CALL state in a call and the radio access technology (RAT) of the network where the second terminal device 150 resides is NR, it indicates that the second terminal device 150 is in a call process and the call is received under the 5G network.

[0133] Step S302: The second terminal device 150 sends a 100Trying signaling to the first terminal device 140.

[0134] The 100Trying signaling may be the first response information, and the 100Trying signaling may indicate that the second terminal device 150 responds to the INVITE signaling sent by the first terminal device 140 to the second terminal device 150 .

[0135] Optionally, the second terminal device 150 may send a 100Trying signaling to the second radio access network device 120. After receiving the 100Trying signaling, the second radio access network device 120 sends the 100Trying signaling received from the second terminal device 150 to the first radio access network device 110. After the first radio access network device 110 receives the 100Trying signaling, the first radio access network device 110 sends the 100Trying signaling received from the second radio access network device 120 to the first terminal device 140.

[0136] Step S303 : The first radio access network device 110 sends a voice dedicated bearer establishment instruction to the first terminal device 140 .

[0137] The voice dedicated bearer establishment instruction includes QCI=1 information, and the voice dedicated bearer establishment instruction can be expressed as an Activate dedicated EPS bearer context request. The voice dedicated bearer establishment instruction can be a first voice bearer establishment instruction, and the voice dedicated bearer establishment instruction can instruct the first terminal device 140 to establish a first voice bearer, and the first voice bearer indicates that the voice resources of the first terminal device 140 have been reserved. The first voice bearer can be a logical path for transmitting voice.

[0138] Optionally, step S204 is performed after the first radio access network device 110 receives the 100Trying signaling. After the first radio access network device 110 receives the 100Trying signaling, the first radio access network device 110 sends a voice dedicated bearer establishment instruction to the first terminal device 140. After the first radio access network device 110 sends the voice dedicated bearer establishment instruction to the first terminal device 140, the first radio access network device 110 instructs the first terminal device 140 to establish a first voice bearer.

[0139] The embodiment of the present application does not limit the specific state of voice resource reservation for the first voice bearer. In the embodiment of the present application, the establishment of the first voice bearer by the terminal device can be understood as the resource reservation state being in a normal state, that is, the terminal device is in a state where it can perform subsequent sending and receiving of voice packets. The embodiment of the present application does not limit the specific time when the first wireless access network device 110 sends a voice dedicated bearer establishment instruction to the first terminal device 140, that is, step S204 can occur at other times after the first wireless access network device 110 in step S202 receives the 100Trying signaling. The specific implementation can refer to the 3GPP standard protocol and other related protocols.

[0140] Step S304 : The second terminal device 150 sends a 183 Session Progress signaling to the first terminal device 140 .

[0141] 183 Session Progress signaling may be first session progress information, including the first handshake information in a three-way handshake (including the first handshake, the second handshake and the third handshake) between the second terminal device and the first terminal device. 183 Session Progress signaling may indicate that the second terminal device 150 negotiates the voice coding with the first terminal device 140.

[0142] Optionally, after the second terminal device 150 sends the 100Trying signaling to the second radio access network device 120, the second terminal device 150 sends the 183Session Progress signaling to the second radio access network device 120. After the second radio access network device 120 receives the 183Session Progress signaling, the second radio access network device 120 sends the 183Session Progress signaling received from the second terminal device 150 to the first radio access network device 110. After the first radio access network device 110 receives the 183Session Progress signaling, the first radio access network device 110 sends the 183Session Progress signaling received from the second radio access network device 120 to the first terminal device 140.

[0143] Step S305 : The first terminal device 140 sends a PRACK signaling to the second terminal device 150 .

[0144] The PRACK signaling may be first confirmation information, and the first confirmation information includes the second handshake information in the three-way handshake. The PRACK signaling may indicate that the first terminal device 140 confirms that the 183 Session Progress signaling sent by the second terminal device 150 has been received.

[0145] Optionally, after the first terminal device 140 receives the 183Session Progress signaling, the first terminal device 140 sends a PRACK signaling to the first radio access network device 110. After the first radio access network device 110 receives the PRACK signaling, the first radio access network device 110 sends the PRACK signaling received from the first terminal device 140 to the second radio access network device 120. After the second radio access network device 120 receives the PRACK signaling, the second radio access network device 120 sends the PRACK signaling received from the first radio access network device 110 to the second terminal device 150.

[0146] Step S306 : The second terminal device 150 sends a 200 OK (PRACK) signaling to the first terminal device 140 .

[0147] It should be noted that the signaling sent at this time is actually a 200OK signaling for replying to the PRACK signaling. In the embodiment of the present application, in order to facilitate expression and distinguish different 200OK signalings, the signaling to be replied is marked in brackets after the 200OK signaling for replying to different signalings for distinction. The 200OK signaling for replying to the PRACK signaling is written as 200OK (PRACK) signaling here, but the writing here is only for example, and the specific expression of the actual sent signaling shall be subject to the 3GPP standard protocol. Other 200OK (PRACK) signalings in this application can also refer to this explanation.

[0148] The 200OK (PRACK) signaling may be the first 200OK signaling, and the 200OK (PRACK) signaling may be the first response information, and the first response information includes the third handshake information in the three-way handshake. The 200OK (PRACK) signaling may indicate that the second terminal device 150 confirms that the PRACK signaling sent by the first terminal device 140 has been received.

[0149] Optionally, after the second terminal device 150 receives the PRACK signaling, the second terminal device 150 sends a 200OK (PRACK) signaling to the second radio access network device 120. After the second radio access network device 120 receives the 200OK (PRACK) signaling, the second radio access network device 120 sends the 200OK (PRACK) signaling received from the second terminal device 150 to the first radio access network device 110. After the first radio access network device 110 receives the 200OK (PRACK) signaling, the first radio access network device 110 sends the 200OK (PRACK) signaling received from the second radio access network device 120 to the first terminal device 140.

[0150] Step S307: The second terminal device 150 switches from 5G to 4G voice call.

[0151] Optionally, the network standard of the second terminal device 150 is configured from the first network standard to the second network standard, the first network standard is 5G, and the second network standard is 4G.

[0152] Alternatively, if Figure 3As shown, the process of the second wireless access network device 120 instructing the second terminal device 150 to switch to the 4G voice call is described. It should be noted that there may be multiple implementation methods for the process of the second wireless access network device 120 instructing the second terminal device 150 to switch to the 4G voice call. The following steps only exemplify one of the switching methods. Other implementation methods include directly issuing a switching instruction without issuing a measurement instruction, and implementing the switching by issuing a mobilityFromNRCommand signaling switching instruction. The name is only for example, and the specific details shall be subject to the relevant protocol.

[0153] Combination Figure 4 As stated, Figure 4 It is a schematic flowchart of the second terminal device 150 switching from 5G to 4G voice call.

[0154] Step S401: The second radio access network device 120 sends RRC signaling to the second terminal device 150.

[0155] RRC signaling can be expressed as RRC Connection Reconfiguration. In the embodiment of the present application, for the convenience of description, the RRC signaling used to send measurements in this scenario is coordinated with RRC signaling, and the specific writing of the signaling shall be subject to the relevant protocol. RRC signaling can carry a measurement instruction sent by the second wireless access network device 120 to the second terminal device 150, measure the 4G signal status of LTE and indicate a reporting threshold value for measuring LTE to the second terminal device 150. When a cell is found to meet the threshold value requirement, a measurement report is reported.

[0156] It should be noted that the cell is described by the high-level from the perspective of resource management or mobility management or service unit. The coverage of each network device can be divided into one or more cells. The cell can be an area within the coverage of the wireless network of the network device. For example, the cell under the coverage of the NR network is called the NR cell, and the cell under the coverage of the LTE network is called the LTE cell. The signal quality strength of the cell can be characterized by the reference signal received power (RSRP) and the reference signal received quality (RSRQ).

[0157] Step S402: The second terminal device 150 reports a first measurement report to the second radio access network device 120.

[0158] Optionally, after receiving the RRC signaling, the second terminal device 150 measures the network conditions of the second terminal device 150 according to the RRC signaling, and reports a first measurement report to the second wireless access network device 120, where the first measurement result refers to the measurement result of the network status of the terminal device.

[0159] Step S403 : The second radio access network device 120 sends a first switching instruction to the second terminal device 150 .

[0160] Optionally, after the second radio access network device 120 receives the first measurement report, after the first switching instruction is issued to the second terminal device 150, the second terminal device 150 is instructed to switch the network standard from 5G to 4G. After the second terminal device 150 receives the first switching instruction issued by the second radio access network device 120, the second terminal device 150 will reply with a response message, which is subject to the relevant protocol and will not be repeated here.

[0161] Optionally, after step S403, the network standard of the second terminal device 150 is configured from the first network standard to the second network standard, the first network standard is 5G, and the second network standard is 4G.

[0162] It should be noted that, in some embodiments, the second radio access network device 120 and the second terminal device 150 do not execute the above steps S401 and S402, and directly execute step S403.

[0163] Step S404: The second terminal device 150 falls back to an LTE cell that meets the threshold requirement according to the redirectedCarrierInfo information included in the received signaling and the instruction of the second radio access network device 120, and determines that the current call is an EPSFB call.

[0164] Step S405 : The second terminal device 150 reports TAU Request signaling to the third radio access network device 130 .

[0165] The TAU Request signaling may be the second request information, and the TAU Request signaling indicates that the second terminal device 150 requests the third wireless access network device 130 to start stationing on the network and perform tracking area update to complete the function of accessing the 4G network.

[0166] Step S406: The third radio access network device 130 sends a TAU Accept signaling to the second terminal device 150.

[0167] The TAU Accept signaling may be the sixth response information, and the TAU Accept signaling indicates that the third radio access network device 130 responds to the TAU Request signaling reported by the second terminal device 150 .

[0168] Step S407 : The second terminal device 150 reports TAU Complete signaling to the third radio access network device 130 .

[0169] The TAU Complete signaling may be the sixth confirmation information, and the TAU Complete signaling indicates that the second terminal device 150 confirms receipt of the TAU Accept signaling sent by the third radio access network device 130 .

[0170] As mentioned above, refer to Figure 3 , steps S401 to S407 describe Figure 3 In step S307, the second wireless access network device 120 instructs the second terminal device 150 to switch to the specific process of the 4G voice call.

[0171] Step S308 : The first terminal device 140 sends an UPDATE signaling to the second terminal device 150 .

[0172] The UPDATE signaling may be first update information, and the UPDATE signaling may indicate that the first terminal device 140 has established the first voice bearer, that is, the first voice bearer has completed establishment or the first voice bearer has been established.

[0173] Optionally, after the first terminal device 140 receives the 200OK (PRACK) signaling, the first terminal device 140 checks whether it has established the first voice bearer, that is, the first voice bearer has been established or the first voice bearer has been established. After the first terminal device 140 confirms that it has received the voice dedicated bearer establishment instruction issued by the first radio access network device 110 in step S303, and has completed the establishment of the first voice bearer according to the voice dedicated bearer establishment instruction, it sends an UPDATE signaling to the first radio access network device 110, and the UPDATE signaling includes information indicating that the first terminal device 140 has established the first voice bearer. After the first radio access network device 110 receives the UPDATE signaling, it sends the UPDATE signaling to the third radio access network device 130. After the third radio access network device 130 receives the UPDATE signaling, it sends the UPDATE signaling to the second terminal device 150.

[0174] After step S308, if the second voice bearer of the second terminal device 150 has not been established, the second terminal device 150 responds to the UPDATE signaling and returns the signaling that the second voice bearer has not been established to the first terminal device 140. In some embodiments, the signaling that the second voice bearer has not been established will be carried in the 200OK (UPDATE) signaling and sent to the first terminal device 140. After step S308, if the second terminal device 150 has completed the establishment of the second voice bearer, the 200OK (UPDATE) signaling can carry the signaling that the second voice bearer has been established.

[0175] For example, in combination Figure 3 As shown, when the second voice bearer of the second terminal device 150 has not yet been established, the steps after step S308 are described:

[0176] Step S309 : The second terminal device 150 sends a 200 OK (UPDATE) signaling to the first terminal device 140 .

[0177] The 200 OK (UPDATE) signaling may indicate that the second terminal device 150 confirms that the UPDATE signaling sent from the first terminal device 140 has been received. The 200 OK (UPDATE) signaling may be the fifth signaling, and the 200 OK (UPDATE) signaling may be the seventh signaling.

[0178] It should be noted that the signaling sent at this time is actually a 200OK signaling for replying to the UPDATE signaling. In the embodiment of the present application, in order to facilitate expression and distinguish different 200OK signaling, the signaling to which it replies is marked in brackets after the 200OK signaling for replying to different signalings for distinction. Here, the 200OK signaling for replying to the UPDATE signaling is written as 200OK (UPDATE) signaling, but the writing here is only for example, and the specific expression of the actual sent signaling shall be subject to the 3GPP standard protocol.

[0179] Optionally, after receiving the UPDATE signaling, the second terminal device 150 checks the voice bearer status of the second terminal device 150. When the second terminal device 150 confirms that it has not received the voice dedicated bearer establishment instruction issued by the third radio access network device 130, that is, when the second voice bearer has not been established, the second terminal device 150 sends a 200OK (UPDATE) signaling containing a=curr:qos local none information to the third radio access network device 130. The a=curr:qos local none information is the syntax of the SDP protocol, and the 200OK (UPDATE) signaling can indicate that the second voice bearer of the second terminal device 150 has not been established. After the third radio access network device 130 receives the 200OK (UPDATE) signaling containing a=curr:qos local none information from the second terminal device 150, it sends a 200OK (UPDATE) signaling containing a=curr:qos local none information to the first radio access network device 110. Based on the fact that the first wireless access network device 110 has received the 200OK (UPDATE) signaling containing the information a=curr:qos local none, the first wireless access network device 110 determines that the current called terminal device, i.e., the second terminal device 150, is not in a state where voice packets can be sent and received, and the first wireless access network device 110 is in a non-connected state, i.e., a state where voice packets cannot be forwarded normally. After the first wireless access network device 110 has received the 200OK (UPDATE) signaling, the 200OK (UPDATE) signaling is sent to the first terminal device 140.

[0180] Step S310: The third radio access network device 130 sends a voice dedicated bearer establishment instruction to the second terminal device 150.

[0181] The dedicated bearer establishment instruction for voice may be the second signaling, the dedicated bearer establishment instruction for voice may be the fourth signaling, and the dedicated bearer establishment instruction for voice may be the sixth signaling. The dedicated bearer establishment instruction for voice may be the bearer QCI=1 information, the dedicated bearer establishment instruction for voice may be expressed as an activated dedicated EPS bearer context request (Activatededicated EPS bearer context request), the dedicated bearer establishment instruction for voice may be the second voice bearer instruction, the dedicated bearer establishment instruction for voice may indicate that the third radio access network device 130 instructs the second terminal device 150 to establish a second voice bearer, and the second voice bearer may be used to indicate the status of voice resource reservation of the second terminal device 150. The dedicated bearer establishment instruction for voice may be expressed as the second signaling, and the second signaling includes QCI=1.

[0182] Optionally, in the embodiment of the present application, step S310 is performed after the second terminal device 150 has switched to the 4G voice solution in step S307. After the third radio access network device 130 sends a voice dedicated bearer establishment instruction to the second terminal device 150, the third radio access network device 130 instructs the second terminal device 150 to establish a second voice bearer. The embodiment of the present application does not limit the specific state of the voice resource reservation of the second voice bearer. In the embodiment of the present application, the establishment of the second voice bearer by the terminal device can be understood as the resource reservation state is normal, that is, the terminal device is in a state where it can perform subsequent sending and receiving of voice packets.

[0183] It should be noted that, combined with Figure 2 If EPSFB does not occur, in some implementations, the second wireless access network device 120 may send a dedicated voice bearer establishment instruction to the second terminal device 150 in step S302 after the second wireless access network device 120 receives the 100Trying signaling. Figure 3 , the third radio access network device 130 sends the dedicated voice bearer establishment instruction only after the second radio access network device 120 sends the switching instruction and the network where the second terminal device 150 resides has switched to 4G. Therefore, the EPSFB process causes the second terminal device 150 to delay the time to complete the second voice bearer establishment during the call.

[0184] Optionally, in some implementations, the third radio access network device 130 does not immediately issue a dedicated voice bearer establishment instruction after the second radio access network device 120 issues the switching instruction and the network where the second terminal device 150 resides has switched to 4G. In other words, the time when the second terminal device 150 receives the dedicated voice bearer establishment instruction may be earlier than the time when it receives the UPDATE signaling, or may be later than the time when it receives the UPDATE signaling. The embodiment of the present application does not limit the specific time when the third radio access network device 130 issues the dedicated voice bearer establishment instruction, and the specific implementation can refer to the 3GPP standard protocol.

[0185] Step S311: The second terminal device 150 sends a 180Ringing signaling to the first terminal device 140.

[0186] The 180Ringing signaling may be the first ringing information, and the 180Ringing signaling may indicate that the second terminal device 150 has established the second voice bearer and is ready to make a call.

[0187] Optionally, after the second terminal device 150 sends the 180Ringing signaling, the call state of the second terminal device 150 is updated to the ringing state, and the second terminal device 150 starts ringing. The ringing state refers to the state in which the called party terminal device rings to remind the user of the incoming call when there is an incoming call and the user has not answered the call; the ringtone when the ringing starts includes: vibration, color ringback tone, beep, personalized music, song, recording, video, etc., which are not limited here. After the third wireless access network device 130 receives the 180Ringing signaling, the third wireless access network device 130 sends the 180Ringing signaling to the first wireless access network device 110. After the first wireless access network device 110 receives the 180Ringing signaling, the first wireless access network device 110 determines that the current called terminal, that is, the second terminal device 150, is in a state where voice packets can be sent and received. The first wireless access network device 110 is in the connected state, that is, the state in which voice packets can be forwarded normally, and the 180Ringing signaling is sent to the first terminal device 140. After the first terminal device 140 receives the 180Ringing signaling, the call state of the first terminal device 140 is updated to the ringback tone state, and the first terminal device 140 starts to play the ringback tone. The ringback tone state refers to the state in which when the call is successful but the called user does not answer the call, the calling party terminal device sends a ringback tone to remind the user that the called user has not answered the call. Ringback tones include: vibration, color ringback, beep, personalized music, songs, recordings, videos, etc., which are not limited here.

[0188] It should be noted that the signaling transmission in step S309 is not delayed due to the delay problem in the interaction between the first core network and the second core network to which the first terminal device 140 and the second terminal device 150 are connected. The 200OK (UPDATE) signaling is transmitted normally to the first terminal device 140, and the disorder problem of the 200OK (UPDATE) signaling and the 180Ringing signaling does not occur.

[0189] Step S312 : The second terminal device 150 sends a 200 OK (INVITE) signaling to the first terminal device 140 .

[0190] It should be noted that, combined with Figure 1 In the scenario shown, after the second terminal device 150 starts ringing, user B answers the call on the second terminal device 150 .

[0191] Optionally, when user B answers the call on the second terminal device 150 , the second terminal device 150 sends a 200 OK (INVITE) signaling to the first terminal device 140 .

[0192] Optionally, in response to user B answering the call on the second terminal device 150 , the second terminal device 150 sends a 200 OK (INVITE) signaling to the first terminal device 140 .

[0193] The 200 OK (INVITE) signaling may be the third 200 OK signaling, and the 200 OK (INVITE) signaling may indicate that the second terminal device 150 responds to the first terminal device 140 that it is ready to send and receive voice packets.

[0194] Optionally, after the second terminal device 150 starts ringing, user B answers the call, and the second terminal device 150 sends a 200OK (INVITE) signaling to the third wireless access network device 130, and the third wireless access network device 130 sends the 200OK (INVITE) signaling received from the second terminal device 150 to the first wireless access network device 110. After the first wireless access network device 110 receives the 200OK (INVITE) signaling, the first wireless access network device 110 sends the 200OK (INVITE) signaling received from the third wireless access network device 130 to the first terminal device 140. After the first terminal device 140 receives the 200OK (INVITE) signaling, the first terminal device 140 displays that the call is connected. Specifically, the first terminal device 140 can display user prompts such as: "Phone call in progress", "Call in progress", "Calling in progress", "Connected" to the user. In general, a call time prompt can also be added, such as "00:01", "00:02", "00:03", etc.

[0195] It should be noted that the timing when the first terminal device 140 displays that the call is connected may be after the first terminal device 140 receives the 200OK (INVITE) signaling in step S312, and before the first terminal device 140 sends the ACK signaling to the second terminal device 150 in step S313. It may also be after the first terminal device 140 sends the ACK signaling to the second terminal device 150 in step S313, and the embodiment of the present application does not limit this timing.

[0196] Step S313 : The first terminal device 140 sends an ACK signaling to the second terminal device 150 .

[0197] The ACK signaling may be second confirmation information, and the ACK signaling may indicate that the first terminal device 140 confirms to the second terminal device 150 that it has received the 200 OK (INVITE) signaling sent by the second terminal device 150 to the first terminal device 140 .

[0198] Optionally, after the first terminal device 140 receives the 200OK (INVITE) signaling, the first terminal device 140 sends an ACK signaling to the first wireless access network device 110, and the first wireless access network device 110 sends the ACK signaling received from the first terminal device 140 to the third wireless access network device 130. After the third wireless access network device 130 receives the ACK signaling, the third wireless access network device 130 sends the received ACK signaling to the second terminal device 150.

[0199] Step S314 : the second terminal device 150 sends a first voice packet to the first terminal device 140 .

[0200] The first voice packet may be IMS RTP SN and Payload. The first voice packet may be voice data.

[0201] Optionally, after the second terminal device sends the 200OK (INVITE) signaling, the second terminal device 150 sends the first voice packet to the third wireless access network device 130, and the third wireless access network device 130 sends the first voice packet received from the second terminal device 150 to the first wireless access network device 110. After the first wireless access network device 110 receives the first voice packet, it sends the first voice packet to the first terminal device 140, and after the first terminal device 140 receives the first voice packet, it plays the voice.

[0202] It should be noted that the embodiment of the present application does not limit the timing of the second terminal device 150 sending the first voice packet to the first wireless access network device 110. For example, after the second terminal device sends the 200OK (INVITE) signaling, the second terminal device 150 sends the first voice packet to the first wireless access network device 110. Alternatively, after the second terminal device receives the ACK signaling, the second terminal device 150 sends the first voice packet to the first wireless access network device 110.

[0203] Step S315 : the first terminal device 140 sends a second voice packet to the second terminal device 150 .

[0204] The second voice packet may be IMS RTP SN and Payload. The second voice packet may be voice data.

[0205] Optionally, after the first terminal device 140 sends the ACK signaling, the first terminal device 140 sends the second voice packet to the first wireless access network device 110, and after the first wireless access network device 110 receives the second voice packet, the first terminal device 140 sends the second voice packet to the third wireless access network device 130. After the third wireless access network device 130 receives the second voice packet, the second voice packet is sent to the second terminal device 150, and after the second terminal device 150 receives the second voice packet, the voice is played.

[0206] It should be noted that the embodiment of the present application does not limit the timing of the first terminal device 140 sending the second voice packet to the first wireless access network device 110. Steps S314 and S315 have no mutual trigger relationship and sequence, and the order of the two can be interchanged. During a call, the voice packets exchanged between the calling terminal device and the called terminal device are not limited to the first voice packet and the second voice packet. The embodiment of the present application will not be repeated, and the first voice packet and the second voice packet are only used as an example to represent the interaction process of the user voice packets between the calling and called terminal devices during the call.

[0207] Therefore, in some possible scenarios, since the 200 OK (UPDATE) signaling and the 180 Ringing signaling are not out of order, the user can make a normal voice call even in the EPSFB scenario.

[0208] like Figure 5 As shown, in other embodiments, combined with Figure 3 In the EPSFB scenario shown in the figure, 200 OK (UPDATE) signaling and 180 Ringing signaling may also be out of order. Figure 3 After step S308 shown, Figure 5 The signaling interaction process in the abnormal scenario shown includes:

[0209] It should be noted that Figure 5 Steps S501 to S508 in Figure 3 The steps S301 to S308 are the same as in the above. For relevant explanations, please refer to the descriptions in steps S301 to S308, which will not be repeated here.

[0210] Step S509 : The second terminal device 150 sends a 200 OK (UPDATE) signaling to the first terminal device 140 .

[0211] Optionally, after receiving the UPDATE signaling, the second terminal device 150 checks the voice bearer status of the second terminal device 150. When the second terminal device 150 confirms that it has not received the voice dedicated bearer establishment instruction issued by the third radio access network device 130, which means that the second voice bearer has not been established, the second terminal device 150 sends a 200OK (UPDATE) signaling containing a=curr:qos local none information to the third radio access network device 130, wherein the a=curr:qos local none information is the syntax of the SDP protocol, and the 200OK (UPDATE) signaling can indicate that the second voice bearer of the second terminal device 150 has not been established. After the third radio access network device 130 receives the 200OK (UPDATE) signaling containing a=curr:qos local none information from the second terminal device 150, it sends a 200OK (UPDATE) signaling containing a=curr:qos local none information to the first radio access network device 110. Based on the fact that the first wireless access network device 110 has received the 200OK (UPDATE) signaling containing the information a=curr:qos local none, the first wireless access network device 110 determines that the current called terminal device, that is, the second terminal device 150, is not in a state where voice packets can be sent and received. The first wireless access network device 110 is in a non-connected state, that is, a state where voice packets cannot be forwarded normally. After the first wireless access network device 110 receives the 200OK (UPDATE) signaling, it sends the 200OK (UPDATE) signaling to the first terminal device 140.

[0212] Since there may be a problem with the network compatibility between the first core network and the second core network to which the first terminal device 140 and the second terminal device 150 are connected, and since the EPSFB process of the second terminal device 150 may cause a delay in signaling transmission, these two reasons ultimately lead to a signaling disorder problem. The signaling disorder problem, that is, the signaling transmission in step S509 is delayed, and the 200OK (UPDATE) signaling cannot be normally transmitted to the first terminal device 140. Since the 200OK (UPDATE) signaling is delayed in transmission between the third wireless access network device 130 and the first wireless access network device 110, the first terminal device 140 first receives the 180Ringing signaling in the following step S511, and then receives the 200OK (UPDATE) signaling containing the information a=curr:qos local none.

[0213] Optionally, Figure 7(a) is the judgment logic of the second terminal device 150 before the second terminal device 150 sends the 200OK (UPDATE) signaling. After the second terminal device 150 receives the UPDATE signaling, the second terminal device 150 determines whether the second voice bearer is established. Under the condition that the second voice bearer is established, the 200OK (UPDATE) signaling sent by the second terminal device 150 contains the information a=curr:qos local sendrecv. Under the condition that the second voice bearer is not established, the 200OK (UPDATE) signaling sent by the second terminal device 150 contains the information a=curr:qos local none.

[0214] It should be noted that, in some other implementations, the information contained in the 200OK (UPDATE) signaling sent by the second terminal device 150 to the first terminal device 140 may be different, depending on the voice bearer status of the second terminal device 150. After receiving the UPDATE signaling, the second terminal device 150 checks the voice bearer status of the second terminal device 150. After the second terminal device 150 confirms that it has received the voice dedicated bearer establishment instruction issued by the third radio access network device 130, and when the second voice bearer is established, the second terminal device 150 sends a 200OK (UPDATE) signaling to the third radio access network device 130, including a=curr:qos local sendrecv information, and the 200OK (UPDATE) signaling enables the first radio access network device 110 to send and receive voice packets normally. After the third radio access network device 130 receives the 200OK (UPDATE) signaling, the third radio access network device 130 sends the 200OK (UPDATE) signaling to the first radio access network device 110. After the first radio access network device 110 receives the 200OK (UPDATE) signaling, the first radio access network device 110 sends the 200OK (UPDATE) signaling to the first terminal device 140. Therefore, after the second terminal device 150 receives the UPDATE signaling, under the condition that the second voice bearer of the second terminal device 150 is established, the second terminal device 150 can send the 200OK (UPDATE) signaling containing the a=curr:qos local sendrecv information to the first radio access network device 110, that is, the first radio access network device 110 can send and receive voice packets normally.

[0215] Step S510: The third radio access network device 130 sends a voice dedicated bearer establishment instruction to the second terminal device 150.

[0216] It should be noted that step S510 is the same as step S310. For relevant explanations, please refer to step S310 and will not be repeated here.

[0217] Step S511: The second terminal device 150 sends a 180Ringing signaling to the first terminal device 140.

[0218] The 180Ringing signaling may be the first ringing information, and the 180Ringing signaling may indicate that the second terminal device 150 has established the second voice bearer and is ready to make a call.

[0219] Optionally, after the second terminal device 150 sends the 180Ringing signaling, the call state of the second terminal device 150 is updated to the ringing state, and the second terminal device 150 starts ringing. The ringing state refers to the state in which when there is an incoming call, the user has not answered the call, and the called party terminal device rings to remind the user of the incoming call. The ringtone when the ringing starts includes: vibration, color ringback tone, beep, personalized music, song, recording, video, etc., which are not limited here. After the third wireless access network device 130 receives the 180Ringing signaling, the third wireless access network device 130 sends the 180Ringing signaling to the first wireless access network device 110. After the first wireless access network device 110 receives the 180Ringing signaling, the first wireless access network device 110 determines that the current called terminal, i.e., the second terminal device 150, is in a state where voice packets can be sent and received, and the first wireless access network device 110 is set to a connected state, i.e., a state where voice packets can be forwarded normally, and sends the 180Ringing signaling to the first terminal device 140. After the first terminal device 140 receives the 180Ringing signaling, the call state of the first terminal device 140 is updated to a ringback tone state, and the first terminal device 140 starts to play the ringback tone. The ringback tone state refers to the state where, when the call is successful but the called user does not answer the call, the calling party terminal device sends a ringback tone to remind the user that the called user has not answered the call; the ringback tone includes: vibration, color ringback tone, beep, personalized music, song, recording, video, etc., which are not limited here.

[0220] It should be noted that, due to the signaling disorder problem caused by the interaction between the first core network and the second core network to which the first terminal device 140 and the second terminal device 150 are connected, the signaling transmission in step S509 is delayed, and the 200OK (UPDATE) signaling cannot be normally transmitted to the first terminal device 140. Since the 200OK (UPDATE) signaling is delayed in transmission between the third radio access network device 130 and the first radio access network device 110, the first terminal device 140 first receives the 180Ringing signaling in step S511, and then receives the 200OK (UPDATE) signaling containing the information a=curr:qos local none in step S509.

[0221] Step S512 : The second terminal device 150 sends a 200 OK (INVITE) signaling to the first terminal device 140 .

[0222] Step S513 : The first terminal device 140 sends an ACK signaling to the second terminal device 150 .

[0223] It should be noted that steps S512 to S513 are Figure 3 The steps S312 to S313 in are the same. For relevant explanations, please refer to the descriptions in steps S312 to S313, which will not be repeated here.

[0224] Step S514 : The second terminal device 150 sends a first voice packet to the first radio access network device 110 .

[0225] The first voice packet may be IMS RTP SN and Payload. The first voice packet may be voice data.

[0226] Optionally, after the second terminal device sends the 200OK (INVITE) signaling, the second terminal device 150 sends the first voice packet to the third wireless access network device 130, and the third wireless access network device 130 sends the first voice packet received from the second terminal device 150 to the first wireless access network device 110. Based on step S509, the first wireless access network device 110 cannot forward the voice packet normally, and the first wireless access network device 110 cannot further send the first voice packet to the first terminal device 140.

[0227] It should be noted that the embodiment of the present application does not limit the timing of the second terminal device 150 sending the first voice packet to the first wireless access network device 110. For example, after the second terminal device sends the 200OK (INVITE) signaling, the second terminal device 150 sends the first voice packet to the first wireless access network device 110. Alternatively, after the second terminal device receives the ACK signaling, the second terminal device 150 sends the first voice packet to the first wireless access network device 110.

[0228] Step S515 : the first terminal device 140 sends a second voice packet to the first radio access network device 110 .

[0229] The second voice packet may be IMS RTP SN and Payload. The second voice packet may be voice data.

[0230] Optionally, after the first terminal device 140 sends the ACK signaling, the first terminal device 140 sends a second voice packet to the first wireless access network device 110. Based on the step S509, the first wireless access network device 110 cannot forward the voice packet normally, and the first wireless access network device 110 cannot further send the second voice packet to the third wireless access network device 130.

[0231] It should be noted that the embodiment of the present application does not limit the timing of the first terminal device 140 sending the second voice packet to the first wireless access network device 110. For example, after the second terminal device 150 sends the first voice packet to the first wireless access network device 110, the first terminal device 140 sends the second voice packet to the first wireless access network device 110. Alternatively, before the second terminal device 150 sends the first voice packet to the first wireless access network device 110, the first terminal device 140 sends the second voice packet to the first wireless access network device 110.

[0232] It should be noted that the embodiment of the present application does not limit the timing of the first terminal device 140 sending the second voice packet to the first wireless access network device 110. Steps S514 and S515 have no mutual trigger relationship and sequence, and the order of the two can be interchanged. During a call, the voice packets exchanged between the calling terminal device and the called terminal device are not limited to the first voice packet and the second voice packet. The embodiment of the present application will not be repeated, and the first voice packet and the second voice packet are only used as an example to represent the interaction process of the user voice packets between the calling and called terminal devices during the call.

[0233] Since the terminal device needs to fall back from the 5G network bearer state to the 4G network bearer state during the EPSFB process, the process will take a certain amount of time, and the second voice bearer needs to be established after the network switching is completed. Therefore, during the EPSFB process, the second voice bearer is established later. Furthermore, since the second voice bearer is established later, when the second terminal device 150 receives the UPDATE signaling in step S508, the second voice bearer has not yet been established. Since the second voice bearer has not yet been established, in step S509, the 200OK (UPDATE) signaling sent by the second terminal device 150 to the first terminal device 140 contains a = curr: qos local none information, and the a = curr: qos localnone information is the syntax of the SDP protocol, and the 200OK (UPDATE) signaling can indicate that the second voice bearer of the second terminal device 150 has not been established.

[0234] Exemplarily, in combination with step S509 to step S515, and Figure 1In the scenario shown, after receiving the 180Ringing signaling in step S511, the first wireless access network device 110 receives the 200OK (UPDATE) signaling in step S509. In step S511, after receiving the 180Ringing signaling, the third wireless access network device 130 sends the 180Ringing signaling to the first wireless access network device 110. In this step S511, after the first wireless access network device 110 receives the 180Ringing signaling, the first wireless access network device 110 determines that the current called terminal, that is, the second terminal device 150, is in a state where voice packets can be sent and received, and the first wireless access network device 110 is in a connected state, that is, a state where voice packets can be forwarded normally, and sends the 180Ringing signaling to the first terminal device 140. After the first terminal device 140 receives the 180Ringing signaling, the first terminal device 140 starts to play the ringback tone, the second terminal device 150 starts to ring, and user B can answer the call. However, due to the network compatibility problem between the first core network to which the first terminal device 140 and the second core network to which the second terminal device 150 access, the transmission of signaling may cause delays, which eventually leads to a signaling disorder problem: the signaling transmission in step S509 is delayed, and the 200OK (UPDATE) signaling containing the information a=curr:qos local none cannot be normally transmitted to the first terminal device 140. Since the transmission of the 200OK (UPDATE) signaling is delayed between the third wireless access network device 130 and the first wireless access network device 110, the first wireless access network device 110 first receives the 180Ringing signaling in step S511, and then receives the 200OK (UPDATE) signaling containing the information a=curr:qos local none in step S509. After receiving the 200OK (UPDATE) signaling containing the information a=curr:qos local none in step S509, the first wireless access network device 110 determines that the current called terminal, i.e., the second terminal device 150, is not in a state where voice packets can be sent and received, and the first wireless access network device 110 is in a non-connected state, i.e., a state where voice packets cannot be forwarded normally.

[0235] Based on the above two problems: (1) Due to EPSFB, the second voice bearer is established late, which eventually causes the 200OK (UPDATE) signaling sent by the second terminal device 150 to the first terminal device 140 to contain the information a=curr:qos local none; (2) The network compatibility problem between the first core network and the second core network causes the signaling disorder problem, and the user call has an abnormal problem. The third wireless access network device 130 sends a 200OK (UPDATE) signaling containing the information a=curr:qos local none to the first wireless access network device 110. Based on the fact that the first wireless access network device 110 receives the 200OK (UPDATE) signaling containing the information a=curr:qos local none, the first wireless access network device 110 cannot forward the voice packet normally. After user B answers the call, although the first terminal device 140 and the second terminal device 150 start to send voice packets, due to the fact that the first wireless access network device 110 cannot forward the voice packets normally, user A cannot hear the call voice from user B from the first terminal device 140; user B also cannot hear the call voice from user A from the second terminal device 150. Optionally, in some embodiments, after the terminal device fails to receive the voice packet for a certain period of time, the call will be dropped, and the dropped call can be manifested as the call automatically ending after a period of time, and the dropped call refers to an abnormal release during the user communication process.

[0236] Optionally, in other embodiments, to solve Figure 5 In the corresponding implementation, the user cannot hear the sound after answering the call. Figure 6 The steps before step S609 are respectively Figure 3 The steps S301 to S308 in the above are the same, and the related explanations can refer to the descriptions in steps S301 to S308, which will not be repeated here. In step S609 and thereafter, Figure 6 The corresponding method may further include the following steps:

[0237] Step S609 : The second terminal device 150 sends a 200 OK (UPDATE) signaling to the first terminal device 140 .

[0238] The 200 OK (UPDATE) signaling may be the second response information, and the 200 OK (UPDATE) signaling may indicate that the second terminal device 150 responds to the UPDATE signaling to the first terminal device 140. The 200 OK (UPDATE) signaling may be the first signaling, and the 200 OK (UPDATE) signaling may be the third signaling.

[0239] It should be noted that the signaling sent at this time is actually a 200OK signaling for replying to the UPDATE signaling. In the embodiment of the present application, in order to facilitate expression and distinguish different 200OK signaling, the signaling to which it replies is marked in brackets after the 200OK signaling for replying to different signalings for distinction. Here, the 200OK signaling for replying to the UPDATE signaling is written as 200OK (UPDATE) signaling, but the writing here is only for example, and the specific expression of the actual sent signaling shall be subject to the 3GPP standard protocol.

[0240] Optionally, after receiving the UPDATE signaling, the second terminal device 150 checks the voice bearer status of the second terminal device 150. When the second terminal device 150 confirms that it has not received the voice dedicated bearer establishment instruction issued by the third radio access network device 130, that is, when the second voice bearer has not been established, the second terminal device 150 sends a 200OK (UPDATE) signaling containing a=curr:qos local sendrecv information to the third radio access network device 130, and the 200OK (UPDATE) signaling can enable the first radio access network device 110 to forward the voice packet normally. After receiving the 200OK (UPDATE) signaling from the second terminal device 150, the third radio access network device 130 sends a 200OK (UPDATE) signaling containing a=curr:qos local sendrecv information to the first radio access network device 110. The first radio access network device 110 receives a 200OK (UPDATE) signaling containing a=curr:qos local sendrecv information, determines that the current called terminal, i.e., the second terminal device 150, is in a state where voice packets can be sent and received, and sets the first radio access network device 110 to an on state, i.e., a state where voice packets can be forwarded normally; and the first radio access network device 110 sends a 200OK (UPDATE) signaling containing a=curr:qos local sendrecv information to the first terminal device 140. The 200OK (UPDATE) signaling containing a=curr:qoslocal sendrecv information can be a first signaling, and the first signaling includes 200OK and a=curr:qos local sendrecv.

[0241] Because the 200OK (UPDATE) signaling received by the first wireless access network device 110 and sent by the third wireless access network device 130 includes the a=curr:qos local sendrecv information, the first wireless access network device 110 can forward the voice packet normally, thereby avoiding the situation where the first wireless access network device 110 cannot forward the voice packet normally after receiving the 200OK (UPDATE) signaling including the a=curr:qos local none information, so that the user cannot hear the call sound after answering the call.

[0242] Optionally, Figure 7 (b) is a possible judgment logic before the second terminal device 150 sends the 200OK (UPDATE) signaling in the improved solution. After the second terminal device 150 receives the UPDATE signaling, the second terminal device 150 sends the 200OK (UPDATE) signaling containing the information a=curr:qos local sendrecv to the first terminal device 140. The 200OK (UPDATE) signaling containing the information a=curr:qos local sendrecv can be the first signaling, and the first signaling includes 200OK and a=curr:qos local sendrecv.

[0243] Optionally, Figure 7 (c) is another possible judgment logic before the second terminal device 150 sends the 200OK (UPDATE) signaling in the improved solution. After the second terminal device 150 receives the UPDATE signaling, the second terminal device 150 determines whether the second voice bearer is established. If the second voice bearer is established, the second terminal device 150 sends the 200OK (UPDATE) signaling containing the information a=curr:qos local sendrecv to the first terminal device 140. If the second voice bearer is not established, the second terminal device 150 sends the 200OK (UPDATE) signaling to the first terminal device 140. Figure 7 The 200OK(UPDATE) signaling including a=curr:qos localnone information shown in (a) is replaced by a 200OK(UPDATE) signaling including a=curr:qos local sendrecv information and sent to the first terminal device 140. The 200OK(UPDATE) signaling including a=curr:qos local sendrecv information may be the first signaling including 200OK and a=curr:qos localsendrecv.

[0244] Optionally, in some embodiments, after receiving the UPDATE signaling, the second terminal device 150 may also perform the following three judgments: (1) judging that the first terminal device 140 supports resource reservation by the resource reservation flag of the first terminal device 140; (2) judging that the second terminal device 150 supports resource reservation by the support field in the received INVITE signaling carrying the precondition flag; (3) judging that the current call is an EPSFB call with reference to step S404. If the second terminal device 150 judges that the above three conditions are met, the second terminal device 150 may Figure 7 As shown in (b), the second terminal device 150 sends a 200 OK (UPDATE) signaling including the information a=curr:qos local none to the first terminal device 140. The embodiment of the present application does not limit the execution time of the above judgment.

[0245] Optionally, in some embodiments, after receiving the UPDATE signaling, the second terminal device 150 may also perform the following three judgments: (1) judging that the first terminal device 140 supports resource reservation by the resource reservation flag of the first terminal device 140; (2) judging that the second terminal device 150 supports resource reservation by the support field in the received INVITE signaling carrying the precondition flag; (3) judging that the current call is an EPSFB call with reference to step S404. If the second terminal device 150 judges that the above three conditions are met, the second terminal device 150 may Figure 7 As shown in (c), under the condition that the second voice bearer is established, the second terminal device 150 sends a 200OK (UPDATE) signaling containing a=curr:qos localsendrecv information to the first terminal device 140. Under the condition that the second voice bearer is not established, the second terminal device 150 sends Figure 7 The 200OK(UPDATE) signaling including the information a=curr:qos local none shown in (a) is replaced by the 200OK(UPDATE) signaling including the information a=curr:qos local sendrecv and sent to the first terminal device 140. The 200OK(UPDATE) signaling including the information a=curr:qos local sendrecv may be the first signaling, and the first signaling includes 200OK and a=curr:qos local sendrecv. The embodiment of the present application does not limit the execution time of the above judgment.

[0246] Step S610: The third radio access network device 130 sends a voice dedicated bearer establishment instruction to the second terminal device 150.

[0247] The dedicated voice bearer establishment instruction may be represented as a second signaling, where the second signaling includes QCI=1.

[0248] The dedicated bearer establishment instruction for voice may be the second signaling, the dedicated bearer establishment instruction for voice may be the fourth signaling, and the dedicated bearer establishment instruction for voice may be the sixth signaling. The dedicated bearer establishment instruction for voice may be the bearer QCI=1 information, the dedicated bearer establishment instruction for voice may be expressed as an activated dedicated EPS bearer context request (Activatededicated EPS bearer context request), the dedicated bearer establishment instruction for voice may be the second voice bearer instruction, the dedicated bearer establishment instruction for voice may indicate that the third radio access network device 130 instructs the second terminal device 150 to establish a second voice bearer, and the second voice bearer may be used to indicate the status of voice resource reservation of the second terminal device 150.

[0249] Optionally, in the embodiment of the present application, step S610 is performed after the second terminal device 150 has switched to the 4G voice solution in step S607. After the third radio access network device 130 sends a voice dedicated bearer establishment instruction to the second terminal device 150, the third radio access network device 130 instructs the second terminal device 150 to establish a second voice bearer. The embodiment of the present application does not limit the specific state of the voice resource reservation of the second voice bearer. In the embodiment of the present application, the establishment of the second voice bearer by the terminal device can be understood as the resource reservation state is normal, that is, the terminal device is in a state where it can perform subsequent sending and receiving of voice packets.

[0250] It should be noted that, combined with Figure 3 If EPSFB does not occur, in some implementations, the second wireless access network device 120 may send a dedicated voice bearer establishment instruction to the second terminal device 150 in step S302 after the second wireless access network device 120 receives the 100Trying signaling. Figure 3 , the third radio access network device 130 sends the dedicated voice bearer establishment instruction only after the second radio access network device 120 sends the switching instruction and the network where the second terminal device 150 resides has switched to 4G. Therefore, the EPSFB process causes the second terminal device 150 to delay the time to complete the second voice bearer establishment during the call.

[0251] Optionally, in some implementations, the third radio access network device 130 does not immediately issue a dedicated voice bearer establishment instruction after the second radio access network device 120 issues the switching instruction and the network where the second terminal device 150 resides has switched to 4G. In other words, the time when the second terminal device 150 receives the dedicated voice bearer establishment instruction may be earlier than the time when it receives the UPDATE signaling, or may be later than the time when it receives the UPDATE signaling. The embodiment of the present application does not limit the specific time when the third radio access network device 130 issues the dedicated voice bearer establishment instruction, and the specific implementation can refer to the 3GPP standard protocol.

[0252] Step S611: The second terminal device 150 sends a 180Ringing signaling to the first terminal device 140.

[0253] The 180Ringing signaling may be the first ringing information, and the 180Ringing signaling may indicate that the second terminal device 150 has established the second voice bearer and is ready to make a call.

[0254] Optionally, in some implementations, after receiving the dedicated voice bearer establishment instruction, the second terminal device 150 sends a 180 Ringing signaling to the first terminal device 140 .

[0255] Optionally, in some implementations, the second terminal device 150 sends 180 Ringing signaling to the first terminal device 140 after the second voice bearer is established.

[0256] Optionally, in some implementations, the second terminal device 150 completes establishment based on the second voice bearer and sends 180 Ringing signaling to the first terminal device 140 .

[0257] Optionally, after the second terminal device 150 sends the 180Ringing signaling, the call state of the second terminal device 150 is updated to the ringing state, and the second terminal device 150 starts ringing. The ringing state refers to the state in which the called party terminal device rings to remind the user of the incoming call when there is an incoming call and the user has not answered the call; the ringtone when the ringing starts includes: vibration, color ringback tone, beep, personalized music, song, recording, video, etc., which are not limited here. After the third wireless access network device 130 receives the 180Ringing signaling, the third wireless access network device 130 sends the 180Ringing signaling to the first wireless access network device 110. After the first wireless access network device 110 receives the 180Ringing signaling, the first wireless access network device 110 determines that the current called terminal, that is, the second terminal device 150, is in a state where voice packets can be sent and received. The first wireless access network device 110 is in the connected state, that is, the state in which voice packets can be forwarded normally, and the 180Ringing signaling is sent to the first terminal device 140. After the first terminal device 140 receives the 180Ringing signaling, the call state of the first terminal device 140 is updated to the ringback tone state, and the first terminal device 140 starts to play the ringback tone. The ringback tone state refers to the state in which when the call is successful but the called user does not answer the call, the calling party terminal device sends a ringback tone to remind the user that the called user has not answered the call. Ringback tones include: vibration, color ringback, beep, personalized music, songs, recordings, videos, etc., which are not limited here.

[0258] Step S612 : The second terminal device 150 sends a 200 OK (INVITE) signaling to the first terminal device 140 .

[0259] Step S613: The first terminal device 140 sends an ACK signaling to the second terminal device 150.

[0260] Step S614 : the second terminal device 150 sends a first voice packet to the first terminal device 140 .

[0261] Step S615 : the first terminal device 140 sends a second voice packet to the second terminal device 150 .

[0262] Understandably, Figure 6 Steps S612 to S615 in Figure 3 The steps S312 to S315 are the same as in the above. For relevant explanations, please refer to the descriptions in steps S312 to S315, which will not be repeated here.

[0263] Therefore, in the embodiment of the present application, the 200OK (UPDATE) signaling received by the first wireless access network device 110 does not include a=curr:qos local none information, but includes a=curr:qos local sendrecv information, and the first wireless access network device 110 can forward the voice packet normally. In the embodiment of the present application, because even if the second voice bearer is established later, the second terminal device 150 will not send a 200OK (UPDATE) signaling including a=curr:qoslocal none information to the first terminal device 140, but sends a 200OK (UPDATE) signaling including a=curr:qos local sendrecv information, so regardless of whether there is a disorder of 180Ringing and 200OK (UPDATE) signaling, the situation of silence, call drop or call drop after silence on both ends of the calling and called terminals during the call will not occur.

[0264] Optionally, in other embodiments, to solve Figure 5 In the corresponding implementation, the user cannot hear the sound after answering the call. Figure 8 As shown, another optimization solution is provided to avoid the problem of silence, call drop or call drop after silence caused by disorder of 180Ringing and 200OK (UPDATE) signaling on the network side. Figure 3 The steps S301 to S308 in the above are the same, and the relevant explanations can refer to the descriptions in the steps S301 to S308, and the relevant explanations can refer to the descriptions in the steps S301 to S308, which will not be repeated here. In step S809 and thereafter, Figure 8 The corresponding method may further include the following steps:

[0265] Step S809: The second terminal device 150 sends a 200 OK (UPDATE) signaling to the third radio access network device 130 and then starts a timer.

[0266] The timer can be expressed as 180_delay_timer, which can cause the second terminal device 150 to delay sending the 180Ringing signaling for a certain period of time, and the certain period of time is not limited in the embodiment of the present application. For ease of description, the timer is written as 180_delay_timer below. This name is only used as an example, and in actual applications, it can be other forms of timers. Starting the timer can be expressed as the second terminal device 150 starting the timing, and the 180Ringing signaling is sent based on the timing duration being greater than the preset duration.

[0267] Optionally, in one implementation, after receiving the UPDATE signaling, the second terminal device 150 checks the voice bearer status of the second terminal device 150. When the second terminal device 150 confirms that it has not received the voice dedicated bearer establishment instruction issued by the third radio access network device 130, that is, when the second voice bearer has not been established, the second terminal device 150 sends a 200OK (UPDATE) signaling to the third radio access network device 130. The 200OK (UPDATE) signaling includes a=curr:qos local none information, and the 200OK (UPDATE) signaling can indicate that the second voice bearer of the second terminal device 150 has not been established. After the second terminal device 150 sends the 200OK (UPDATE) signaling to the third radio access network device 130, the 180_delay_timer is started.

[0268] Optionally, in another implementation, after receiving the UPDATE signaling, the second terminal device 150 checks the voice bearer status of the second terminal device 150. When the second terminal device 150 confirms that it has not received the voice dedicated bearer establishment instruction issued by the third wireless access network device 130, that is, when the second voice bearer has not been established, the second terminal device 150 starts 180_delay_timer. After the second terminal device 150 starts 180_delay_timer, the second terminal device 150 starts timing. After the timing ends, the second terminal device 150 sends a 200OK (UPDATE) signaling to the third wireless access network device 130, and the 200OK (UPDATE) signaling contains a = curr: qos local none information.

[0269] Optionally, combined Fig. 9 After the second terminal device 150 receives the UPDATE signaling, the second terminal device 150 determines whether to send a 200OK (UPDATE) signaling containing the information a=curr:qos local none. Under the condition that the second terminal device 150 sends a 200OK (UPDATE) signaling containing the information a=curr:qos local none, the timer is started; under the condition that the second terminal device 150 sends a 200OK (UPDATE) signaling that does not contain the information a=curr:qos local none, the timer is not started. The embodiment of the present application does not limit the execution time of the above judgment.

[0270] Optionally, in some embodiments, the second terminal device 150 may also perform the following four judgments after sending a 200OK (UPDATE) signaling to the third wireless access network device 130: (1) judging that the first terminal device 140 supports resource reservation through the resource reservation flag of the first terminal device 140; (2) judging that the second terminal device 150 supports resource reservation through the support field in the received INVITE signaling carrying a precondition tag; (3) judging that the current call is an EPSFB call with reference to step S404; (4) judging that the sent 200OK (UPDATE) signaling contains a=curr:qos local none information. If the second terminal device 150 judges that the above four conditions are met, the second terminal device 150 starts the timer. The embodiments of the present application do not limit the execution timing of the above judgments.

[0271] It should be noted that the start time of 180_delay_timer may be after the second terminal device 150 sends a 200OK (UPDATE) signaling to the third radio access network device 130 and before the third radio access network device 130 sends a voice dedicated bearer establishment instruction to the second terminal device 150. The start time may also be after the third radio access network device 130 sends a voice dedicated bearer establishment instruction to the second terminal device 150.

[0272] Step S810: The third radio access network device 130 sends a voice dedicated bearer establishment instruction to the second terminal device 150.

[0273] It should be noted that Figure 8 Step S810 in Figure 3 The same as step S310 in , the relevant explanations can refer to the description in step S310, which will not be repeated here.

[0274] Step S811: After the 180_delay_timer times out, the second terminal device 150 sends a 180Ringing signaling to the first terminal device 140.

[0275] Optionally, after the second terminal device 150 checks and finds that its own second voice bearer has been established, the second terminal device 150 sends the 180Ringing signaling only after the 180_delay_timer times out. After the second terminal device 150 sends the 180Ringing signaling, the call state of the second terminal device 150 is updated to the ringing state, and the second terminal device 150 starts ringing. The ringing state refers to the state in which when there is an incoming call, the user has not answered the call, and the called party's terminal device rings to remind the user of the incoming call; the ringtones when the ringing starts include: vibration, color ringback tone, beep, personalized music, songs, recordings, videos, etc., which are not limited here. After the third wireless access network device 130 receives the 180Ringing signaling, the third wireless access network device 130 network is set to the connected state, the first wireless access network device 110 determines that the current called terminal, that is, the second terminal device 150, is in a state where voice packets can be sent and received, and the first wireless access network device 110 is set to the connected state, that is, the state where voice packets can be forwarded normally, and sends the 180Ringing signaling to the first terminal device 140; after the first terminal device 140 receives the 180Ringing signaling, the call state of the first terminal device 140 is updated to the ringback tone state, and the first terminal device 140 starts to play the ringback tone. The ringback tone state refers to the state in which the calling party terminal device sends a ringback tone to remind the user that the called party user has not answered the call when the call is successful and the called party user has not answered the call; the ringback tone includes: vibration, color ringback, beep, personalized music, song, recording, video, etc., which are not limited here.

[0276] In some implementations, the preset duration of 180_delay_timer is greater than the time taken by the third radio access network device 130 to send a 200OK (UPDATE) signaling to the first terminal device 140. Therefore, the embodiment of the present application provides a method that can ensure that the time when the first radio access network device 110 receives the 180Ringing signaling is later than the time when it receives the 200OK (UPDATE) signaling, so that the first radio access network device 110 can forward the voice packet normally. It can be understood that in the embodiment of the present application, the preset duration of 180_delay_timer can be 0.3s, 0.5s, etc., which is sufficient to ensure that the above-mentioned effect is achieved, and the embodiment of the present application does not impose specific restrictions on the waiting duration.

[0277] Figure 8 Steps S812 to S815 in Figure 3 The steps S312 to S315 are the same as in the above. For relevant explanations, please refer to the descriptions in steps S312 to S315, which will not be repeated here.

[0278] exist Figure 8In the steps S809 to S811 shown, the second terminal device 150 sends a 200OK (UPDATE) signaling to the third wireless access network device 130 and starts the 180_delay_timer thereafter, so that the second terminal device 150 sends the 180Ringing signaling to the first terminal device 140 only after the 180_delay_timer times out. The embodiment of the present application ensures that the first wireless access network device 110 first receives the 200OK (UPDATE) signaling containing the information a=curr:qos local none, and then receives the 180Ringing signaling, so that the network state of the first wireless access network device 110 can be refreshed to a state where voice packets can be forwarded normally. The embodiment of the present application provides a communication method for dealing with the silence, call drop, or call drop after silence of the calling and called terminals caused by the disorder of the 180Ringing and 200OK (UPDATE) signaling on the network side, so as to ensure that the voice of the terminal device is normal in abnormal scenarios.

[0279] Optionally, in other embodiments, to solve Figure 5 In the corresponding implementation, the user cannot hear the sound after answering the call, such as Fig.10 As shown, another communication method is provided. Figure 3 , the steps before step S1007 are respectively Figure 3 The steps S301 to S306 in the embodiment are the same as those in the embodiment. For the related explanations, please refer to the descriptions in the steps S301 to S306, which will not be repeated here. Figure 5 , Fig.10 In the method shown, steps S1007 to S1015 are Figure 5 After step S1013, the first terminal device 140 and the second terminal device 150 cannot receive voice from each other. Fig.10 The method shown in the figure further includes the following steps after step S1015:

[0280] Step S1016 : The first terminal device 140 sends a first reINVITE signaling to the second terminal device 150 .

[0281] The first reINVITE signaling may be first re-request information. The first reINVITE signaling includes a=sendonly information. The first reINVITE signaling may indicate that the first terminal device 140 informs the second terminal device 150 that the first terminal device 140 is currently in a sendonly state.

[0282] The first reINVITE signaling may be the third INVITE signaling, and the first reINVITE signaling may include invite. The first reINVITE signaling may include INVITE. The reINVITE signaling may be written as INVITE signaling, reinvite signaling, re-invite signaling, or other forms, which shall be subject to the relevant protocols. However, in order to facilitate the expression and to indicate the difference from the INVITE signaling in other steps, this application uniformly writes reINVITE signaling. The first reINVITE signaling includes the same SIP Call ID as the INVITE signaling in step S1001, i.e., step S301. Other reINVITE signaling in this application may refer to the explanation here.

[0283] Optionally, the first terminal device 140 determines that the following conditions are met based on the 180Ringing signaling and 200OK (UPDATE) signaling received during the call establishment process: (1) the 180Ringing signaling is received first and the 200OK (UPDATE) signaling is received later; (2) and the 200OK (UPDATE) signaling contains a=curr:qos local none information, the first terminal device 140 sends a first reINVITE signaling to the first wireless access network device 110. After the first wireless access network device 110 receives the first reINVITE signaling, it sends the first reINVITE signaling to the third wireless access network device 130. After the third wireless access network device 130 receives the first reINVITE signaling, it sends the first reINVITE signaling to the second terminal device 150.

[0284] Optionally, combined Fig.12After the first terminal device 140 receives the 200OK (INVITE) signaling, the first terminal device 140 determines whether the time when it receives the 180Ringing signaling is earlier than the time when it receives the 200OK (UPDATE) signaling. Under the condition that the time when the first terminal device 140 receives the 180Ringing signaling is later than the time when it receives the 200OK (UPDATE) signaling, the first terminal device 140 does not send the first reINVITE signaling. Under the condition that the time when the first terminal device 140 receives the 180Ringing signaling is earlier than the time when it receives the 200OK (UPDATE) signaling, the first terminal device 140 determines whether the received 200OK (UPDATE) signaling contains local none information. Under the condition that the 200OK (UPDATE) signaling received by the first terminal device 140 does not contain local none information, the first terminal device 140 does not send the first reINVITE signaling. Under the condition that the 200 OK (UPDATE) signaling received by the first terminal device 140 includes local none information, the first terminal device 140 sends a first reINVITE signaling.

[0285] Optionally, in some embodiments, the first terminal device 140 can also perform the following four judgments: (1) judging that the first terminal device 140 supports resource reservation through the resource reservation flag of the first terminal device 140; (2) judging that the second terminal device 150 supports resource reservation through the support field in the received INVITE signaling carrying the precondition flag; (3) judging that the current call is an EPSFB call with reference to step S404; (4) judging that the 180Ringing signaling is received first, and then the 200OK (UPDATE) signaling is received and the 200OK (UPDATE) signaling contains a=curr:qos local none information. When the first terminal device 140 judges that the above four conditions are met, the first terminal device 140 sends a first reINVITE signaling to the second terminal device 150 and performs the following steps. The embodiments of the present application do not limit the execution timing of the above judgments.

[0286] Step S1017 : The second terminal device 150 sends a first 200 OK (reINVITE) signaling to the first terminal device 140 .

[0287] The first 200OK (reINVITE) signaling may be the fourth 200OK signaling, which may indicate that the second terminal device 150 informs the first terminal device 140 that the first reINVITE signaling has been received and that the second terminal device 150 is currently in the recvonly state. The first 200OK (reINVITE) signaling includes a=recvonly.

[0288] The first 200OK (reINVITE) signaling can be written as 200OK signaling, 200OK (REINVITE) signaling, or other forms, which are subject to the relevant protocols. However, for the convenience of expression and to show the difference from the 200OK signaling in other steps, this application uniformly writes it as 200OK (reINVITE) signaling. Other 200OK (reINVITE) signaling in this application can refer to the explanation here.

[0289] Optionally, after the second terminal device 150 receives the first reINVITE signaling, the second terminal device 150 sends a first 200OK (reINVITE) signaling to the third wireless access network device 130, and after the third wireless access network device 130 receives the first 200OK (reINVITE) signaling, it sends the first 200OK (reINVITE) signaling to the first wireless access network device 110, and after the first wireless access network device 110 receives the first 200OK (reINVITE) signaling, it sends the first 200OK (reINVITE) signaling to the first terminal device 140.

[0290] Step S1018 : The first terminal device 140 sends a first ACK signaling to the second terminal device 150 .

[0291] The first ACK signaling may be the third confirmation information, and the first ACK signaling may indicate that the first terminal device 140 confirms to the second terminal device 150 that it has received the first 200 OK (reINVITE) signaling sent by the second terminal device 150 to the first terminal device 140 .

[0292] Optionally, after the first terminal device 140 receives the first 200OK (reINVITE) signaling, the first terminal device 140 sends a first ACK signaling to the first wireless access network device 110, and the first wireless access network device 110 sends the first ACK signaling received from the first terminal device 140 to the third wireless access network device 130. After the third wireless access network device 130 receives the first ACK signaling, the third wireless access network device 130 sends the received first ACK signaling to the second terminal device 150.

[0293] Step S1019 : The first terminal device 140 sends a second reINVITE signaling to the second terminal device 150 .

[0294] The second reINVITE signaling may be a second re-request message, the second reINVITE signaling includes a=sendrecv information, and the second reINVITE signaling may indicate that the first terminal device 140 tells the second terminal device 150 that the first terminal device 140 is currently in the sendrecv state. The second reINVITE signaling may be a second INVITE signaling, and the second reINVITE signaling may include invite. The second reINVITE signaling includes the same SIP Call ID as the first INVITE signaling in step S1001, i.e., step S301.

[0295] Optionally, the first terminal device 140 sends a second reINVITE signaling to the first wireless access network device 110, and after the first wireless access network device 110 receives the second reINVITE signaling, sends a second reINVITE signaling to the third wireless access network device 130, and after the third wireless access network device 130 receives the second reINVITE signaling, sends a second reINVITE signaling to the second terminal device 150.

[0296] Step S1020 : The second terminal device 150 sends a second 200 OK (reINVITE) signaling to the first terminal device 140 .

[0297] The second 200OK (reINVITE) signaling may be the fifth response information, and the second 200OK (reINVITE) signaling may indicate that the second terminal device 150 notifies the first terminal device 140 that the second reINVITE signaling has been received, and notifies the first terminal device 140 that the second terminal device 150 is currently in the sendrecv state. The second 200OK (reINVITE) signaling includes 200OK and a=sendrecv.

[0298] Optionally, after the second terminal device 150 receives the second reINVITE signaling, the second terminal device 150 sends a second 200OK (reINVITE) signaling to the third wireless access network device 130. After the third wireless access network device 130 receives the second 200OK (reINVITE) signaling, it sends a second 200OK (reINVITE) signaling to the first wireless access network device 110. The first wireless access network device 110 receives the second 200OK (reINVITE) signaling containing sendrecv information, determines to restore the normal state of sending and receiving voice packets, and after the first wireless access network device 110 receives the second 200OK (reINVITE) signaling, it sends a second 200OK (reINVITE) signaling to the first terminal device 140.

[0299] Step S1021 : the first terminal device 140 sends a second ACK signaling to the second terminal device 150 .

[0300] The second ACK signaling may be fourth confirmation information, and the second ACK signaling may indicate that the first terminal device 140 confirms to the second terminal device 150 that it has received the second 200 OK (reINVITE) signaling sent by the second terminal device 150 to the first terminal device 140 for the second time.

[0301] Optionally, after the first terminal device 140 receives the second 200OK (reINVITE) signaling, the first terminal device 140 sends a second ACK signaling to the first wireless access network device 110, and the first wireless access network device 110 sends the second ACK signaling received from the first terminal device 140 to the third wireless access network device 130. After the third wireless access network device 130 receives the second ACK signaling, the third wireless access network device 130 sends the received second ACK signaling to the second terminal device 150.

[0302] It should be noted that Fig.10 Steps S1022 to S1023 in Figure 3 The steps S314 to S315 are the same as in the above. For relevant explanations, please refer to the descriptions in steps S314 and S315, which will not be repeated here.

[0303] exist Fig.10In steps S1016 to S1021 shown, when the conditions described in step S1016 are met, the first terminal device 140 actively sends a first reINVITE signaling and a second reINVITE signaling to the second terminal device 150, and the signaling respectively includes a=sendonly information and a=sendrecv information. The first wireless access network device 110 determines that the second terminal device is in a state where it can normally send and receive voice packets, and sets the first wireless access network device 110 to a state where it can normally forward voice packets, so that user B can hear the sound normally after the call is connected, ensuring that the voice of the terminal device is normal in abnormal scenarios.

[0304] Optionally, in other embodiments, to solve Figure 5 In the corresponding implementation, the user cannot hear the sound after answering the call, such as Fig.11 As shown, another communication method is provided. Figure 3 , the steps before step S1107 are respectively Figure 3 The steps S301 to S308 in the embodiment are the same as those in the embodiment. For the related explanations, please refer to the descriptions in the steps S301 to S308, which will not be repeated here. Figure 5 , Fig.11 In the method shown, steps S1109 to S1115 are Figure 5 After step S1113, the first terminal device 140 and the second terminal device 150 cannot receive voice from each other. Fig.11 The method shown in the figure further includes the following steps after step S1115:

[0305] Step S1116 : The first terminal device 140 sends a third reINVITE signaling to the second terminal device 150 .

[0306] The third reINVITE signaling may be a third re-request message, the third reINVITE signaling includes a=sendrecv information, and the third reINVITE signaling may indicate that the first terminal device 140 tells the second terminal device 150 that the first terminal device 140 is currently in the sendrecv state. The third reINVITE signaling may be the second INVITE signaling, and the third reINVITE signaling may include invite. The third reINVITE signaling includes the same SIP Call ID as the first INVITE signaling in step S1001, i.e., step S301.

[0307] Optionally, the first terminal device 140 determines that the following conditions are met based on the 180Ringing signaling and 200OK (UPDATE) signaling received during the call establishment process: (1) the 180Ringing signaling is received first and the 200OK (UPDATE) signaling is received later; (2) and the 200OK (UPDATE) signaling contains the information a=curr:qos local none, the first terminal device 140 sends a third reINVITE signaling to the first wireless access network device 110, and after the first wireless access network device 110 receives the third reINVITE signaling, the first terminal device 140 sends a third reINVITE signaling to the third wireless access network device 130, and after the third wireless access network device 130 receives the third reINVITE signaling, the third reINVITE signaling is sent to the second terminal device 150.

[0308] Optionally, combined Fig.12 After the first terminal device 140 receives the 200OK (INVITE) signaling, the first terminal device 140 determines whether the time when it receives the 180Ringing signaling is earlier than the time when it receives the 200OK (UPDATE) signaling. Under the condition that the time when the first terminal device 140 receives the 180Ringing signaling is later than the time when it receives the 200OK (UPDATE) signaling, the first terminal device 140 does not send a reINVITE signaling. Under the condition that the time when the first terminal device 140 receives the 180Ringing signaling is earlier than the time when it receives the 200OK (UPDATE) signaling, the first terminal device 140 determines whether the received 200OK (UPDATE) signaling contains local none information. Under the condition that the 200OK (UPDATE) signaling received by the first terminal device 140 does not contain local none information, the first terminal device 140 does not send a reINVITE signaling. Under the condition that the 200OK (UPDATE) signaling received by the first terminal device 140 contains local none information, the first terminal device 140 sends a reINVITE signaling.

[0309] Optionally, in some embodiments, the first terminal device 140 can also perform the following four judgments: (1) judging that the first terminal device 140 supports resource reservation through the resource reservation flag of the first terminal device 140; (2) judging that the second terminal device 150 supports resource reservation through the support field in the received INVITE signaling carrying the precondition flag; (3) judging that the current call is an EPSFB call with reference to step S404; (4) judging that the 180Ringing signaling is received first, and then the 200OK (UPDATE) signaling is received and the 200OK (UPDATE) signaling contains a=curr:qos local none information. When the first terminal device 140 judges that the above four conditions are met, the first terminal device 140 sends a third reINVITE signaling to the second terminal device 150 and performs the following steps. The embodiments of the present application do not limit the execution timing of the above judgments.

[0310] Step S1117 : The second terminal device 150 sends a third 200 OK (reINVITE) signaling to the first terminal device 140 .

[0311] The third 200OK (reINVITE) signaling may be the fifth 200OK signaling, which may indicate that the second terminal device 150 informs the first terminal device 140 that the third reINVITE signaling has been received and informs the first terminal device 140 that the second terminal device 150 is currently in the sendrecv state. The third 200OK (reINVITE) signaling includes 200OK and a=sendrecv.

[0312] Optionally, after the second terminal device 150 receives the third reINVITE signaling, the second terminal device 150 sends a third 200OK (reINVITE) signaling to the third wireless access network device 130. After the third wireless access network device 130 receives the third 200OK (reINVITE) signaling, it sends a third 200OK (reINVITE) signaling to the first wireless access network device 110. The first wireless access network device 110 receives the third 200OK (reINVITE) signaling containing sendrecv information and resumes normal sending and receiving of voice packets. After the first wireless access network device 110 receives the third 200OK (reINVITE) signaling, it sends a third 200OK (reINVITE) signaling to the first terminal device 140.

[0313] Step S1118 : The first terminal device 140 sends an ACK signaling to the second terminal device 150 .

[0314] The ACK signaling may be fifth confirmation information, and the ACK signaling may indicate that the first terminal device 140 confirms to the second terminal device 150 that it has received the third 200 OK (reINVITE) signaling sent by the second terminal device 150 to the first terminal device 140 .

[0315] Optionally, after the first terminal device 140 receives the third 200OK (reINVITE) signaling, the first terminal device 140 sends an ACK signaling to the first wireless access network device 110, and the first wireless access network device 110 sends the ACK signaling received from the first terminal device 140 to the third wireless access network device 130. After the third wireless access network device 130 receives the ACK signaling, the third wireless access network device 130 sends the received ACK signaling to the second terminal device 150.

[0316] It should be noted that Fig.11 Steps S1119 to S1120 in Figure 3 The steps S314 to S315 are the same as in the above. For relevant explanations, please refer to the descriptions in steps S314 and S315, which will not be repeated here.

[0317] exist Fig.11 In the steps S1118 to S1120 shown, when the conditions described in step S1118 are met, the first terminal device 140 actively sends a reINVITE signaling to the second terminal device 150, and the signaling includes a=sendrecv information. After receiving the third 200OK (reINVITE) signaling, the network status of the first wireless access network device 110 determines that the second terminal device 150 can normally send and receive voice packets. The status of the first wireless access network device 110 is set to a status in which voice packets can be sent and received normally, so that user B can hear the sound normally after the call is connected, ensuring that the voice of the terminal device is normal in abnormal scenarios.

[0318] It should be noted that Figures 2 to 12 The interaction diagram shown in the figure is only for ease of understanding, and is not intended to limit the embodiments of the present application to the examples shown in the figure. Figures 2 to 12 The examples in can be equivalently transformed to obtain more implementation methods.

[0319] Combination of the above Figures 2 to 12 , describes in detail the communication method provided by the embodiment of the present application. Fig.13 It should be noted that the communication device of the embodiment of the present application can execute various communication methods of the aforementioned embodiment of the present application, that is, the specific working process of the following various products can refer to the corresponding process in the aforementioned method embodiment.

[0320] The call request processing method provided in the embodiments of the present application can be applicable to mobile phones, tablet computers, desktops, laptops, notebook computers, ultra-mobile personal computers (UMPC), handheld computers, netbooks, personal digital assistants (PDA), wearable electronic devices, smart watches and other electronic devices that can support calls. The UE mentioned above may also belong to such electronic devices.

[0321] By way of example, the hardware structure of the terminal device is described. Fig.13 As shown, Fig.13 The terminal device 1300 may include a processor 1310 , a power management module 1341 , a battery 1342 , an audio module 1370 , a sensor module 1380 , and a display screen 1394 .

[0322] Among them, the sensor module includes a touch sensor 1380K, which can be a touch screen, also known as a "touch panel". The touch sensor 1380K can be set together with the display screen 1394, and the touch sensor 1380K and the display screen 1394 form a touch screen, also known as a "touch screen". The touch sensor 1380K is used to detect touch operations acting on or near it. The touch sensor can pass the detected touch operation to the application processor to determine the type of touch event. Visual output related to the touch operation can be provided through the display screen 1394. In other embodiments, the touch sensor 1380K can also be set on the surface of the terminal device 1300, which is different from the position of the display screen 1394. The display screen 1394 is used to display images, videos, etc.

[0323] The processor 1310 may include one or more processing units, for example: the processor 1310 may include an application processor (application processor, AP), a modem processor, a graphics processor (graphics processing unit, GPU), an image signal processor (image signal processor, ISP), a controller, a memory, a video codec, a digital signal processor (digital signal processor, DSP), a baseband processor, and / or a neural-network processing unit (neural-network processing unit, NPU), etc. Among them, different processing units can be independent devices or integrated in one or more processors. A memory can also be set in the processor 1310 for storing instructions and data. In some embodiments, the processor 1310 may include one or more interfaces. The interface may include an inter-integrated circuit (I2C) interface, an inter-integrated circuit sound (I2S) interface, a pulse code modulation (PCM) interface, a universal asynchronous receiver / transmitter (UART) interface, a mobile industry processor interface (MIPI), a general-purpose input / output (GPIO) interface, a subscriber identity module (SIM) interface, and / or a universal serial bus (USB) interface, etc.

[0324] It is understandable that the interface connection relationship between the modules illustrated in this embodiment is only a schematic illustration and does not constitute a structural limitation on the electronic device 1300. In other embodiments of the present application, the electronic device 1300 may also adopt different interface connection methods in the above embodiments, or a combination of multiple interface connection methods.

[0325] Optionally, the terminal device 1300 may also include an external memory interface 1320, an internal memory 1321, a universal serial bus (USB) interface 1330, a charging management module 1340, an antenna 1, an antenna 2, a mobile communication module 1350, a wireless communication module 1360, a button 1390, a motor 1391, an indicator 1392, a camera 1393, and a subscriber identification module (SIM) card interface 1395, etc.

[0326] The internal memory 1321 can be used to store computer executable program codes, and the executable program codes include instructions. The processor 1310 executes various functional applications and data processing of the electronic device 1300 by running the instructions stored in the internal memory 1321. The internal memory 1321 may include a program storage area and a data storage area. Among them, the program storage area may store an operating system, an application required for at least one 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 1321 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. The processor 1310 executes various functional applications and data processing of the electronic device by running the instructions stored in the internal memory 1321, and / or the instructions stored in the memory provided in the processor.

[0327] The electronic device implements the display function through a GPU, a display screen 1330, and an application processor. The GPU is a microprocessor for image processing, connecting the display screen 1330 and the application processor. The GPU is used to perform mathematical and geometric calculations for graphics rendering. The processor 1310 may include one or more GPUs that execute program instructions to generate or change display information.

[0328] The display screen 1330 is used to display images, videos, etc. The display screen 1330 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 or an active-matrix organic light-emitting diode (AMOLED), a flexible light-emitting diode (FLED), Miniled, MicroLed, Micro-oled, a quantum dot light-emitting diode (QLED), etc. In some embodiments, the electronic device may include 1 or N display screens 1330, where N is a positive integer greater than 1.

[0329] The electronic device can realize the shooting function through the ISP, the camera 1340, the video codec, the GPU, the display screen 1330 and the application processor.

[0330] The ISP is used to process the data fed back by the camera 1340. For example, when taking a photo, the shutter is opened, and the light is transmitted to the camera photosensitive element through the lens. The light signal is converted into an electrical signal, and the camera photosensitive element transmits the electrical signal to the ISP for processing and converts it into an image visible to the naked eye. The ISP can also perform algorithm optimization on the noise, brightness, and skin color of the image. The ISP can also optimize the exposure, color temperature and other parameters of the shooting scene. In some embodiments, the ISP can be set in the camera 1340.

[0331] The wireless communication function of the electronic device can be implemented through antenna 1, antenna 2, mobile communication module 1350, wireless communication module 1360, modem processor and baseband processor.

[0332] Antenna 1 and antenna 2 are used to transmit and receive electromagnetic wave signals. Each antenna in the electronic device can be used to cover a single or multiple communication frequency bands. Different antennas can also be reused to improve the utilization of the antennas. For example, antenna 1 can be reused as a diversity antenna for a wireless local area network. In some other embodiments, the antenna can be used in combination with a tuning switch.

[0333] The mobile communication module 1350 can provide solutions for wireless communications including 2G / 3G / 4G / 5G applied to electronic devices. The mobile communication module 1350 may include at least one filter, a switch, a power amplifier, a low noise amplifier (LNA), etc. The mobile communication module 1350 can receive electromagnetic waves from the antenna 1, and filter, amplify, and process the received electromagnetic waves, and transmit them to the modulation and demodulation processor for demodulation. The mobile communication module 1350 can also amplify the signal modulated by the modulation and demodulation processor, and convert it into electromagnetic waves for radiation through the antenna 1. In some embodiments, at least some of the functional modules of the mobile communication module 1350 can be set in the processor 1310. In some embodiments, at least some of the functional modules of the mobile communication module 1350 can be set in the same device as at least some of the modules of the processor 1310.

[0334] In some embodiments, the electronic device initiates or receives a call request through the mobile communication module 1350 and the antenna 1.

[0335] The wireless communication module 1360 can provide wireless communication solutions including wireless local area networks (WLAN) (such as wireless fidelity (Wi-Fi) networks), bluetooth (BT), global navigation satellite system (GNSS), frequency modulation (FM), near field communication (NFC), infrared (IR), etc., which are applied to electronic devices. The wireless communication module 1360 can be one or more devices integrating at least one communication processing module. The wireless communication module 1360 receives electromagnetic waves via antenna 3, modulates and filters the electromagnetic wave signals, and sends the processed signals to the processor 1310. The wireless communication module 1360 can also receive the signal to be sent from the processor 1310, modulate the frequency, amplify it, and convert it into electromagnetic waves for radiation through antenna 2.

[0336] Optionally, in one implementation, the audio module 1370 may include a speaker 1370A, a receiver 1370B, a microphone 1370C, and an earphone jack 1370D; the sensor module 1380 may include a touch sensor 1380K, and may also include at least one of a pressure sensor 1380A, a gyroscope sensor 1380B, an air pressure sensor 1380C, a magnetic sensor 1380D, an acceleration sensor 1380E, a distance sensor 1380F, a proximity light sensor 1380G, a fingerprint sensor 1380H, a temperature sensor 1380J, an ambient light sensor 1380L, and a bone conduction sensor 1380M.

[0337] The electronic device 1300 can implement audio functions such as music playing and recording through the audio module 1370, the speaker 1370A, the receiver 1370B, the microphone 1370C, the headphone jack 1370D, and the application processor.

[0338] The audio module 1370 is used to convert digital audio information into analog audio signal output, and is also used to convert analog audio input into digital audio signal. The audio module 1370 can also be used to encode and decode audio signals. In some embodiments, the audio module 1370 can be arranged in the processor 1310, or some functional modules of the audio module 1370 can be arranged in the processor 1310.

[0339] The speaker 1370A, also called a "speaker", is used to convert an audio electrical signal into a sound signal. The electronic device 1300 can listen to music or listen to a hands-free call through the speaker 1370A.

[0340] The receiver 1370B, also called a "earpiece", is used to convert audio electrical signals into sound signals. When the electronic device 1300 receives a call or voice message, the voice can be received by placing the receiver 1370B close to the human ear.

[0341] Microphone 1370C, also called "microphone" or "microphone", is used to convert sound signals into electrical signals. When making a call or sending a voice message, the user can speak by putting their mouth close to the microphone 1370C to input the sound signal into the microphone 1370C. The electronic device 1300 can be provided with at least one microphone 1370C. In other embodiments, the electronic device 1300 can be provided with two microphones 1370C, which can not only collect sound signals but also realize noise reduction function. In other embodiments, the electronic device 1300 can also be provided with three, four or more microphones 1370C to collect sound signals, reduce noise, identify the source of sound, realize directional recording function, etc.

[0342] The earphone jack 1370D is used to connect a wired earphone and can be a USB interface, or a 3.5 mm open mobile terminal platform (OMTP) standard interface, or a cellular telecommunications industry association of the USA (CTIA) standard interface.

[0343] It should be noted that the structure illustrated in the embodiment of the present application does not constitute a specific limitation on the terminal device 1300. In other embodiments of the present application, the terminal device 1300 may include more or fewer components than shown in the figure, or combine some components, or split some components, or arrange the components differently. The components shown in the figure may be implemented in hardware, software, or a combination of software and hardware.

[0344] In addition, an operating system runs on the above components, such as an iOS operating system, an Android operating system, a Windows operating system, etc. Application programs can be installed and run on the operating system.

[0345] Exemplarily, the software architecture of the terminal device is described. The terminal device may be Fig.13 The terminal device 1300 shown, the software system of the terminal device can adopt a layered architecture, an event-driven architecture, a micro-core architecture, a micro-service architecture, or a cloud architecture. The embodiment of the present application takes a software system of a layered architecture as an example to exemplify the software structure of the terminal device 1300. Fig.14 This is a software architecture block diagram of a terminal device provided in an embodiment of the present application. Fig.14 by Fig.13 The software architecture of the terminal device 1300 shown in FIG. 1 is used as an example for explanation. Fig.14 It is a software structure block diagram of the electronic device according to an embodiment of the present application.

[0346] The layered architecture divides the software into several layers, each with clear roles and division of labor. The layers communicate with each other through software interfaces. In some embodiments, the Android system is divided into four layers, from top to bottom: the application layer, the application framework layer, the Android runtime and system library, and the kernel layer.

[0347] The application layer can include a series of application packages. Fig.14 As shown, the application package may include camera, gallery, calendar, call, map, navigation, WLAN, Bluetooth, music, video, short message and other applications.

[0348] The application framework layer provides application programming interface (API) and programming framework for the applications in the application layer. The application framework layer includes some predefined functions. Fig.14 As shown, the application framework layer may include a window manager, a content provider, a phone manager, a resource manager, a notification manager, a view system, and the like.

[0349] The window manager is used to manage window programs. The window manager can obtain the display screen size, determine whether there is a status bar, lock the screen, capture the screen, etc.

[0350] Content providers are used to store and retrieve data and make it accessible to applications. The data may include videos, images, audio, calls made and received, browsing history and bookmarks, phone books, etc.

[0351] The phone manager is used to provide communication functions for electronic devices, such as the management of call status (including answering, hanging up, etc.).

[0352] The resource manager provides various resources for applications, such as localized strings, icons, images, layout files, video files, and so on.

[0353] The notification manager enables applications to display notification information in the status bar. It can be used to convey notification-type messages and can disappear automatically after a short stay without user interaction. For example, the notification manager is used to notify download completion, message reminders, etc. The notification manager can also be a notification that appears in the system top status bar in the form of a chart or scroll bar text, such as notifications of applications running in the background, or a notification that appears on the screen in the form of a dialog window. For example, a text message is displayed in the status bar, a prompt sound is emitted, an electronic device vibrates, an indicator light flashes, etc.

[0354] The view system includes visual controls, such as controls for displaying text, controls for displaying images, etc. The view system can be used to build applications. A display interface can be composed of one or more views. For example, a display interface including a text notification icon can include a view for displaying text and a view for displaying images.

[0355] The core library consists of two parts: one is the function that needs to be called by the Java language, and the other is the Android core library.

[0356] The application layer and the application framework layer run in a virtual machine. The virtual machine executes the Java files of the application layer and the application framework layer as binary files. The virtual machine is used to perform functions such as object life cycle management, stack management, thread management, security and exception management, and garbage collection.

[0357] The system library may include multiple functional modules, such as surface manager, media library, 3D graphics processing library (such as OpenGL ES), 2D graphics engine (such as SGL), etc.

[0358] The surface manager is used to manage the display subsystem and provide the fusion of 2D and 3D layers for multiple applications.

[0359] The media library supports playback and recording of a variety of commonly used audio and video formats, as well as static image files, etc. The media library can support a variety of audio and video encoding formats, such as: MPEG2, H.262, MP3, AAC, AMR, JPG, PNG, etc.

[0360] The 3D graphics processing library is used to implement 3D graphics drawing, image rendering, synthesis and layer processing.

[0361] A 2D graphics engine is a drawing engine for 2D drawings.

[0362] The kernel layer is the layer between hardware and software. The kernel layer contains at least display driver, camera driver, audio driver, sensor driver, etc.

[0363] It should be noted that although the embodiments of the present application are described using the Android system as an example, its basic principles are also applicable to electronic devices based on operating systems such as iOS and Windows.

[0364] Fig.15 is a schematic block diagram of a communication device according to an embodiment of the present application. The communication device embodiment corresponds to the method embodiment, and similar descriptions can refer to the method embodiment. Fig.15 The communication device 1500 shown can be used to support execution corresponding to Figures 2 to 12 All steps performed by the first terminal device 140 and the second terminal device 150 in each embodiment of the present invention. The communication device 1500 includes: a processor 1510, a memory 1520 and an antenna 1530. The processor 1510, the memory 1520 and the antenna 1530 are connected by communication. The memory 1520 stores instructions. The processor 1510 is used to execute the instructions stored in the memory 1520. The antenna 1530 is used to perform specific signal transmission and reception under the drive of the processor 1510.

[0365] The processor 1510 is configured to, when the first terminal device 140 initiates a call to the second terminal device 150, receive an INVITE signaling sent by the first terminal device 150; based on the INVITE signaling, send a first signaling to the first terminal device 150, the first signaling including 200OK and a=curr:qos local sendrecv, and the first signaling is sent before receiving the second signaling, the second signaling including QCI=1; after the call is connected, receive voice data sent by the first terminal device 150.

[0366] The various components in the communication device 1500 are connected by communication, that is, the processor 1510, the memory 1520 and the antenna 1530 communicate with each other through the internal connection path to transmit control and / or data signals. The above method embodiments of the present application can be applied to the processor, or the steps of the above method embodiments are implemented by the processor. The processor may be an integrated circuit chip with signal processing capabilities. In the implementation process, the steps of the above method embodiments can be completed by hardware integrated logic circuits in the processor or software instructions. The above processor can be a central processing unit (CPU), a network processor (NP) or a combination of CPU and NP, a digital signal processor (DSP), an application specific integrated circuit (ASIC), a field programmable gate array (FPGA) or other programmable logic devices, discrete gates or transistor logic devices, discrete hardware components. The various methods, steps and logic block diagrams disclosed in this application can be implemented or executed. The general processor can be a microprocessor or the processor can also be any conventional processor, etc. The steps of the method disclosed in the present application can be directly embodied as being executed by a hardware decoding processor, or can be executed by a combination of hardware and software modules in the decoding processor. The software module can be located in a mature storage medium in the art, such as a random access memory, a flash memory, a read-only memory, a programmable read-only memory, or an electrically erasable programmable memory, a register, etc. The storage medium is located in a memory, and the processor reads the information in the memory and completes the steps of the above method in combination with its hardware.

[0367] It should be noted that in the embodiment of the present application, the processor 1510 may be implemented by a processing module, the memory 1520 may be implemented by a storage module, and the antenna 1530 may be implemented by a transceiver module, such as Fig.16As shown, the communication device 1600 may include a processing module 1610 , a storage module 1620 and a transceiver module 1630 .

[0368] Fig.15 The communication device 1500 shown or Fig.16 The communication device 1600 shown can implement the aforementioned Figures 2 to 12 For all the steps in the method, similar descriptions can refer to the description of the method. To avoid repetition, they will not be repeated here.

[0369] Fig.17 A possible schematic structural diagram of a terminal device 1700 involved in the above embodiment is shown, and the terminal device 1700 may be the first terminal device 140 or the second terminal device 150. Fig.17 As shown, the terminal device 1700 may include: a processing module 1710 and a communication module 1720. The processing module 1710 may be used to control and manage the actions of the terminal device. The communication module 1720 may be used to support the communication between the terminal device and other devices.

[0370] The communication module 1720 can be used to support the terminal device 1700 to perform the above Figures 2 to 12 All the steps in .

[0371] The processing module 1710 can be used to support the terminal device to display that the call is connected, play a ringback tone, ring, play voice, etc.

[0372] It should be noted that all relevant contents of each step involved in the above method embodiment can be referred to the functional description of the corresponding functional module and will not be repeated here.

[0373] The terminal device provided in this embodiment is used to execute the above communication method, and thus can achieve the same effect as the above implementation method.

[0374] Among them, the processing module can be a processor or a controller. It can implement or execute various exemplary logic boxes, modules and circuits described in conjunction with the disclosure of this application. The processor can also be a combination that implements computing functions, such as a combination of one or more microprocessors, a combination of digital signal processing (DSP) and a microprocessor, etc. The storage module can be a memory. The communication module can specifically be a device that interacts with other terminal devices, such as a radio frequency circuit, a Bluetooth chip, a Wi-Fi chip, etc.

[0375] In some embodiments, the communication module and the processing module may be integrated into one processor; in other embodiments, the communication module and the processing module may be two processors that implement the functions of the communication module and the processing module respectively.

[0376] Among them, the terminal device, computer storage medium, computer program product or chip provided in this embodiment is used to execute the corresponding method provided above. Therefore, the beneficial effects that can be achieved can refer to the beneficial effects in the corresponding method provided above, and will not be repeated here.

[0377] It is understandable that some optional features in the embodiments of the present application may be implemented independently in certain scenarios without relying on other features, such as the solution on which they are currently based, to solve corresponding technical problems and achieve corresponding effects, or may be combined with other features according to needs in certain scenarios. Accordingly, the devices provided in the embodiments of the present application may also realize these features or functions accordingly, which will not be elaborated here.

[0378] Those skilled in the art may also understand that the various illustrative logical blocks and steps listed in the embodiments of the present application may be implemented by electronic hardware, computer software, or a combination of the two. Whether such functions are implemented by hardware or software depends on the specific application and the design requirements of the entire system. Those skilled in the art may use various methods to implement the functions described for each specific application, but such implementation should not be understood as exceeding the scope of protection of the embodiments of the present application.

[0379] The technology described in this application can be implemented in various ways. For example, these technologies can be implemented in a combination of hardware, software or hardware. For hardware implementation, the processing unit used to perform these technologies at a communication device (e.g., a base station, a terminal, a network entity, or a chip) can be implemented in one or more general-purpose processors, DSPs, digital signal processing devices, ASICs, programmable logic devices, FPGAs, or other programmable logic devices, discrete gates or transistor logic, discrete hardware components, or any combination thereof. The general-purpose processor can be a microprocessor, and optionally, the general-purpose processor can also be any traditional processor, controller, microcontroller or state machine. The processor can also be implemented by a combination of computing devices, such as a digital signal processor and a microprocessor, a plurality of microprocessors, one or more microprocessors in conjunction with a digital signal processor core, or any other similar configuration to implement.

[0380] It can be understood that the memory in the embodiments of the present application can be a volatile memory or a non-volatile memory, or can include both volatile and non-volatile memories. Among them, the non-volatile memory can be a read-only memory (ROM), a programmable read-only memory (PROM), an erasable programmable read-only memory (EPROM), an electrically erasable programmable read-only memory (EEPROM), or a flash memory. The volatile memory can be a random access memory (RAM), which is used as an external cache. By way of example and not limitation, many forms of RAM are available, such as static RAM (SRAM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), double data rate SDRAM (DDR SDRAM), enhanced SDRAM (ESDRAM), synchronous link DRAM (SLDRAM), and direct RAM (DR RAM). It should be noted that the memory of the systems and methods described herein is intended to include, but is not limited to, these and any other suitable types of memory.

[0381] The present application also provides a device, which may specifically be a chip, component or module, and the device may include a connected processor, a memory and a communication module; wherein the memory is used to store computer-executable instructions, and when the device is running, the processor may execute the computer-executable instructions stored in the memory so that the chip executes the communication method in the above-mentioned method embodiments.

[0382] This embodiment also provides a computer storage medium, in which computer instructions are stored. When the computer instructions are executed on a terminal device, the terminal device executes the above-mentioned related method steps to implement the communication method in the above-mentioned embodiment.

[0383] The present application also provides a computer-readable medium on which a computer program is stored. When the computer program is executed by a computer, the functions of any of the above method embodiments are implemented.

[0384] This embodiment also provides a computer program product. When the computer program product is run on a computer, the computer is enabled to execute the above-mentioned related steps to implement the communication method in the above-mentioned embodiment.

[0385] In the above embodiments, it can be implemented in whole or in part by software, hardware, firmware or any combination thereof. When implemented using software, it can be implemented in whole or in part in the form of a computer program product. The computer program product includes one or more computer instructions. When the computer instructions are loaded and executed on a computer, the process or function described in the embodiment of the present application is generated in whole or in part. The computer may be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. The computer instructions may be stored in a computer-readable storage medium, or transmitted from one computer-readable storage medium to another computer-readable storage medium, for example, the computer instructions may be transmitted from a website site, computer, server or data center by wired (e.g., coaxial cable, optical fiber, digital subscriber line (digital subscriber line, DSL)) or wireless (e.g., infrared, wireless, microwave, etc.) mode to another website site, computer, server or data center. The computer-readable storage medium may be any available medium that a computer can access or a data storage device such as a server or data center that includes one or more available media integrated. The available medium may be a magnetic medium (eg, a floppy disk, a hard disk, a magnetic tape), an optical medium (eg, a high-density digital video disc (DVD)), or a semiconductor medium (eg, a solid state disk (SSD)).

[0386] In each of the above embodiments, the electronic device may perform some or all of the steps in each of the embodiments. These steps or operations are merely examples, and the embodiments of the present application may also perform other operations or variations of various operations. In addition, each step may be performed in a different order as presented in each of the embodiments, and it is possible that all of the operations in the embodiments of the present application are not to be performed. Moreover, the size of the sequence number of each step does not mean the order of execution, and the order of execution of each process should be determined by its function and inherent logic, and should not constitute any limitation on the implementation process of the embodiments of the present application.

[0387] Those of ordinary skill in the art will appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of this application.

[0388] Those skilled in the art can clearly understand that, for the convenience and brevity of description, the specific working processes of the systems, devices and units described above can refer to the corresponding processes in the aforementioned method embodiments and will not be repeated here.

[0389] In the several embodiments provided in the present application, it should be understood that the disclosed systems, 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 units is only a logical function division. There may be other division methods in actual implementation, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of devices or units, which can be electrical, mechanical or other forms.

[0390] The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0391] In addition, each functional unit in each embodiment of the present application may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit.

[0392] If the functions are implemented in the form of software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present application can be essentially or partly embodied in the form of a software product that contributes to the prior art. The computer software product is stored in a storage medium and includes several instructions for a computer device (which can be a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the methods described in the various embodiments of the present application. The aforementioned storage media include: various media that can store program codes, such as USB flash drives, mobile hard disks, read-only memories ROM, random access memories RAM, magnetic disks or optical disks.

[0393] It should be noted that in the various embodiments of the present application, the size of the serial number of each process does not mean the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present application.

[0394] In addition, the terms "system" and "network" are often used interchangeably in this article. The term "and / or" in this article is only a description of the association relationship of associated objects, indicating that there can be three relationships. For example, A and / or B can mean: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in this article generally indicates that the associated objects before and after are in an "or" relationship. For example, A / B can mean A or B.

[0395] The terms (or numbers) "first", "second", ..., etc. that appear in the embodiments of the present application are only used for descriptive purposes, that is, only to distinguish different objects, such as different "measurement results", etc., and cannot be understood as indicating or implying relative importance or implicitly indicating the number of indicated technical features. Thus, the features defined as "first", "second", ..., etc. may explicitly or implicitly include one or more features. In the description of the embodiments of the present application, "at least one (item)" refers to one or more. "Multiple" means two or more. "At least one of the following (item)" or similar expressions thereof refers to any combination of these items, including any combination of a single (item) or a plurality of (items).

[0396] For example, the meaning of the expression similar to "the item includes at least one of the following: A, B, and C" in the embodiments of the present application, unless otherwise specified, generally means that the item can be any one of the following: A; B; C; A and B; A and C; B and C; A, B and C; A and A; A, A and A; A, A and B; A, A and C, A, B and B; A, C and C; B and B, B, B and B, B, B and C, C and C; C, C and C, and other combinations of A, B and C. The above is an example of three elements, A, B and C, to illustrate the optional items of the item. When it is expressed as "the item includes at least one of the following: A, B, ..., and X", that is, when there are more elements in the expression, the items that can be applied to the item can also be obtained according to the above rules.

[0397] In short, the above is only a preferred embodiment of the technical solution of this application, and is not intended to limit the protection scope of this application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of this application should be included in the protection scope of this application.

Claims

1. A communication method, characterized in that: include: The second terminal device receives the first call initiated by the first terminal device; Based on the first call, the second terminal device sends a first signaling to the first terminal device, the first signaling includes 200OK and a=curr:qos local sendrecv information, and the first signaling is sent before the second terminal device receives a second signaling, and the second signaling includes QCI=1 information; After receiving the call initiated by the first terminal device and before receiving the first signaling, the second terminal device performs an evolved packet system fallback EPS fallback; After the second terminal device connects to the first call, the second terminal device receives the voice sent by the first terminal device.

2. The method according to claim 1, characterized in that Also includes: Before the second terminal device sends the first signaling to the first terminal device, receiving the UPDATE signaling sent by the first terminal device based on the first call; The first signaling is sent to the first terminal device in response to the UPDATE signaling.

3. The method according to claim 1, characterized in that The first signaling is received after the second terminal device completes EPS fallback.

4. The method according to any one of claims 1 to 3, characterized in that: Also includes: Before the network standard of the second terminal device is configured as the second network standard, receiving a first switching instruction, the second network standard being 4G; The network standard of the second terminal device is configured as the second network standard in response to the first switching instruction.

5. The method according to claim 4, characterized in that Also includes: Before the second terminal device receives the first switching instruction, in response to the first call initiated by the first terminal device, the second terminal device sends a 100Trying signaling to the first terminal device; The first switching instruction is received based on the 100Trying signaling.

6. The method according to claim 1, characterized in that The second terminal device receiving a first call initiated by the first terminal device includes: The first terminal device sends an INVITE signaling to the second terminal device.

7. The method according to claim 1, characterized in that The second signaling is used to indicate the status of voice resource reservation of the second terminal device.

8. The method according to claim 1, characterized in that The second terminal device receives the voice sent by the first terminal device, including: The second terminal device receives a first voice packet sent by the first terminal device, where the first voice packet is IMSRTP SN and Payload; After the second terminal device receives the first voice packet sent by the first terminal device, the second terminal device plays the voice.

9. The method according to claim 1, characterized in that: After the second terminal device receives the second signaling, the voice bearer of the second terminal device is established.

10. The method according to claim 9, characterized in that Before the second terminal device connects the first call, the method further includes: After the voice bearer of the second terminal device is established, the second terminal device sends a 180 Ringing signaling to the first terminal device.

11. The method according to claim 10, characterized in that After the second terminal device sends the 180Ringing signaling to the first terminal device, the method further includes: The second terminal device starts ringing, and the ringing tone includes: vibration, color ringback tone, beep, personalized music, song, recording, and / or video.

12. The method according to claim 11, characterized in that After the second terminal device sends the 180Ringing signaling to the first terminal device, the method further includes: The first terminal device receives the 180Ringing signaling; After the first terminal device receives the 180Ringing signaling, the first terminal device starts to play the ringback tone, and the ringback tone includes: vibration, color ringback tone, beep, personalized music, song, recording, and / or video.

13. A communication device, characterized in that: The communication device includes a processor, an antenna and a memory, wherein the memory is used to store instructions, and the processor is used to execute the instructions stored in the memory to control the antenna to receive or send signals, so that the method according to any one of claims 1 to 12 is executed.

14. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores a computer-executable program, and when the computer-executable program is called by a computer, the computer executes the method according to any one of claims 1 to 12.

15. A chip system, characterized in that: It includes a processor, which is used to execute a computer executable program so that a device equipped with the chip system executes the method described in any one of claims 1 to 12.

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