Voice call fallback method, electronic device, storage medium and program product

Abstract

The invention discloses a voice call fallback method, electronic equipment, a storage medium and a program product. The method comprises the steps that under the condition that a voice calling party is initiated, frequency point indication information is acquired, and the frequency point indication information is used for indicating a geostationary orbit mobile radio network to be searched by terminal equipment; according to the frequency point indication information, circuit switched fallback is carried out, and the circuit switched fallback is used for enabling the terminal equipment to fall back to the geostationary orbit mobile radio network from the non-ground network Internet of Things. The technical problem that the current related standard does not support the voice service based on the non-ground internet of things to fall back to the geostationary orbit mobile radio network is solved.

Description

Technical Field

[0001] This application relates to the field of satellite communication technologies, and in particular, to a voice call fallback method, an electronic device, a storage medium, and a program product. Background Art

[0002] Voice services based on high-orbit satellite communication systems have been widely used in the industrial and consumer fields, with a wide foundation and good user experience. However, the single-user rate of its packet data service is low, and the IoT NTN (Internet of Things Non-Terrestrial Networking) system based on high-orbit satellites and 3GPP (Third Generation Partnership Project) native standards does not support voice services. In response to this problem, CSFB (Circuit Switched Fallback) has become a possible solution.

[0003] However, the current relevant standards do not support the fallback of voice services based on the IoT NTN system to the GMR (Geostationary earth orbit Mobile Radio) network, lacking the signaling process for IoT NTN to GMR fallback. In addition, the access delay of the high-orbit satellite system is large, leaving room for optimization.

[0004] In response to the above problems, no effective solution has been proposed yet. Summary of the Invention

[0005] Embodiments of this application provide a voice call fallback method, an electronic device, a storage medium, and a program product to at least solve the technical problem that the current relevant standards do not support the fallback of voice services based on the Internet of Things non-terrestrial network to the geostationary earth orbit mobile radio network.

[0006] According to one aspect of the embodiments of this application, a voice call fallback method is provided, including: when initiating a voice call, obtaining frequency point indication information, where the frequency point indication information is used to indicate the geostationary earth orbit mobile radio network that the terminal device needs to search for; and performing circuit switched fallback based on the frequency point indication information, where the circuit switched fallback is used to fallback the terminal device from the Internet of Things non-terrestrial network to the geostationary earth orbit mobile radio network.

[0007] Optionally, the frequency point indication information includes at least one of the following: the neighbor cell frequency points of the geostationary earth orbit mobile radio network preset in the Internet of Things non-terrestrial network, the broadcast frequency point list of the geostationary earth orbit mobile radio network preset in the terminal device.

[0008] Optionally, the method further includes: when initiating a voice call, sending a first request message to the non-terrestrial network Internet of Things, where the first request message is used to trigger a circuit switched fallback process; obtaining a first response message returned by the non-terrestrial network Internet of Things in response to the first request message, where the first response message includes: neighboring cell frequencies of the geostationary orbit mobile radio network preset in the non-terrestrial network Internet of Things.

[0009] Optionally, the first request message includes: an extended service request message, and the service type in the extended service request message includes: mobile-originated circuit switched fallback (MO CSFB); the first response message includes: a radio resource control connection release message, and the radio resource control connection release message includes: a circuit switched fallback release cause value, and the target cell frequency of the geostationary orbit mobile radio network.

[0010] Optionally, the method further includes: when receiving the first response message, performing frequency scanning to search for the geostationary orbit mobile radio network signal based on the neighboring cell frequencies of the geostationary orbit mobile radio network; performing random access to attempt to access the geostationary orbit mobile radio network.

[0011] Optionally, the method further includes: when initiating a voice call, sending a first request message to the non-terrestrial network Internet of Things, and performing frequency scanning to search for the geostationary orbit mobile radio network signal based on the broadcast frequency list of the geostationary orbit mobile radio network preset in the terminal device, where the first request message is used to trigger a circuit switched fallback process.

[0012] Optionally, the method further includes: when receiving the first response message returned by the non-terrestrial network Internet of Things in response to the first request message, performing random access to attempt to access the geostationary orbit mobile radio network, where the first response message includes: a circuit switched fallback release cause value.

[0013] Optionally, after completing random access, the method further includes: sending a circuit domain service request message to the geostationary orbit mobile radio network, where the circuit domain service request message includes: the service category of mobile-originated voice, and a temporary mobile subscriber identity; when the geostationary orbit mobile radio network completes the preprocessing process for the terminal device, establishing a voice media stream and making a voice call under the geostationary orbit mobile radio network, where the preprocessing process includes at least one of the following: authentication, security check, call setup, allocation of radio access bearer, and start of ringing.

[0014] Optionally, the method further includes: when the voice call is hung up and the resources of the geostationary mobile radio network are released, sending a tracking area update request message to the non-terrestrial network Internet of Things, where the evolved packet system update type carried in the tracking area update request message is a combined tracking area / location area update; accepting the tracking area update acceptance message returned by the non-terrestrial network Internet of Things, so that the terminal device switches back to the non-terrestrial network Internet of Things.

[0015] Optionally, the terminal device supports a dual protocol stack for the non-terrestrial network Internet of Things and the geostationary mobile radio network; the terminal device supports combined registration for the non-terrestrial network Internet of Things and the geostationary mobile radio network.

[0016] Optionally, the non-terrestrial network Internet of Things and the geostationary mobile radio network support the SGs interface to enable connectivity between the non-terrestrial network Internet of Things and the geostationary mobile radio network.

[0017] According to another aspect of the embodiments of the present application, another voice call fallback method is further provided, including: when initiating a voice call, sending a first request message to the non-terrestrial network Internet of Things, where the first request message is used to trigger a circuit switched fallback process; obtaining a first response message returned by the non-terrestrial network Internet of Things in response to the first request message, where the first response message includes: the neighboring cell frequency points of the geostationary mobile radio network pre-set in the non-terrestrial network Internet of Things, and the circuit switched fallback release cause value; performing circuit switched fallback based on the neighboring cell frequency points of the geostationary mobile radio network, where the circuit switched fallback is used to fallback the terminal device from the non-terrestrial network Internet of Things to the geostationary mobile radio network.

[0018] According to yet another aspect of the embodiments of the present application, another voice call fallback method is further provided, including: when initiating a voice call, sending a first request message to the non-terrestrial network Internet of Things, and performing frequency scanning to search for geostationary mobile radio network signals based on the broadcast frequency point list of the geostationary mobile radio network pre-set in the terminal device, where the first request message is used to trigger a circuit switched fallback process; performing circuit switched fallback when receiving the first response message returned by the non-terrestrial network Internet of Things in response to the first request message, where the first response message includes: the circuit switched fallback release cause value, and the circuit switched fallback is used to fallback the terminal device from the non-terrestrial network Internet of Things to the geostationary mobile radio network.

[0019] According to another aspect of the embodiments of the present application, another voice call fallback method is further provided, including: receiving a first request message sent by a terminal device when initiating a voice call, where the first request message is used to trigger a circuit switched fallback process; returning a first response message to the terminal device, where the first response message includes at least one of the following: a neighboring cell frequency point of a geostationary orbit mobile radio network preset in the non-terrestrial network Internet of Things, a circuit switched fallback release cause value; where the terminal device is used to perform circuit switched fallback when receiving the first response message, and the circuit switched fallback is used to fallback the terminal device from the non-terrestrial network Internet of Things to the geostationary orbit mobile radio network.

[0020] Optionally, the method further includes: receiving a tracking area update request message sent by the terminal device when the voice call is hung up and the resources of the geostationary orbit mobile radio network are released, where the evolved packet system update type carried in the tracking area update request message is a combined tracking area / location area update; returning a tracking area update acceptance message to the terminal device to enable the terminal device to switch back from the geostationary orbit mobile radio network to the non-terrestrial network Internet of Things.

[0021] According to another aspect of the embodiments of the present application, an electronic device is further provided, including: a memory and a processor, where the processor is used to run a program stored in the memory, and when the program runs, it executes the voice call fallback method.

[0022] According to still another aspect of the embodiments of the present application, a non-volatile storage medium is further provided, where the non-volatile storage medium includes a stored computer program, and the device where the non-volatile storage medium is located executes the voice call fallback method by running the computer program.

[0023] According to still another aspect of the embodiments of the present application, a computer program product is further provided, including a computer program, and when the computer program is executed by a processor, it implements the steps of the voice call fallback method.

[0024] In the embodiments of the present application, when initiating a voice call, frequency point indication information is obtained, where the frequency point indication information is used to indicate the geostationary orbit mobile radio network that the terminal device needs to search for; according to the frequency point indication information, circuit switched fallback is performed, where the circuit switched fallback is used to fallback the terminal device from the non-terrestrial network Internet of Things to the geostationary orbit mobile radio network. In this way, when the terminal device initiates a voice call, CSFB is performed using the frequency point indication information, making it possible for satellite-based IoT NTN voice CSFB to GMR, and further solving the technical problem that the current relevant standards do not support the fallback of voice services based on the non-terrestrial network Internet of Things to the geostationary orbit mobile radio network. Description of the Drawings

[0025] The accompanying drawings described herein are used to provide a further understanding of the present application and form a part of the present application. The schematic embodiments of the present application and their descriptions are used to explain the present application and do not constitute an improper limitation of the present application. In the drawings:

[0026] Figure 1 is a signaling flowchart of the calling party in the GMR voice call process in a related technology according to an embodiment of the present application;

[0027] Figure 2 is a signaling flowchart of the called party in the GMR voice call process in a related technology according to an embodiment of the present application;

[0028] Figure 3 is a signaling flowchart of CSFB in a related technology according to an embodiment of the present application;

[0029] Figure 4 is a schematic diagram of a method flow of voice call fallback according to an embodiment of the present application;

[0030] Figure 5 is a signaling flowchart of a voice fallback system according to an embodiment of the present application;

[0031] Figure 6 is another signaling flowchart of a voice fallback system according to an embodiment of the present application;

[0032] Figure 7 is another schematic diagram of a method flow of voice call fallback according to an embodiment of the present application;

[0033] Figure 8 is another schematic diagram of a method flow of voice call fallback according to an embodiment of the present application;

[0034] Figure 9 is another schematic diagram of a method flow of voice call fallback according to an embodiment of the present application;

[0035] Figure 10 is a hardware structure block diagram of a computer terminal (or electronic device) for implementing a method of voice call fallback according to an embodiment of the present application. Detailed implementation manners

[0036] To enable those skilled in the art to better understand the solution of this application, the technical solutions in the embodiments of this application will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of this application. Obviously, the described embodiments are only a part of the embodiments of this application, rather than all the embodiments. Based on the embodiments in this application, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the scope of protection of this application.

[0037] It should be noted that the terms "first", "second", etc. in the description and claims of this application and the above-mentioned drawings are used to distinguish similar objects, and do not necessarily have to be used to describe a specific order or sequence. It should be understood that such data can be interchanged under appropriate circumstances so that the embodiments of this application described here can be implemented in an order other than those illustrated or described here. In addition, the terms "comprising" and "having" and any variations thereof are intended to cover non-exclusive inclusion. For example, a process, method, system, product or device that includes a series of steps or units does not necessarily have to be limited to those steps or units clearly listed, but may include other steps or units not clearly listed or inherent to these processes, methods, products or devices.

[0038] To facilitate a better understanding of the embodiments of this application by those skilled in the art, the relevant technologies involved in the embodiments of this application are introduced as follows:

[0039] 1) GMR voice call process;

[0040] Figure 1 and Figure 2 are the signaling flowcharts corresponding to the calling party and the called party in the GMR voice call process respectively.

[0041] Such as Figure 1As shown in the figure, the signaling interaction process in the signaling process of the calling terminal initiating a voice call is as follows: The terminal sends an RRC (Radio Resource Control) connection request to the access network, requesting to establish a radio connection (RRC CONNECTION REQUEST); the access network sends an RRC connection setup message (RRC CONNECTIONSETUP) to the terminal, agreeing to establish a radio connection; the terminal sends an RRC connection setup complete message (RRC CONNECTIONSETUP COMPLETE) to the access network, confirming that the radio connection has been established; the terminal sends an initial DT (Direct Transfer) message (Call Management (CM) Service Request) to the access network; the access network forwards the initial UE message (INITIAL UE MESSAGE) to the core network, including the CM service request; the core network authenticates and performs a security check on the terminal to ensure the legality of the terminal's identity; the terminal sends a DT (Setup) message to the access network, which is the step where the terminal sends a message to the access network, requesting to establish a voice call; the access network sends a DT (Setup) message to the core network, requesting the core network to allocate resources for the voice call; the core network sends a DT (Call Proceeding) message to the access network, indicating that the call is being processed, to notify the access network that the call is being established; the access network sends a DT (Call Proceeding) message to the terminal, indicating that the call is being processed, to notify the terminal that the call is being established; a radio access bearer (RAB) is allocated for the voice call to transmit voice data; the called terminal rings and the call is connected; the voice media stream starts to be transmitted (Media), and both parties start the call; after the call ends, the terminal hangs up the phone and releases the occupied resources.

[0042] As Figure 2As shown in the figure, when a terminal is the called party, the signaling interaction process from the core network to the access network and then to the terminal is as follows: The core network sends a paging message (PAGE) to the access network, requesting the access network to page the called terminal; the access network sends a paging type 4 message to the terminal, indicating that there is an incoming call for the called terminal; the called terminal sends an RRC connection request to the access network, responding to the paging and requesting to establish a radio connection; the access network sends an RRC connection establishment message to the called terminal, agreeing to establish a radio connection; the called terminal sends an RRC connection establishment complete message to the access network, confirming that the radio connection has been established; the called terminal sends an initial DT message to the access network as a response to the paging (Paging Response); the access network forwards the initial UE message to the core network, including the paging response; the core network authenticates and performs a security check on the called terminal to ensure the legality of the terminal identity; the core network sends a DT setup message to the access network, indicating that the access network allocates resources for a voice call; the access network sends a DT setup message to the called terminal, indicating that the terminal allocates resources for a voice call; the terminal sends a DT call confirmation message to the access network, indicating that the call has been established on the terminal side; the access network sends a DT call confirmation message to the core network, indicating that the call has been established on the access network side; a radio access bearer (RAB) is allocated for the voice call to transmit voice data; the called terminal rings and the call is connected; the voice media stream starts to be transmitted and the two parties start a call; after the call ends, the called terminal hangs up the phone and releases the occupied resources.

[0043] 2) CSFB technology;

[0044] During the evolution, deployment, and popularization of the LTE (Long Term Evolution) network, initial LTE only supports packet data services and does not support voice services, that is, VoLTE (Voice over LTE). In this stage, the LTE network carries packet data services. When a voice call service is made, the CSFB technology is required to make the terminal fall back to the 2 / 3G network to complete the voice call service, and then return to the LTE network after hanging up the phone and releasing the resources.

[0045] Specifically, Figure 3 is the signaling flow chart of CSFB in the related technology, as Figure 3As shown in the figure, the user equipment (UE) is registered in the LTE network and the 2G / 3G network at the same time, so that it can fall back to the 2G / 3G network for voice calls when needed; when the UE needs to make a voice call, it sends an extended service request to the LTE network, and the request type is MO CSFB (Mobile Originated CS Fallback); the LTE network sends an RRC connection release message to the UE and provides the adjacent frequency information of the 2G network (GERAN) so that the UE can switch to the 2G network; the UE performs a random access process based on the provided frequency information and attempts to access the 2G / 3G network; the UE sends a circuit domain service request to the 2G / 3G network, carrying the service category and temporary mobile user identity (TMSI); the 2G / 3G network authenticates and performs security checks on the UE, sets up the call, allocates a radio access bearer (RAB), and starts ringing; the voice media stream starts to be transmitted and the call is established; after the call ends, the UE hangs up the phone and the 2G / 3G network releases related resources; the UE sends a tracking area update (TAU) request to the LTE network to update its location information; the LTE network accepts the TAU request and updates the UE's location information so that the UE can continue to use data services in the LTE network.

[0046] In order to enable the IoT NTN system to support the functions of cross-system redirection and CSFB, it is necessary to enhance the RRC Connection Release message defined in the existing 3GPP standard protocol. On the basis that the RRC connection release can specify the CSFB release reason and carry the cross-system carrier frequency, the embodiment of the present application proposes a wireless side fallback acceleration solution for the terminal to fall back to the GMR system in the voice call scenario of the IoT NTN system, so that the satellite-based IoT NTN voice CSFB to GMR becomes possible, so as to solve the problem that the current relevant standards do not support the fallback of voice services based on the IoT NTN system to the GMR network, and lack the signaling process for the IoT NTN to GMR fallback. The detailed description is as follows.

[0047] According to an embodiment of the present application, a method embodiment of voice call fallback is provided. It should be noted that the steps shown in the flowchart of the accompanying drawings can be executed in a computer system such as a set of computer executable instructions, and although a logical order is shown in the flowchart, in some cases, the steps shown or described can be executed in an order different from that shown here.

[0048] The embodiment of the present application provides a voice call fallback method. Specifically, in the satellite-based IoT NTN voice CSFB to GMR voice solution of the embodiment of the present application, the following points are included:

[0049] 1) The GMR+IoT NTN hybrid networking mode is adopted, which combines the satellite communication system (providing NTN services) and the ground GMR system. This hybrid network can give full play to the wide-area coverage advantages of satellite communication and the high-quality voice communication capabilities of the GMR system;

[0050] 2) The terminal device needs to be able to co-register on both the GMR and IoT NTN networks to ensure communication in different network environments. This co-registration mechanism allows the terminal to switch between the two networks based on network conditions and business needs.

[0051] 3) Under normal circumstances, the IoT NTN network is mainly used to carry data services, such as remote monitoring and data transmission of IoT devices. This is because satellite communications have the advantages of wide coverage and no geographical restrictions, which are suitable for data communications. When the terminal needs to make a voice call, since the IoT NTN network itself does not support voice services, it needs to fall back to the GMR network through the CSFB mechanism to complete the voice service. In this way, the mature voice communication capabilities of the GMR network can be used to ensure the quality and reliability of voice calls. In addition, after the voice call ends, the terminal needs to return from the GMR network to the IoT NTN network and continue to use satellite communications for data services or other communication services.

[0052] In the embodiment of the present application, the focus is on the fallback process of the voice service, which is described in detail below.

[0053] Figure 4 is a schematic diagram of a method flow for voice call fallback provided according to an embodiment of the present application, which can be applied to terminal devices such as Figure 4 As shown, the method comprises the following steps:

[0054] Step S402, in the case of initiating a voice call, obtaining frequency indication information, wherein the frequency indication information is used to indicate a geostationary orbit mobile radio network to be searched by the terminal device;

[0055] Step S404: Perform circuit switched fallback according to the frequency indication information, wherein the circuit switched fallback is used to fallback the terminal device from the non-terrestrial network Internet of Things to the geostationary orbit mobile radio network.

[0056] Through the above steps, when the terminal device initiates a voice call, CSFB is performed using the frequency indication information, making satellite-based IoT NTN voice CSFB to GMR possible, thereby solving the technical problem that the current relevant standards do not support the fallback of voice services based on non-terrestrial network IoT to the geostationary orbit mobile radio network.

[0057] The voice call fallback method in step S402 to step S404 of the embodiment of the present application is further introduced below.

[0058] In the embodiment of the present application, the method for obtaining the above-mentioned frequency indication information can be divided into two cases, as follows.

[0059] In some embodiments of the present application, the frequency indication information includes at least one of the following: a neighboring frequency of a geostationary orbit mobile radio network pre-set in a non-terrestrial network Internet of Things, and a broadcast frequency list of a geostationary orbit mobile radio network pre-set in a terminal device. That is, it is possible to choose to preset a GMR neighboring carrier frequency in the IoT NTN network, or to preset a broadcast frequency on the terminal device side.

[0060] The following introduces two different ways of setting the frequency indication information.

[0061] Method 1: IoT NTN network presets GMR neighboring cell carrier frequency;

[0062] In this way, when the IoT NTN network and the GMR network are deployed, the neighboring frequency of the GMR network needs to be pre-set in the IoT NTN network for the cross-system redirection CSFB fallback from the IoT NTN to the GMR. The terminal is notified in the RRC connection release message, and the terminal scans the frequency to search for the GMR network and connects to the GMR network. The specific steps are as follows.

[0063] In some embodiments of the present application, the method also includes the following steps: in the case of initiating a voice call, sending a first request message to the non-terrestrial network Internet of Things, wherein the first request message is used to trigger the circuit switching fallback process; obtaining a first response message returned by the non-terrestrial network Internet of Things in response to the first request message, wherein the first response message includes: a neighboring frequency point of the geostationary orbit mobile radio network pre-set in the non-terrestrial network Internet of Things.

[0064] In some embodiments of the present application, the method also includes the following steps: upon receiving the first response message, performing a frequency scanning search to search for geostationary orbit mobile radio network signals based on the neighboring frequency points of the geostationary orbit mobile radio network; and performing random access to attempt to access the geostationary orbit mobile radio network.

[0065] In this embodiment, the first request message includes: an extended service request message (Extended ServiceRequest), and the service type in the extended service request message includes: mobile initiated circuit switched fallback MO CSFB, that is, the carried Service type is MO CSFB;

[0066] The first response message includes: a radio resource control connection release message (RRC ConnectionRelease), and the radio resource control connection release message includes: a circuit switched fallback release reason value, and a target cell frequency of the geostationary orbit mobile radio network (ie, the frequency indication information).

[0067] The complete signaling interaction process in the above method 1 is further introduced below. Figure 5 As shown, the details are as follows.

[0068] During network deployment, the neighboring frequency points of the GMR network are pre-set in the IoT NTN network for cross-system redirection CSFB fallback from the IoT NTN to the GMR. This step is the key to achieving fast fallback because it allows the terminal to quickly find and access the GMR network when needed. The terminal device completes joint registration in the IoT NTN network and the GMR network so that it can communicate in different network environments.

[0069] When the user makes a call on the terminal device and initiates a voice call, the terminal device sends an Extended Service Request message (i.e., the first request message) to the IoT NTN network, and the service type Servicetype carried is MO CSFB (Mobile Originated Circuit Switched Fallback).

[0070] Afterwards, the IoT NTN network sends an RRC Connection Release message (i.e., the first response message) to the terminal device, which carries: a CSFB release reason value and a GMR target cell frequency, to instruct the terminal device to release IoT NTN network resources and prepare to fall back to the GMR network;

[0071] After receiving the RRC Connection Release message, the terminal device can scan the network according to the frequency indication information of the network configuration (i.e., the GMR target cell frequency) carried in the message to search for the GMR network signal; and perform the random access process to complete the random access in the GMR network;

[0072] After accessing the GMR network, you can fall back from the IoT NTN network to the GMR network for voice calls. The specific steps are as follows.

[0073] In some embodiments of the present application, after random access is completed, the method further includes the following steps: sending a circuit domain service request message to a geostationary orbit mobile radio network, where the circuit domain service request message includes: the service category of mobile-originated voice, and a temporary mobile subscriber identity; when the geostationary orbit mobile radio network completes the preprocessing process for the terminal device, establishing a voice media stream and conducting a voice call under the geostationary orbit mobile radio network, where the preprocessing process includes at least one of the following: authentication, security check, call setup, allocation of a radio access bearer, and start of ringing.

[0074] Specifically, the terminal sends a CM Service Request message (circuit domain service request message) to the GMR network to request the establishment of a voice call, which carries the TMSI (Temporary Mobile Subscriber Identity) and the service category of MO (Mobile Originated Voice) voice; then, the terminal completes the authentication, security process, and signaling processes such as Setup, RAB allocation, and ringing under the GMR network, that is, the GMR network authenticates and conducts a security check on the terminal, sets up a call, allocates a radio access bearer, and starts ringing. After the call is connected, the voice media stream starts to be transmitted, the call is established, and a voice call is conducted under the GMR network.

[0075] After the call ends, the terminal device returns to the IoT NTN network, and the specific steps are as follows.

[0076] In some embodiments of the present application, the method further includes the following steps: when the voice call is hung up and the resources of the geostationary orbit mobile radio network are released, sending a tracking area update request message to the non-terrestrial network Internet of Things, where the evolved packet system update type carried in the tracking area update request message is a combined tracking area / location area update; accepting the tracking area update acceptance message returned by the non-terrestrial network Internet of Things to enable the terminal device to switch back to the non-terrestrial network Internet of Things.

[0077] Specifically, after the call is hung up, the GMR network resources are released; the terminal sends a TAU (Tracking Area Update Request) Request message to the IoT NTN network to update its location information. The EPS (Evolved Packet System) update type carried in this message is combined TA / LA updating; then, the IoT NTN network accepts the TAU request, updates the location information of the terminal, and sends a TAU Accept message to the terminal so that the terminal can continue to use data services in the IoT NTN network, completing the process of the terminal returning to the IoT NTN network.

[0078] It should be noted that in order to implement the fallback process corresponding to the above-mentioned Method 1, the terminal and the network need to be enhanced accordingly in this embodiment. Specifically, the terminal device supports the dual protocol stacks of IoT NTN and GMR, which enables the terminal to seamlessly switch between the two networks; it supports the joint registration of IoT NTN and GMR networks, which ensures that the terminal can maintain a continuous connection between the two networks; the terminal supports actively sending ESR to trigger CSFB in the calling-initiated scenario under the joint registration state; the terminal supports decoding and processing the new format of RRC connection release messages sent by the IoT NTN network and triggering GMR frequency scanning and network searching.

[0079] In addition, the neighbor cell frequency points of the GMR network are pre-set in the IoT NTN network, which provides a basis for rapid fallback; the non-terrestrial network Internet of Things and the geostationary orbit mobile radio network support the SGs interface to connect the IoT NTN and the GMR core network, ensuring effective communication between the two networks; the IoT NTN network supports receiving and processing ESR messages to trigger CSFB; when the IoT NTN network receives an ESR to trigger CSFB, it sends the GMR target cell frequency point when sending an RRC connection release to the terminal.

[0080] Method 2: The terminal device pre-sets broadcast frequency points and performs frequency scanning in advance when the calling party falls back.

[0081] In this method, the terminal side pre-sets a list of common broadcast frequency points of the GMR network for frequency scanning and network searching under the GMR network, including frequency scanning and network searching when falling back from the IoT NTN network to the GMR network. Compared with Method 1, in this method, the neighbor cell frequency points of the GMR network do not need to be pre-set in the IoT NTN network. During the fallback process, only the cause value of CSFB release needs to be notified to the terminal through the RRC connection release message, and the GMR neighbor cell carrier frequency points do not need to be notified to the terminal. After the terminal sends an ESR message, it immediately starts GMR network frequency scanning in advance and randomly accesses immediately after receiving the RRC connection release request to optimize the fallback delay. The specific steps are as follows.

[0082] In some embodiments of the present application, the method further includes the following steps: in the case of initiating a voice call, sending a first request message to the non-terrestrial network Internet of Things, and performing frequency scanning to search for a geostationary mobile radio network signal according to the broadcast frequency list of the geostationary mobile radio network pre-set in the terminal device, where the first request message is used to trigger a circuit switched fallback process.

[0083] In some embodiments of the present application, the method further includes the following steps: in the case of receiving a first response message returned by the non-terrestrial network Internet of Things in response to the first request message, performing random access to attempt to access the geostationary mobile radio network, where the first response message includes: a circuit switched fallback release cause value.

[0084] In this embodiment, the above first request message includes: an Extended Service Request message, and the service type in the Extended Service Request message includes: Mobile Originated Circuit Switched Fallback (MO CSFB), that is, the carried Service type is MO CSFB;

[0085] The above first response message includes: a Radio Resource Control Connection Release message, and the Radio Resource Control Connection Release message includes: a circuit switched fallback release cause value, and does not include the target cell frequency of the geostationary mobile radio network.

[0086] The following further introduces the complete signaling interaction process in the case of the above method two, as Figure 6 shown, specifically as follows.

[0087] In method two, when the network is deployed, a common broadcast frequency list of the GMR network needs to be pre-set on the terminal side, so that the terminal can quickly access the GMR network when needed; the terminal device completes joint registration in the IoT NTN network and the GMR network, so as to be able to communicate in different network environments.

[0088] When the user makes a call on the terminal device to initiate a voice call, the terminal device sends an Extended Service Request message (i.e., the above first request message) to the IoT NTN network, and the carried service type Service type is MO CSFB (Mobile Originated Circuit Switched Fallback);

[0089] In Mode 2, after the terminal device sends the Extended Service Request message, it does not need to wait for the IoT NTN network to send the RRC Connection Release message before performing frequency scanning and network search. Instead, it can immediately switch to the GMR broadcast frequency points according to the pre-set list of common broadcast frequency points of the GMR network after sending the ESR message. For example, the list can be set to 7 common frequency points. Generally, after scanning all these 7 pre-set frequency points, the terminal will receive the RRC Connection Release message sent by the IoT NTN network; after completing the GMR frequency scanning, the terminal does not immediately initiate random access, but switches to the IoT NTN frequency point and waits for the IoT NTN network to send the RRC Connection Release;

[0090] The IoT NTN network sends the RRC Connection Release message (i.e., the above-mentioned first response message) to the terminal device, which carries the CSFB release cause value and does not carry the GMR target cell frequency point;

[0091] After receiving the RRC Connection Release message, the terminal device performs the random access process and completes the random access under the GMR network;

[0092] By the method of the terminal and the network running in parallel, where the terminal switches to the GMR frequency point for frequency scanning in advance and waits for the network to process the ESR and send the RRC connection request, the fallback latency can be optimized.

[0093] After accessing the GMR network, it is possible to fall back from the IoT NTN network to the GMR network for a voice call. The specific steps are as follows.

[0094] In some embodiments of the present application, after completing the random access, the method further includes the following steps: sending a circuit domain service request message to the geostationary mobile radio network, where the circuit domain service request message includes: the service category of the mobile-initiated voice, the temporary mobile subscriber identity; in the case where the geostationary mobile radio network completes the preprocessing process for the terminal device, establishing a voice media stream and performing a voice call under the geostationary mobile radio network, where the preprocessing process includes at least one of the following: authentication, security check, call setup, allocation of radio access bearer, start of ringing.

[0095] Specifically, the terminal sends a CM Service Request message (Circuit Domain Service Request message) to the GMR network to request the establishment of a voice call, which carries the TMSI (Temporary Mobile Subscriber Identity) and the service category of MO (Mobile Originated Voice) voice. After that, the terminal completes the authentication, security process, and signaling processes such as Setup, RAB allocation, and ringing under the GMR network, that is, the GMR network authenticates and performs a security check on the terminal, sets up the call, allocates a radio access bearer, and starts ringing. After the call is connected, the voice media stream starts to be transmitted, the call is established, and a voice call is made under the GMR network.

[0096] After the call ends, the terminal device returns to the IoT NTN network. The specific steps are as follows.

[0097] In some embodiments of the present application, the method further includes the following steps: when the voice call is hung up and the resources of the geostationary mobile radio network are released, sending a Tracking Area Update Request message to the non-terrestrial network Internet of Things, where the evolved packet system update type carried in the Tracking Area Update Request message is combined tracking area / location area update; accepting the Tracking Area Update Accept message returned by the non-terrestrial network Internet of Things to enable the terminal device to switch back to the non-terrestrial network Internet of Things.

[0098] Specifically, after the call is hung up, the GMR network resources are released; the terminal sends a TAU (Tracking Area Update Request) Request message to the IoT NTN network to update its location information, and the EPS (Evolved Packet System) update type carried in this message is combined TA / LA updating; after that, the IoT NTN network accepts the TAU request, updates the location information of the terminal, and sends a TAU Accept message to the terminal so that the terminal can continue to use data services in the IoT NTN network, completing the process of the terminal returning to the IoT NTN network.

[0099] It should be noted that in order to implement the fallback process corresponding to the above-mentioned second method, the terminal and the network need to be enhanced accordingly in this embodiment. Specifically, the terminal device supports the dual protocol stacks of IoT NTN and GMR, which enables the terminal to seamlessly switch between the two networks; supports the joint registration of IoT NTN and GMR networks, which ensures that the terminal can maintain a continuous connection between the two networks; the terminal supports actively sending ESR to initiate CSFB in the calling scenario under the joint registration state; the terminal supports presetting the list of common broadcast frequency points of GMR, and immediately switches to the preset GMR frequency points for frequency scanning and network searching after the IoT NTN network issues an ESR to trigger CSFB. At the same time, it waits for the RRC connection release message sent by the IoT NTN network, and optimizes the fallback delay through this parallel method; the terminal supports decoding and processing the new format of the RRC connection release message sent by the IoT NTN network, and triggers the random access of the GMR network.

[0100] In addition, the Internet of Things in the non-terrestrial network and the geostationary orbit mobile radio network support the SGs interface to connect the IoT NTN and the GMR core network, ensuring effective communication between the two networks; the IoT NTN network supports receiving and processing ESR messages to trigger CSFB; when the IoT NTN network sends an RRC connection release to the terminal after receiving an ESR to trigger CSFB, it carries the CSFB release reason value and does not carry the GMR target cell frequency point.

[0101] The solution of this application proposes a signaling process method for a terminal to fall back from IoT NTN to GMR, and proposes two different setting methods for frequency point indication information in this method, including: proposing that the IoT NTN network presets the GMR neighbor cell carrier frequency points (Method 1) for notifying the terminal to switch to the GMR frequency points for frequency scanning and network searching during the fallback process, and proposing that the terminal presets the list of common broadcast frequency points of GMR (Method 2) for switching to the GMR frequency points for frequency scanning and network searching during the fallback process from IoT NTN to GMR.

[0102] By using the frequency point indication information for circuit switched fallback when the terminal device initiates a voice call, the problem of network switching during voice calls in the Internet of Things in the non-terrestrial network is effectively solved, ensuring the continuity and quality of voice calls. This method not only improves the stability of calls, but also optimizes the switching efficiency of the terminal device between different networks, providing a smoother call experience for users. In practical applications, this method can significantly improve the utilization efficiency of network resources and reduce the possibility of call interruption, which is of great benefit to promoting the integration of the non-terrestrial network and the geostationary orbit mobile radio network, and enhancing the communication experience of users during movement.

[0103] According to the embodiment of this application, another embodiment of the method for voice call fallback is also provided.Figure 7 is a schematic diagram of another method flow for voice call fallback provided by an embodiment of the present application, which can be applied to a terminal device, such as Figure 7 As shown, the method includes the following steps:

[0104] Step S702, when initiating a voice call, send a first request message to the non-terrestrial network Internet of Things, where the first request message is used to trigger the circuit switched fallback process;

[0105] Step S704, obtain a first response message returned by the non-terrestrial network Internet of Things in response to the first request message, where the first response message includes: the neighboring cell frequency points of the geostationary orbit mobile radio network preset in the non-terrestrial network Internet of Things, and the circuit switched fallback release cause value;

[0106] Step S706, perform circuit switched fallback according to the neighboring cell frequency points of the geostationary orbit mobile radio network, where the circuit switched fallback is used to fallback the terminal device from the non-terrestrial network Internet of Things to the geostationary orbit mobile radio network.

[0107] It should be noted that the method embodiment of voice call fallback provided in this embodiment is a method embodiment corresponding to the relevant process of Mode 1 in the Figure 4 shown voice call fallback method. Therefore, the relevant explanations of the relevant process of Mode 1 in the above voice call fallback method also apply to the embodiments of the present application, and will not be elaborated here.

[0108] According to an embodiment of the present application, another method embodiment of voice call fallback is also provided. Figure 8 is a schematic diagram of another method flow for voice call fallback provided by an embodiment of the present application, which can be applied to a terminal device, such as Figure 8 As shown, the method includes the following steps:

[0109] Step S802, when initiating a voice call, send a first request message to the non-terrestrial network Internet of Things, and perform frequency scanning and network searching for the geostationary orbit mobile radio network signal according to the broadcast frequency point list of the geostationary orbit mobile radio network preset in the terminal device, where the first request message is used to trigger the circuit switched fallback process;

[0110] Step S804, when receiving the first response message returned by the non-terrestrial network Internet of Things in response to the first request message, perform circuit switched fallback, where the first response message includes: the circuit switched fallback release cause value, and the circuit switched fallback is used to fallback the terminal device from the non-terrestrial network Internet of Things to the geostationary orbit mobile radio network.

[0111] It should be noted that the method embodiment of voice call fallback provided in this embodiment is a method embodiment corresponding to the related process of Method 2 in the Figure 4 voice call fallback method shown. Therefore, the related explanations of the related process of Method 2 in the above voice call fallback method also apply to the embodiments of this application and will not be elaborated here.

[0112] According to the embodiments of this application, another method embodiment of voice call fallback is also provided. Figure 9 FIG. is a schematic diagram of another method flow of voice call fallback provided according to the embodiments of this application, which can be applied to non-terrestrial network Internet of Things, such as Figure 9 shown. The method includes the following steps:

[0113] Step S902, receiving a first request message sent by a terminal device when initiating a voice call, where the first request message is used to trigger a circuit switched fallback process;

[0114] Step S904, returning a first response message to the terminal device, where the first response message includes at least one of the following: a neighbor cell frequency point of a geostationary orbit mobile radio network preset in the non-terrestrial network Internet of Things, a circuit switched fallback release cause value;

[0115] Wherein, the terminal device is used to perform circuit switched fallback when receiving the first response message, and the circuit switched fallback is used to fallback the terminal device from the non-terrestrial network Internet of Things to the geostationary orbit mobile radio network.

[0116] Optionally, the method further includes: receiving a tracking area update request message sent by the terminal device when the voice call is hung up and the resources of the geostationary orbit mobile radio network are released, where the evolved packet system update type carried in the tracking area update request message is a combined tracking area / location area update; returning a tracking area update acceptance message to the terminal device to enable the terminal device to switch back from the geostationary orbit mobile radio network to the non-terrestrial network Internet of Things.

[0117] It should be noted that the method embodiment of voice call fallback provided in this embodiment is a method embodiment corresponding to the voice call fallback method Figure 4 shown. Therefore, the related explanations of the above voice call fallback method also apply to the embodiments of this application and will not be elaborated here.

[0118] An embodiment of the present application also provides a non-volatile storage medium. The non-volatile storage medium stores a computer program. The device where the non-volatile storage medium is located executes the following voice call fallback method by running the computer program: When initiating a voice call, obtain frequency point indication information, where the frequency point indication information is used to indicate the geostationary orbit mobile radio network that the terminal device needs to search for; according to the frequency point indication information, perform circuit switched fallback, where the circuit switched fallback is used to fallback the terminal device from the non-terrestrial network Internet of Things to the geostationary orbit mobile radio network.

[0119] Alternatively, when initiating a voice call, send a first request message to the non-terrestrial network Internet of Things, where the first request message is used to trigger the circuit switched fallback process; obtain a first response message returned by the non-terrestrial network Internet of Things in response to the first request message, where the first response message includes: the neighboring cell frequency points of the geostationary orbit mobile radio network pre-set in the non-terrestrial network Internet of Things, the circuit switched fallback release cause value; according to the neighboring cell frequency points of the geostationary orbit mobile radio network, perform circuit switched fallback, where the circuit switched fallback is used to fallback the terminal device from the non-terrestrial network Internet of Things to the geostationary orbit mobile radio network.

[0120] Alternatively, when initiating a voice call, send a first request message to the non-terrestrial network Internet of Things and perform frequency scanning and network search for the geostationary orbit mobile radio network signal according to the broadcast frequency point list of the geostationary orbit mobile radio network pre-set in the terminal device, where the first request message is used to trigger the circuit switched fallback process; when receiving the first response message returned by the non-terrestrial network Internet of Things in response to the first request message, perform circuit switched fallback, where the first response message includes: the circuit switched fallback release cause value, and the circuit switched fallback is used to fallback the terminal device from the non-terrestrial network Internet of Things to the geostationary orbit mobile radio network.

[0121] Alternatively, receive the first request message sent by the terminal device when initiating a voice call, where the first request message is used to trigger the circuit switched fallback process; return a first response message to the terminal device, where the first response message includes at least one of the following: the neighboring cell frequency points of the geostationary orbit mobile radio network pre-set in the non-terrestrial network Internet of Things, the circuit switched fallback release cause value; where the terminal device is used to perform circuit switched fallback when receiving the first response message, and the circuit switched fallback is used to fallback the terminal device from the non-terrestrial network Internet of Things to the geostationary orbit mobile radio network.

[0122] An embodiment of this application also provides a computer program product, including a computer program. When the computer program is executed by a processor, it implements the steps of the voice call fallback method described in each embodiment of this application: when initiating a voice call, obtain frequency point indication information, where the frequency point indication information is used to indicate the geostationary mobile radio network that the terminal device needs to search for; according to the frequency point indication information, perform circuit switched fallback, where the circuit switched fallback is used to fallback the terminal device from the non-terrestrial network Internet of Things to the geostationary mobile radio network.

[0123] Alternatively, when initiating a voice call, send a first request message to the non-terrestrial network Internet of Things, where the first request message is used to trigger a circuit switched fallback process; obtain a first response message returned by the non-terrestrial network Internet of Things in response to the first request message, where the first response message includes: the neighboring cell frequency points of the geostationary mobile radio network pre-set in the non-terrestrial network Internet of Things, the circuit switched fallback release cause value; according to the neighboring cell frequency points of the geostationary mobile radio network, perform circuit switched fallback, where the circuit switched fallback is used to fallback the terminal device from the non-terrestrial network Internet of Things to the geostationary mobile radio network.

[0124] Alternatively, when initiating a voice call, send a first request message to the non-terrestrial network Internet of Things, and perform frequency scanning and network search for the geostationary mobile radio network signal according to the broadcast frequency point list of the geostationary mobile radio network pre-set in the terminal device, where the first request message is used to trigger a circuit switched fallback process; when receiving the first response message returned by the non-terrestrial network Internet of Things in response to the first request message, perform circuit switched fallback, where the first response message includes: the circuit switched fallback release cause value, and the circuit switched fallback is used to fallback the terminal device from the non-terrestrial network Internet of Things to the geostationary mobile radio network.

[0125] Alternatively, receive the first request message sent by the terminal device when initiating a voice call, where the first request message is used to trigger a circuit switched fallback process; return a first response message to the terminal device, where the first response message includes at least one of the following: the neighboring cell frequency points of the geostationary mobile radio network pre-set in the non-terrestrial network Internet of Things, the circuit switched fallback release cause value; where the terminal device is used to perform circuit switched fallback when receiving the first response message, and the circuit switched fallback is used to fallback the terminal device from the non-terrestrial network Internet of Things to the geostationary mobile radio network.

[0126] The method embodiments provided by the embodiments of this application can be executed in a mobile terminal, a computer terminal or a similar computing device. Figure 10The figure shows a hardware block diagram of a computer terminal (or electronic device) for implementing a voice call fallback method. As Figure 10 shown, the computer terminal 100 (or electronic device) may include one or more processors 1002 (illustrated as 1002a, 1002b, ……, 1002n in the figure) (the processor 1002 may include, but is not limited to, processing devices such as a microprocessor MCU or a programmable logic device FPGA), a memory 1004 for storing data, and a transmission device 1006 for communication functions. In addition, it may further include: a display, an input / output interface (I / O interface), a universal serial bus (USB) port (which may be included as one of the ports of the BUS bus), a network interface, a power supply, and / or a camera. Those of ordinary skill in the art can understand that Figure 10 the structure shown is only schematic and does not limit the structure of the above-mentioned electronic device. For example, the computer terminal 100 may further include more or fewer components than those Figure 10 shown, or have a different configuration from that Figure 10 shown.

[0127] It should be noted that the above one or more processors 1002 and / or other data processing circuits are generally referred to as "data processing circuits" herein. The data processing circuit may be embodied in software, hardware, firmware, or any combination thereof, in whole or in part. In addition, the data processing circuit may be a single independent processing module, or be incorporated in whole or in part into any one of the other elements in the computer terminal 100 (or electronic device). As involved in the embodiments of the present application, the data processing circuit is used for a processor control (such as the selection of a variable resistor terminal path connected to an interface).

[0128] The memory 1004 may be used to store software programs and modules of application software, such as the program instructions / data storage device corresponding to the voice call fallback method in the embodiments of the present application. The processor 1002 executes various functional applications and data processing by running the software programs and modules stored in the memory 1004, that is, implements the above-mentioned voice call fallback method. The memory 1004 may include a high-speed random access memory, and may further include a non-volatile memory, such as one or more magnetic storage devices, flash memories, or other non-volatile solid-state memories. In some instances, the memory 1004 may further include a memory remotely set relative to the processor 1002, and these remote memories may be connected to the computer terminal 100 through a network. Examples of the above-mentioned network include, but are not limited to, the Internet, an enterprise intranet, a local area network, a mobile communication network, and combinations thereof.

[0129] The transmission device 1006 is used to receive or send data via a network. Specific examples of the above-mentioned network may include a wireless network provided by the communication provider of the computer terminal 100. In one example, the transmission device 1006 includes a network adapter (Network Interface Controller, NIC), which can be connected to other network devices through a base station so as to communicate with the Internet. In one example, the transmission device 1006 can be a Radio Frequency (RF) module, which is used to communicate with the Internet wirelessly.

[0130] The display can be, for example, a touch-screen liquid crystal display (LCD), which enables the user to interact with the user interface of the computer terminal 100 (or electronic device).

[0131] The serial numbers of the embodiments of the present application are only for description and do not represent the superiority or inferiority of the embodiments.

[0132] In the above embodiments of the present application, the descriptions of the various embodiments have their own emphases. For the parts not detailed in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0133] In the several embodiments provided by the present application, it should be understood that the disclosed technical content can be implemented in other ways. Among them, the device embodiments described above are only illustrative. For example, the division of the units can be a logical function division. In actual implementation, there can be other division methods. For example, 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 displayed or discussed couplings or direct couplings or communication connections to each other can be through some interfaces. The indirect couplings or communication connections of the units or modules can be in an electrical or other form.

[0134] The units described as separate components may or may not be physically separated. The components displayed as units may or may not be physical units, that is, they can be located in one place or distributed to multiple units. Some or all of the units can be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0135] In addition, the functional units in the various embodiments of the present application can be integrated into one processing unit, or each unit can exist physically alone, or two or more units can be integrated into one unit. The above integrated units can be implemented in the form of hardware or in the form of software functional units.

[0136] When the integrated unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, or all or part of this technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions for causing a computer device (which can be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the methods described in various embodiments of this application. The aforementioned storage medium includes: various media that can store program codes, such as USB flash drives, read-only memories (ROM, Read-Only Memory), random access memories (RAM, Random Access Memory), mobile hard disks, magnetic disks, or optical discs.

[0137] The above are only the preferred embodiments of this application. It should be noted that for those of ordinary skill in the art of this technology, without departing from the principle of this application, several improvements and refinements can be made, and these improvements and refinements should also be regarded as the protection scope of this application.

Claims

1. A voice call fallback method, applied to a terminal device, characterized in that: include: In the case of initiating a voice call, obtaining frequency indication information, wherein the frequency indication information is used to indicate a geostationary orbit mobile radio network to be searched by the terminal device; Circuit switched fallback is performed according to the frequency indication information, wherein the circuit switched fallback is used to fallback the terminal device from the non-terrestrial network Internet of Things to the geostationary orbit mobile radio network.

2. The voice call fallback method according to claim 1, characterized in that: The frequency indication information includes at least one of the following: a neighboring frequency of the geostationary orbit mobile radio network pre-set in the non-terrestrial network Internet of Things, and a broadcast frequency list of the geostationary orbit mobile radio network pre-set in the terminal device.

3. The voice call fallback method according to claim 2, characterized in that: The method further comprises: In the case of initiating a voice call, sending a first request message to the non-terrestrial network Internet of Things, wherein the first request message is used to trigger a circuit switched fallback process; Obtain a first response message returned by the non-terrestrial network Internet of Things in response to the first request message, wherein the first response message includes: a neighboring frequency point of the geostationary orbit mobile radio network pre-set in the non-terrestrial network Internet of Things.

4. The voice call fallback method according to claim 3, characterized in that: The first request message includes: an extended service request message, and the service type in the extended service request message includes: mobile initiated circuit switched fallback MOCSFB; the first response message includes: a radio resource control connection release message, and the radio resource control connection release message includes: a circuit switched fallback release reason value and a target cell frequency of the geostationary orbit mobile radio network.

5. The voice call fallback method according to claim 3, characterized in that: The method further comprises: When the first response message is received, performing a frequency scanning search according to the neighboring frequency points of the geostationary orbit mobile radio network to search for geostationary orbit mobile radio network signals; A random access is performed to attempt to access the geostationary mobile radio network.

6. The voice call fallback method according to claim 2, characterized in that: The method further comprises: In the case of initiating a voice call, a first request message is sent to the non-terrestrial network Internet of Things, and a frequency scanning search is performed based on the broadcast frequency list of the geostationary orbit mobile radio network pre-set in the terminal device to search for the geostationary orbit mobile radio network signal, wherein the first request message is used to trigger the circuit switching fallback process.

7. The voice call fallback method according to claim 6, characterized in that: The method further comprises: Upon receiving a first response message returned by the non-terrestrial network Internet of Things in response to the first request message, random access is performed to attempt to access the geostationary orbit mobile radio network, wherein the first response message includes: a circuit switched fallback release cause value.

8. The voice call fallback method according to claim 5 or 7, characterized in that: After completing the random access, the method further includes: Sending a circuit domain service request message to the geostationary orbit mobile radio network, wherein the circuit domain service request message includes: a service category of mobile originated voice and a temporary mobile user identity; When the geostationary mobile radio network completes a preprocessing process for the terminal device, a voice media stream is established and a voice call is performed under the geostationary mobile radio network, wherein the preprocessing process includes at least one of the following: authentication, security check, call setting, allocation of wireless access bearer, and start of ringing.

9. The voice call fallback method according to claim 8, characterized in that: The method further comprises: When the voice call is hung up and the resources of the geostationary orbit mobile radio network are released, sending a tracking area update request message to the non-terrestrial network Internet of Things, wherein the evolved packet system update type carried in the tracking area update request message is a joint tracking area / location area update; Accept the tracking area update acceptance message returned by the non-terrestrial network Internet of Things, so that the terminal device switches back to the non-terrestrial network Internet of Things.

10. The voice call fallback method according to claim 1, characterized in that: The terminal device supports dual protocol stacks of the non-terrestrial network Internet of Things and the geostationary orbit mobile radio network; the terminal device supports joint registration of the non-terrestrial network Internet of Things and the geostationary orbit mobile radio network.

11. The voice call fallback method according to claim 1, characterized in that: The non-terrestrial network Internet of Things and the geostationary orbit mobile radio network support an SGs interface to achieve connectivity between the non-terrestrial network Internet of Things and the geostationary orbit mobile radio network.

12. A voice call fallback method, applied to a terminal device, characterized in that: include: In the case of initiating a voice call, sending a first request message to the non-terrestrial network Internet of Things, wherein the first request message is used to trigger a circuit switched fallback process; Obtain a first response message returned by the non-terrestrial network Internet of Things in response to the first request message, wherein the first response message includes: a neighboring frequency point and a circuit switched fallback release reason value of a geostationary orbit mobile radio network pre-set in the non-terrestrial network Internet of Things; Circuit switched fallback is performed according to a neighboring frequency of the geostationary orbit mobile radio network, wherein the circuit switched fallback is used to fallback the terminal device from the non-terrestrial network Internet of Things to the geostationary orbit mobile radio network.

13. A voice call fallback method, applied to a terminal device, characterized in that: include: In the case of initiating a voice call, sending a first request message to the non-terrestrial network Internet of Things, and performing a frequency scanning search according to a broadcast frequency list of the geostationary orbit mobile radio network pre-set in the terminal device to search for a geostationary orbit mobile radio network signal, wherein the first request message is used to trigger a circuit switched fallback process; Upon receiving a first response message returned by the non-terrestrial network Internet of Things in response to the first request message, circuit switched fallback is performed, wherein the first response message includes: a circuit switched fallback release reason value, and the circuit switched fallback is used to fall back the terminal device from the non-terrestrial network Internet of Things to the geostationary orbit mobile radio network.

14. A voice call fallback method, applied to non-terrestrial network Internet of Things, characterized in that: include: Receiving a first request message sent by a terminal device when initiating a voice call, wherein the first request message is used to trigger a circuit switched fallback process; Returning a first response message to the terminal device, wherein the first response message includes at least one of the following: a neighboring frequency point of a geostationary orbit mobile radio network pre-set in the non-terrestrial network Internet of Things and a circuit switching fallback release reason value; The terminal device is used to perform circuit switched fallback when receiving the first response message, wherein the circuit switched fallback is used to fallback the terminal device from the non-terrestrial network Internet of Things to the geostationary orbit mobile radio network.

15. The voice call fallback method according to claim 14, characterized in that: The method further comprises: Receiving a tracking area update request message sent by the terminal device when the voice call is hung up and the resources of the geostationary orbit mobile radio network are released, wherein the evolved packet system update type carried in the tracking area update request message is a joint tracking area / location area update; A tracking area update accept message is returned to the terminal device so that the terminal device switches back from the geostationary mobile radio network to the non-terrestrial network Internet of Things.

16. An electronic device, characterized in that: include: A memory and a processor, wherein the processor is used to run a program stored in the memory, wherein the voice call fallback method according to any one of claims 1 to 15 is executed when the program is run.

17. A non-volatile storage medium, characterized in that: The non-volatile storage medium includes a stored computer program, wherein the device where the non-volatile storage medium is located executes the voice call fallback method according to any one of claims 1 to 15 by running the computer program.

18. A computer program product, comprising a computer program, characterized in that When the computer program is executed by a processor, the steps of the voice call fallback method according to any one of claims 1 to 15 are implemented.

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