Emergency call method, device, user equipment and computer readable storage medium

Abstract

This disclosure relates to an emergency call method, apparatus, user equipment, and computer-readable storage medium, applied to a UE. The method includes: releasing an established emergency bearer in response to satisfying a release condition for the emergency bearer; wherein the emergency bearer is a bearer for transmitting signaling for emergency call services; and after the emergency bearer is released, redirection from a first communication system to a second communication system; wherein the system performance of the first communication system is lower than that of the second communication system. According to this disclosure, in scenarios where a UE initiates an EPS Fallback emergency call while camped on a 5G network, problems such as the inability to initiate a call, the inability to connect to a called party, and the inability to initiate data services can be avoided for a period of time after re-entering 5G.

Description

Technical Field

[0001] The present disclosure relates to the field of communication technology, and in particular to an emergency call method, device, user equipment, and computer-readable storage medium. Background Art

[0002] The ultimate goal of the evolution of 5G voice solutions is to carry voice services through VoNR (Voice over New Radio). In the stage where the 5G network cannot fully support VoNR, EPS Fallback (Evolved Packet System Fallback) can be used as a transition solution, so that users can experience high-speed Internet access while also using voice services normally. Specifically, during the call initiation or answering stage, the UE (User Equipment) residing in the 5G network can first fall back to the 4G network through network redirection or switching, and perform voice services through the VoLTE technology of the 4G network. After the voice service is completed, it can return to the 5G network through network redirection.

[0003] Among them, according to the provisions of the 3GPP (3rd Generation Partnership Project) agreement, in the single registration mode, since there is an N26 interface that supports interoperability between the MME (Mobility Management Entity) network element of the 4G core network and the AMF (Access and Mobility Management Function) network element of the 5G core network, when a change occurs from 4G to 5G (or 5G to 4G), the existing PDN connection (or PDU session) can be maintained and the user context can be switched between the two networks without re-establishing existing bearers and re-registering existing services.

[0004] In the related technology, when the UE resides in the 5G network, it initiates an EPS Fallback emergency call. When returning to the 5G network from the 4G network, the IMS default bearer and the data default bearer are abnormally released, causing the VoLTE service and data service to be unavailable for a period of time after the UE returns to the 5G network. Summary of the invention

[0005] The present disclosure provides an emergency call method, apparatus, user equipment and computer-readable storage medium to address deficiencies in related technologies.

[0006] According to a first aspect of an embodiment of the present disclosure, an emergency call method is proposed, which is applied to a UE. The method includes:

[0007] In response to satisfying a release condition of the emergency bearer, releasing the established emergency bearer; wherein the emergency bearer is a bearer used to transmit signaling of an emergency call service;

[0008] After the emergency bearer is released, it is redirected from the first communication system to the second communication system; wherein the system performance of the first communication system is lower than the system performance of the second communication system.

[0009] Optionally, the releasing the established emergency bearer includes:

[0010] Sending a packet data network PDN connection release request message for requesting to release the emergency bearer to a network side device; wherein the PDN connection release request message includes a bearer identifier of the emergency bearer;

[0011] receiving a deactivation evolved packet system EPS bearer context request message sent by the network side device;

[0012] After sending the EPS bearer context deactivation confirmation message to the network side device, it is determined that the emergency bearer release is completed.

[0013] Optionally, the release conditions include:

[0014] Receiving a first radio resource control RRC release message sent by a network side device; or

[0015] It is detected that the first emergency call process corresponding to the emergency call service is ended.

[0016] Optionally, when the release condition includes receiving a first RRC release message sent by the network side device, the method further includes:

[0017] After the first emergency call process is completed, the established emergency bearer is multiplexed to initiate a second emergency call process corresponding to the emergency call service.

[0018] Optionally, the first RRC release message includes cell frequency information of the second communication system; and after the emergency bearer release is completed, redirecting from the first communication system to the second communication system includes:

[0019] In response to determining that the emergency bearer release is completed, sending a registration request message to the network side device according to the first RRC release message; wherein the registration request message is used to indicate that the IMS default bearer and the data default bearer have been activated in the first communication system;

[0020] receiving a registration acceptance message sent by the network side device; wherein the registration acceptance message is used to indicate that the IMS default bearer and the data default bearer have been activated in the second communication system;

[0021] After sending the registration completion message to the network side device, it is determined that the redirection to the second communication system is completed.

[0022] Optionally, before releasing the established emergency bearer in response to satisfying a release condition of the emergency bearer, the method further includes:

[0023] dialing an emergency call number in the second communication system currently residing;

[0024] In response to receiving a second RRC release message sent by the network side device, redirecting from the second communication system to the first communication system;

[0025] Establishing the emergency bearer and performing IMS emergency registration;

[0026] Based on the established emergency bearer, a first emergency call process corresponding to the emergency call service is initiated.

[0027] Optionally, the second RRC release message includes cell frequency information of the first communication system;

[0028] The redirecting from the second communication system to the first communication system comprises:

[0029] Sending a tracking area update TAU request message to the network side device according to the second RRC release message; wherein the TAU request message is used to indicate that the IMS default bearer and the data default bearer have been activated in the second communication system;

[0030] receiving a TAU acceptance message sent by a network side device; wherein the TAU acceptance message is used to indicate that the IMS default bearer and the data default bearer have been activated in the first communication system;

[0031] After sending the TAU completion message to the network side device, it is determined that the redirection to the first communication system is completed.

[0032] According to a second aspect of an embodiment of the present disclosure, an emergency call device is provided, the device comprising:

[0033] A release module, configured to release the established emergency bearer in response to satisfying a release condition of the emergency bearer; wherein the emergency bearer is a bearer for transmitting signaling of an emergency call service;

[0034] The first redirection module is used to redirect from the first communication system to the second communication system after the emergency bearer is released; wherein the system performance of the first communication system is lower than the system performance of the second communication system.

[0035] According to a third aspect of an embodiment of the present disclosure, a user equipment is provided, including:

[0036] processor;

[0037] a memory for storing processor-executable instructions;

[0038] Wherein, the processor is used to implement the above emergency call method.

[0039] According to a fourth aspect of an embodiment of the present disclosure, there is provided a computer-readable storage medium on which a computer program is stored. When the computer program is executed by a processor, it is used to implement the above-mentioned emergency call method.

[0040] The technical solution provided by the embodiments of the present disclosure may at least include the following beneficial effects:

[0041] According to an embodiment of the present disclosure, the UE can release the established emergency bearer in response to meeting the release condition of the emergency bearer, and after the release of the emergency bearer is completed, it can be redirected from the first communication system to the second communication system. Therefore, in the scenario where the UE initiates an EPS Fallback emergency call when it resides in the 5G network, since the UE can return to the 5G network after the release of the established emergency bearer is completed, the established IMS default bearer and the data default bearer can be mapped normally to the 5G network, and there is no need to re-register the IMS. On the one hand, after returning to the 5G network after the EPS Fallback emergency call, it can avoid the problem that the caller cannot initiate, the called party cannot be connected, and the data service cannot be initiated; on the other hand, compared with the signaling process of reconstructing the IMS default bearer, re-registering the IMS, and reconstructing the data default bearer after returning to the 5G network, by adding the release process of the emergency bearer before returning to the 5G network, the signaling overhead can be reduced, the power consumption can be reduced, and unexpected errors can be avoided in the processing of additional signaling. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] In order to more clearly illustrate the technical solutions in the embodiments of the present disclosure, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present disclosure. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0043] Figure 1It is a schematic flow chart of an emergency call method according to an embodiment of the present disclosure.

[0044] Figure 2 It is a schematic flow chart of another emergency call method according to an embodiment of the present disclosure.

[0045] Figure 3 It is a schematic flow chart of another emergency call method according to an embodiment of the present disclosure.

[0046] Figure 4 It is a schematic flow chart of another emergency call method according to an embodiment of the present disclosure.

[0047] Figure 5 It is a schematic flow chart of another emergency call method according to an embodiment of the present disclosure.

[0048] Figure 6 It is a signaling interaction diagram of an emergency call method according to an embodiment of the present disclosure.

[0049] Figure 7 It is a schematic block diagram of an emergency call device according to an embodiment of the present disclosure.

[0050] Figure 8 It is a schematic block diagram of another emergency call device according to an embodiment of the present disclosure.

[0051] Fig. 9 It is a schematic block diagram of another emergency call device according to an embodiment of the present disclosure.

[0052] Fig.10 It is a schematic block diagram of another emergency call device according to an embodiment of the present disclosure.

[0053] Fig.11 It is a schematic block diagram of another emergency call device according to an embodiment of the present disclosure.

[0054] Fig.12 It is a schematic block diagram of an emergency call device according to an embodiment of the present disclosure. DETAILED DESCRIPTION

[0055] The following will be combined with the drawings in the embodiments of the present disclosure to clearly and completely describe the technical solutions in the embodiments of the present disclosure. Obviously, the described embodiments are only part of the embodiments of the present disclosure, not all of the embodiments. Based on the embodiments in the present disclosure, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present disclosure.

[0056] Each generation upgrade of the communication system will be a long process. In the early stage of commercial use of 5G communication systems, 5G network coverage can start with hotspot coverage and gradually achieve full regional coverage. During this process, 4G networks will continue to undertake the task of wide-area coverage. It can be seen that in the process of upgrading from 4G to 5G, in order to ensure the user's voice and data experience, a complete VoLTE (Voice over Long-Term Evolution) network is needed as the basis.

[0057] The ultimate goal of the evolution of 5G voice solutions is to carry voice services through VoNR (Voice over New Radio). Since the support of 5G networks for VoNR solutions is not achieved overnight, in the stage where 5G networks cannot fully support VoNR, EPS Fallback (Evolved Packet System Fallback) can be used as a transition solution, so that users can experience high-speed Internet access while also using voice services normally. Specifically, during the call initiation or answering stage, the UE (User Equipment) residing in the 5G network can first fall back to the 4G network through network redirection or switching, and perform voice services through the VoLTE technology of the 4G network. After the voice service is completed, it can return to the 5G network through network redirection.

[0058] In the above EPS Fallback solution, when the UE falls back from 5G to 4G, it needs to perform a TAU (Tracking Area Update) process to complete the registration update of the 4G network; when the UE returns from 4G to 5G, it needs to perform a registration update process (Registration procedure) to complete the registration update of the 5G network. According to the provisions of the 3GPP (3rd Generation Partnership Project) protocol, in the single registration mode, since there is an N26 interface that supports intercommunication between the MME (Mobility Management Entity) network element of the 4G core network and the AMF (Access and Mobility Management Function) network element of the 5G core network, when a change occurs from 4G to 5G (or 5G to 4G), the existing PDN connection (or PDU session) can be maintained, and the user context can be switched between the two networks without re-establishing the existing bearer and re-registering the existing service.

[0059] Among them, if the UE initiates an emergency call service in the 5G network, it can first fall back to the 4G network, establish an emergency bearer, perform IMS (IP Multimedia Subsystem) emergency registration, and then perform the emergency call process based on the emergency bearer, such as: establishing a voice-dedicated bearer, voice connection, and releasing the voice-dedicated bearer after hanging up; after the emergency call process ends, the UE can return to the 5G network.

[0060] However, the current 5G network does not support emergency call services, and the established emergency bearer cannot be mapped to the 5G network; and when the UE returns to the 5G network, if the emergency bearer mapping is abnormal, all established bearers (including IMS default bearers and data default bearers) may be abnormally released, which may cause the UE to experience unavailability of VoLTE services and data services after returning to 5G.

[0061] In the related technology, after the UE completes the registration update process of returning to 5G, since the IMS default bearer and the data default bearer are abnormally released, it is usually necessary to re-establish the IMS default bearer and execute the IMS registration process to restore the VoLTE service, and it is also necessary to re-establish the data default bearer to restore the data service.

[0062] It can be seen that in the relevant technology, on the one hand, after returning to the 5G network after the EPS Fallback emergency call, until the IMS default bearer is rebuilt, the IMS re-registration and the data default bearer are rebuilt, the UE will have problems such as being unable to initiate calls, being unable to connect to the called party, and being unable to initiate data services; on the other hand, the IMS default bearer and default data bearer reconstruction process, as well as the IMS re-registration process, will bring additional signaling overhead and power consumption to the UE, and may even cause unexpected errors in the processing of additional signaling.

[0063] The emergency call method provided by the present disclosure is introduced below through specific embodiments and in combination with specific application scenarios.

[0064] In the embodiments of the present disclosure, the UE involved may include but is not limited to electronic devices such as mobile phones, tablet computers, wearable devices, sensors, and Internet of Things devices. The UE may communicate with a base station. The base station may include but is not limited to a 4G base station, a 5G base station, a 6G base station, or a base station of any generation of communication system.

[0065] In the embodiments of the present disclosure, the network side equipment involved may include the base station, and may also include the core network corresponding to the base station. The core network may include but is not limited to EPC (Evolved Packet Core), 5GC (5Generation Core, 5G core network), etc.

[0066] See also Figure 1 , Figure 1 is a schematic flow chart of an emergency call method according to an embodiment of the present disclosure. The method can be applied to the UE, such as Figure 1 As shown, the method may include:

[0067] In step 102, in response to a release condition of an emergency bearer being met, the established emergency bearer is released; wherein the emergency bearer is a bearer used to transmit signaling of an emergency call service.

[0068] For example, in the first communication system where the UE currently resides, an emergency bearer for transmitting signaling for emergency call services has been established, and the UE can perform an emergency call process corresponding to the emergency call service based on the established emergency bearer; in response to satisfying the release condition of the emergency bearer, the UE can release the emergency bearer established in the first communication system. It should be noted that the emergency call process may specifically include establishing a voice-dedicated bearer, voice connection, releasing the voice-dedicated bearer after hanging up, etc., which is similar to the normal call process and will not be elaborated here.

[0069] Optionally, in step 102, the release condition of the emergency bearer may include: receiving a first RRC (Radio Resource Control) release message sent by a network side device; or detecting that the first emergency call process corresponding to the emergency call service is terminated.

[0070] For example, in response to receiving the first RRC release message sent by the network side device, the UE can determine that the release condition of the emergency bearer is met and release the established emergency bearer. The first RRC release message may specifically include an RRCConnection Release message (that is, an RRC connection release message); the RRC Connection Release message can be used to release the connection in the 4G network to redirect to the 5G network.

[0071] For another example, the UE may perform a first emergency call process corresponding to the emergency call service based on the established emergency bearer; in response to detecting that the first emergency call process ends, the UE may determine that the release condition of the emergency bearer is met and release the established emergency bearer.

[0072] It should be noted that in the embodiments shown above, only two release conditions are described by way of example, and this does not limit the present disclosure. During implementation, technicians in this field may configure other emergency bearer release conditions for the UE according to actual needs, which cannot be listed here one by one.

[0073] In step 104, after the emergency bearer is released, the first communication system is redirected to the second communication system; wherein the system performance of the first communication system is lower than the system performance of the second communication system.

[0074] For example, since the UE falls back to the first communication system to perform the emergency call process, after the established emergency bearer is released, the UE can be redirected by the network and return from the first communication system to the second communication system with higher system performance.

[0075] Optionally, the first communication system may include a 4G communication system; the second communication system may include a 5G communication system based on SA (Standalone, independent networking).

[0076] It should be noted that the present disclosure can be applied to application scenarios in which the UE initiates an EPS Fallback emergency call when it resides in a 5G SA network and returns to 5G after the emergency call. Since the above scenario involves the process of switching the core network (from EPC to 5GC), the emergency bearer may not be released, resulting in abnormal mapping of the IMS default bearer and the data default bearer, which in turn causes the VoLTE service to be unavailable and the data service to be unavailable for a period of time after the UE returns to 5G. However, when initiating an emergency call service in a 5G NSA (Non-Standalone) network based on the ENDC (E-UTRA NR Dual-Connectivity) mode, the above-mentioned abnormality may not occur.

[0077] It can be seen from the above embodiments that the UE can release the established emergency bearer in response to meeting the release condition of the emergency bearer, and after the release of the emergency bearer is completed, it can be redirected from the first communication system to the second communication system. Therefore, in the scenario where the UE initiates an EPS Fallback emergency call when it resides in the 5G network, since the UE can return to the 5G network after the release of the established emergency bearer is completed, the established IMS default bearer and data default bearer can be mapped to the 5G network normally, and there is no need to re-register the IMS. On the one hand, after returning to the 5G network after the EPS Fallback emergency call, it can avoid the problems of the caller being unable to initiate, the called party being unable to connect, and temporary data network loss; on the other hand, compared with the signaling process of reconstructing the IMS default bearer, re-registering the IMS, and reconstructing the data default bearer after returning to the 5G network, by adding the release process of the emergency bearer before returning to the 5G network, the signaling overhead can be reduced, the power consumption can be reduced, and unexpected errors can be avoided in the processing of additional signaling.

[0078] See also Figure 2 , Figure 2 is based on Figure 1 A schematic flow chart of another emergency call method is shown based on the embodiment shown. Figure 2 As shown, the releasing of the established emergency bearer may specifically include:

[0079] In step 202, a PDN connection release request message for requesting to release the emergency bearer is sent to a network side device; wherein the PDN connection release request message includes a bearer identifier of the emergency bearer.

[0080] For example, in response to meeting the release conditions of the emergency bearer, the UE may send a PDN connection release request message (i.e., a PDN DISCONNECT REQUEST message) to the network side device to request the release of the emergency bearer; wherein the PDN connection release request message may carry the bearer identifier of the emergency bearer requested to be released (e.g., EBI=7).

[0081] It should be noted that in the above-described embodiment, the bearer identifier of the emergency bearer is EBI (EPS Bearer Identity, EPS bearer ID) which is only an exemplary implementation method, and the present disclosure does not limit it; when implementing, those skilled in the art may also adopt other methods to indicate to the network side device the emergency bearer requested to be released. For example, a designated bit may be pre-configured in the PDN connection release request message, and when the designated bit is set to 1, it may indicate to the network side device a request to release the established emergency bearer.

[0082] In step 204, a deactivation EPS bearer context request message sent by the network side device is received.

[0083] For example, after the UE sends a PDN connection release request message for requesting the release of the emergency bearer to the network side device, the UE may receive a deactivate EPS bearer context request message (ie, a DEACTIVATE EPS BEARER CONTEXT REQUEST message) returned by the network side device.

[0084] In step 206, after sending a deactivation EPS bearer context confirmation message to the network side device, it is determined that the emergency bearer release is completed.

[0085] For example, in response to the received deactivate EPS bearer context request message, the UE may send a deactivate EPS bearer context confirm message (ie, a DEACTIVATE EPS BEARER CONTEXT ACCEPT message) to the network side device to determine that the emergency bearer release is complete.

[0086] It can be seen from the above embodiments that in response to meeting the release conditions of the emergency bearer, the UE and the core network device can release the established emergency bearer through the above-mentioned EPS bearer deactivation signaling interaction process, and after the emergency bearer release is completed, it can be redirected from the first communication system to the second communication system. Therefore, in the scenario where the UE initiates an EPS Fallback emergency call when it resides in the 5G network, it can avoid the problems of the caller being unable to initiate, the called party being unable to connect, and temporary data network disconnection for a period of time after returning to 5G; in addition, compared to executing the signaling process of rebuilding the IMS default bearer, re-registering IMS, and rebuilding the data default bearer after returning to the 5G network, by adding the release process of the emergency bearer before returning to the 5G network, the signaling overhead can be reduced, the power consumption can be reduced, and unexpected errors can be avoided during the processing of additional signaling.

[0087] See also Figure 3 , Figure 3 is based on Figure 1 A schematic flow chart of another emergency call method is shown based on the embodiment shown. Figure 3 As shown, when the release condition includes receiving a first RRC release message sent by the network side device, and the first RRC release message includes the cell frequency information of the second communication system; after the emergency bearer release is completed, redirecting from the first communication system to the second communication system may specifically include:

[0088] In step 302, in response to determining that the emergency bearer release is completed, a registration request message is sent to the network side device according to the first RRC release message; wherein the registration request message is used to indicate that the IMS default bearer and the data default bearer have been activated in the first communication system.

[0089] For example, in response to receiving a first RRC release message sent by a network side device, the UE can release the established emergency bearer, and the first RRC release message may include the cell frequency information of the 5G communication system, such as: the RRC Connection Release message sent by the network side carries a redirectedCarrierInfo information element parameter, which may include the frequency information and subcarrier spacing parameters of the NR cell; in response to determining that the emergency bearer release is completed, the UE can return to the residence of the 5G cell according to the frequency information of the NR cell, that is, the UE can send a registration request message (that is, a REGISTRATION REQUEST message) to the network side device on the NR cell to start the mobility registration update process.

[0090] The registration request message may carry parameters for indicating the activation status of the IMS default bearer and the data default bearer in the first communication system. For example, EBI_5=1 and EBI_6=1 may be used to indicate that the IMS default bearer and the data default bearer are activated in the 4G communication system.

[0091] In step 304, a registration acceptance message sent by the network side device is received; wherein the registration acceptance message is used to indicate that the IMS default bearer and the data default bearer have been activated in the second communication system.

[0092] For example, after sending a registration request message to the network side device, the UE may receive a registration acceptance message (ie, a REGISTRATION ACCEPT message) returned by the network side device.

[0093] The registration acceptance message may carry parameters for indicating the activation status of the IMS default bearer and the data default bearer in the second communication system. For example, PSI[1]=1 and PSI[2]=1 may be used to indicate that the corresponding PDU Session has been activated, that is, to indicate that the IMS default bearer and the data default bearer are in an activated state in the 5G communication system.

[0094] It should be noted that in the above-mentioned related technologies, since the emergency bearer that has not been released cannot be mapped to the 5G network, in the registration acceptance message sent by the network side to the UE, all items in the PSI list in the PDU Session Status are set to 0, indicating that there is currently no activated PDU Session; at this time, the IMS default bearer and the data default bearer are abnormally released, and both the VoLTE service and the data service are interrupted.

[0095] In step 306, after sending the registration completion message to the network side device, it is determined that the redirection to the second communication system is completed.

[0096] For example, in response to receiving the registration acceptance message returned by the network side device, the UE may send a registration completion message (ie, REGISTRATION COMPLETE message) to the network side device, and the mobility update registration is completed, and it may be determined that the redirection to the 5G communication system is completed.

[0097] It can be seen from the above embodiment that in response to receiving the first RRC release message sent by the network side device, the UE can release the established emergency bearer; in response to determining that the emergency bearer release is completed, the UE can execute the registration update process according to the first RRC release message to return to the 5G network. As a result, in the scenario where the UE initiates an EPS Fallback emergency call when it resides in the 5G network, it can avoid the problem that the caller cannot initiate, the called party cannot be connected, and the data service cannot be initiated for a period of time after returning to 5G; in addition, compared with executing the signaling process of rebuilding the IMS default bearer, re-registering IMS, and rebuilding the data default bearer after returning to the 5G network, by adding the release process of the emergency bearer before returning to the 5G network, the signaling overhead can be reduced, the power consumption can be reduced, and unexpected errors can be avoided in the processing of additional signaling.

[0098] See also Figure 4 , Figure 4 is based on Figure 1 A schematic flow chart of another emergency call method is shown based on the embodiment shown. Figure 4 As shown, before releasing the established emergency bearer in response to satisfying the release condition of the emergency bearer, the method may further include:

[0099] In step 402, an emergency call number is dialed in the second communication system currently resident.

[0100] For example, a UE currently residing in a 5G network dials an emergency call number, that is, requests to initiate an emergency call service.

[0101] The emergency call number may include any number in the emergency call number list issued by the network side device. For example, the emergency call number may specifically include but is not limited to 110, 119, 120, 122 and the like.

[0102] Optionally, before step 402, the method may further include: sending a registration request message to the network side device; receiving a registration acceptance message sent by the network side device, wherein the registration acceptance message includes the emergency call number list, and the emergency call numbers include at least one emergency call number; after sending a registration completion message to the network side device, completing the residency in the second communication system.

[0103] For example, the UE can initiate a mobility registration update process to reside in the 5G SA network; specifically, the UE can send a REGISTRATION ACCEPT message to the network side device, in which the reg_type parameter included can be set to the mob reg updating type; the UE can receive the REGISTRATION ACCEPT message sent by the network side device, which may include PSI[1]=1, PSI[2]=1, used to indicate that the IMS default bearer and the data default bearer are activated in the 5G communication system, and may also include an emergency call number list (emergency num list); the UE can send a REGISTRATION COMPLETE message to the network side device, and the mobility update registration is completed, and the UE can reside in the 5G network.

[0104] In step 404, in response to receiving a second RRC release message sent by the network side device, the second communication system is redirected to the first communication system.

[0105] For example, after a UE currently residing in a 5G network dials an emergency call number, it can receive a second RRC release message sent by the network side device, that is, it is necessary to perform the emergency call process through the EPS Fallback solution; in response to receiving the second RRC release message, the UE can fall back from the 5G network to the 4G network. Among them, the second RRC release message can specifically include an RRC Release message (also known as an RRC release message); the RRC Release message can be used to release the connection in the 5G network to redirect to the 4G network.

[0106] In step 406, the emergency bearer is established.

[0107] For example, the UE can send a PDN connection request message (i.e., a PDN CONNECTIVITY REQUEST message) to the network side device for requesting to establish the emergency bearer, wherein the type of the PDN connection request message is an emergency type, which is used to request to establish an emergency bearer; the UE can receive an activate EPS bearer context request message (i.e., an ACTIVATE DEFAULT EPS BEARER CONTEXTREQUEST message) sent by the network side device for activating the emergency bearer, wherein the activate EPS bearer context request message may include the P-CSCF IP address allocated by the network side to the UE for IMS emergency registration; the UE can send an activate EPS bearer context accept message (i.e., an ACTIVATE DEFAULT EPS BEARER CONTEXT ACCEPT message) to the network side device, and the emergency bearer establishment is completed.

[0108] In step 408, IMS emergency registration is performed.

[0109] For example, the UE may send a REGISTER message to the network side device according to the P-CSCF IP address allocated by the network side to initiate an IMS emergency registration; and complete the IMS emergency registration in response to receiving a 200OK message sent by the network side device.

[0110] In step 410, based on the established emergency bearer, a first emergency call process corresponding to the emergency call service is initiated.

[0111] For example, after establishing the emergency bearer and performing IMS emergency registration, the UE may send an INVITE message to the network side device, and the INVITE message may include a target address for the emergency call; the UE may perform a first emergency call process based on the established emergency bearer.

[0112] The target address of the emergency call is the address corresponding to the dialed emergency call number. For example, if the dialed emergency call number is 110, the target address may be urn:service:sos.police.

[0113] Among them, in the embodiment of the present disclosure, the first emergency call process corresponding to the emergency call service can be understood as the first emergency call process performed after the UE falls back to the 4G network through the EPS Fallback solution when it resides in the 5G network. Correspondingly, the second emergency call process corresponding to the emergency call service can be understood as the second emergency call process performed after the UE falls back to the 4G network and before returning to the 5G network.

[0114] Optionally, in step 404, the second RRC release message may include the cell frequency information of the first communication system; the redirection from the second communication system to the first communication system may specifically include: sending a TAU request message to the network side device according to the second RRC release message; wherein the TAU request message is used to indicate that the IMS default bearer and the data default bearer have been activated in the second communication system; receiving a TAU acceptance message sent by the network side device; wherein the TAU acceptance message is used to indicate that the IMS default bearer and the data default bearer have been activated in the first communication system; after sending a TAU completion message to the network side device, determining that the redirection to the first communication system is completed.

[0115] For example, in response to receiving a second RRC release message sent by the network side device, the second RRC release message may include the cell frequency information of the 4G communication system, such as: the RRC Release message sent by the network side may include the frequency information of E-UTRA and the message reselection priority; the UE can fall back to the 4G network according to the cell frequency information of the 4G communication system, that is, the UE can send a TAU request message (that is, a TRACKING AREA UPDATE REQUEST message) to the network side device, in which the eps_update_type parameter included therein can be set to TA updating; the UE can receive a TAU acceptance message (that is, a TRACKING AREA UPDATE ACCEPT message) returned by the network side device; the UE can send a TAU completion message (that is, a TRACKING AREA UPDATECOMPLETE message) to the network side device, the EPS Fallback process is completed, and it can be determined that the redirection to the 4G communication system is completed.

[0116] The TAU request message may carry parameters for indicating the activation status of the IMS default bearer and the data default bearer in the second communication system. For example, PSI[1]=1 and PSI[2]=1 may be used to indicate that the IMS default bearer and the data default bearer are in an activated state in the 5G communication system, respectively.

[0117] The TAU accept message may carry parameters for indicating the activation status of the IMS default bearer and the data default bearer in the first communication system. For example, EBI_5=1 and EBI_6=1 may be used to indicate that the IMS default bearer and the data default bearer are activated in the 4G communication system.

[0118] It can be seen from the above embodiments that after the UE dials the emergency call number in the currently resident 5G communication system, it can receive the second RRC release message sent by the network side device, and the 5G communication system is redirected to the 4G communication system; further, the UE can establish an emergency bearer, perform IMS emergency registration, and initiate the first emergency call process based on the established emergency bearer; subsequently, in response to meeting the release condition of the emergency bearer, the UE returns to 5G through network redirection after releasing the emergency bearer. Therefore, in the case that the current 5G network cannot fully support the VoNR solution, the UE can initiate an emergency call through the EPS Fallback solution when it resides in the 5G network, and can avoid the problem of the caller being unable to initiate, the called party being unable to connect, and temporary data network loss for a period of time after returning to 5G; in addition, compared with the signaling process of reconstructing the IMS default bearer, re-registering IMS, and reconstructing the data default bearer after returning to the 5G network, by adding the release process of the emergency bearer before returning to the 5G network, the signaling overhead can be reduced, the power consumption can be reduced, and unexpected errors can be avoided in the processing of additional signaling.

[0119] It should be noted that the present disclosure is not applicable to the scenario where the UE dials an emergency call number in the manner of a normal call service, because when the UE dials an emergency call number in the manner of an emergency call service, it is necessary to first establish an emergency bearer and then perform the call process, which will result in the technical problems in the above-mentioned related technologies.

[0120] See also Figure 5 , Figure 5 is based on Figure 1 A schematic flow chart of another emergency call method is shown based on the embodiment shown. Figure 5 As shown, in the case where the release condition includes receiving a first RRC release message sent by the network side device, before releasing the established emergency bearer in response to satisfying the release condition of the emergency bearer, the method may further include:

[0121] In step 502, after the first emergency call process is completed, the established emergency bearer is multiplexed to initiate a second emergency call process corresponding to the emergency call service.

[0122] For example, after the UE establishes the emergency bearer in the 4G network, performs IMS emergency registration, and completes the first emergency call process corresponding to the emergency call service based on the emergency bearer, there is no need to immediately return to the 5G network, and the emergency bearer can be reused, that is, the second emergency call process corresponding to the emergency call service can be continued to be initiated based on the established emergency bearer; subsequently, in response to receiving the first RRC release message sent by the network side device, the emergency bearer can be released and redirected to the 5G communication system.

[0123] It can be seen from the above embodiment that if the UE releases the established emergency bearer in response to detecting the end of the first emergency call process, then the next emergency call number will be dialed immediately, and the emergency bearer will need to be re-established, that is, the emergency bearer cannot be reused. Therefore, if the UE releases the established emergency bearer in response to receiving the first RRC release message sent by the network side device, the emergency bearer can be reused, thereby saving the signaling overhead required to create the emergency bearer and making full use of the existing communication resources.

[0124] See also Figure 6 , Figure 6 FIG. 1 is a schematic diagram of signaling interaction of an emergency call method according to an embodiment of the present disclosure. Figure 6 As shown, the method can be applied to the UE; taking the release condition of the emergency bearer including receiving the first RRC release message sent by the network side device as an example, the following signaling interaction can be performed between the UE and the network side device (RADIO NETWORK) to implement the emergency call method.

[0125] The UE may send a REGISTRATION REQUEST message to the network side device;

[0126] The UE may receive a REGISTRATION ACCEPT message sent by the network side device; the message may include an emergency num list (emergency call number list), and the emergency call number list may include at least one emergency call number;

[0127] The UE may send a REGISTRATION COMPLETE message to the network side device to complete the stay in the 5G network;

[0128] The UE may dial any emergency call number in the emergency call number list to request to initiate an emergency call service;

[0129] The UE may receive an RRC Release message sent by the network side device; the message may include at least frequency information of E-UTRA;

[0130] The UE may send a TRACKING AREA UPDATE REQUEST message to the network side device;

[0131] The UE may receive a TRACKING AREA UPDATE ACCEPT message sent by the network side device;

[0132] The UE may send a TRACKING AREA UPDATE COMPLETE message to the network side device to complete the stay in the 4G network;

[0133] The UE may send a PDN CONNECTIVITY REQUEST message of the emergency type to the network side device to request to establish an emergency bearer;

[0134] The UE may receive an ACTIVATE DEFAULTEPS BEARER CONTEXT REQUEST message sent by the network side device for activating the emergency bearer, which may include a P-CSCF IP address allocated to the UE for IMS emergency registration;

[0135] The UE may send an ACTIVATE DEFAULT EPS BEARER CONTEXT ACCEPT message to the network side device;

[0136] The UE may send a REGISTER message to the network side device according to the P-CSCF IP address to initiate an IMS emergency registration; wherein, if the UE initiates an IMS emergency registration to the P-CSCF IP address for the first time, the network side device may send a 401 response message, and "UNAUTHORIZED" may be used to prompt that the UE is unauthorized; further, the UE may send a REGISTER message to the network side device again, in which a response parameter for authentication is added; the network side device may send a 200OK message after successful authentication, and the UE completes the IMS emergency registration process;

[0137] The UE may send an INVITE message to the network side device, which may include a target address of the emergency call; and the UE may perform a first emergency call process based on the established emergency bearer.

[0138] The target address of the emergency call is the address corresponding to the emergency call number dialed; for example, if the emergency call number dialed is 110, the target address may be urn:service:sos.police;

[0139] The UE may initiate an emergency call process corresponding to the emergency call service based on the established emergency bearer;

[0140] After the emergency call process is completed, the UE may receive an RRCConnection Release message sent by a network side device, which may include at least frequency information of the NR cell;

[0141] The UE may send a PDN DISCONNECT REQUEST message to the network side device; the message may carry the bearer identifier of the emergency bearer requested to be released (eg, EBI=7);

[0142] The UE may receive the DEACTIVATE EPS BEARER CONTEXT REQUEST message returned by the network side device;

[0143] The UE may send a DEACTIVATE EPS BEARER CONTEXT ACCEPT message to the network side device, and the emergency bearer release is completed;

[0144] The UE may send a REGISTRATION REQUEST message to the network side device;

[0145] The UE may receive a REGISTRATION ACCEPT message returned by the network side device;

[0146] The UE can send a REGISTRATION COMPLETE message to the network side device to return to the 5G network.

[0147] For matters not described in detail in the above embodiments, please refer to other embodiments shown in the present disclosure and will not be described in detail here.

[0148] Corresponding to the aforementioned embodiment of the emergency call method, the present disclosure also provides an embodiment of an emergency call device.

[0149] See also Figure 7 , Figure 7 FIG. 1 is a schematic block diagram of an emergency call device according to an embodiment of the present disclosure. Figure 7 As shown, the device may include:

[0150] A release module 702, configured to release the established emergency bearer in response to satisfying a release condition of the emergency bearer; wherein the emergency bearer is a bearer for transmitting signaling of an emergency call service;

[0151] The first redirection module 704 is configured to redirect from the first communication system to the second communication system after the emergency bearer is released; wherein the system performance of the first communication system is lower than the system performance of the second communication system.

[0152] Optionally, the release conditions include:

[0153] receiving a first radio resource control RRC release message sent by the network side device; or

[0154] It is detected that the first emergency call process corresponding to the emergency call service is ended.

[0155] See also Figure 8 , Figure 8 is based on Figure 7 A schematic block diagram of another emergency call device is shown based on the embodiment shown. Figure 8 As shown, the release module 702 includes:

[0156] The first sending submodule 802 is used to send a packet data network PDN connection release request message for requesting to release the emergency bearer to the network side device; wherein the PDN connection release request message includes a bearer identifier of the emergency bearer;

[0157] A first receiving submodule 804 is configured to receive a deactivation evolved packet system EPS bearer context request message sent by the network side device;

[0158] The first determining submodule 806 is configured to determine that the emergency bearer release is completed after sending a deactivation EPS bearer context confirmation message to the network side device.

[0159] See also Fig. 9 , Fig. 9 is based on Figure 7 A schematic block diagram of another emergency call device is shown based on the embodiment shown. Fig. 9 As shown, the release condition includes: receiving a first radio resource control RRC release message sent by the network side device; the first RRC release message includes the cell frequency information of the second communication system; the first redirection module 704 includes:

[0160] A second sending submodule 902 is configured to, in response to determining that the emergency bearer release is completed, send a registration request message to the network side device according to the first RRC release message; wherein the registration request message is used to indicate that the IMS default bearer and the data default bearer have been activated in the first communication system;

[0161] The second receiving submodule 904 is used to receive a registration acceptance message sent by the network side device; wherein the registration acceptance message is used to indicate that the IMS default bearer and the data default bearer have been activated in the second communication system;

[0162] The second determining submodule 906 is configured to determine that redirection to the second communication system is completed after sending a registration completion message to the network side device.

[0163] See also Fig.10 , Fig.10 is based on Figure 7 A schematic block diagram of another emergency call device is shown based on the embodiment shown. Fig.10 As shown, the device also includes:

[0164] A dialing module 1002, configured to dial an emergency call number in the second communication system currently resident;

[0165] A second redirection module 1004 is configured to redirect the second communication system to the first communication system in response to receiving a second RRC release message sent by the network side device;

[0166] Establishing module 1006, used to establish the emergency bearer and perform IMS emergency registration;

[0167] The second initiating module 1008 is configured to initiate a first emergency call process corresponding to the emergency call service based on the established emergency bearer.

[0168] Optionally, the second RRC release message includes cell frequency information of the first communication system; and the second redirection module 1004 includes:

[0169] A third sending submodule is used to send a tracking area update TAU request message to the network side device according to the second RRC release message; wherein the TAU request message is used to indicate that the IMS default bearer and the data default bearer have been activated in the second communication system;

[0170] A third receiving submodule, configured to receive a TAU acceptance message sent by the network side device; wherein the TAU acceptance message is used to indicate that the IMS default bearer and the data default bearer have been activated in the first communication system;

[0171] The third determining submodule is used to determine that the redirection to the first communication system is completed after sending the TAU completion message to the network side device.

[0172] See also Fig.11 , Fig.11 is based on Figure 7 A schematic block diagram of another emergency call device is shown based on the embodiment shown. Fig.11 As shown, when the release condition includes receiving a first RRC release message sent by the network side device, the apparatus further includes:

[0173] The first initiating module 1102 is used to multiplex the established emergency bearer to initiate a second emergency call process corresponding to the emergency call service after the first emergency call process is completed.

[0174] Regarding the device in the above embodiment, the specific manner in which each module performs the operation has been described in detail in the embodiment of the relevant method, and will not be elaborated here.

[0175] For the device embodiment, since it basically corresponds to the method embodiment, the relevant parts can refer to the partial description of the method embodiment. The device embodiment described above is only schematic, wherein the modules described as separate components may or may not be physically separated, and the components displayed as modules may or may not be physical modules, that is, they may be located in one place, or they may be distributed on multiple network modules. Some or all of the modules may be selected according to actual needs to achieve the purpose of the disclosed solution. A person of ordinary skill in the art can understand and implement it without paying creative labor.

[0176] Accordingly, the present disclosure also provides a user equipment, including:

[0177] processor;

[0178] a memory for storing processor-executable instructions;

[0179] Wherein, the processor is used to implement the above emergency call method.

[0180] Correspondingly, the present disclosure further provides a computer-readable storage medium, wherein the storage medium stores a computer program, and when the computer program is executed by a processor, the emergency call method described above is implemented.

[0181] like Fig.12 As shown, Fig.121 is a schematic block diagram of an emergency call device 1200 according to an embodiment of the present disclosure. For example, the device 1200 may be a mobile phone, a computer, a digital broadcast terminal, a messaging device, a game console, a tablet device, a medical device, a fitness device, a personal digital assistant, etc.

[0182] Reference Fig.12 , the device 1200 may include one or more of the following components: a processing component 1202 , a memory 1204 , a power component 1206 , a multimedia component 1208 , an audio component 1210 , an input / output (I / O) interface 1212 , a sensor component 1214 , and a communication component 1216 .

[0183] The processing component 1202 generally controls the overall operation of the device 1200, such as operations associated with display, phone calls, data communications, camera operations, and recording operations. The processing component 1202 may include one or more processors 1220 to execute instructions to perform all or part of the steps of the above-described method. In addition, the processing component 1202 may include one or more modules to facilitate the interaction between the processing component 1202 and other components. For example, the processing component 1202 may include a multimedia module to facilitate the interaction between the multimedia component 1208 and the processing component 1202.

[0184] The memory 1204 is configured to store various types of data to support the operation of the device 1200. Examples of such data include instructions for any application or method operating on the device 1200, contact data, phone book data, messages, pictures, videos, etc. The memory 1204 can be implemented by any type of volatile or non-volatile storage device or a combination thereof, such as static random access memory (SRAM), electrically erasable programmable read-only memory (EEPROM), erasable programmable read-only memory (EPROM), programmable read-only memory (PROM), read-only memory (ROM), magnetic memory, flash memory, magnetic disk or optical disk.

[0185] The power supply component 1206 provides power to the various components of the device 1200. The power supply component 1206 may include a power management system, one or more power supplies, and other components associated with generating, managing, and distributing power to the device 1200.

[0186] The multimedia component 1208 includes a screen that provides an output interface between the device 1200 and the user. In some embodiments, the screen may include a liquid crystal display (LCD) and a touch panel (TP). If the screen includes a touch panel, the screen may be implemented as a touch screen to receive input signals from the user. The touch panel includes one or more touch sensors to sense touch, slide, and gestures on the touch panel. The touch sensor may not only sense the boundaries of the touch or slide action, but also detect the duration and pressure associated with the touch or slide operation. In some embodiments, the multimedia component 1208 includes a front camera and / or a rear camera. When the device 1200 is in an operating mode, such as a shooting mode or a video mode, the front camera and / or the rear camera may receive external multimedia data. Each front camera and rear camera may be a fixed optical lens system or have a focal length and optical zoom capability.

[0187] The audio component 1210 is configured to output and / or input audio signals. For example, the audio component 1210 includes a microphone (MIC), and when the device 1200 is in an operation mode, such as a call mode, a recording mode, and a speech recognition mode, the microphone is configured to receive an external audio signal. The received audio signal can be further stored in the memory 1204 or sent via the communication component 1216. In some embodiments, the audio component 1210 also includes a speaker for outputting audio signals.

[0188] I / O interface 1212 provides an interface between processing component 1202 and peripheral interface modules, such as keyboards, click wheels, buttons, etc. These buttons may include but are not limited to: home button, volume button, start button, and lock button.

[0189] The sensor assembly 1214 includes one or more sensors for providing various aspects of the status assessment of the device 1200. For example, the sensor assembly 1214 can detect the open / closed state of the device 1200, the relative positioning of components, such as the display and keypad of the device 1200, the sensor assembly 1214 can also detect the position change of the device 1200 or a component of the device 1200, the presence or absence of user contact with the device 1200, the orientation or acceleration / deceleration of the device 1200, and the temperature change of the device 1200. The sensor assembly 1214 can include a proximity sensor configured to detect the presence of a nearby object without any physical contact. The sensor assembly 1214 can also include an optical sensor, such as a CMOS or CCD image sensor, for use in imaging applications. In some embodiments, the sensor assembly 1214 can also include an accelerometer, a gyroscope sensor, a magnetic sensor, a pressure sensor, or a temperature sensor.

[0190] The communication component 1216 is configured to facilitate wired or wireless communication between the device 1200 and other devices. The device 1200 can access a wireless network based on a communication standard, such as WiFi, 2G or 3G, 4G LTE, 5G NR, or a combination thereof. In an exemplary embodiment, the communication component 1216 receives a broadcast signal or broadcast-related information from an external broadcast management system via a broadcast channel. In an exemplary embodiment, the communication component 1216 also includes a near field communication (NFC) module to facilitate short-range communication. For example, the NFC module can be implemented based on radio frequency identification (RFID) technology, infrared data association (IrDA) technology, ultra-wideband (UWB) technology, Bluetooth (BT) technology and other technologies.

[0191] In an exemplary embodiment, the device 1200 can be implemented by one or more application-specific integrated circuits (ASICs), digital signal processors (DSPs), digital signal processing devices (DSPDs), programmable logic devices (PLDs), field programmable gate arrays (FPGAs), controllers, microcontrollers, microprocessors or other electronic components to execute the methods described in any of the above embodiments.

[0192] In an exemplary embodiment, a non-transitory computer-readable storage medium including instructions is also provided, such as a memory 1204 including instructions, and the instructions can be executed by the processor 1220 of the device 1200 to perform the above method. For example, the non-transitory computer-readable storage medium can be a ROM, a random access memory (RAM), a CD-ROM, a magnetic tape, a floppy disk, an optical data storage device, etc.

[0193] Those skilled in the art will readily appreciate other embodiments of the present disclosure after considering the specification and practicing the disclosure disclosed herein. This application is intended to cover any variations, uses, or adaptations of the present disclosure that follow the general principles of the present disclosure and include common knowledge or customary techniques in the art that are not disclosed in the present disclosure. The description and examples are intended to be exemplary only, and the true scope and spirit of the present disclosure are indicated by the following claims.

[0194] It should be understood that the present disclosure is not limited to the exact structures that have been described above and shown in the drawings, and that various modifications and changes may be made without departing from the scope thereof. The scope of the present disclosure is limited only by the appended claims.

[0195] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. The terms "include", "comprises" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the statement "comprises a ..." do not exclude the presence of other identical elements in the process, method, article or device including the elements.

[0196] The method and device provided in the embodiments of the present disclosure are introduced in detail above. Specific examples are used in this article to illustrate the principles and implementation methods of the present disclosure. The description of the above embodiments is only used to help understand the method of the present disclosure and its core idea. At the same time, for those skilled in the art, according to the idea of ​​the present disclosure, there will be changes in the specific implementation methods and application scopes. In summary, the content of this specification should not be understood as a limitation on the present disclosure.

Claims

1. An emergency call method, characterized in that: Applied to user equipment UE, the method includes: In response to satisfying a release condition of an emergency bearer, releasing the established emergency bearer; wherein the emergency bearer is a bearer for transmitting signaling of an emergency call service; the release condition includes receiving a first radio resource control RRC release message sent by a network side device; the first RRC release message includes cell frequency information of the second communication system; In response to determining that the emergency bearer release is completed, sending a registration request message to the network side device according to the first RRC release message; wherein the registration request message is used to indicate that the IMS default bearer and the data default bearer have been activated in the first communication system; receiving a registration acceptance message sent by the network side device; wherein the registration acceptance message is used to indicate that the IMS default bearer and the data default bearer have been activated in the second communication system; After sending a registration completion message to the network side device, it is determined that redirection to the second communication system is completed; wherein, the system performance of the first communication system is lower than the system performance of the second communication system; and the second communication system does not support establishment of the emergency bearer.

2. The method according to claim 1, characterized in that The releasing the established emergency bearer includes: Sending a packet data network PDN connection release request message for requesting to release the emergency bearer to a network side device; wherein the PDN connection release request message includes a bearer identifier of the emergency bearer; receiving a deactivation evolved packet system EPS bearer context request message sent by the network side device; After sending the EPS bearer context deactivation confirmation message to the network side device, it is determined that the emergency bearer release is completed.

3. The method according to claim 1, characterized in that The release conditions include: It is detected that the first emergency call process corresponding to the emergency call service is ended.

4. The method according to claim 3, characterized in that In a case where the release condition includes receiving a first RRC release message sent by the network side device, the method further includes: After the first emergency call process is completed, the established emergency bearer is multiplexed to initiate a second emergency call process corresponding to the emergency call service.

5. The method according to claim 1, characterized in that Before releasing the established emergency bearer in response to satisfying a release condition of the emergency bearer, the method further includes: dialing an emergency call number in the second communication system currently residing; In response to receiving a second RRC release message sent by the network side device, redirecting from the second communication system to the first communication system; Establishing the emergency bearer and performing IMS emergency registration; Based on the established emergency bearer, a first emergency call process corresponding to the emergency call service is initiated.

6. The method according to claim 5, characterized in that The second RRC release message includes the cell frequency information of the first communication system; The redirecting from the second communication system to the first communication system comprises: Sending a tracking area update TAU request message to the network side device according to the second RRC release message; wherein the TAU request message is used to indicate that the IMS default bearer and the data default bearer have been activated in the second communication system; receiving a TAU accept message sent by the network side device; wherein the TAU accept message is used to indicate that the IMS default bearer and the data default bearer have been activated in the first communication system; After sending the TAU completion message to the network side device, it is determined that the redirection to the first communication system is completed.

7. An emergency call device, characterized in that: The device comprises: A release module, configured to release the established emergency bearer in response to satisfying a release condition of the emergency bearer; wherein the emergency bearer is a bearer for transmitting signaling of an emergency call service; the release condition comprises receiving a first radio resource control RRC release message sent by a network side device; the first RRC release message comprises cell frequency information of the second communication system; A second sending submodule, configured to, in response to determining that the emergency bearer release is completed, send a registration request message to the network side device according to the first RRC release message; wherein the registration request message is used to indicate that the IMS default bearer and the data default bearer have been activated in the first communication system; A second receiving submodule, configured to receive a registration acceptance message sent by the network side device; wherein the registration acceptance message is used to indicate that the IMS default bearer and the data default bearer have been activated in the second communication system; The second determination submodule is used to determine that redirection to the second communication system is completed after sending a registration completion message to the network side device; wherein the system performance of the first communication system is lower than the system performance of the second communication system; and the second communication system does not support the establishment of the emergency bearer.

8. The device according to claim 7, characterized in that The release module comprises: A first sending submodule is used to send a packet data network PDN connection release request message for requesting to release the emergency bearer to a network side device; wherein the PDN connection release request message includes a bearer identifier of the emergency bearer; A first receiving submodule, configured to receive a deactivation evolved packet system EPS bearer context request message sent by the network side device; The first determining submodule is used to determine that the emergency bearer release is completed after sending a deactivation EPS bearer context confirmation message to the network side device.

9. The device according to claim 7, characterized in that The release conditions include: It is detected that the first emergency call process corresponding to the emergency call service is ended.

10. The device according to claim 9, characterized in that In a case where the release condition includes receiving a first RRC release message sent by the network side device, the apparatus further includes: The first initiating module is used to multiplex the established emergency bearer and initiate a second emergency call process corresponding to the emergency call service after the first emergency call process is completed.

11. The device according to claim 7, characterized in that The device also includes: A dialing module, used for dialing an emergency call number in the second communication system currently resident; A second redirection module, configured to redirect the second communication system to the first communication system in response to receiving a second RRC release message sent by the network side device; An establishment module, used to establish the emergency bearer and perform IMS emergency registration; The second initiating module is used to initiate a first emergency call process corresponding to the emergency call service based on the established emergency bearer.

12. The device according to claim 11, characterized in that The second RRC release message includes the cell frequency information of the first communication system; The second redirection module includes: A third sending submodule is used to send a tracking area update TAU request message to the network side device according to the second RRC release message; wherein the TAU request message is used to indicate that the IMS default bearer and the data default bearer have been activated in the second communication system; A third receiving submodule, configured to receive a TAU acceptance message sent by a network side device; wherein the TAU acceptance message is used to indicate that the IMS default bearer and the data default bearer have been activated in the first communication system; The third determining submodule is used to determine that the redirection to the first communication system is completed after sending the TAU completion message to the network side device.

13. A user equipment, characterized in that: include: processor; a memory for storing processor-executable instructions; The processor is used to implement the method according to any one of claims 1 to 6.

14. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the method according to any one of claims 1 to 6 is implemented.

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