CN110831257B

CN110831257B - Method, terminal and base station for initiating voice service

Info

Publication number: CN110831257B
Application number: CN201810896661.5A
Authority: CN
Inventors: 刘潇蔓; 陈卓
Original assignee: China Mobile Communications Group Co Ltd; China Mobile Communications Ltd Research Institute
Current assignee: China Mobile Communications Group Co Ltd; China Mobile Communications Ltd Research Institute
Priority date: 2018-08-08
Filing date: 2018-08-08
Publication date: 2021-09-10
Anticipated expiration: 2038-08-08
Also published as: CN110831257A

Abstract

The invention provides a method, a terminal and a base station for initiating voice service, belonging to the technical field of wireless communication, wherein the method for initiating voice service applied to the base station of a first network comprises the following steps: when RRC connection for carrying out voice service is established with a terminal, whether EPS fallback needs to be initiated for the terminal to realize the voice service is determined; when the EPS fallback does not need to be initiated for the terminal, establishing a QoS flow so as to complete a voice service by adopting the QoS flow; and when the EPS fallback needs to be initiated for the terminal, initiating switching or redirection so that the terminal falls back to the second network. In the invention, if the EPS fallback needs to be initiated for the terminal, the process of establishing the QoS flow which is useless for the EPS fallback can be saved, the time of initiating the voice service by the terminal through the EPS fallback is shortened, and unnecessary signaling interaction is reduced.

Description

Method, terminal and base station for initiating voice service

Technical Field

The present invention relates to the field of wireless communication technologies, and in particular, to a method, a terminal, and a base station for initiating a voice service.

Background

In a 4G (fourth generation mobile communication technology) network, when a UE (User Equipment, terminal) initiates a voice service, there are two ways: VoLTE (Voice over LTE, Voice over LTE (Long Term Evolution) bearer) and CS fallback (circuit domain fallback). For the CS fallback mode, the UE may carry an ESR (Extended Service Request) to the core network device when initiating the voice Service, and directly initiate the CS fallback.

Two voice access methods are also defined in 5G (fifth generation mobile communication technology) networks: VoNR (Voice over NR, new air interface carries Voice) and EPS fallback (evolved packet system fallback). The VoNR scheme is that a 5G access network and a core network provide a voice service based on an IMS (IP multimedia Subsystem), and the EPS fallback scheme is that a terminal falls back to 4G when initiating an IMS call on the 5G network, and the voice service is implemented through the 4G network.

In the existing EPS fallback scheme, the UE first performs core network side attachment (generally referred to as registration in a 5G network), and implements IMS domain registration (IMS registration), and then enters idle state. When there is voice service, firstly, a corresponding QoS flow (Quality of service flow, QoS flow, Quality of service flow) is established for the voice service, and then the RAN (radio access network) side decides whether to initiate EPS fallback or VoNR, which involves multiple interactions between the wireless side and the core network. For EPS fallback, the established QoS flow is useless, but the time delay and unnecessary signaling interaction are additionally increased.

Disclosure of Invention

In view of this, the present invention provides a method, a terminal and a base station for initiating a voice service, which are used to solve the problems of extra delay and unnecessary signaling interaction caused by the establishment of a useless QoS flow process in the existing EPS fallback scheme.

In order to solve the above technical problem, in a first aspect, the present invention provides a method for initiating a voice service, which is applied to a base station of a first network, and includes the following steps:

when RRC connection for carrying out voice service is established with a terminal, determining whether EPS fallback needs to be initiated for the terminal to realize the voice service;

when the EPS fallback does not need to be initiated for the terminal, establishing a QoS flow so as to complete the voice service by adopting the QoS flow;

and when the EPS fallback needs to be initiated for the terminal, initiating switching or redirection so that the terminal falls back to a second network.

Preferably, before the step of determining whether to initiate an EPS fallback for the terminal to implement the voice service when establishing the RRC connection for performing the voice service with the terminal, the method further includes:

and receiving an EPS fallback indication sent by the terminal, wherein the EPS fallback indication is used for indicating that the terminal needs to perform EPS fallback.

Preferably, the EPS fallback indication is sent to the base station by the terminal through MSG3 or MSG 5.

Preferably, the EPS fallback indication is carried by an added indication bit in the MSG5, or carried by an added indication bit in a service request message sent together with the MSG5, or carried by an additional service request message.

Preferably, the EPS fallback indication further includes a VoLTE indication for indicating that the terminal implements the voice service through VoLTE after performing EPS fallback, or includes a CS fallback indication for indicating that the terminal implements the voice service through CS fallback after performing EPS fallback.

Preferably, the step of determining whether to initiate an EPS fallback for the terminal to implement the voice service includes:

determining whether an EPS fallback needs to be initiated for the terminal to realize the voice service according to at least one of the following specified information:

a preference of the terminal;

capability information of the terminal;

capability information of the base station;

wireless environment information.

Preferably, when the specification information includes capability information of the terminal,

before the step of determining whether an EPS fallback needs to be initiated for the terminal to implement the voice service, the method further includes:

receiving capability information actively sent by the terminal; or,

acquiring the capability information of the terminal from core network equipment of a first network; or,

and initiating capability information inquiry to the terminal and acquiring the capability information fed back by the terminal.

Preferably, the step of initiating a handover or a redirection when an EPS fallback needs to be initiated for the terminal, so that the terminal falls back to a second network includes:

sending a switching request or a redirection request to core network equipment of a first network, wherein the switching request is used for requesting the core network equipment of the first network to start a switching process so as to switch the terminal into the second network, and the redirection request is used for requesting the core network equipment of the first network to start a redirection process so as to redirect the terminal into the second network.

Preferably, after the step of sending the handover request or the redirection request to the core network device of the first network, the method further includes:

and sending a first information interaction instruction to the core network equipment of the first network, and instructing the core network equipment of the first network to perform interaction of relevant information of the terminal with the core network equipment of the second network through a network interface between the first network and the second network, so that the terminal can realize the voice service after falling back to the second network.

Preferably, before the step of sending the handover request or the redirection request to the core network device of the first network, the method further includes:

receiving a dual-IMS registration identifier sent by the terminal, wherein the dual-IMS registration identifier is used for indicating that the terminal performs IMS registration through the first network and also performs IMS registration through the second network;

after the step of sending the handover request or the redirection request to the core network device of the first network, the method further includes:

and releasing the connection between the terminal and the first network according to the dual IMS registration identification.

directly initiating connection release of a first network, and releasing the connection between the terminal and the first network;

sending a second information interaction instruction to core network equipment of a first network, wherein the second information interaction instruction is used for instructing the core network equipment of the first network to transmit the relevant information of the terminal to the core network equipment of a second network through a network interface between the first network and the second network;

or,

sending a connection release request to core network equipment of a first network, wherein the connection release request is used for requesting the core network equipment of the first network to initiate connection release of the terminal and the first network, and transmitting relevant information of the terminal to the core network equipment of a second network through a network interface between the first network and the second network.

In a second aspect, the present invention further provides a method for initiating a voice service, which is applied to a terminal and includes:

after RRC connection for voice service is established with a base station of a first network, if the base station determines that EPS fallback does not need to be initiated for the terminal, the voice service is completed according to QoS flow established by the base station; or if the base station determines that an EPS fallback needs to be initiated for the terminal, the terminal falls back to a second network according to the switching or redirection initiated by the base station.

Preferably, before the step of establishing the RRC connection for performing the voice service with the base station of the first network, the method further includes:

a joint attachment is made between the first network and the second network or an attachment is made only to the first network.

Preferably, before the step of switching or redirecting back to a second network according to the initiation of the base station if the base station determines that an EPS fallback needs to be initiated for the terminal, the method further includes:

and sending an EPS fallback indication to the base station, wherein the EPS fallback indication is used for indicating that the terminal needs to perform EPS fallback.

Preferably, the EPS fallback indication is carried by an added indication bit in the MSG5, or carried by a newly added indication bit in a service request message sent together with the MSG5, or carried by an additional service request message sent together with the MSG 5.

Preferably, if the base station determines that an EPS fallback needs to be initiated for the terminal, the step of switching or redirecting back to the second network according to the handover or redirection initiated by the base station includes:

and initiating attachment to the second network, so that the core network equipment of the first network sends the IMS related information of the terminal to the core network equipment of the second network through the IMS anchor point shared by the first network and the second network.

Preferably, after the step of switching or redirecting back to a second network according to the initiation of the base station if the base station determines that an EPS fallback needs to be initiated for the terminal, the method further includes:

voice service is realized by adopting a VoLTE mode; or,

and a CS fallback mode is adopted to realize the voice service.

In a third aspect, the present invention further provides a base station, including:

the processor is used for determining whether an EPS fallback needs to be initiated for a terminal to realize a voice service when an RRC connection for the voice service is established with the terminal; when the EPS fallback does not need to be initiated for the terminal, establishing a QoS flow so as to complete the voice service by adopting the QoS flow; and when the EPS fallback needs to be initiated for the terminal, initiating switching or redirection so that the terminal falls back to a second network.

Preferably, the base station further comprises:

and the transceiver is used for receiving an EPS fallback instruction sent by the terminal, wherein the EPS fallback instruction is used for indicating that the terminal needs to perform EPS fallback.

Preferably, the processor is configured to determine whether an EPS fallback needs to be initiated for the terminal to implement the voice service according to at least one of the following specific information:

a preference of the terminal;

capability information of the terminal;

capability information of the base station;

wireless environment information.

Preferably, the base station further comprises:

the transceiver is used for receiving the capability information actively sent by the terminal; or, acquiring the capability information of the terminal from the core network equipment of the first network; or initiating a capability information inquiry to the terminal and acquiring the capability information fed back by the terminal.

Preferably, the processor is configured to send a handover request or a redirection request to a core network device of a first network when an EPS fallback needs to be initiated for the terminal, where the handover request is used to request the core network device of the first network to start a handover procedure, so as to switch the terminal to the second network, and the redirection request is used to request the core network device of the first network to start a redirection procedure, so as to redirect the terminal to the second network.

Preferably, the processor is further configured to send a first information interaction instruction to a core network device of the first network, to instruct the core network device of the first network to perform interaction of relevant information of the terminal with a core network device of a second network through a network interface between the first network and the second network, so that the terminal can implement the voice service after falling back to the second network.

Preferably, the processor is further configured to receive a dual IMS registration identifier sent by the terminal, where the dual IMS registration identifier is used to indicate that the terminal performs IMS registration both through the first network and through the second network; and releasing the connection between the terminal and the first network according to the dual IMS registration identification.

Preferably, the processor is configured to directly initiate connection release of a first network, and release the connection between the terminal and the first network; sending a second information interaction instruction to core network equipment of a first network, wherein the second information interaction instruction is used for instructing the core network equipment of the first network to transmit the relevant information of the terminal to the core network equipment of a second network through a network interface between the first network and the second network; or, the apparatus is configured to send a connection release request to a core network device of a first network, where the connection release request is used to request the core network device of the first network to initiate connection release between the terminal and the first network, and transmit relevant information of the terminal to the core network device of a second network through a network interface between the first network and the second network.

In a fourth aspect, the present invention further provides a terminal, including:

the processor is used for establishing RRC connection for voice service with a base station of a first network, and if the base station determines that EPS fallback does not need to be initiated for the terminal, completing the voice service according to QoS flow established by the base station; or if the base station determines that an EPS fallback needs to be initiated for the terminal, the terminal falls back to a second network according to the switching or redirection initiated by the base station.

Preferably, the processor is further configured to perform a joint attachment between the first network and the second network or an attachment only to the first network.

Preferably, the terminal further includes a transceiver configured to send an EPS fallback indication to the base station, where the EPS fallback indication is used to indicate that the terminal is to perform EPS fallback.

Preferably, the processor is configured to initiate an attach to the second network, so that the core network device of the first network sends the IMS related information of the terminal to the core network device of the second network through an IMS anchor point shared by the first network and the second network.

Preferably, the processor is further configured to implement a voice service in a VoLTE manner; or, a CS fallback mode is adopted to realize the voice service.

In a fifth aspect, the present invention also provides a base station, comprising a memory, a processor, and a computer program stored on the memory and executable on the processor; the processor, when executing the computer program, implements any of the above methods for initiating a voice service applied to a base station of a first network.

In a sixth aspect, the present invention further provides a terminal, including a memory, a processor, and a computer program stored on the memory and executable on the processor; the processor implements any of the above methods for initiating a voice service applied to a terminal when executing the computer program.

In a seventh aspect, the present invention also provides a computer-readable storage medium, on which a computer program is stored, which, when being executed by a processor, implements the steps of any of the above methods for initiating a voice service.

The technical scheme of the invention has the following beneficial effects:

in the embodiment of the invention, when the base station of the first network establishes the RRC connection for the voice service with the terminal, whether the EPS fallback needs to be initiated for the terminal to realize the voice service is determined, instead of deciding whether to initiate the EPS fallback or realize the voice service by using a VoNR mode after the QoS flow is established. Therefore, if it is determined that the EPS fallback needs to be initiated for the terminal, the process of establishing the QoS flow which is useless for the EPS fallback can be omitted, the time of initiating the voice service by the terminal through the EPS fallback is shortened, the flow is optimized, and unnecessary signaling interaction is reduced.

Drawings

Fig. 1 is a schematic flow chart of a conventional EPS fallback scheme;

fig. 2 is a flowchart illustrating a method for initiating a voice service according to a first embodiment of the present invention;

fig. 3 is a schematic diagram of a basic flow (signaling flow) of an existing terminal initiating an EPS fallback in a 5G network;

fig. 4 is a flowchart illustrating a method for initiating a voice service according to a seventh embodiment of the present invention;

fig. 5 is a schematic structural diagram of a base station in an eighth embodiment of the present invention;

fig. 6 is a schematic structural diagram of a terminal according to a ninth embodiment of the present invention;

fig. 7 is a schematic structural diagram of a base station in a tenth embodiment of the present invention;

fig. 8 is a schematic structural diagram of a terminal in an eleventh embodiment of the present invention.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the drawings of the embodiments of the present invention. It is to be understood that the embodiments described are only a few embodiments of the present invention, and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the described embodiments of the invention, are within the scope of the invention.

For the 5G terminal, the processes of attachment, registration and the like are carried out after the terminal is started, and the terminal enters an idle state after IMS registration is carried out. Thereafter, the calling/called (voice service) of the idle terminal sends invite signaling to the IMS through a Scheduling Request (SR) process, a Protocol Data Unit (PDU) session reconstruction, and the like. After the Invite signaling is sent to the IMS, the IMS indicates a core network (5G), the core network (5G) requires the base station (5G) to perform bearer establishment (QoS flow establishment), the base station (5G) determines to use VoNR or trigger EPS fallback to implement voice service according to UE capability, AMF indication (Access and Mobility Management Function), network configuration (whether there is a network interface between the 5G network and the 4G network), and radio conditions (radio environment information), and the like, specifically refer to the flowchart of the existing EPS fallback scheme shown in fig. 1, wherein, NG RAN is a (5G) wireless access network, E-UTRAN is a mobile communication wireless network, AMF is an access and mobility management function, MME is a mobility management entity, SGW is a service gateway, PGW is a packet data gateway, SMF is a session management function, UPF is a user plane function, and IMS is an IP multimedia subsystem.

Referring to fig. 2, fig. 2 is a flowchart illustrating a method for initiating a voice service according to an embodiment of the present invention, where the method is applied to a base station of a first network, and includes the following steps:

step 11: when establishing an RRC (Radio Resource Control) connection for performing a voice service with a terminal, determining whether an EPS fallback needs to be initiated for the terminal to implement the voice service;

step 12: when the EPS fallback does not need to be initiated for the terminal, establishing a QoS flow so as to complete the voice service by adopting the QoS flow;

step 13: and when the EPS fallback needs to be initiated for the terminal, initiating switching or redirection so that the terminal falls back to a second network.

Wherein the first network has a faster wire speed than the second network, for example, the first network may be a 5G network and the second network may be a 4G network, or the first network may be a higher-level network and the second network may be a next-level or multi-level network than the first network. Hereinafter, if not specifically stated, the base station refers to a base station of the first network, and when the first network is a 5G network, the base station refers to a base station of the 5G network, or referred to as a 5G base station.

In addition, in step 12, when it is not necessary to initiate an EPS fallback for the terminal, that is, when it is necessary to initiate a VoNR for the terminal, after the terminal context establishment and RRC reconfiguration are completed, that is, after an RRC connection for performing a voice service is established with the terminal, a QoS flow is established for an SIP (Session Initiation Protocol) signaling, and an invite signaling is sent, so that the voice service is completed. In step 13, when an EPS fallback needs to be initiated for the terminal, after the reconfiguration is completed, a handover or redirection is initiated.

In the method for initiating a voice service provided in the embodiment of the present invention, when an RRC connection for performing a voice service is established between a base station (that is, RAN side) of a first network and a terminal, it is determined whether to initiate an EPS fallback for the terminal to implement the voice service, instead of determining whether to initiate the EPS fallback or to implement the voice service using a VoNR method after a QoS flow is established. Therefore, if it is determined that the EPS fallback needs to be initiated for the terminal, the process of establishing the QoS flow which is useless for the EPS fallback can be omitted, the time of initiating the voice service by the terminal through the EPS fallback is shortened, the flow is optimized, and unnecessary signaling interaction is reduced. Fig. 3 is a schematic diagram of a basic flow (signaling flow) of an existing terminal initiating an EPS fallback in a first network (5G network), where steps in a rectangular frame are signaling interactions that can be reduced if the embodiment of the present invention is adopted.

In the embodiment of the invention, after the terminal falls back to the second network (4G) in a switching or redirection mode, the voice service is completed according to the scheme of the existing 4G network.

The method for initiating voice service is exemplified below.

In an optional specific embodiment, before the step of determining whether to initiate an EPS fallback for the terminal to implement the voice service (i.e., step 11) when establishing an RRC connection for performing the voice service with the terminal, the method further includes:

In a 5G network, there may be terminals that can only support EPS fallback but not VoNR, and when a terminal of this type initiates a voice service (calling/called), as it does not support VoNR, EPS fallback must be performed; or a terminal which needs to directly initiate the EPS fallback exists according to own preference or requirement. For the two terminals, an EPS fallback indication may be directly sent to the 5G base station to inform the 5G base station that the EPS fallback needs to be initiated for the terminal.

Specifically, the EPS fallback indication is sent to the base station by the terminal through MSG3 or MSG 5. The MSG3(Message 3) is an RRC Connection Request (RRC Connection Request) Message or an RRC reestablishment Request Message sent by the terminal to the base station, and the MSG5(Message 5) is an RRC Connection Setup Complete Message or an RRC reestablishment Complete Message sent by the terminal to the base station. Both of them are transmitted to the 5G base station by the terminal when the 5G base station establishes an RRC connection with the terminal for conducting a voice service.

Further, as for the manner of sending the EPS fallback indication to the 5G base station through the MSG5, the EPS fallback indication is carried by an added indication bit in the MSG5, or carried by a newly added indication bit in a service request message (service request) sent together with the MSG5, or carried by an extra service request message (similar to an Extended Service Request (ESR) in 4G). The base station (wireless side) can read whether the EPS fallback indication is carried by expanding the service request message (i.e. adding new indicator bits) or introducing an additional service request message like in 4G.

In the embodiment of the present invention, if the terminal needs to perform the EPS fallback or can perform the EPS fallback only, when the RRC connection for performing the voice service is established with the base station, the MSG3 or MSG5 sent to the base station carries the EPS fallback indication, so that the base station can determine that the EPS fallback needs to be initiated for the terminal in time before the QoS flow is established to implement the voice service, and extra signaling interaction can be reduced.

In addition, the EPS fallback indication may further include a VoLTE indication for indicating that the terminal implements the voice service through VoLTE after performing the EPS fallback, or a CS fallback indication for indicating that the terminal implements the voice service through CS fallback after performing the EPS fallback. In other invention embodiments, the VoLTE indication or the CS fallback indication may also be sent not together with the EPS fallback indication but through other signaling.

In another optional specific embodiment, the step of determining whether to initiate an EPS fallback for the terminal to implement the voice service (i.e., step 11) includes:

a preference of the terminal;

capability information of the terminal;

capability information of the base station;

wireless environment information.

Specifically, the base station may comprehensively determine whether to initiate an EPS fallback or a VoNR for the terminal according to the capability information of the terminal, the radio environment information (radio conditions), and the capability information of the base station, or determine whether to initiate the EPS fallback for the terminal only according to its own capability regardless of the capability of the terminal. The base station may also determine whether to initiate an EPS fallback for the terminal according to the capability information and the radio environment information of the base station, or determine whether to initiate the EPS fallback for the terminal according to the capability information of the terminal and/or the preference of the terminal. The preference of the terminal and the capability information of the terminal may be sent to a base station of the first network when the terminal establishes an RRC connection for performing a voice service with the base station.

When the specific information includes the capability information of the terminal, before the step of determining whether to initiate an EPS fallback for the terminal to implement the voice service (i.e., before step 11), the method further includes:

receiving capability information actively sent by the terminal; or,

That is, the base station may obtain the capability information of the terminal in the above several manners, which may be specifically selected according to the convenience of obtaining the capability information of the terminal.

When the base station determines that an EPS fallback needs to be initiated for the terminal according to at least one of an EPS fallback indication sent by the terminal or the specified information, the following specific process is further included.

In one embodiment, the step of initiating a handover or a redirection when an EPS fallback needs to be initiated for the terminal (i.e. step 13) so that the terminal falls back to the second network includes:

In the embodiment of the invention, the switching request or the redirection request is directly sent to the core network equipment of the first network to request the core network equipment of the first network to start the switching process, so that the core network can be ready for switching or redirection in advance.

Specifically, after the step of sending the handover request or the redirection request to the core network device of the first network, the method further includes:

In the embodiment of the present invention, when there is an interface between the first network (5G network) and the second network (4G network), that is, if there is a corresponding interface between the MME (second network) and the AMF (first network), after determining that it is necessary to initiate an EPS fallback for the terminal, the base station instructs the core network device of the first network to send the relevant information of the terminal to the core network device of the second network through the network interface. The relevant information of the terminal specifically includes registration information, capability information, IMS registration information, an IP address, and the like of the terminal, that is, the terminal realizes joint attachment (attach) between the first network and the second network through interaction between core networks, and performs IMS registration through the second network, so that the terminal can directly perform a voice service after falling back to the second network without performing additional work such as attachment to the second network and IMS registration through the second network.

In addition, while the core network device of the first network sends the relevant information of the terminal to the core network device of the second network through the network interface, the core network device of the first network and the core network of the second network also negotiate according to the capability of the terminal, the past service habit and other factors, and confirm whether to release the connection of the terminal in the first network or maintain other services of the terminal in the first network when the terminal needs to perform voice services through the second network.

Or, after the step of sending the handover request or the redirection request to the core network device of the first network, the method further includes:

and when the terminal needs to fall back to the second network and initiates attachment to the second network, the core network equipment of the first network sends the IMS related information of the terminal to the core network equipment of the second network through the IMS anchor point shared by the first network and the second network.

In the embodiment of the present invention, after the base station determines that an EPS fallback needs to be initiated for the terminal, the terminal needs to initiate an attach to the second network and complete the attach, or the terminal has performed a joint attach in advance in the first network and the second network, and the terminal also needs to perform IMS registration through the second network, at this time, the core network device of the second network may directly go to an IMS anchor point (if any) shared by the first network and the second network to obtain the relevant information of the terminal IMS, that is, the core network device of the first network sends the relevant information of the terminal to the core network device of the second network through the IMS anchor point shared by the first network and the second network.

Or, before the step of sending the handover request or the redirection request to the core network device of the first network, the method further includes:

In the embodiment of the invention, as the terminal knows the capability limit, the requirement or the preference of the terminal and needs to initiate the EPS fallback, the IMS registration is also carried out through the second network (4G network) in advance. When the terminal initiates a voice service, the terminal also carries an extra dual-IMS registration identifier, after receiving the dual-IMS registration identifier, the base station of the first network can directly release the information of the terminal in the first network, and the terminal receives the service on the second network.

In another embodiment, the step of initiating a handover or redirection when an EPS fallback needs to be initiated for the terminal, so that the terminal falls back to the second network (i.e. step 13) includes:

or,

In the embodiment of the present invention, the method for directly initiating RRC connection release (where the base station directly initiates or requests initiation of a core network of the first network) is only applicable to a case where there is a network interface between the first network and the second network. The connection release directly initiated by the base station of the first network is small in time delay, and the core network of the first network can keep the relevant information of the terminal. The method for sending the connection release request to the core network device of the first network to request the core network device of the first network to initiate the connection release has a long time delay, and the core network of the first network deletes the relevant information of the terminal.

The second embodiment of the present invention provides a method for initiating a voice service, including:

step 21: the terminal initiates voice service, and the MSG3 carries the RRC connection establishment cause as voice service (cause value is mo-VoiceCall);

step 22: the terminal sends its own preferences in MSG5, e.g. indicating that it is to initiate EPS fallback through 1bit signaling;

step 23: after receiving an instruction that the terminal wants to initiate an EPS fallback, the base station (5G base station) determines that the EPS fallback needs to be initiated for the terminal according to the instruction, and determines whether to initiate handover or redirection for the terminal, so that the terminal returns to the 4G network.

The third embodiment of the present invention provides a method for initiating a voice service, including:

step 31: the terminal initiates voice service, and the MSG3 carries detailed RRC connection establishment reasons, such as cause value mo-VoiceCallEPSfallback or mo-VoiceCallVoNR;

step 32: after receiving the information, if the base station is mo-VoiceCallEPSfallback, the base station determines that EPS fallback needs to be initiated for the terminal by comprehensively considering information such as the current wireless environment under the condition that the capability of the base station is satisfied, and determines whether to initiate handover or redirection for the terminal, so that the terminal returns to the 4G network.

The fourth embodiment of the present invention provides a method for initiating a voice service, including:

step 41: the terminal initiates voice service, and the MSG3 carries the RRC connection establishment cause as voice service (cause value is mo-VoiceCall);

step 42: the base station judges whether to initiate EPS fallback for the terminal according to the capability of the terminal obtained from the 5G core network, by combining the capability of the base station, the wireless environment and other factors, and if the EPS fallback is initiated, the terminal is dropped to the 4G network to complete the voice service in a switching mode or a redirection mode.

An embodiment of the present invention provides a method for initiating a voice service, including:

step 51: the terminal initiates voice service, and the MSG3 carries RRC connection establishment reason as voice service;

step 52: the base station does not obtain the capability of the terminal from the core network and initiates capability inquiry to the terminal;

step 53: after obtaining the capability information of the terminal fed back by the terminal, the base station judges whether to initiate an EPS fallback for the terminal by combining the capability of the base station, the wireless environment and other factors, and if the EPS fallback is initiated, the terminal is dropped to the 4G network to complete the voice service by adopting a switching mode or a redirection mode.

The sixth embodiment of the present invention provides a method for initiating a voice service, including:

step 61: the terminal initiates voice service, and the MSG3 carries RRC connection establishment reason as voice service;

step 62: and the base station directly determines to initiate the EPS fallback for the terminal after comprehensively considering the wireless environment according to the self capability and enables the terminal to return to the 4G network.

Referring to fig. 4, fig. 4 is a flowchart illustrating a method for initiating a voice service according to a seventh embodiment of the present invention, where the method is applied to a terminal, and includes the following steps:

step 71: after RRC connection for voice service is established with a base station of a first network, if the base station determines that EPS fallback does not need to be initiated for the terminal, the voice service is completed according to QoS flow established by the base station; or if the base station determines that an EPS fallback needs to be initiated for the terminal, the terminal falls back to a second network according to the switching or redirection initiated by the base station.

In the embodiment of the present invention, when a base station (that is, RAN side) of a first network establishes an RRC connection for performing a voice service with a terminal, it determines whether to initiate an EPS fallback for the terminal to implement the voice service, instead of deciding whether to initiate the EPS fallback or implement the voice service using a VoNR method after a QoS flow is established. Therefore, if it is determined that the EPS fallback needs to be initiated for the terminal, the process of establishing the QoS flow which is useless for the EPS fallback can be omitted, the time of initiating the voice service by the terminal through the EPS fallback is shortened, the flow is optimized, and unnecessary signaling interaction is reduced.

In this embodiment of the present invention, before the step of establishing an RRC connection for performing a voice service with a base station of a first network, the method further includes:

a joint attachment is made between the first network and the second network or only the first network (generally referred to as registration in a 5G network).

The terminal registers in the 5G network only, and when all the services of the terminal do not need to fall back to the 4G network, the interaction of signaling can be reduced, and the waste of communication resources is avoided. And the terminal performs joint attachment between the 4G network and the 5G network, and when the service of the terminal later needs to fall back to the 4G network, the time delay of the subsequent service can be reduced.

In this embodiment of the present invention, before the step of, if the base station determines that an EPS fallback needs to be initiated for the terminal, switching or redirecting to fall back to a second network according to the handover or redirection initiated by the base station, the method further includes:

In a 5G network, there may be terminals that can only support EPS fallback but not VoNR, and when a voice service (calling/called) occurs in this type of terminal, as it does not support VoNR, EPS fallback must be performed; or a terminal which needs to directly initiate the EPS fallback exists according to own preference or requirement. For the two terminals, an EPS fallback indication may be directly sent to the 5G base station to inform the 5G base station that the EPS fallback needs to be initiated for the terminal.

Specifically, the EPS fallback indication is sent to the base station by the terminal through MSG3 or MSG 5. The MSG3 is an RRC setup request message or an RRC reestablishment request message sent by the terminal to the base station, and the MSG5 is an RRC setup complete message or an RRC reestablishment complete message sent by the terminal to the base station. Both of them are transmitted to the 5G base station by the terminal when the 5G base station establishes an RRC connection with the terminal for conducting a voice service.

Further, the EPS fallback indication is carried by an indication bit added in the MSG5, or carried by a newly added indication bit in the service request message sent together with the MSG5, or carried by an additional service request message sent together with the MSG 5.

In addition, the EPS fallback indication further includes a VoLTE indication for indicating that the terminal implements the voice service through VoLTE after performing the EPS fallback, or includes a CS fallback indication for indicating that the terminal implements the voice service through CS fallback after performing the EPS fallback. In other invention embodiments, the VoLTE indication or the CS fallback indication may also be sent not together with the EPS fallback indication but through other signaling.

In this embodiment of the present invention, if the base station determines that an EPS fallback needs to be initiated for the terminal, the step of switching or redirecting back to the second network according to the handover or redirection initiated by the base station includes:

When the base station determines that an EPS fallback needs to be initiated for the terminal, the terminal needs to initiate an attach to the second network and complete the attach, or a joint attach has been performed in the first network and the second network in advance, and the terminal also needs to perform IMS registration through the second network, at this time, the core network device of the second network may directly go to an IMS anchor point (if any) shared by the first network and the second network to obtain relevant information of the terminal IMS, that is, the core network device of the first network sends the relevant information of the terminal IMS anchor point to the core network device of the second network through the IMS shared by the first network and the second network.

In this embodiment of the present invention, after the step of switching or redirecting back to a second network according to the base station initiation if the base station determines that an EPS fallback needs to be initiated for the terminal, the method further includes:

voice service is realized by adopting a VoLTE mode; or,

and a CS fallback mode is adopted to realize the voice service.

For example, when the EPS fallback indication further includes a VoLTE indication for indicating that the terminal implements the voice service through VoLTE after performing the EPS fallback, the voice service is implemented in a VoLTE manner; and when the EPS fallback indication further comprises a CS fallback indication for indicating the terminal to realize the voice service through the CS fallback after the EPS fallback is performed, the CS fallback mode is adopted to realize the voice service. Or, it may also be determined whether to implement the voice service in the VoLTE mode or the CS fallback mode according to other factors.

Referring to fig. 5, fig. 5 is a schematic structural diagram of a base station according to an eighth embodiment of the present invention, where the base station is a base station in a first network, and the base station 400 includes:

a processor 401, configured to determine whether an EPS fallback needs to be initiated for a terminal to implement a voice service when an RRC connection for performing the voice service is established with the terminal; when the EPS fallback does not need to be initiated for the terminal, establishing a QoS flow so as to complete the voice service by adopting the QoS flow; and when the EPS fallback needs to be initiated for the terminal, initiating switching or redirection so that the terminal falls back to a second network.

Optionally, the base station further includes: and the transceiver is used for receiving an EPS fallback instruction sent by the terminal, wherein the EPS fallback instruction is used for indicating that the terminal needs to perform EPS fallback.

Specifically, the EPS fallback indication is sent to the base station by the terminal through MSG3 or MSG 5.

Further, the EPS fallback indication is carried by an indication bit added in the MSG5, or carried by an additional indication bit in a service request message sent together with the MSG5, or carried by an additional service request message.

In addition, the EPS fallback indication further includes a VoLTE indication for indicating that the terminal implements the voice service through VoLTE after performing the EPS fallback, or includes a CS fallback indication for indicating that the terminal implements the voice service through CS fallback after performing the EPS fallback.

Optionally, the processor 401 is configured to determine whether an EPS fallback needs to be initiated for the terminal to implement the voice service according to at least one of the following specific information:

a preference of the terminal;

capability information of the terminal;

capability information of the base station;

wireless environment information.

Specifically, the base station further includes: the transceiver is used for receiving the capability information actively sent by the terminal; or, acquiring capability information of the terminal from a core network device of the first network; or initiating a capability information inquiry to the terminal and acquiring the capability information fed back by the terminal.

Further, the processor 401 is configured to send a handover request or a redirection request to a core network device of a first network when an EPS fallback needs to be initiated for the terminal, where the handover request is used to request the core network device of the first network to start a handover procedure, so as to switch the terminal to the second network, and the redirection request is used to request the core network device of the first network to start a redirection procedure, so as to redirect the terminal to the second network.

Optionally, the processor 401 is further configured to send a first information interaction instruction to a core network device of the first network, to instruct the core network device of the first network to perform interaction of relevant information of the terminal with a core network device of a second network through a network interface between the first network and the second network, so that the terminal can implement the voice service after falling back to the second network.

Optionally, the processor 401 is further configured to receive a dual IMS registration identifier sent by the terminal, where the dual IMS registration identifier is used to indicate that the terminal performs IMS registration both through the first network and through the second network; and releasing the connection between the terminal and the first network according to the dual IMS registration identification.

Optionally, the processor 401 is configured to directly initiate connection release of a first network, and release the connection between the terminal and the first network; sending a second information interaction instruction to core network equipment of a first network, wherein the second information interaction instruction is used for instructing the core network equipment of the first network to transmit the relevant information of the terminal to the core network equipment of a second network through a network interface between the first network and the second network; or, the apparatus is configured to send a connection release request to a core network device of a first network, where the connection release request is used to request the core network device of the first network to initiate connection release between the terminal and the first network, and transmit relevant information of the terminal to the core network device of a second network through a network interface between the first network and the second network.

The embodiment of the present invention is a device embodiment corresponding to the above embodiment, and therefore, detailed description is omitted here, and please refer to the first embodiment in detail.

Referring to fig. 6, fig. 6 is a schematic structural diagram of a terminal according to a ninth embodiment of the present invention, where the terminal 500 includes:

a processor 501, configured to establish an RRC connection for performing a voice service with a base station of a first network, and if the base station determines that an EPS fallback does not need to be initiated for the terminal, complete the voice service according to a QoS flow established by the base station; or if the base station determines that an EPS fallback needs to be initiated for the terminal, the terminal falls back to a second network according to the switching or redirection initiated by the base station.

In the embodiment of the invention, when the base station of the first network establishes RRC connection for voice service with the terminal, whether EPS fallback needs to be initiated for the terminal to realize the voice service is determined, instead of deciding whether to initiate EPS fallback or realize the voice service by using a VoNR mode after QoS flow is established. Therefore, if it is determined that the EPS fallback needs to be initiated for the terminal, the process of establishing the QoS flow which is useless for the EPS fallback can be omitted, the time of initiating the voice service by the terminal through the EPS fallback is shortened, the flow is optimized, and unnecessary signaling interaction is reduced.

Specifically, the processor 501 is further configured to perform joint attachment between a first network and a second network or attach only to the first network.

Optionally, the terminal further includes a transceiver configured to send an EPS fallback indication to the base station, where the EPS fallback indication is used to indicate that the terminal is to perform EPS fallback.

Specifically, the processor is configured to initiate attachment to the second network, so that the core network device of the first network sends the IMS related information of the terminal to the core network device of the second network through an IMS anchor point shared by the first network and the second network.

Specifically, the processor 501 is further configured to implement a voice service in a VoLTE manner; or, a CS fallback mode is adopted to realize the voice service.

The embodiment of the present invention is an embodiment of an apparatus corresponding to the seventh embodiment, and therefore, details are not described herein, and please refer to the seventh embodiment in detail.

Referring to fig. 7, fig. 7 is a schematic structural diagram of a base station according to a tenth embodiment of the present invention, where the terminal 600 includes a processor 601, a memory 602, and a computer program stored in the memory 602 and operable on the processor 601; the processor 601, when executing the computer program, implements the following steps:

Optionally, the computer program when executed by the processor 601 may further implement the following steps:

before the step of determining whether to initiate an EPS fallback for the terminal to implement the voice service when establishing the RRC connection for performing the voice service with the terminal, the method further includes:

Optionally, the EPS fallback indication is sent to the base station by the terminal through MSG3 or MSG 5.

Optionally, the EPS fallback indication is carried by an indication bit added in the MSG5, or carried by a newly added indication bit in a service request message sent together with the MSG5, or carried by an additional service request message.

Optionally, the EPS fallback indication further includes a VoLTE indication for indicating that the terminal implements the voice service through VoLTE after performing the EPS fallback, or includes a CS fallback indication for indicating that the terminal implements the voice service through CS fallback after performing the EPS fallback.

the step of determining whether an EPS fallback needs to be initiated for the terminal to implement the voice service includes:

a preference of the terminal;

capability information of the terminal;

capability information of the base station;

wireless environment information.

when the specification information includes capability information of the terminal,

receiving capability information actively sent by the terminal; or,

acquiring the capability information of the terminal from the core network equipment of the first network; or,

the step of initiating switching or redirection when the EPS fallback needs to be initiated for the terminal, so that the terminal falls back to a second network, includes:

before the step of sending the handover request or the redirection request to the core network device of the first network, the method further includes:

or,

The base station provided in the embodiment of the present invention can implement each process in the first embodiment, and is not described herein again to avoid repetition.

Referring to fig. 8, fig. 8 is a schematic structural diagram of a terminal according to an eleventh embodiment of the present invention, where the terminal 700 includes a processor 701, a memory 702, and a computer program stored in the memory 702 and operable on the processor 701; the processor 701 implements the following steps when executing the computer program:

Optionally, the computer program may further implement the following steps when executed by the processor 701:

before the step of establishing the RRC connection for performing the voice service with the base station of the first network, the method further includes:

before the step of switching or redirecting back to a second network according to the initiation of the base station if the base station determines that the EPS fallback needs to be initiated for the terminal, the method further includes:

Optionally, the EPS fallback indication is carried by an indication bit added in the MSG5, or carried by a newly added indication bit in a service request message sent together with the MSG5, or carried by an additional service request message sent together with the MSG 5.

if the base station determines that an EPS fallback needs to be initiated for the terminal, the step of switching or redirecting back to a second network according to the initiation of the base station includes:

after the step of determining, by the base station, that an EPS fallback needs to be initiated for the terminal and switching or redirecting back to a second network according to the handover initiated by the base station, the method further includes:

voice service is realized by adopting a VoLTE mode; or,

and a CS fallback mode is adopted to realize the voice service.

The terminal provided by the embodiment of the present invention can implement each process in the seventh embodiment, and is not described herein again to avoid repetition.

A twelfth embodiment of the present invention provides a computer-readable storage medium, on which a computer program is stored, where the computer program, when executed by a processor, implements the steps in the method for initiating a voice service according to any one of the first and seventh embodiments. The specific working process is the same as that in the first and seventh embodiments, and therefore, detailed description is not repeated here, and please refer to the description of the method steps in the corresponding embodiments.

The Base Station in the embodiment of the present invention may be a Base Transceiver Station (BTS) in Global System for Mobile communications (GSM) or Code Division Multiple Access (CDMA), a Base Station (NodeB, NB) in Wideband Code Division Multiple Access (WCDMA), an evolved Node B (eNB, eNodeB) in LTE, a relay Station, an Access point, a Base Station in a future 5G network, and the like, which are not limited herein.

The terminal in the embodiments of the present invention may be a wireless terminal or a wired terminal, and the wireless terminal may be a device providing voice and/or other service data connectivity to a user, a handheld device having a wireless connection function, or other processing devices connected to a wireless modem. A wireless terminal, which may be a mobile terminal such as a mobile telephone (or "cellular" telephone) and a computer having a mobile terminal, e.g., a portable, pocket, hand-held, computer-included, or vehicle-mounted mobile device, may communicate with one or more core networks via a Radio Access Network (RAN), and may exchange language and/or data with the RAN. For example, devices such as Personal Communication Service (PCS) phones, cordless phones, Session Initiation Protocol (SIP) phones, Wireless Local Loop (WLL) stations, and Personal Digital Assistants (PDAs) are used. A wireless Terminal may also be referred to as a system, a Subscriber Unit (Subscriber Unit), a Subscriber Station (Subscriber Station), a Mobile Station (Mobile), a Remote Station (Remote Station), a Remote Terminal (Remote Terminal), an Access Terminal (Access Terminal), a User Terminal (User Terminal), a User Agent (User Agent), and a Terminal (User Device or User Equipment), which are not limited herein.

Such computer-readable media, which include both non-transitory and non-transitory, removable and non-removable media, may implement information storage by any method or technology. The information may be computer readable instructions, data structures, modules of a program, or other data. Examples of computer storage media include, but are not limited to, phase change memory (PRAM), Static Random Access Memory (SRAM), Dynamic Random Access Memory (DRAM), other types of Random Access Memory (RAM), Read Only Memory (ROM), Electrically Erasable Programmable Read Only Memory (EEPROM), flash memory or other memory technology, compact disc read only memory (CD-ROM), Digital Versatile Discs (DVD) or other optical storage, magnetic cassettes, magnetic tape magnetic disk storage or other magnetic storage devices, or any other non-transmission medium that can be used to store information that can be accessed by a computing device.

While the foregoing is directed to the preferred embodiment of the present invention, it will be understood by those skilled in the art that various changes and modifications may be made without departing from the spirit and scope of the invention as defined in the appended claims.

Claims

1. A method for initiating voice service is applied to a base station of a first network, and is characterized by comprising the following steps:

2. The method of claim 1, wherein before the step of determining whether to initiate an EPS fallback for the terminal to implement the voice service when the RRC connection for performing the voice service is established with the terminal, the method further comprises:

3. The method of initiating voice traffic of claim 2, wherein the EPS fallback indication is sent by the terminal to the base station through MSG3 or MSG 5.

4. The method of claim 3, wherein the EPS fallback indication is carried by an indication bit added in MSG5, or carried by an indication bit added in a service request message sent together with MSG5, or carried by an extra service request message.

5. The method of initiating a voice service according to claim 2, wherein the EPS fallback indication further includes a VoLTE indication for indicating the terminal to implement the voice service through VoLTE after performing the EPS fallback, or includes a CS fallback indication for indicating the terminal to implement the voice service through CS fallback after performing the EPS fallback.

6. The method of claim 1, wherein the step of determining whether to initiate an EPS fallback for the terminal to implement the voice service comprises:

a preference of the terminal;

capability information of the terminal;

capability information of the base station;

wireless environment information.

7. The method of initiating a voice service according to claim 6, wherein when the specification information includes capability information of the terminal,

receiving capability information actively sent by the terminal; or,

8. The method of claim 1, wherein the step of initiating a handover or redirection when an EPS fallback needs to be initiated for the terminal, so that the terminal falls back to a second network comprises:

9. The method of initiating a voice service according to claim 8, wherein after the step of sending the handover request or the redirection request to the core network device of the first network, the method further comprises:

10. The method of initiating voice traffic of claim 8,

11. The method of claim 1, wherein the step of initiating a handover or redirection when an EPS fallback needs to be initiated for the terminal, so that the terminal falls back to a second network comprises:

or,

12. A method for initiating voice service is applied to a terminal, and is characterized by comprising the following steps:

13. The method of initiating a voice service according to claim 12, wherein the step of establishing an RRC connection with the base station of the first network for conducting the voice service is preceded by the step of:

14. The method of claim 12, wherein if the base station determines that an EPS fallback needs to be initiated for the terminal, before the step of switching or redirecting back to a second network according to the base station, the method further comprises:

15. The method of initiating voice traffic of claim 14, wherein the EPS fallback indication is sent by the terminal to the base station through MSG3 or MSG 5.

16. The method of claim 15, wherein the EPS fallback indication is carried by an added indicator bit in the MSG5, or carried by an added indicator bit in a service request message sent with the MSG5, or carried by an additional service request message sent with the MSG 5.

17. The method of initiating a voice service according to claim 14, wherein the EPS fallback indication further includes a VoLTE indication for indicating the terminal to implement the voice service through VoLTE after performing the EPS fallback, or includes a CS fallback indication for indicating the terminal to implement the voice service through CS fallback after performing the EPS fallback.

18. The method of claim 12, wherein if the base station determines that an EPS fallback needs to be initiated for the terminal, the step of dropping back to a second network according to the handover or redirection initiated by the base station comprises:

19. The method according to claim 12 or 17, wherein, if the base station determines that an EPS fallback needs to be initiated for the terminal, after the step of dropping back to the second network according to the handover or redirection initiated by the base station, the method further comprises:

voice service is realized by adopting a VoLTE mode; or,

and a CS fallback mode is adopted to realize the voice service.

20. A base station, the base station being a base station in a first network, comprising:

21. The base station of claim 20, further comprising:

22. The base station of claim 21, wherein the EPS fallback indication is sent by the terminal to the base station through MSG3 or MSG 5.

23. The BS of claim 22, wherein the EPS fallback indication is carried by an added indication bit in MSG5, or is carried by an added indication bit in a service request message sent together with MSG5, or is carried by an extra service request message.

24. The base station of claim 21, wherein the EPS fallback indication further includes a VoLTE indication for indicating that the terminal implements the voice service through VoLTE after performing EPS fallback, or includes a CS fallback indication for indicating that the terminal implements the voice service through CS fallback after performing EPS fallback.

25. The base station of claim 20, wherein the processor is configured to determine whether an EPS fallback needs to be initiated for the terminal to implement the voice service according to at least one of the following specific information:

a preference of the terminal;

capability information of the terminal;

capability information of the base station;

wireless environment information.

26. The base station of claim 25, further comprising:

27. The base station according to claim 20, wherein the processor is configured to send, when an EPS fallback needs to be initiated for the terminal, a handover request or a redirection request to a core network device of a first network, where the handover request is used to request the core network device of the first network to start a handover procedure so as to handover the terminal to the second network, and the redirection request is used to request the core network device of the first network to start a redirection procedure so as to redirect the terminal to the second network.

28. The base station of claim 27, wherein the processor is further configured to send a first information interaction indication to a core network device of the first network, where the first information interaction indication indicates that the core network device of the first network interacts with a core network device of a second network through a network interface between the first network and the second network, so that the terminal can implement the voice service after falling back to the second network.

29. The base station of claim 27, wherein the processor is further configured to receive a dual IMS registration identifier sent by the terminal, and wherein the dual IMS registration identifier is used to indicate that the terminal performs IMS registration through both the first network and the second network; and releasing the connection between the terminal and the first network according to the dual IMS registration identification.

30. The base station of claim 20, wherein the processor is configured to directly initiate connection release of a first network, and release the connection of the terminal with the first network; sending a second information interaction instruction to core network equipment of a first network, wherein the second information interaction instruction is used for instructing the core network equipment of the first network to transmit the relevant information of the terminal to the core network equipment of a second network through a network interface between the first network and the second network; or, the apparatus is configured to send a connection release request to a core network device of a first network, where the connection release request is used to request the core network device of the first network to initiate connection release between the terminal and the first network, and transmit relevant information of the terminal to the core network device of a second network through a network interface between the first network and the second network.

31. A terminal, comprising:

32. The terminal of claim 31, wherein the processor is further configured to perform a joint attachment between the first network and the second network or an attachment only to the first network.

33. The terminal of claim 31, further comprising a transceiver configured to send an EPS fallback indication to the base station, where the EPS fallback indication indicates that the terminal is to perform EPS fallback.

34. The terminal of claim 33, wherein the EPS fallback indication is sent by the terminal to the base station through MSG3 or MSG 5.

35. The terminal of claim 34, wherein the EPS fallback indication is carried by an indication bit added in the MSG5, or carried by an indication bit added in a service request message sent with the MSG5, or carried by an additional service request message sent with the MSG 5.

36. The terminal according to claim 33, wherein the EPS fallback indication further includes a VoLTE indication for indicating that the terminal implements the voice service through VoLTE after performing EPS fallback, or includes a CS fallback indication for indicating that the terminal implements the voice service through CS fallback after performing EPS fallback.

37. The terminal of claim 31, wherein the processor is configured to initiate an attach to the second network, so that the core network device of the first network sends the IMS related information of the terminal to the core network device of the second network through an IMS anchor point shared by the first network and the second network.

38. The terminal of claim 31 or 36, wherein the processor is further configured to implement a voice service in a VoLTE manner; or, a CS fallback mode is adopted to realize the voice service.

39. A base station comprising a memory, a processor and a computer program stored on the memory and executable on the processor; characterized in that the processor, when executing the computer program, implements a method of initiating a voice service according to any of claims 1-11.

40. A terminal comprising a memory, a processor and a computer program stored on the memory and executable on the processor; a method of initiating a voice service according to any one of claims 12-19, when the computer program is executed by the processor.

41. A computer-readable storage medium, on which a computer program is stored which, when being executed by a processor, carries out the steps of the method of initiating a voice service according to any one of claims 1-19.