CN112584411A

Movatterモバイル変換

Info

Publication number: CN112584411A
Application number: CN201910944772.3A
Authority: CN
Inventors: 卜翘楚
Original assignee: ZTE Corp
Current assignee: ZTE Corp
Priority date: 2019-09-30
Filing date: 2019-09-30
Publication date: 2021-03-30

Abstract

Embodiments of the present invention provide a fallback recovery and control method, apparatus, terminal, device, and storage medium, where an IMS session is at least created in an attach flow, or an IMS PDN session and a dedicated voice bearer are simultaneously established after the attach flow is completed, so that compared with a method in which the attach flow, the IMS PDN session establishment flow, and the dedicated voice bearer establishment flow are sequentially and serially performed in related technologies, a longer time required for fallback recovery can be reduced to a greater extent, and a voice bearer recovery efficiency is improved, thereby improving user experience satisfaction.

Description

Fallback recovery and control method, fallback recovery and control device, terminal, equipment and storage medium

Technical Field

The present invention relates to the field of communications, and in particular, to a fallback recovery method and apparatus, a terminal, a device, and a storage medium.

Background

In the 5G network, if the base station does not support an IMS (IP Multimedia Subsystem) voice service, in the process of using the 5G voice service by the terminal, an EPS (Evolved Packet System) Fallback is triggered to drop back to 4G to use the IMS voice service, and the specific flow is that when the terminal uses the 5G voice service, in the process of creating a voice dedicated bearer by the 5G network, since the 5G base station does not support the 5G voice service, the creation of the 5G voice dedicated bearer is rejected, the terminal is triggered to drop back to the 4G network, and the voice dedicated bearer is continuously created in the 4G network to complete the IMS voice call.

Under networking without N26, because there is no interface between MME (Mobility Management Entity) and AMF (Access and Mobility Management Function), the user context can not be transferred to MME during the fall back process, so the terminal needs to be re-attached and registered in MME after the terminal falls back to 4G, the establishment of IMS PDN session is initiated after the attachment is completed, and the establishment of voice dedicated bearer is initiated at last; the above attachment flow, the IMS PDN session establishment flow and the voice dedicated bearer establishment flow are performed sequentially and serially, so that the time required for the whole fallback recovery is long, the efficiency is low, and the user experience satisfaction is poor.

Disclosure of Invention

The fallback recovery and control method, device, terminal, device and storage medium provided by the embodiments of the present invention solve the problems in the related art that, in the fallback recovery process, an attachment flow, an IMS PDN session establishment flow and a voice dedicated bearer establishment flow are sequentially performed in series, which results in long fallback recovery time, low efficiency and poor user experience satisfaction.

To solve the foregoing technical problem, an embodiment of the present invention provides a fallback recovery control method, including:

receiving an IMS session establishment request of an IP multimedia subsystem, wherein the IMS session establishment request is triggered by a terminal in an EPS Fallback process of an evolved packet system;

when the IMS session establishment request is triggered by a packet data network connection request which sends an access point name APN to the IMS in an attachment flow of the terminal, at least establishing an IP multimedia subsystem packet data network (IMS) PDN session according to the IMS session establishment request;

and when the IMS session establishment request is triggered by sending a packet data network connection request with APN as IMS after the terminal is attached, establishing an IMS PDN session and a voice dedicated bearer simultaneously according to the IMS session establishment request.

In order to solve the above technical problem, an embodiment of the present invention further provides a fallback recovery method, including:

receiving a radio resource control Release RRC Release message including an EPS Fallback indication from a base station;

in an attachment process, sending a packet data network connection request with APN as IMS to MME to trigger the MME to send an IMS session establishment request to management network element equipment, and triggering the management network element equipment to at least establish an IMS PDN session through the IMS session establishment request;

or the like, or, alternatively,

after the attachment is completed, sending a packet data network connection request with APN as IMS to MME to trigger the MME to send an IMS session establishment request to management network element equipment, and triggering the management network element equipment to establish an IMS PDN session and a voice dedicated bearer simultaneously through the IMS session establishment request.

In order to solve the above technical problem, an embodiment of the present invention further provides a fallback control device, including:

a first receiving module, configured to receive an IMS session establishment request of an IP multimedia subsystem, where the IMS session establishment request is triggered by a terminal in an EPS Fallback process of an evolved packet system;

a first processing module, configured to at least establish an IP multimedia subsystem packet data network IMS PDN session according to the IMS session establishment request when the IMS session establishment request is triggered by a packet data network connection request for sending an access point name, APN, for the IMS in an attach procedure of the terminal;

and the gateway is used for simultaneously establishing an IMS PDN session and a voice special bearer according to the IMS session establishment request when the IMS session establishment request is triggered by sending a packet data network connection request with APN as IMS after the attachment of the terminal is completed.

To solve the above technical problem, an embodiment of the present invention further provides a fallback recovery device, including:

a second receiving module, configured to receive, from the base station, a radio resource control Release RRC Release message including an EPS Fallback indication;

a second processing module, configured to send, to an MME, a packet data network connection request with an APN of an IMS in an attach procedure, so as to trigger the MME to send an IMS session creation request to a management network element device, and trigger the management network element device to at least establish an IMS PDN session through the IMS session creation request;

or, after the attachment is completed, sending a packet data network connection request with the APN being the IMS to an MME, so as to trigger the MME to send an IMS session creation request to a management network element device, and triggering the management network element device to simultaneously establish an IMS PDN session and a dedicated voice bearer through the IMS session creation request.

In order to solve the foregoing technical problem, an embodiment of the present invention further provides a management network element device, including a first processor, a first memory, and a first communication bus;

the first communication bus is used for connecting the first processor and the first memory;

the first processor is configured to execute a first computer program stored in the memory to implement the steps of the fallback control method as described above.

In order to solve the above technical problem, an embodiment of the present invention further provides a terminal, including a second processor, a second memory, and a second communication bus;

the second communication bus is used for connecting the second processor and the second memory;

the second processor is configured to execute a second computer program stored in the memory to implement the steps of the fallback control method as described above.

In order to solve the above technical problem, an embodiment of the present invention further provides a computer-readable storage medium, where a first computer program is stored, and when the first computer program is executed by a first processor, the steps of the fallback recovery control method are implemented;

alternatively, the computer readable storage medium stores a second computer program which, when executed by a second processor, implements the steps of the fallback recovery method as described above.

Advantageous effects

According to the Fallback recovery and control method, device, terminal, device and storage medium provided by the embodiments of the present invention, after receiving an IMS session establishment request in an EPS Fallback process, a management network element device at least establishes an IMS PDN session according to the IMS session establishment request when the IMS session establishment request is triggered by sending an access point name APN to a packet data network connection request of an IMS in an attach flow of the terminal; when the IMS session establishment request is triggered by sending an APN (access point name) to a packet data network connection request of the IMS after the attachment of the terminal is completed, establishing an IMSPDN (Internet protocol digital network) session and a voice special bearer simultaneously according to the IMS session establishment request; the embodiment of the invention at least establishes the IMS session in the attachment process, or simultaneously establishes the IMS PDN session and the voice special bearer after the attachment process is finished, so that compared with the method that the attachment process, the IMS PDN session establishment process and the voice special bearer establishment process are sequentially and serially performed in the related technology, the method can shorten the long time required by the fallback recovery to a greater extent, improve the voice bearer recovery efficiency and further improve the user experience satisfaction.

Additional features and corresponding advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention.

Drawings

Fig. 1 is a schematic flow chart of a fall-back recovery method according to a first embodiment of the present invention;

fig. 2 is a schematic flow chart of a fall-back recovery control method according to a first embodiment of the present invention;

fig. 3 is a first flowchart illustrating a method for fast recovering a voice bearer according to a first embodiment of the present invention;

fig. 4 is a flowchart illustrating a method for fast recovering voice bearer according to a first embodiment of the present invention;

fig. 5 is a schematic structural diagram of a fall-back recovery control device according to a second embodiment of the present invention;

fig. 6 is a schematic structural diagram of a fall-back recovery device according to a second embodiment of the present invention;

fig. 7 is a schematic diagram of a fall-back triggering process according to a second embodiment of the present invention;

fig. 8 is a schematic diagram of a base station trigger redirection procedure according to a second embodiment of the present invention;

fig. 9 is a first schematic flow chart illustrating fall-back recovery control according to a second embodiment of the present invention;

fig. 10 is a schematic diagram of a fall-back recovery control flow according to a second embodiment of the present invention;

fig. 11 is a schematic structural diagram of a management network element device according to a third embodiment of the present invention;

fig. 12 is a schematic structural diagram of a terminal according to a third embodiment of the present invention.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, embodiments of the present invention are described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

The first embodiment is as follows:

the problem that long time is needed for fallback recovery due to the fact that an attachment process, an IMS PDN session establishment process and a voice dedicated bearer establishment process are sequentially and serially conducted in the related technology is solved. In the fallback recovery and control method provided in this embodiment, at least the IMS session is established simultaneously in the attach procedure, or the IMS PDN session and the dedicated voice bearer are established simultaneously after the attach procedure is completed, so that compared with a method in which the attach procedure, the IMS PDN session establishment procedure, and the dedicated voice bearer establishment procedure are performed sequentially and serially in the related art, a longer time required for fallback recovery can be reduced to a greater extent, the voice bearer recovery efficiency is improved, and further, the user experience satisfaction is improved.

For ease of understanding, the present embodiment is described below with reference to respective method steps of the terminal side and the management network element device side as examples.

The method provided by the embodiment is suitable for, but not limited to, a scenario without N26 networking. When a terminal initiates a voice call in a 5G network, a core network side initiates a dedicated voice bearer establishment flow, a 5G base station triggers an EPS Fallback flow because the base station does not support IMS voice bearer, and then the base station triggers redirection to send RRC (Radio Resource Control) Release to the terminal, wherein the RRC Release carries an EPS Fallback indication of an evolved packet system, so as to indicate the terminal to perform subsequent Fallback processing after receiving the RRC Release. The fallback in this embodiment includes, but is not limited to, fallback to the 4G network, and the voice bearer continues to be established in the 4G network to complete the IMS voice call.

In order to improve the reduction of the time required for fall-back recovery and improve the efficiency of voice bearer recovery, in this embodiment, the fall-back recovery method performed by the terminal side can be as shown in fig. 1, which can include:

s101: the terminal receives a radio resource control Release RRC Release message including an EPS Fallback indication from the base station.

S1021: in the attachment process, the terminal sends an Access Point Name (APN) to the MME as a packet data network connection Request PDN Connectivity Request of the IMS so as to trigger the MME to send an IMS session creation Request to the management network element equipment, and the management network element equipment is triggered to at least establish an IMS PDN session through the IMS session creation Request.

Or the like, or, alternatively,

s1022: after the terminal completes the attachment, a packet data network connection request with APN as IMS is sent to the MME so as to trigger the MME to send an IMS session establishment request to the management network element equipment, and the IMS PDN session and the voice special bearer are established simultaneously by triggering the management network element equipment through the IMS session establishment request.

Accordingly, in order to improve the reduction of the time required for fall-back recovery and improve the efficiency of voice bearer recovery, in this embodiment, a fall-back recovery control method executed by the management network element device side may be as shown in fig. 2, and may include:

s201: the management network element equipment receives an IMS session establishment request, wherein the IMS session establishment request is triggered by a terminal in an EPS Fallback process of an evolved packet system.

The Management network element device in this embodiment may be, but is not limited to, an SMF (Session Management Function) network element/PGW (PDN Gateway) network element.

In an example of this embodiment, the receiving, by the SMF network element/PGW network element, the IMS session creation request includes:

the SMF network element/PGW network element receives an IMS session creating request which is sent by an SGW (Serving Gateway) and contains an identifier supporting parallel establishment. The identifier supporting parallel establishment in this embodiment may be any identification information capable of representing the capability supporting parallel establishment, such as Piggybacking Supported.

In an example of this embodiment, the IMS session creation request sent by the SGW is triggered and sent according to an IMS session creation request containing an identifier supporting parallel establishment and received from a mobility management entity MME; the IMS session creation request sent by the MME is triggered and sent according to the received packet data network connection request with the APN being IMS.

S2021: when the IMS session establishment request is triggered by a packet data network connection request which sends an access point name APN to the IMS in an attachment process of a terminal, the management network element equipment at least establishes an IP multimedia subsystem packet data network IMS PDN session according to the IMS session establishment request.

In this case, when the terminal determines that the redirection is triggered by the EPS Fallback, the terminal directly uses the IMS APN for attach after the Fallback, so that at least the creation of the IMS PDN session can be performed in the attach procedure, and the creation of the IMS PDN session is not required after the attach is completed, thereby greatly shortening the Fallback recovery time. In this case, when the IMS session creation request is triggered by sending a packet data network connection request with an APN of IMS in the attach procedure, the establishing of at least the IMS pdn session according to the IMS session creation request may include one of the following two ways:

the first method is as follows: and the management network element equipment simultaneously establishes an IMS PDN session and a voice special bearer according to the IMS session establishment request.

In this embodiment, the SMF/PGW network element simultaneously performing establishment of an IMSPDN session and a dedicated voice bearer according to the IMS session establishment request includes: the SMF network element/PGW network element sends an IMS session establishment response message including a voice special bearer request to an MME through an SGW to trigger the MME to send an initial context establishment request to a base station, and triggers the base station to simultaneously send an attachment acceptance response, an IMS session bearer establishment request and the voice special bearer establishment request to a terminal through the initial context establishment request to trigger the terminal to perform attachment completion processing, IMS session bearer establishment processing and voice special bearer establishment processing.

The second method comprises the following steps: the management network element equipment completes the attachment and the establishment of the IMS PDN session according to the IMS session establishment request, establishes the voice special bearer after the IMS PDN session is established, and the process for establishing the voice special bearer can adopt the establishment process before the application, which is not described herein again.

In this embodiment, the step of completing, by the SMF network element/PGW network element, the attach and the establishment of the IMSPDN session according to the IMS session establishment request includes:

an SMF network element/PGW network element sends an IMS session establishment response message to an MME through an SGW to trigger the MME to send an initial context establishment request to a base station, and triggers the base station to simultaneously send an attachment acceptance response and an IMS session bearer establishment request to a terminal through the initial context establishment request to trigger the terminal to perform attachment completion processing and IMS session bearer establishment processing; after the establishment of the IMS session bearer is completed, the SMF network element/PGW network element can trigger the establishment of the voice special bearer.

S2022: and when the IMS session establishment request is triggered by sending a packet data network connection request with APN as IMS after the attachment of the terminal is completed, the management network element equipment establishes an IMS PDN session and a voice special bearer simultaneously according to the IMS session establishment request.

In this embodiment, the case in S2022 may be referred to as a third mode, where the IMS session creation request is triggered by sending a packet data network connection request with an APN of the IMS after the terminal completes attachment; at this time, the establishment of the IMS PDN session and the dedicated voice bearer by the SMF network element/PGW network element according to the IMS session establishment request may include:

the SMF Network element/PGW Network element sends an IMS session establishment response message including a voice special Bearer request to an MME through an SGW to trigger the MME to send an E-RAB (Evolved UMTS Terrestrial Radio Access Network, Evolved Access Network Radio Access Bearer) establishment request to a base station, and triggers the base station to simultaneously send the IMS session Bearer establishment request and the voice special Bearer establishment request to a terminal through the E-RAB establishment request.

It should be understood that "simultaneously" in the above steps of the present embodiment is not strictly limited to being performed at the same time, and includes being performed at the same step, and may be performed at the same time or slightly different in time.

For ease of understanding, the present embodiment is described below with reference to a specific application example. In this application scenario there is no N26 networking. Referring to fig. 3, a method for quickly recovering an EPS Fallback voice bearer attached by an IMS APN after Fallback based on that the terminal determines that the redirection is triggered by an EPS Fallback includes the following steps:

s301: the terminal initiates a voice call in the 5G network, and the core network side initiates a voice special bearer establishment flow.

S302: the 5G base station triggers an EPS Fallback flow because the IMS voice bearing is not supported; and the 5G base station triggers redirection and sends RRC Release carrying the EPS Fallback indication to the terminal.

For example, the addition of EPS fallback indication to the Redirected CarrierInfo parameter in the RRC Release message is as follows:

s303: and the terminal uses the IMS APN (Access Point Name) of the voice session to initiate attachment after falling back to 4G according to the EPS Fallback indication.

S304: the MME carries a parallel establishment identifier Piggybacking Supported indication to the SGW in an IMS session establishment request message.

S305: and the SGW sends an IMS session establishment request message to the SMF/PGW and also carries a Piggybacking Supported indication.

S306: the SMF/PGW determines that the IMS session establishment request message is triggered by an EPS Fallback flow and is currently in an EPS Fallback state, triggers a Piggybacking flow, and establishes an IMS session and simultaneously triggers the establishment of a voice special load.

In this step, the SMF/PGW carries the voice-specific bearer creation request message to the SGW in the message for sending the IMS session establishment response, and the SGW sends the IMS session establishment response to the MME. This way, namely, the IMS PDN session and the dedicated voice bearer are established at the same time, and the first way is applied. It should be understood that, in some application scenarios, this step may also be performed only for establishing the IMS PDN session, and the dedicated voice bearer may be performed after the IMS PDN session is established, that is, corresponding to the above second method.

S307: and after receiving the IMS session establishment response message, the MME simultaneously sends an IMS session establishment request and a voice special load establishment request.

In this step, the MME may send an initial context setup request message to the 4G base station to set up two bearers, which may specifically include an attach accept, a default bearer setup request (i.e., an IMS session setup request), and a dedicated bearer setup request (i.e., a voice dedicated bearer setup request) message to the terminal.

S308: the terminal establishes IMS session and voice special load at the same time, and returns attachment completion, default load establishment acceptance and special load establishment acceptance messages to the MME.

In this step, the terminal may return an initial context setup response message to the MME through the 4G base station, where the initial context setup response message may include an attach complete, a default bearer setup accept, and a dedicated bearer setup accept message.

S309: the MME sends a request message for modifying the bearing to the SGW, and the message carries a response message for creating the bearing.

S310: and the SGW sends a bearer creation response message to the SMF/PGW, and the IMS session and the voice special bearer are created.

S311: after the voice dedicated bearer is established, if the terminal needs to initiate data service, the establishment of a data PDN is initiated.

For ease of understanding, the present embodiment is described below with reference to another application example. In this example, fall-back control is performed in the above-described manner three, that is, after a terminal falls back, attach is initiated by using the APN, after the attach is completed, an IMS PDN connection is initiated, and a voice bearer is simultaneously established in the IMS PDN connection process; the process is shown in fig. 4, and includes:

s401: the terminal initiates a voice call in the 5G network, and the core network side initiates a voice special bearer establishment flow.

S402: the 5G base station triggers an EPS Fallback flow because the IMS voice bearing is not supported; and the 5G base station triggers redirection and sends RRC Release carrying the EPS Fallback indication to the terminal.

S403: the terminal uses the APN to initiate attachment after falling back to 4G according to the EPS Fallback indication; and after the attachment is completed, initiating an IMS session establishment request. It should be understood that any attachment process before the application is adopted in the specific attachment process in this embodiment will not be described herein again.

S404: the MME carries a parallel establishment identifier Piggybacking Supported indication to the SGW in an IMS session establishment request message.

S405: and the SGW sends an IMS session establishment request message to the SMF/PGW and also carries a Piggybacking Supported indication.

S406: the SMF/PGW determines that the IMS session establishment request message is triggered by an EPS Fallback flow and is currently in an EPS Fallback state, triggers a Piggybacking flow, and establishes an IMS session and simultaneously triggers the establishment of a voice special load.

In this step, the SMF/PGW carries the voice-specific bearer creation request message to the SGW in the message for sending the IMS session establishment response, and the SGW sends the IMS session establishment response to the MME.

S407: and after receiving the IMS session establishment response message, the MME simultaneously sends an IMS session establishment request and a voice special load establishment request.

In this step, the MME may send an E-RAB establishment request message to the 4G base station to establish two bearers, which may specifically include a default bearer establishment request (i.e., an IMS session establishment request) and a dedicated bearer establishment request (i.e., a voice dedicated bearer establishment request) message to the terminal.

S408: the terminal establishes IMS session and voice special load at the same time, and returns a default load establishment acceptance message and a special load establishment acceptance message to the MME.

S409: the MME sends a request message for modifying the bearing to the SGW, and the message carries a response message for creating the bearing.

S410: and the SGW sends a bearer creation response message to the SMF/PGW, and the IMS session and the voice special bearer are created.

S411: after the voice dedicated bearer is established, if the terminal needs to initiate data service, the establishment of a data PDN is initiated.

Therefore, the fallback recovery method optimizes the signaling interaction flow after fallback, reduces the time for establishing the IMS voice bearer, shortens the voice fallback delay under the non-N26 networking, and improves the user voice experience.

Example two:

the present embodiment provides a fallback recovery control device, which can be disposed in a management network element device, please refer to fig. 5, including:

afirst receiving module 501, configured to receive an IMS session creation request, where the IMS session creation request is triggered by a terminal in an EPS Fallback process of an evolved packet system, for a specific process, see what is shown in the foregoing embodiments, and details are not described here.

A first processing module 502, configured to at least establish an IP multimedia subsystem packet data network, IMS, PDN session according to an IMS session establishment request when the IMS session establishment request is triggered by sending a packet data network connection request with an access point name, APN, for the IMS in an attach procedure of a terminal;

and when the IMS session establishment request is triggered by sending the APN to the packet data network connection request of the IMS after the attachment of the terminal is completed, establishing an IMSPDN session and a voice dedicated bearer according to the IMS session establishment request; for a specific processing procedure, please refer to the above embodiments, which are not described herein. It should be understood that the functions of thefirst receiving module 501 and the first processing module 502 described above may be implemented by, but are not limited to, the first processor of the management gateway device.

The embodiment further provides a fallback recovery device, which can be disposed in a terminal, as shown in fig. 6, including:

asecond receiving module 601, configured to receive a radio resource control Release RRC Release message including an EPS Fallback indication from a base station; for a specific process, please refer to the above embodiments, which are not described herein.

A second processing module 602, configured to send, to the MME, a packet data network connection request with an APN of the IMS in the attach procedure, so as to trigger the MME to send an IMS session creation request to the management network element device, and trigger the management network element device to at least establish an IMS PDN session through the IMS session creation request;

or, after the attachment is completed, sending a packet data network connection request with the APN being the IMS to the MME, so as to trigger the MME to send an IMS session creation request to the management network element device, and triggering the management network element device to simultaneously establish an IMS PDN session and a dedicated voice bearer through the IMS session creation request. For a specific processing procedure, please refer to the above embodiments, which are not described herein. It should be understood that the functions of thesecond receiving module 601 and the second processing module 602 described above can be implemented by, but are not limited to, the second processor of the terminal.

For ease of understanding, the present embodiment is described below with reference to a specific application scenario as an example.

Referring to fig. 7, in a Fallback triggering scenario, after a terminal initiates a voice call after 5G is accessed, a base station does not support IMS voice bearer, and triggers an EPS Fallback procedure to fall back to 4G, including:

s701: the terminal accesses and establishes an IMS PDU (Packet Data Unit) session at 5G;

s702: a terminal initiates a voice call, triggers the establishment of a voice special load, and an SMF initiates a PDU session modification flow to establish the voice special load;

s703: the base station does not support IMS voice special load, and an EPS Fallback flow is triggered;

s704: the base station refuses the establishment of the voice special load and returns a failed PDU session modification response message.

Referring to fig. 8, the base station triggers redirection, sends RRC Release to the terminal, and carries an epsmallback indication, including:

s801: and the base station sends an RRC Release message to the terminal and carries an EPS Fallback indication.

Referring to the fall-back recovery control process shown in fig. 9, after the terminal falls back to 4G, it initiates attachment in 4G, and carries APN as IMS, including:

s901: the terminal initiates an attachment flow, and sends an attachment Request Attach Request to the MME, wherein the APN carried in a packet data network connection Request PDN Connectivity Request triggered in the process is IMS;

s902: the MME sends a Create Session Request message to the SGW, and the message carries a Piggybacking Supported indication;

s903: the SGW sends a Create Session Request message to the SMF/PGW, wherein the message carries a Piggybacking Supported indication;

s904: the SMF/PGW determines that the current state is in an EPS Fallback state, establishes a voice special load in the IMS Session establishment process, sends a Create Session Response message and carries a Create load Request Create Bearer Request message to the SGW;

s905: the SGW sends a Create Session Response message and carries a Create Bearer Request message to the MME;

s906: the MME sends an Initial Context Setup Request message to a base station, wherein the message carries an IMS session and a voice bearer; NAS (Non-Access-Stratum) -PDU carries Attach Accept Message (ESM Message Container includes Message for activating Default EPS Bearer Context Request, and Message for activating Dedicated EPS Bearer Context Request), and the base station forwards the Attach Accept Message to the terminal;

s907: the base station returns an Initial Context Setup Response message to the MME;

s908: the terminal returns an Attach Complete Message (the ESM Message Container comprises an Activate Default EPS Bearer Context request accepting and an Activate Dedicated EPS Bearer Context request accepting Message) to the MME;

s909: the MME sends a modification Bearer Request message to the SGW, and carries a Create Bearer Response message;

s910: the SGW sends a Create beer Response message to the SMF/PGW;

s911: the SGW sends a Modify Bearer Response message to the MME.

Referring to the fall-back recovery control procedure shown in fig. 10, after the terminal falls back to 4G and the attachment is completed, the IMS PDN session establishment is initiated, and the procedure includes:

s1001: the terminal initiates the establishment of an IMS PDN session, and APN carried in a packet data network connection Request PDNConnection Request is IMS;

s1002: the MME sends a Create Session Request message to the SGW, and the message carries a Piggybacking Supported indication;

s1003: the SGW sends a Create Session Request message to the SMF/PGW, wherein the message carries a Piggybacking Supported indication;

s1004: the SMF/PGW judges that the current state is in an EPS Fallback state, establishes a voice special load in the IMS Session establishment process, sends a Create Session Response message and carries a Create beer Request message to the SGW;

s1005: the SGW sends a Create Session Response message and carries a Create Bearer Request message to the MME;

s1006: the MME sends an E-RAB Setup Request message to the base station, wherein the message carries an IMS session and a voice bearer; the NAS-PDU carries an active Default EPS Bearer Context Request message and an active Default EPS Bearer Context Request message, and the base station forwards the active Default EPS Bearer Context Request message and the active Default EPS Bearer Context Request message to the terminal;

s1007: the base station returns an E-RAB Setup Response message to the MME;

s1008: the terminal returns an active Default EPS Bearer Context Accept message and an active Default EPS Bearer Context Accept message to the MME;

s1009: the MME sends a Modify Bearer Request message to the SGW, and carries a Create Bearer Response message;

s1010: the SGW sends a Create beer Response message to the SMF/PGW;

s1011: the SGW sends a Modify Bearer Response message to the MME.

Therefore, in the embodiment, at least the IMS session can be created in the attach flow through the above-mentioned flows, or the IMS PDN session and the dedicated voice bearer can be simultaneously established after the attach flow is completed, so that compared with a method in which the attach flow, the IMS PDN session establishment flow, and the dedicated voice bearer establishment flow are sequentially performed in series in the related art, a longer time required for fallback recovery can be reduced to a greater extent, the voice bearer recovery efficiency is improved, and further the user experience satisfaction is improved.

Example three:

the present embodiment also provides a management network element device, which may be but is not limited to an SMF network element/PGW network element, as shown in fig. 11, and includes afirst processor 1101, afirst memory 1102 and afirst communication bus 1103;

thefirst communication bus 1103 is used for realizing communication connection between thefirst processor 1101 and thefirst memory 1102;

in one example, thefirst processor 1101 may be configured to execute a first computer program stored in thefirst memory 1102 to implement the fall-back recovery control method steps in the embodiments described above.

The present embodiment further provides a terminal, as shown in fig. 12, which includes asecond processor 1201, asecond memory 1202, and asecond communication bus 1203;

asecond communication bus 1203 is used for realizing communication connection between thesecond processor 1201 and thesecond memory 1202;

in one example, thesecond processor 1201 may be configured to execute a second computer program stored in thesecond memory 1202 to implement the fall-back recovery method steps in the embodiments described above.

The present embodiments also provide a computer-readable storage medium including volatile or non-volatile, removable or non-removable media implemented in any method or technology for storage of information such as computer-readable instructions, data structures, computer program modules or other data. Computer-readable storage media include, but are not limited to, RAM (Random Access Memory), ROM (Read-Only Memory), EEPROM (Electrically Erasable Programmable Read-Only Memory), flash Memory or other Memory technology, CD-ROM (Compact disk Read-Only Memory), Digital Versatile Disks (DVD) or other optical disk storage, magnetic cassettes, magnetic tape, magnetic disk storage or other magnetic storage devices, or any other medium which can be used to store the desired information and which can be accessed by a computer.

In one example, the computer readable storage medium in the present embodiment may be used to store a first computer program, which may be executed by a first processor, to implement the fall-back recovery control method steps in the above embodiments.

In another example, the computer readable storage medium in the present embodiment may be used to store a second computer program, which may be executed by a second processor to implement the fall-back recovery method steps in the above embodiments.

The present embodiment further provides a first computer program (or first computer software), which can be distributed on a computer readable medium and executed by a computing device, so as to implement the fall-back recovery control method steps shown in the above embodiments. And in some cases at least one of the steps shown or described may be performed in an order different than that described in the embodiments above.

The present embodiment further provides a second computer program (or called second computer software), which can be distributed on a computer-readable medium and executed by a computing device, so as to implement at least one step of the fallback recovery method shown in the above embodiments; and in some cases at least one of the steps shown or described may be performed in an order different than that described in the embodiments above.

The present embodiments also provide a computer program product comprising a computer readable means on which any of the computer programs as set out above is stored. The computer readable means in this embodiment may include a computer readable storage medium as shown above.

It will be apparent to those skilled in the art that all or some of the steps of the methods, systems, functional modules/units in the devices disclosed above may be implemented as software (which may be implemented in computer program code executable by a computing device), firmware, hardware, and suitable combinations thereof. In a hardware implementation, the division between functional modules/units mentioned in the above description does not necessarily correspond to the division of physical components; for example, one physical component may have multiple functions, or one function or step may be performed by several physical components in cooperation. Some or all of the physical components may be implemented as software executed by a processor, such as a central processing unit, digital signal processor, or microprocessor, or as hardware, or as an integrated circuit, such as an application specific integrated circuit.

In addition, communication media typically embodies computer readable instructions, data structures, computer program modules or other data in a modulated data signal such as a carrier wave or other transport mechanism and includes any information delivery media as known to one of ordinary skill in the art. Thus, the present invention is not limited to any specific combination of hardware and software.

The foregoing is a more detailed description of embodiments of the present invention, and the present invention is not to be considered limited to such descriptions. For those skilled in the art to which the invention pertains, several simple deductions or substitutions can be made without departing from the spirit of the invention, and all shall be considered as belonging to the protection scope of the invention.

Claims

1. A fallback control method comprising:

2. The fallback recovery control method of claim 1, wherein said receiving an IMS session creation request comprises:

receiving an IMS session establishing request which is sent by a service gateway SGW and contains a support parallel establishing identifier;

the IMS session establishment request sent by the SGW is triggered and sent according to the IMS session establishment request which is received from a mobility management entity MME and contains a support parallel establishment identifier;

and the IMS session creation request sent by the MME is triggered and sent according to the received packet data network connection request with the APN being IMS.

3. The fallback control method according to claim 1 or 2, wherein the IMS session creation request is triggered by sending a packet data network connection request with APN for IMS in an attach procedure of the terminal;

the establishing of at least an IMS PDN session according to the IMS session establishing request comprises:

according to the IMS session establishment request, firstly completing the attachment and the establishment of an IMS PDN session, and after the IMS PDN session is established, establishing a voice special bearer;

or the like, or, alternatively,

and establishing an IMS PDN session and a voice special bearer simultaneously according to the IMS session establishing request.

4. The fallback control method of claim 3 wherein said completing the attachment and establishment of the IMS PDN session first according to the IMS session creation request comprises:

sending an IMS session establishment response message to an MME through an SGW to trigger the MME to send an initial context establishment request to a base station, and triggering the base station to simultaneously send an attachment acceptance response and an IMS session bearer establishment request to the terminal through the initial context establishment request.

5. The fallback recovery method of claim 3 wherein the concurrently establishing an IMS PDN session and a voice dedicated bearer according to the IMS session creation request comprises:

sending an IMS session establishment response message including a voice special bearer request to an MME through an SGW to trigger the MME to send an initial context establishment request to a base station, and triggering the base station to simultaneously send an attachment acceptance response, an IMS session bearer establishment request and the voice special bearer establishment request to the terminal through the initial context establishment request.

6. The fallback recovery control method according to claim 1 or 2, wherein the IMS session creation request is triggered by sending a packet data network connection request with APN for IMS after the terminal completes the attach;

the establishing of the IMS PDN session and the voice dedicated bearer simultaneously according to the IMS session establishing request comprises the following steps:

sending an IMS session establishment response message including a voice special bearer request to an MME through an SGW to trigger the MME to send an evolved access network radio access bearer E-RAB establishment request to a base station, and triggering the base station to simultaneously send the IMS session bearer establishment request and the voice special bearer establishment request to the terminal through the E-RAB establishment request.

7. A fallback method comprising:

or the like, or, alternatively,

8. A fallback control device, comprising:

9. A fall-back recovery device, comprising:

10. A managing network element device comprising a first processor, a first memory and a first communication bus;

the first processor is adapted to execute a first computer program stored in the memory to implement the steps of the fallback control method according to any one of the claims 1-6.

11. A terminal comprising a second processor, a second memory, and a second communication bus;

the second processor is configured to execute a second computer program stored in the memory to implement the steps of the fallback control method as claimed in claim 7.

12. A computer-readable storage medium, characterized in that the computer-readable storage medium stores a first computer program which, when executed by a first processor, implements the steps of the fallback recovery control method according to any one of claims 1-6;

alternatively, the computer readable storage medium stores a second computer program which, when executed by a second processor, implements the steps of the fallback recovery method as claimed in claim 7.