CN108966291B

CN108966291B - Method and device for recovering circuit switched fallback, mobile management entity and user terminal

Info

Publication number: CN108966291B
Application number: CN201710349375.2A
Authority: CN
Inventors: 周山长; 徐雯; 于进刚
Original assignee: ZTE Corp
Current assignee: ZTE Corp
Priority date: 2017-05-17
Filing date: 2017-05-17
Publication date: 2021-06-11
Anticipated expiration: 2037-05-17
Also published as: CN108966291A

Abstract

The invention relates to a method and a device for recovering circuit switched fallback, a mobile management entity and a user terminal. The circuit switched fallback recovery method comprises the following steps: receiving a circuit domain recovery request message which is sent by a first mobile switching center and carries a paging identifier of a user terminal; sending a paging request message to the user terminal according to the paging identifier, wherein the paging request message carries a unique identifier of a home terminal mobile management entity; receiving a first connection request message sent by a base station, wherein the first connection request message carries information that the user terminal requests to connect a local terminal mobile management entity according to the paging request message; and sending a location updating request message to a second mobile switching center, and configuring the second mobile switching center as an access location after the circuit domain fallback of the user terminal. The invention can not re-establish the mobile management entity with damaged interface with the user terminal, and improves the recovery success rate of the circuit switched fallback.

Description

Method and device for recovering circuit switched fallback, mobile management entity and user terminal

Technical Field

The present invention relates to the field of network communication technologies, and in particular, to a method and an apparatus for recovering a circuit switched fallback, a mobility management entity, and a user equipment.

Background

At present, circuit domain fallback voice services are already used in a large amount in an existing network and will exist for a long time, and occupy more and more important positions, in an actual commercial scene, in order to avoid an impact on the services caused by a network element or an interface failure due to an emergency, an MME (Mobility Management Entity) POOL or MSC/VLR (Mobile Switching Center/visual Location Register) POOL disaster-tolerant manner is generally adopted for networking deployment of a core network by an operator. Therefore, in the disaster recovery mode, whether a network element or an interface failure can guarantee normal operation of the circuit domain fallback service is a very concern of an operator.

The conventional processing mode after a network element or interface failure is generally processed according to the description of a 3GPP TS 23007 protocol, specifically, an MME POOL disaster recovery networking VLR judges an MME failure based on a coupled broken link, and starts to execute a recovery procedure of a called circuit domain fallback service, when only an interface between the MME and the VLR, namely an SGs port broken link, is used, the circuit domain fallback called recovery procedure triggers a user to reconnect, and a base station may select an MME with an SGs port failure, which may cause a paging failure. For SGs connection reestablishment, when the VLR for reestablishment of connection is inconsistent with the paging VLR, the VLR may trigger the mobile final call roaming retry or the mobile final call roaming forwarding flow, resulting in an increase in the time delay of the entire CSFB service.

At present, no better method is available for ensuring that the circuit switched fallback service of the user terminal can be successfully paged after the SGs port is broken.

Disclosure of Invention

Therefore, it is necessary to provide a method and an apparatus for recovering a circuit switched fallback, a mobility management entity and a user equipment, which are directed to the problem of low success rate of the circuit switched fallback paging.

A method for recovering circuit switched fallback is applied to a mobile management entity, and the method comprises the following steps:

receiving a circuit domain recovery request message which is sent by a first mobile switching center and carries a paging identifier of a user terminal;

sending a paging request message to the user terminal according to the paging identifier, wherein the paging request message carries a unique identifier of a home terminal mobile management entity;

receiving a first connection request message sent by a base station, wherein the first connection request message carries information that the user terminal requests to connect a local terminal mobile management entity according to the paging request message;

and sending a location updating request message to a second mobile switching center, and configuring the second mobile switching center as an access location after the circuit domain fallback of the user terminal.

A first storage medium, the storage medium being arranged to store program code for performing the steps of:

and sending a location updating request message to the second mobile switching center, and configuring the second mobile switching center as an access location after the circuit domain of the user terminal falls back.

A method for recovering circuit switched fallback is applied to a user terminal, and comprises the following steps:

receiving a paging request message which is sent by a mobile management entity and carries a unique identifier of the mobile management entity;

sending a wireless connection request message carrying information of a mobile management entity corresponding to the unique identifier to a base station, so that the base station sends a first connection request message to the mobile management entity;

and when receiving a second response message which is sent by the mobile management entity and indicates that the second mobile switching center allows access, determining that the second mobile switching center is the access position after the circuit domain of the user terminal falls back.

A second storage medium, the storage medium being arranged to store program code for performing the steps of:

A first circuit switched fall back recovery apparatus, the apparatus comprising:

a recovery request message receiving module, configured to receive a circuit domain recovery request message sent by a first mobile switching center;

a paging request message sending module, configured to send a paging request message to the ue according to the paging identifier, where the paging request message carries a unique identifier of a home mobility management entity;

a second connection request message receiving module, configured to receive a first connection request message sent by a base station, where the first connection request message carries information that the user terminal requests to connect to a local mobility management entity according to the paging request message;

and the location updating message sending module is used for sending a location updating request message to a second mobile switching center, and configuring the second mobile switching center as the access location after the circuit domain of the user terminal falls back.

A second apparatus for circuit switched fallback, the apparatus comprising:

a paging request message receiving module, configured to receive a paging request message that is sent by a mobility management entity and carries a unique identifier of the mobility management entity;

a first connection request message sending module, configured to send a wireless connection request message carrying information of a mobility management entity that requests to connect to the unique identifier to a base station, so that the base station sends the first connection request message to the mobility management entity;

and the access position determining module is used for determining that the second mobile switching center is the access position after the circuit domain of the user terminal falls back when receiving a second response message which is sent by the mobile management entity and indicates that the second mobile switching center allows access.

A mobile management entity comprises a memory, a first processor and a computer program which is stored on the memory and can run on the processor, wherein the first processor realizes the steps of the recovery method of the circuit domain fallback when executing the program.

A user terminal comprises a memory, a second processor and a computer program which is stored on the memory and can run on the processor, and the second processor realizes the steps of the recovery method of the circuit domain fallback when executing the program.

The paging message added with the unique identifier of the mobile management entity is sent to the user terminal, so that the user terminal can send the unique identifier of the mobile management entity to the base station when sending the connection request message to the base station, and the base station selects the mobile management entity accessed by the user terminal as the mobile management entity corresponding to the unique identifier according to the connection request message, thereby ensuring that the mobile management entity with damaged interface is not re-established with the user terminal and improving the recovery success rate of circuit domain fallback.

Drawings

Fig. 1 is a flowchart of a method for recovering a circuit switched fallback applied to a mobility management entity according to an embodiment of the present invention;

fig. 2 is a flowchart of a method for recovering a circuit switched fallback applied to a user equipment according to an embodiment of the present invention;

fig. 3 is a networking diagram related to the current circuit switched fallback service;

FIG. 4 is a timing diagram illustrating a recovery method of circuit switched fallback in the first conventional method;

FIG. 5 is a timing diagram illustrating a recovery method of circuit switched fallback in the second conventional method;

FIG. 6 is a timing diagram of a recovery method of a circuit switched fallback according to an embodiment of the present invention;

FIG. 7 is a block diagram of a first recovery apparatus for circuit switched fallback according to an embodiment of the present invention;

FIG. 8 is a block diagram of a second recovery apparatus for circuit switched fallback according to an embodiment of the present invention;

fig. 9 is a block diagram of a circuit switched fallback paging system in accordance with an embodiment of the present invention.

Detailed Description

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

Fig. 1 is a flowchart of a method for restoring a cs fallback applied to a mobility management entity according to an embodiment of the present invention, and the method for restoring a cs fallback applied to a mobility management entity according to an embodiment of the present invention is described below with reference to fig. 1, and includes the following steps S101 to S105.

S101, receiving a circuit domain recovery request message sent by a first mobile switching center.

In this step, the mobile Switching center, namely, msc (mobile Switching center), the circuit domain restoration request message carries a circuit domain restoration indication csri (cs restoration indicator) indicating that a visitor Location register vlr (visited Location register) of the mobile Switching center is disconnected from a previously connected mobility management entity MME1, and requests the home mobility management entity MME2 to restore the circuit domain fallback service with the user equipment.

In the MME POOL of the visitor location register of each mobile switching center, unique identifiers of at least two MMEs, i.e., MME1 and MME2, are pre-stored for each circuit domain fallback service, so that when an interface from one of the mobility management entities to the visitor location register of the mobile switching center is broken, the circuit domain fallback service with the user terminal can be restored by sending a request to the other mobility management entity. After detecting the disconnection with the mobility management entity MME1 connected previously, the mobile switching center selects to send a circuit domain restoration request message to the home mobility management entity MME2 by looking up the unique identifier of the home in the MME POOL.

S102, the paging identification of the user terminal carried in the circuit domain recovery request message is analyzed.

According to an example of this embodiment, the paging identifier is an international Mobile Subscriber identity imsi (international Mobile Subscriber identity number) of the ue.

S103, sending a paging request message to the user terminal according to the paging identifier, wherein the paging request message carries the unique identifier of the home terminal mobile management entity.

In this step, when the number of the MMEs pre-stored in the MME POOL is three or more, the unique identifier may be the unique identifier of the home mobility management entity, and the pre-stored MMEs may not include any other MME except the MME with a damaged interface. Further, a paging request message is sent to the ue corresponding to the IMSI, where the paging request message carries a Unique identifier of the home mobility management entity MME2, for example, a GUMMEI (Globally Unique MME Identity) identifier of the MME 2.

Further, the paging request message also carries an IMSI number of the user terminal, and sets a CN (Core Network) domain indication to PS (Packet Switch).

The purpose of this step is to make the user terminal send the radio connection request message to the base station with the unique identifier of the mobility management entity, so that the base station does not select the MME requesting connection according to the weight of the MME by using the conventional method, but selects the MME2 according to the MME corresponding to the specified unique identifier, so as to avoid the base station sending the connection request message to the MME1 with interface failure again.

According to an example of this embodiment, the paging request message is provided with a field for storing a unique identifier of the mobility management entity.

S104, receiving a first connection request message sent by the base station, wherein the first connection request message carries information that the user terminal requests to connect the local terminal mobile management entity according to the paging request message.

According to an example of this embodiment, the triggering condition for sending the first connection request message is that the base station receives a radio connection request message carrying information of a mobility management entity corresponding to the unique identifier, where the radio connection request message is sent by the user equipment.

S105, sending a location update request message to a second mobile switching center, and configuring the second mobile switching center as an access location after the circuit domain fallback of the user terminal.

The selection of the second mobile switching center is shown in fig. 3, and may be performed in a network element involved in the circuit switched fallback service, and may select MSC1/VLR1 or MSC2/VLR 2.

Further, the step of sending the location update request message to the second mobile switching center is specifically the following step (1) and step (2):

(1) and sending a location update request message to the mobile switching center which sends the circuit domain recovery request message, namely the first mobile switching center is the same as the second mobile switching center.

In this step, the location register accessed after the user terminal performs Circuit Switched Fallback (CSFB) is defined as the visitor location register of the mobile switching center that sends the circuit Switched fallback request message, so that the MSC/VLR accessed after the CSFB is the same as the MSC/VLR accessed before the CSFB, so that the user terminal roaming retry or forwarding is not triggered, and the time delay of the whole CSFB service is reduced.

Further, the location update request message carries an international mobile subscriber identity of the ue, and the step of configuring the second mobile switching center as the access location after the circuit switched domain fallback of the ue includes:

(2) and receiving a first response message which is sent back by the second Mobile switching center and indicates that access is allowed, wherein the first response message carries the Temporary Mobile Subscriber Identity (TMSI) after the International Mobile Subscriber Identity (IMSI) is converted.

And sending a second response message of the first connection request message to the user terminal, wherein the second response message carries the temporary mobile subscriber identification code.

According to a first storage medium provided in an embodiment of the present invention, the storage medium is configured to store program code for performing the steps of:

receiving a circuit domain recovery request message sent by a first mobile switching center;

analyzing the paging identification of the user terminal carried in the circuit domain recovery request message;

Fig. 2 is a flowchart of a method for restoring a circuit switched fallback applied to a user terminal according to an embodiment of the present invention, and the method for restoring a circuit switched fallback applied to a user terminal according to an embodiment of the present invention is described below with reference to fig. 2, and includes the following steps S201, S202, and S203.

S201, receiving a paging request message which is sent by a mobile management entity and carries a unique identifier of the mobile management entity.

The Unique identifier of the mobility management entity is the gummei (global Unique MME identity) of the MME 2.

Further, the method further comprises:

the unique identifier of the mobility management entity in the paging request message is parsed.

S202, sending a wireless connection request message carrying information of the mobile management entity corresponding to the unique identifier to the base station, so that the base station can send a first connection request message to the mobile management entity.

Further, the radio connection request message carries the IMSI number of the ue and the unique identifier of the MME 2.

According to an example of this embodiment, the radio connection request message is provided with a field for storing a unique identifier of the mobility management entity.

This step encapsulates the unique identifier of the mobility management entity into the radio connection request message, so that the base station selects the mobility management entity MME2 as the user terminal connection object when sending the first connection request message, instead of using the conventional method of selecting an MME according to weight, so as to prevent the connection object of the user terminal from being determined again as the interface-damaged MME 1.

S203, when receiving a second response message indicating that the second mobile switching center allows access, sent by the mobility management entity, determining that the second mobile switching center is an access location after the circuit switched domain of the ue falls back.

The step of sending the wireless connection request message carrying the information of the mobile management entity corresponding to the unique identifier to the base station further comprises:

receiving a response message of the wireless connection request message sent by the base station;

and sending a second connection request message carrying the international mobile subscriber identity of the user terminal to the base station, so that the base station sends the first connection request message to the mobile management entity.

According to a second storage medium provided by the present embodiment, the storage medium is configured to store program code for performing the steps of:

Fig. 3 is a networking diagram related to a current circuit switched fallback service, in which a base station eNB, i.e., an Evolved Node B, further includes a first mobility management entity MME1, a second mobility management entity MME2, a visitor location register MSC1/VLR1 of the first mobile switching center, and a visitor location register MSC2/VLR2 of the second mobile switching center.

Fig. 4 is a timing diagram of a recovery method of circuit switched fallback in a first conventional method, where a flow of a failure recovery of a called CSFB service at an SGs port is shown in fig. 4, and the recovery method of circuit switched fallback in the first conventional method generally includes the following steps 201 to 208.

201, the user is attached (i.e. connected) to an EPC (Evolved Packet Core) network jointly and registered successfully on MME1 and VLR 1;

202, after the SGs port connection from MME1 to VLR1 and VLR2 is disconnected, VLR1 receives the call terminating voice service of the user, VLR1 needs to page the user through the SGs port, detects that the connection of MME1 is disconnected, VLR1 sends a paging message to another MME in MME POOL, i.e., MME 2. The paging message carries a csri (cs reception indicator) indication.

203, after receiving the paging message carrying the CSRI indication, the MME2 triggers the CSFB service recovery procedure of the called user, initiates paging to the user terminal, where the paging message carries the user imsi (international Mobile Subscriber identity number), and sets the cn (core network) domain indication to PS (Packet Switch, Packet switching).

204, when the ue receives an EPS (Evolved Packet System) service paging message carrying the IMSI, and after local detach, the EPS update state is set to EU2(EPS update status2, the update state of the EPS is 2, which indicates an un-updated state). The user needs to initiate an attachment service flow again, and initiates a request for establishing wireless resource connection to the eNB, wherein the request carries the IMSI of the user.

205, the eNB sends a response to the user terminal to establish the radio resource connection.

206, the user sends a joint attach request to the eNB, and the eNB selects MME1 to forward the attach request message according to the weights of MME1 and MME2 in MME POOL.

207, when the MME1 receives the joint attach request message, it determines that the VLR1 and VLR2 office direction has been disconnected, the SGs location update fails, and after waiting for the completion of the execution of other procedures of the attach service, it sends an attach accept message to the user terminal, carrying the temporary unreachable reason of msc (mobile Switching center).

208, after the user terminal receives the attach accept message, only EPC is attached successfully, and the subsequent CSFB service flow will not be executed continuously, and fallback fails.

Fig. 5 is a timing diagram of a recovery method of circuit switched fallback in a second conventional method, where when a called CSFB service recovers that a paging VLR is not consistent with a VLR of a reestablished SGs port, a service flow of the method is as shown in fig. 5, and the recovery method of circuit switched fallback in the second conventional method generally includes the following steps 301 to 313.

301, the user is jointly attached to the EPC network, and successfully registered on MME1 and VLR 1;

302, after the SGs port of MME1 to VLR1 is disconnected, VLR1 receives the call voice service of the user, VLR1 needs to page the user through the SGs port, detects that the connection of MME1 is disconnected, VLR1 sends a paging message to another MME in MME POOL, that is, MME 2. The CSRI indication is carried in the paging message.

303, after receiving the paging message carrying the CSRI indication, the MME2 triggers the CSFB service recovery procedure of the called user, initiates paging to the user terminal, where the paging message carries the IMSI of the user, and sets the CN domain indication to "PS".

304, when receiving the EPS service paging message carrying IMSI, the ue sets the EPS update state to EU2(EPS update status2) not updated after local detach. The user needs to initiate an attachment service flow again, and initiates a request for establishing wireless resource connection to the eNB, wherein the request carries the IMSI of the user.

305, the eNB sends a radio resource connection establishment response to the user terminal.

306, the user sends a joint attach request to the eNB, which selects MME1 to forward the attach request message according to the weights of MME1 and MME2 in MME POOL.

307, when the MME1 receives the joint attach request message, it determines that the VLR1 office direction has been disconnected, and the MME1 selects the VLR2 office direction to initiate an SGs location update request.

308, after the VLR2 receives the location request, it finds that the user is in the called service flow in the location updating process, and triggers the retry of the mobile terminated call roaming or the forwarding flow of the mobile terminated call roaming.

309, VLR1 and VLR2 execute the retry of mobile terminated call roaming or the forwarding service flow of mobile terminated call roaming, and the specific flow is referred to protocol 3GPP TS 23018.

310, VLR2 sends a location update response message to MME1, carrying the user TMSI identification.

311, after receiving the SGs port location update response message, the MME1 continues to execute the attach service flow, and then sends a joint attach successful reception message to the user equipment.

312, VLR2 sends a paging request message to MME1, carrying the user tmsi (temporal Mobile Station identity) identity.

313, after receiving the paging message, the MME1 initiates a normal CSFB fallback service flow.

Because of MME POOL networking, when SGs port fails, called CSFB (Circuit switched fallback) recovers to trigger user reattachment, when the eNB selects the MME according to the weight, the MME with the SGs port failure can be selected to cause CSFB service failure; or when the user is jointly attached and the SGs port location is updated, and the VLR selected by the MME is inconsistent with the paged VLR, the VLR may trigger the mobile terminal to retry roaming or forward the service flow, thereby causing an increase in the delay of the entire CSFB service flow.

In order to overcome the problem and the defect that a CSFB (Circuit switched fallback) called service may fail or a CSFB service is too long in time delay under the condition that an SGs port of an MME POOL networking fails in the conventional technology, an implementation method for recovering the CSFB service of the called MME POOL disaster recovery networking is provided, and the implementation method is realized by carrying a GUMMEI (Global unified MME identity) of an MME on a paging message and a radio resource connection establishment request message on the basis of a 3GPP TS 23007 protocol definition disaster recovery processing flow, and specifically comprises the following steps (1) to (5).

(1) The MME carries the GUMMEI of the MME when receiving the paging message carrying the CSRI indication of the VLR and sending the paging message to the user terminal;

(2) when the user terminal is re-attached, sending a wireless resource establishment request to the eNB, wherein the request carries the GUMMEI;

(3) when the eNB receives the re-attachment message of the terminal user, the MME is selected to forward the attachment request message according to the GUMMEI in the wireless resource establishment request;

(4) the MME receives the attachment request message and selects the VLR which sends the paging message to reestablish SGs port connection;

(5) and after the attachment is successful, the normal CSFB fallback service flow is continuously initiated subsequently.

Fig. 6 is a timing diagram of a method for recovering a circuit domain fallback according to an embodiment of the present invention, and the method for recovering a circuit domain fallback according to an embodiment of the present invention is described in detail below with reference to fig. 6, where the MME carries the GUMMEI information of the home mobility management entity MME (i.e., MME2) in a paging message, and then carries the GUMMEI in a terminal radio resource setup request message to the eNB, and the eNB selects an MME according to the GUMMEI in processing a subsequent attach (i.e., connection) request message, as shown in fig. 6, and the method includes the following steps 401 to 412.

401. The user jointly attaches to the 4G network and successfully registers on the MME1 and the VLR 1;

402. after the SGs ports of MME1 to VLR1 and VLR2 are disconnected, VLR1 receives the call terminating voice service of the user, VLR1 needs to page the user through the SGs ports, detects that the connection of MME1 is disconnected, VLR1 sends a paging message to another MME in MME POOL, that is, MME 2. The paging message carries a CSRI indication;

403. after receiving the paging message carrying the CSRI indication by the VLR1, the MME2 records the VLR1 office direction information, triggers the CSFB service recovery procedure of the called subscriber, initiates paging to the user terminal, carries the IMSI of the subscriber in the paging message, and sets the CN domain indication to "PS". Adding an MME Global ID field in the paging message, and filling values into GUMMEI of the MME 2;

404. and when the user terminal receives the EPS service paging message carrying the IMSI, after local detachment, setting the EPS updating state as an EU2 non-updating state. The user needs to initiate an attachment service flow again, initiates a request for establishing the radio resource connection to the eNB, carries the IMSI of the user, adds an MME Global ID field in the message, and fills the value of the MME Global ID field in the paging message, namely the GUMMEI of the MME 2;

405. the eNB sends a wireless resource connection establishment response to the user terminal;

406. the user sends a joint attachment request to the eNB, and the eNB selects the MME2 to forward the attachment request message according to the value of the MME Global ID field in the radio resource establishment request message;

407. when MME2 receives the joint attachment request message, the VLR that sends the paging message, namely VLR1, sends the SGs location update message to rebuild the SGs port connection;

408. VLR1 receives the SGs port location updating request message, allocates TMSI for the user, and processes the location updating service flow;

409. after the VLR1 processes the update service, it sends a location response message to the MME2, carrying the user TMSI, and continues processing the call service flow. Because the VLR of the location update is just the VLR for processing the call service, the process of retrying or forwarding the roaming call does not need to be triggered at the moment;

410. after receiving the SGs port location update response message and continuing to execute the attach service flow, the MME2 sends a joint attach successful reception message to the user terminal;

411. VLR1 resends the paging message to MME2, carrying the user TMSI identification;

412. the MME2 receives the paging message from the VLR1 and initiates a normal CSFB fallback operation.

Compared with the traditional technology, the method solves the problems and defects that the CSFB called service may fail or the CSFB service has too long time delay under the condition that the SGs port of the MME POOL networking fails, improves the paging success rate of the CSFB service and reduces the time delay.

Fig. 7 is a block diagram of a first recovery apparatus for circuit domain fallback according to an embodiment of the present invention, and as shown in fig. 7, the first recovery apparatus 10 for circuit domain fallback includes:

a recovery request message receiving module 11, configured to receive a circuit domain recovery request message sent by a first mobile switching center;

the parsing module 12 is configured to parse the paging identifier of the user equipment carried in the circuit domain restoration request message;

a paging request message sending module 13, configured to send a paging request message to the ue according to the paging identifier, where the paging request message carries a unique identifier of a home mobility management entity;

a second connection request message receiving module 14, configured to receive a first connection request message sent by a base station, where the first connection request message carries information that the user equipment requests to connect to a local mobility management entity according to the paging request message;

a location update message sending module 15, configured to send a location update request message to a second mobile switching center, and configure the second mobile switching center as an access location after the circuit switched domain of the ue falls back.

Further, the first mobile switching center is the same as the second mobile switching center.

Optionally, the location update message sending module 15 further includes:

a first response message receiving module, configured to receive a first response message indicating that access is allowed and sent back by the second mobile switching center, where the first response message carries the temporary mobile subscriber identity code after the international mobile subscriber identity code is converted;

and a second response message sending module, configured to send a second response message of the first connection request message to the ue, where the second response message carries the temporary mobile subscriber identity.

Further, a field for storing a unique identifier of the mobility management entity is provided in the paging request message.

Further, the paging identifier of the ue is the international mobile subscriber identity of the ue.

Fig. 8 is a block diagram of a second recovery apparatus for circuit domain fallback according to an embodiment of the present invention, and as shown in fig. 8, the second recovery apparatus 20 for circuit domain fallback includes:

a paging request message receiving module 21, configured to receive a paging request message that is sent by a mobility management entity and carries a unique identifier of the mobility management entity;

a first connection request message sending module 22, configured to send a wireless connection request message carrying information of a mobility management entity that requests to connect to the unique identifier to a base station, so that the base station sends the first connection request message to the mobility management entity;

the access location determining module 23 is configured to determine, when receiving a second response message indicating that the second mobile switching center allows access, that the second mobile switching center is the access location after the circuit switched domain of the ue falls back, where the second response message is sent by the mobility management entity.

Optionally, the second recovery apparatus 20 for circuit domain fallback further includes:

a response message receiving module, configured to receive a response message of the wireless connection request message sent by the base station;

and a second connection request message sending module, configured to send a second connection request message carrying the international mobile subscriber identity of the ue to the base station, so that the base station sends the first connection request message to the mobility management entity.

Further, a field for storing a unique identifier of the mobility management entity is provided in the radio connection request message.

According to an embodiment of the present invention, there is provided a mobility management entity, including a memory, a first processor, and a computer program stored in the memory and executable on the processor, wherein the first processor implements the steps of the method for recovering a circuit domain fallback described above when executing the program.

According to another embodiment of the present invention, a user terminal is provided, which includes a memory, a second processor and a computer program stored in the memory and executable on the processor, wherein the second processor implements the steps of the method for recovering the circuit domain fallback when executing the program.

The Memory may be a magnetic disk, an optical disk, a usb disk, a Read-Only Memory (ROM), a Random Access Memory (RAM), or the like.

Fig. 9 is a block diagram of a circuit domain fallback paging system according to an embodiment of the present invention, where a direction indicated by an arrow in fig. 9 indicates a flow direction of information, and as shown in fig. 9, after detecting that a first mobility management entity 400 connected in advance is disconnected, a first mobile switching center 500 sends a recovery request message of circuit domain fallback to a second mobile switching center 100 by using a recovery request message sending module 51, and after receiving the message, a recovery request message receiving module 11 of the second mobile switching center 100 sends the message to a parsing module 12, parses a paging identifier of a ue in the message, and a paging request message sending module 13 sends a paging request message to a paging request message receiving module 21 of a corresponding ue 200 according to the paging identifier, where the paging request message carries a unique identifier of the second mobility management entity, after receiving the paging request message, the paging request message receiving module 21 sends a connection request message to the base station through the first connection request message sending module 22 to request to connect to the second mobility management entity 100 corresponding to the unique identifier, the base station 300 receives the connection request message through the first connection request message receiving module 31, then selects a connection object of the user terminal as the second mobility management entity 100 according to the unique identifier of the second mobility management entity, and sends a connection request message to the second connection request message receiving module 14 of the second mobility management entity through the second connection request message sending module 32, after receiving the message, the second connection request message receiving module 14 sends a location update request to the first mobile switching center 500 sending the circuit domain fallback request message through the location update message sending module 15, after the location update message receiving module 52 of the first mobile switching center 500 receives the location update request message, the first response message sending module 53 sends the first response message to the first response message receiving module 16 of the second mobile management entity, and the second response message sending module 17 sends a response message allowing access to the access location determining module 23 of the terminal user, so far, the user terminal completes the recovery service of circuit domain fallback, and then normal circuit domain fallback can be performed.

In this embodiment, the paging message added with the unique identifier of the mobility management entity is sent to the user terminal, so that the user terminal can send the unique identifier of the mobility management entity to the base station when sending the connection request message to the base station, so that the base station selects the mobility management entity accessed by the user terminal as the mobility management entity corresponding to the unique identifier according to the connection request message, thereby ensuring that the mobility management entity with the damaged interface is not re-established with the user terminal, and improving the success rate of recovery of circuit domain fallback.

The technical features of the embodiments described above may be arbitrarily combined, and for the sake of brevity, all possible combinations of the technical features in the embodiments described above are not described, but should be considered as being within the scope of the present specification as long as there is no contradiction between the combinations of the technical features.

The above-mentioned embodiments only express several embodiments of the present invention, and the description thereof is more specific and detailed, but not construed as limiting the scope of the invention. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the inventive concept, which falls within the scope of the present invention. Therefore, the protection scope of the present patent shall be subject to the appended claims.

Claims

1. A method for recovering circuit switched fallback is applied to a mobility management entity, and the method includes:

and sending a location updating request message to a second mobile switching center, and configuring the second mobile switching center as an access location after the circuit domain of the user terminal falls back.

2. The method of claim 1, wherein the first mobile switching center is the same as the second mobile switching center.

3. The method of claim 1, wherein the location update request message carries an international mobile subscriber identity of the ue, and the step of configuring the second msc as an access location after the cs domain fallback of the ue comprises:

receiving a first response message which is sent back by the second mobile switching center and indicates that access is allowed, wherein the first response message carries the temporary mobile subscriber identification code after the international mobile subscriber identification code is converted;

and sending a second response message of the first connection request message to the user terminal, wherein the second response message carries the temporary mobile user identification code.

4. A method according to any of claims 1 to 3, wherein a field is provided in the paging request message for storing a unique identifier of the mobility management entity.

5. A method according to any one of claims 1 to 3, wherein the paging identity of the user terminal is the international mobile subscriber identity of the user terminal.

6. A method for recovering circuit switched fallback is applied to a user equipment, and the method includes:

7. The method according to claim 6, wherein the step of sending a radio connection request message carrying information requesting to connect to the mobility management entity corresponding to the unique identifier to the base station further comprises:

and sending a second connection request message carrying the international mobile subscriber identity of the user terminal to a base station, so that the base station sends a first connection request message to the mobile management entity.

8. The method according to claim 6 or 7, wherein a field for storing a unique identifier of the mobility management entity is provided in the radio connection request message.

9. A first circuit switched fall recovery apparatus, comprising:

a recovery request message receiving module, configured to receive a circuit domain recovery request message carrying a paging identifier of a user equipment and sent by a first mobile switching center;

a paging request message sending module, configured to send a paging request message to the user equipment according to the paging identifier, where the paging request message carries a unique identifier of a home terminal mobility management entity;

and the location updating message sending module is used for sending a location updating request message to a second mobile switching center, and configuring the second mobile switching center as an access location after the circuit domain of the user terminal falls back.

10. A second apparatus for circuit switched fallback, the apparatus comprising:

11. A mobility management entity comprising a memory, a first processor and a computer program stored on the memory and executable on the processor, characterized in that the steps of the method according to any of claims 1 to 5 are implemented when the first processor executes said program.

12. A user terminal comprising a memory, a second processor and a computer program stored on the memory and executable on the processor, characterized in that the steps of the method according to any of claims 6 to 8 are implemented when the program is executed by the second processor.