CN106413009B

CN106413009B - Reverse single wireless voice call continuity switching method, device and communication system

Info

Publication number: CN106413009B
Application number: CN201510456191.7A
Authority: CN
Inventors: 吴孟泽
Original assignee: Nanning Fugui Precision Industrial Co Ltd
Current assignee: Nanning Fulian Fugui Precision Industrial Co Ltd
Priority date: 2015-07-29
Filing date: 2015-07-29
Publication date: 2019-12-31
Anticipated expiration: 2035-07-29
Also published as: CN106413009A

Abstract

A reverse single wireless voice call continuity switching method, device and system, the method includes receiving rSRVCC pre-request message from mobile switching center MSC; establishing an rSRVCC voice resource path according to the pre-request message; and sending a notification message containing the voice resource path information to the MSC so as to provide the voice resource path information to User Equipment (UE) through the MSC, so that the UE can acquire voice resources according to the provided voice resource path. Compared with the existing mode, the implementation mode of the invention reduces the complexity and the signaling data of the rSRVCC switching because the voice resource path is established in advance, improves the execution success rate of the switching, and effectively reduces the voice delay of the rSRVCC switching, especially the voice delay of the rSRVCC switching under the roaming state.

Description

Reverse single wireless voice call continuity switching method, device and communication system

Technical Field

The invention relates to the technical field of communication, in particular to a reverse single wireless voice call continuity switching method, a reverse single wireless voice call continuity switching device and a communication system.

Background

In the existing mobile communication service, the method can be divided into the following steps according to the network bearer mechanism:

1. services carried by a Circuit Switched (CS) domain, such as voice telephony, short message and supplementary services, etc.;

2. services carried in a Packet Switching (PS) domain include data services and session services, and the session services may also be referred to as Voice over Internet Protocol (VoIP) services;

the voice service may be carried in the CS domain or the PS domain, and due to the problems of signal coverage, network load, and the like, the voice service may be switched between the CS domain and the PS domain. For example, when a user makes a Voice Call in a CS domain of 2G or 3G, due to the load of the CS network and other problems, the Call needs to be converted from the CS domain to LTE or UTRAN, which is called Reverse Single Radio Voice Call Continuity (rSRVCC), and the rSRVCC handover is essentially a handover from the CS domain to the PS domain.

The PS domain is further divided into a Home network packet domain (PS domain, PS (h)) and a visited network packet domain (PS domain, PS (v)), and when the CS domain is switched to the PS (v) domain or the PS (h) domain, it is easy to cause a sound delay in voice communication, wherein the sound delay in switching to the PS (v) domain is the most serious. In the document 3GPP-TR23.885[2], it is mentioned that the voice delay may not exceed 300ms in roaming (roaming) or non-roaming (non-roaming) situations, but in the present situation, the voice resource establishment often causes too long delay due to busy network, especially in roaming situations.

Disclosure of Invention

In view of the foregoing, an object of the present invention is to provide a reverse single radio voice call continuity handover method, apparatus and communication system for reducing voice delay of rSRVCC handover.

In order to achieve the above object, an embodiment of the present invention provides a reverse single radio voice call continuity rSRVCC handover method, which is applied in a first mobility management entity mme (v) in a visited network packet ps (v) domain, and the method includes: receiving an rSRVCC pre-request message from a Mobile Switching Center (MSC); establishing an rSRVCC voice resource path according to the pre-request message; and sending a notification message containing the voice resource path information to the MSC so as to provide the voice resource path information to User Equipment (UE) through the MSC, so that the UE can acquire voice resources according to the provided voice resource path.

Preferably, the pre-request message is a request message sent by the MSC after the MSC knows that the UE is connected to the base station BS in the CS domain and confirms that the UE can perform rSRVCC handover.

Preferably, the step of establishing an rSRVCC voice resource path according to the pre-request message specifically includes: sending the pre-request message to a first IP multimedia system, ims, (v) in the ps (v) domain; receiving a response message of the IMS (v), wherein the response message comprises information of whether the IMS (v) can provide voice resources or not; and according to the response message, informing a first Service Gateway (SGW) (v) and a first packet data gateway (PGW) (v) in the PS (v) domain to establish an rSRVCC voice resource path.

Preferably, the step of establishing an rSRVCC voice resource path according to the pre-request message further includes: sending the pre-request message to a second IP Multimedia System (IMS) (h) in a domain (PS) (h) through a second Mobility Management Entity (MME) (h) in the domain of a home network Packet (PS) (h); after the ims (h) sends a response message to the second mme (h), the first mme (v) notifies the second serving gateway sgw (h) and the second packet data gateway pgw (h) in the ps (h) domain to establish the rSRVCC voice resource path through the second mme (h).

The embodiment of the invention also provides a reverse single wireless voice call continuity (rSRVCC) switching method, which is applied to a second Mobility Management Entity (MME) (h) in a home network Packet (PS) (h) domain, and comprises the following steps: receiving an rSRVCC pre-request message of a first mobility management entity MME (v) in a domain of a visited network packet PS (v); pre-establishing an rSRVCC voice resource path according to the rSRVCC pre-request message; and (v) sending a notification message containing the voice resource path information to a Mobile Switching Center (MSC) through the first MME (mobility management entity), so that the voice resource path information is provided to a User Equipment (UE) through the MSC, and the UE can acquire voice resources according to the provided voice resource path.

Preferably, the resource request message is a request message of the first mme (v) in response to the MSC pre-request message; the MSC pre-request message is a request message sent by the MSC after the MSC learns that the UE is connected with the base station BS of the CS domain and confirms that the UE can execute rSRVCC switching.

Preferably, the step of establishing an rSRVCC voice resource path in advance according to the resource request message specifically includes: sending the pre-request message to a second IP multimedia system, ims, (h) in the ps (h) domain; receiving a response message of the IMS (h), wherein the response message comprises information of whether the IMS (h) can provide voice resources or not; and according to the response message, informing a second Service Gateway (SGW) (h) and a second packet data gateway (PGW) (h) in the PS (h) domain to establish the rSRVCC voice resource path.

The embodiment of the invention also provides a reverse single wireless voice call continuity (rSRVCC) switching method, which is applied to a Mobile Switching Center (MSC), and the method comprises the following steps: sending an rSRVCC pre-request message to a Mobility Management Entity (MME), so that the MME establishes an rSRVCC voice resource path according to the pre-request message; receiving a first notification message of the MME, wherein the first notification message comprises the voice resource path information established by the MME; saving the voice resource path information; receiving a second notification message of the BS, wherein the second notification message comprises third information that the UE requests rSRVSS handover; and sending the voice resource path information to the UE according to the second notification message so that the UE can acquire voice resources through the voice resource path information.

Preferably, the step of sending the rSRVCC pre-request message to the mobility management entity MME further includes a confirmation step before the step, which specifically includes: receiving a third notification message from the BS, the third notification message including first information that the BS and the UE establish a connection; after receiving the third notification message, acquiring second information of the UE through a Home Subscriber System (HSS); and confirming whether the UE can execute rSRVSS switching or not according to the second information.

Preferably, the MME comprises a first mobility management entity MME (v) in the visited network packet ps (v) domain and a first mobility management entity MME (h) in the home network packet ps (h) domain; the step of sending the rSRVCC pre-request message to a mobility management entity MME, so that the step of the MME establishing an rSRVCC voice resource path according to the pre-request message specifically includes: sending an rSRVCC pre-request message to the first mme (v) to notify, by the first mme (v), a first serving gateway sgw (v) and a first packet data gateway sgw (v) in the ps (v) domain to establish an rSRVCC voice resource path; receiving a fourth notification message of the first MME (v), wherein the fourth notification message comprises voice resource path information of SGW/PGW (v).

Preferably, the step of sending the rSRVCC pre-request message to a mobility management entity MME so that the MME establishes an rSRVCC voice resource path according to the pre-request message further includes: (v) sending an rSRVCC pre-request message to the second mme (h) by sending the first mme (v) to notify a second serving gateway sgw (h) and a second packet data gateway sgw (h) in the ps (h) domain to establish an rSRVCC voice resource path through the second mme (h); receiving, by the first MME, (v) a fifth notification message of the second MME (h), the fifth notification message including the voice resource path information of SGW (h)/SGW (h).

The embodiment of the invention also provides a mobility management entity MME, which is applied to the access network packet PS (v) domain, and the device comprises: the device comprises a first receiving module, an establishing module and a first sending module, wherein: a first receiving module, configured to receive a reverse single radio voice call continuity rSRVCC pre-request message from a mobile switching center MSC; the establishing module is used for establishing an rSRVCC voice resource path according to the pre-request message; a first sending module, configured to send a notification message including the voice resource path information to the MSC, so as to provide the voice resource path information to a user equipment UE through the MSC, so that the UE can obtain voice resources according to the provided voice resource path.

Preferably, the establishing module further includes a second sending module, a second receiving module and a first notifying module, wherein: the second sending module is configured to send the pre-request message to a first IP multimedia system ims (v) in the ps (v) domain; the second receiving module is configured to receive a response message of the ims (v), where the response message includes information about whether the ims (v) can provide voice resources; the first notifying module is configured to notify the first serving gateway sgw (v) and the first packet data gateway pgw (v) in the ps (v) domain to establish an rSRVCC voice resource path according to the response message.

Preferably, the establishing module further includes a third sending module and a second notifying module: the third sending module is configured to send the pre-request message to a second IP multimedia system ims (h) in a home network packet ps (h) domain through a second mobility management entity mme (h) in the ps (h) domain; the second notifying module is configured to notify, by the second mme (h), a second serving gateway sgw (h) and a second packet data gateway pgw (h) in the ps (h) domain to establish an rSRVCC voice resource path after the ims (h) sends a response message to the second mme (h).

The embodiment of the invention also provides a mobility management entity MME, which is applied to the home network packet PS (h), and the device comprises: a first receiving module, configured to receive an rSRVCC pre-request message of a first mobility management entity mme (v) in a visited network packet ps (v) domain; the establishing module is used for establishing an rSRVCC voice resource path in advance according to the pre-request message; and a first sending module, configured to send a notification message containing the voice resource path information to a mobile switching center MSC through the first mme (v), so as to provide the voice resource path information to a user equipment UE through the MSC, so that the UE can obtain voice resources according to the provided voice resource path.

Preferably, the establishing module further includes a second sending module, a second receiving module and a notifying module, wherein: the second sending module is configured to send the received resource request message to a second IP multimedia system ims (h) in the ps (h) domain; the second receiving module is configured to receive a response message of the ims (h), where the response message includes information about whether the ims (h) can provide voice resources; and the notifying module is configured to notify the second serving gateway sgw (h) and the second packet data gateway pgw (h) in the ps (h) domain to establish an rSRVCC voice resource path according to the response message.

The embodiment of the invention also provides a mobile switching center MSC, and the device comprises: a first sending module, configured to send an rSRVCC pre-request message to a mobility management entity MME, so that the MME establishes an rSRVCC voice resource path according to the pre-request message; a first receiving module, configured to receive a first notification message of the MME, where the first notification message includes the voice resource path information established by the MME; the storage module is used for storing the voice resource path information; a second receiving module, configured to receive a second notification message of the BS, where the second notification message includes third information that the UE requests srvss handover; and the second sending module is used for sending the voice resource path information to the UE according to the second notification message so that the UE can acquire voice resources through the voice resource path information.

Preferably, the apparatus further comprises a third receiving module, an obtaining module and a confirming module, wherein: the third receiving module is configured to receive a third notification message from the BS, where the third notification message includes first information for establishing a connection between the BS and the UE; the acquiring module is used for acquiring second information of the UE through a Home Subscriber System (HSS) after receiving the third notification message; and the confirming module is used for confirming whether the UE can execute rSRVSS switching or not according to the second information.

Preferably, the MME comprises a first mobility management entity MME (v) in the visited network packet ps (v) domain and a second mobility management entity MME (h) in the home network packet ps (h) domain; the first sending module comprises a third sending module and a fourth receiving module, wherein: the first sending module comprises a third sending module and a fourth sending module, wherein: the third sending module, configured to send an rSRVCC pre-request message to the first mme (v) to notify, by the first mme (v), a first serving gateway sgw (v) and a first packet data gateway sgw (v) in the ps (v) domain to establish an rSRVCC voice resource path; the fourth sending module is configured to send, by the first mme (v), an rSRVCC pre-request message to the second mme (h) to notify, by the second mme (h), a second serving gateway sgw (h) and a second packet data gateway sgw (h) in the ps (h) domain to establish an rSRVCC voice resource path.

Preferably, the first sending module further includes a fourth receiving module and a fifth receiving module, wherein: the fourth receiving module is configured to receive a fourth notification message of the first mme (v), where the fourth notification message includes voice resource path information of an SGW/pgw (v); the fifth receiving module is configured to receive a fifth notification message of the second mme (h) through the first mme (v), where the fifth notification message includes the voice resource path information of the SGW/pgw (h).

An embodiment of the present invention further provides a communication system, including: a first mobility management entity MME (v), a second mobility management entity MME (h), a mobile switching center MSC, wherein:

the MSC is configured to send an rSRVCC pre-request message to the first mme (v) and the second mme (h), so that the first mme (v) and the second mme (h) establish an rSRVCC voice resource path according to the pre-request message; receiving a first notification message of a first MME (v), wherein the first notification message comprises the voice resource path information established by the first MME (v) and a second MME (h); saving the voice resource path information; receiving a second notification message of the BS, wherein the second notification message comprises third information that the UE requests rSRVSS handover; and sending the voice resource path information to the UE according to the second notification message so that the UE can acquire voice resources through the voice resource path information;

the first MME (v) serving in a visited network packet PS (v) domain, for receiving the rSRVCC pre-request message of the MSC; establishing an rSRVCC voice resource path according to the pre-request message; sending a notification message containing the voice resource path information to the MSC;

the second MME (h) serves in a home network packet PS (h) domain and is used for receiving the rSRVCC pre-request message forwarded by the first MME (v); pre-establishing an rSRVCC voice resource path according to the resource request message; (v) sending a notification message containing the voice resource path information to the MSC via the first mme.

Preferably, the first mme (v) is further configured to send the pre-request message to a first IP multimedia system ims (v) in the ps (v) domain according to the pre-request message; receiving a response message of the IMS (v), wherein the response message comprises information of whether the IMS (v) can provide voice resources or not; and according to the response message, informing a first Service Gateway (SGW) (v) and a first packet data gateway (PGW) (v) in the PS (v) domain to establish an rSRVCC voice resource path.

Preferably, the second mme (h) is further configured to send the pre-request message to a second IP multimedia system ims (h) in the ps (h) domain according to the pre-request message; receiving a response message of the IMS (h), wherein the response message comprises information of whether the IMS (h) can provide voice resources or not; and according to the response message, informing a second Service Gateway (SGW) (h) and a second packet data gateway (PGW) (h) in the PS (h) domain to establish the rSRVCC voice resource path.

Preferably, the system further comprises an evolved node B eNB, and the UE is connected with the eNB and then acquires voice resources of the IP multimedia system IMS according to the voice resource path information.

The method, device and system for switching rSRVCC of the embodiment of the invention, when confirming that UE is connected with BS of CS domain, namely, the MSC sends a pre-request message of rSRVCC to MME, so that MME informs SGW and PGW to pre-establish voice resource path, therefore, when UE needs to be switched from CS domain to PS domain (namely, rSRVCC switching), IMS voice resource can be rapidly acquired by using the pre-established voice resource path to complete rSRVCC switching, thereby effectively reducing voice delay of rSRVCC switching.

Compared with the existing mode, the implementation mode of the invention reduces the complexity and the signaling data of the rSRVCC switching because the voice resource path is established in advance, improves the execution success rate of the switching, and effectively reduces the voice delay of the rSRVCC switching, especially the voice delay of the rSRVCC switching under the roaming state.

The invention is described in detail below with reference to the drawings and specific examples, but the invention is not limited thereto.

Drawings

Fig. 1 is an architecture diagram of a communication system according to an embodiment of the present invention.

Fig. 2 is a network architecture diagram of rSRVCC handover in roaming state.

Fig. 3 is a flowchart illustrating the operation of performing rSRVCC handover in roaming status in the communication system according to the embodiment of the present invention.

FIG. 4 is a functional block diagram of an MME according to an embodiment of the invention.

FIG. 5 is a block diagram of an MME according to another embodiment of the invention.

FIG. 6 is a functional block diagram of an MME according to another embodiment of the present invention.

Fig. 7 is a functional block diagram of an MSC in accordance with another embodiment of the present invention.

Fig. 8 is a flowchart of the operation of the MSC of fig. 7.

Fig. 9 is a functional block diagram of an MSC in accordance with another embodiment of the present invention.

Fig. 10 is a flowchart of the operation of the MSC of fig. 9.

Fig. 11 is a flowchart of an rSRVCC handover method according to an embodiment of the present invention.

Fig. 12 is a flowchart of an rSRVCC handover method according to another embodiment of the present invention.

FIG. 13 is a flowchart illustrating a corresponding operation of the handover method of FIG. 12 in a system environment.

Fig. 14 is a flowchart of an rSRVCC handover method according to another embodiment of the present invention.

FIG. 15 is a flowchart illustrating a corresponding operation of the handover method of FIG. 14 in a system environment.

Fig. 16 is a flowchart of an rSRVCC handover method according to another embodiment of the present invention.

FIG. 17 is a flowchart illustrating a corresponding operation of the handover method of FIG. 16 in a system environment.

Fig. 18 is a flowchart of an rSRVCC handover method according to another embodiment of the present invention.

FIG. 19 is a flowchart illustrating a corresponding operation of the handover method of FIG. 18 in a system environment.

Description of the main elements

Communication system 100

MSC 110

First MME (v), MME 112

Second MME (h), MME114

Memory cells 1120, 1142, 1100

Processing units 1122, 1144, 1102

Communication units 1124, 1146

First receiving module 1126, 1148, 1108

Building blocks 1128, 1150

First sending module 1130, 1152, 1106

Second transmission module 1132, 1154, 1114

Second receiving module 1134, 1156, 1112

First notification module 1136, 1158

Third sending module 1138, 1106A

Second notification module 1140

Signal transmission module 1104

Saving module 1110

Third receiving module 1116A

Acquisition module 1116B

Confirmation module 1116C

Fourth sending module 1106B

Fourth receiving module 1108A

Fifth receiving module 1108B

The following detailed description will further describe the present invention with reference to the above drawings, it should be noted that the above modules may use the same names, but their contents are not necessarily the same, for example, the first receiving module 1130 and the first receiving module 1106 are different, and it should be understood that the contents of the respective modules should be determined by the description thereof in the detailed description.

Detailed Description

Technical words and their english abbreviations that may be involved in this embodiment:

a base station: BS, Base Station

An evolution base station: eNB, Evolved NodeB

Circuit bearer domain: CS, Circuit Switch

Packet bearer domain: PS, Packet Switch

Attributing a subscriber system: HSS, Home Subscriber System

Based on the IP multimedia system: IMS, IP Multimedia System

A mobility management entity: MME, Mobile Management Entity

A mobile switching center: MSC, Mobile Switching Center

A packet data network gateway: PGW/PDNGW, Packet Data Network Gateway

The service gateway: SGW, Serving Gateway

GPRS service support node: SGSN, Serving GPRS Support Node

Reverse single wireless voice call continuity: rSRVCC, Reverse Single Radio Voice Continuity

A user terminal: UE, User Equipment

Home network: (h) home network

Accessing a network: (v) visit network

Roaming: roaming

To facilitate understanding of those skilled in the art, the following first describes a communication system for the rSRVCC handover, and fig. 1 is an architecture diagram of a communication system 100 according to the present embodiment, where the communication system 100 includes an MSC110, a first mme (v)112, a second mme (v)114, and an eNB, where:

the MSC110 is configured to send an rSRVCC pre-request message to the first mme (v) (112) and the second mme (h) (114), so that the first mme (v) (112) and the second mme (h) (114) establish an rSRVCC voice resource path according to the pre-request message; receiving a first notification message of a first MME (v)112, wherein the first notification message comprises the voice resource path information established by the first MME (v)112 and a second MME (h) 114; saving the voice resource path information; receiving a second notification message of the BS, wherein the second notification message comprises third information that the UE requests rSRVSS handover; and sending the voice resource path information to the UE according to the second notification message so that the UE can acquire voice resources through the voice resource path information;

the first mme (v)112, serving in a visited network packet ps (v) domain, for receiving an rSRVCC pre-request message for the MSC 110; sending the pre-request message to a first IP multimedia system, ims, (v) in the ps (v) domain; receiving a response message of the IMS (v), wherein the response message comprises information of whether the IMS (v) can provide voice resources or not; according to the response message, notifying a first Service Gateway (SGW) (v) and a first packet data gateway (PGW) (v) in the PS (v) domain to establish an rSRVCC voice resource path; sending a notification message containing the voice resource path information to the MSC 110;

the second mme (h)114, serving in a home network packet ps (h) domain, is configured to receive the rSRVCC pre-request message forwarded by the first mme (v) 112; sending the pre-request message to a second IP multimedia system, ims, (h) in the ps (h) domain; receiving a response message of the IMS (h), wherein the response message comprises information of whether the IMS (h) can provide voice resources or not; according to the response message, notifying a first Service Gateway (SGW) (v) and a first packet data gateway (PGW) (v) in the PS (v) domain to establish an rSRVCC voice resource path; sending a notification message containing the voice resource path information to the MSC110 via the first MME (v) 112.

And after the UE and the eNB are accessed, the voice resource of the IP multimedia system IMS is obtained according to the voice resource path information.

The working flow of the communication system 100 in the roaming state is described below with reference to fig. 2 and 3, so as to facilitate a clear understanding of the working principle of the communication system 100 for those skilled in the art.

Fig. 2 is a network architecture diagram of rSRVCC handover in roaming state. When the UE accesses the domain of the home network CS (h), the UE can be switched to the domain of the visited network PS (v), and can also be switched to the domain of the home network PS (h) through the domain of PS (v). Fig. 3 is a flowchart illustrating the operation of the communication system 100 performing rSRVCC handover in UE roaming state. It is noted that for clarity, a plurality of external devices may be involved, as described earlier.

Step S110, the UE accesses the BS;

step S112, the BS informs the MSC that the MSC has accessed the UE;

step S114, MSC sends request message to HSS to obtain UE related information from HSS;

step S116, MSC receives feedback message of HSS, the feedback message includes whether UE can execute rSRVCC switching;

step S118, MSC sends rSRVCC pre-request message to first MME (v);

step S120, the first MME (v) sends the pre-request message to IMS (v), and the IMS (v) judges whether available voice resources exist;

step S122, the first MME (v) receives the feedback message of IMS (v);

step S124, the first mme (v) further forwards the pre-request message to the second mme (h);

step S126, the second MME (h) sends the pre-request message to IMS (h), and IMS (h) judges whether available voice resources exist;

step S128, the second MME (h) receives the feedback message of IMS (h);

step S130, the first MME (v) and the second MME (h) establish the voice resource path of rSRVCC roaming through the corresponding SGW (v), PGW (v), SGW (h) and PGW (h);

step S132, notifying the established voice resource path information to the MSC;

step S134, MSC waits for switching request of rSRVCC of BS to start switching of rSRVCC roaming;

and step S136, switching rSRVCC roaming.

After the switching of the rSRVCC roaming is completed, the UE may access and acquire the voice resources of ims (v) and ims (h) through the paths of SGW/pgw (v) and SGW/pgw (h) by the eNB of ps (v).

In the embodiment of the present invention, the MSC may be replaced by other network elements, such as SGSN; the PWG may be replaced by the PDN-GW, or by other devices, and the invention is not limited to the above-listed devices.

FIG. 4 is a functional block diagram of the MME 112 according to an embodiment of the invention. The MME 112, which is used in the visited network packet ps (v) domain, includes a storage unit 1120, a processing unit 1122, and a communication unit 1124. The MME 112 further includes a first receiving module 1126, an establishing module 1128, and a first sending module 1130 configured to be executed by one or more processors (processing unit 1122 in this embodiment) to complete the present invention. The modules 1126-1130 of the present invention are computer program segments for performing a specific function and are stored in the storage unit 1120. Wherein:

a first receiving module 1126, configured to receive an rSRVCC pre-request message of an MSC. In this embodiment, the pre-request message is a request message sent by the MSC after the MSC knows that the UE is connected to the base station BS in the CS domain and confirms that the UE can perform rSRVCC handover; the pre-request message also includes number information of the UE in the CS domain.

An establishing module 1128, configured to establish an rSRVCC voice resource path according to the pre-request message. In this embodiment, after receiving the pre-request message, the IMS in ps (v) and ps (h) sends a request to determine whether voice resources are available, and after obtaining an active response, notifies the interfaces to establish a connection tunnel, that is, a voice resource path. It should be noted that, multiple connection tunnels may be established, and the quality of each connection tunnel may be detected.

A first sending module 1130, configured to send a notification message including the voice resource path information to the MSC, so as to provide the voice resource path information to a user equipment UE through the MSC, so that the UE can obtain voice resources according to the provided voice resource path. In this embodiment, after the voice resource path information is sent to the MSC, the MSC temporarily stores the voice resource information and waits for a request packet of the UE, and when the UE requests to switch from the CS domain to the PS domain, the UE provides the voice resource information to the UE, and the UE rapidly obtains the voice resource of the IMS through the eNB according to the voice resource path information, thereby reducing the voice delay and the time delay of the rSRVCC handover.

FIG. 5 is a block diagram of the MME 112 according to another embodiment of the invention. The MME 112, which is used in the visited network packet ps (v) domain, includes a storage unit 1120, a processing unit 1122, and a communication unit 1124. The MME 112 further includes a first receiving module 1126, an establishing module 1128, and a first sending module 1130, where the establishing module 1128 includes a second sending module 1132, a second receiving module 1134, a first notifying module 1136, a third sending module 1138, and a second notifying module 1140. The modules are configured to be executed by one or more processors (processing unit 1122 in this embodiment) to implement the present invention. The modules 1126-1140 of the present invention are computer program segments for performing a specific function and are stored in the storage unit 1120. Wherein:

An establishing module 1128, configured to establish an rSRVCC voice resource path according to the pre-request message. The establishing module 1128 specifically includes: including a second sending module 1132, a second receiving module 1134, a first notifying module 1136, a third sending module 1138, and a second notifying module 1140.

It should be noted that the second sending module 1132, the second receiving module 1134 and the first notifying module 1136 are used to enable the UE to obtain ims (v) voice resources in the domain of the access network ps (v); the third sending module 1138 and the second notifying module 1140 are for enabling the UE to acquire ims (h) voice resources in the ps (h) domain of the home network. The voice service provided by the IMS (h) voice resource in the domain of the home network PS (h) has lower time delay.

The second sending module 1132, configured to send the pre-request message to a first IP multimedia system ims (v) in the ps (v) domain. In this embodiment, after receiving the pre-request message, ims (v) detects whether the visited network has available Voice resources, i.e. whether VOIP (Voice over Internet Protocol) service can be provided, and responds to MME 112 with the detection result.

The second receiving module 1134 is configured to receive a response message of the ims (v), where the response message includes information about whether the ims (v) can provide voice resources.

The first notifying module 1136 is configured to notify the first serving gateway sgw (v) and the first packet data gateway pgw (v) in the ps (v) domain to establish an rSRVCC voice resource path according to the response message. In this embodiment, the first notifying module 1136 may establish a plurality of rSRVCC voice resource paths according to the number of interfaces between the swg (v) and the pgw (v).

The third sending module 1138 is configured to send the pre-request message to a second IP multimedia system ims (h) in a home network packet ps (h) domain through a second mobility management entity mme (h) in the ps (h) domain. In this embodiment, after receiving the pre-request message, ims (h) detects whether there is an available Voice resource in the home network, i.e. whether VOIP (Voice over Internet Protocol) service can be provided, and responds to MME 112 with the detection result.

The second notifying module 1140 is configured to notify, through the second mme (h), a second serving gateway sgw (h) and a second packet data gateway pgw (h) in the ps (h) domain to establish an rSRVCC voice resource path after the ims (h) sends a response message to the second mme (h). In this embodiment, the second notification module 1140 may establish a plurality of rSRVCC voice resource paths according to the number of interfaces between the swg (h) and the pgw (h).

The MME 112 in the implementation of the present invention further includes a first sending module 1130, configured to send a notification message including srvcc voice resource path resource information established by the first notifying module 1136 and the second notifying module 1140 to the MSC, so as to provide the voice resource path information to a user equipment UE through the MSC, so that the UE obtains voice resources according to the provided voice resource path. In this embodiment, after the voice resource path information is sent to the MSC, the MSC temporarily stores the voice resource information and waits for a request packet of the UE, and when the UE requests to switch from the CS domain to the PS domain, the UE provides the voice resource information to the UE, and the UE rapidly obtains the voice resource of ims (v) or ims (h) through the eNB according to the voice resource path information and preferentially obtains the voice resource of ims (h), thereby reducing the voice delay of the rSRVCC handover, i.e., the time delay.

FIG. 6 is a block diagram of an MME114 according to another embodiment of the invention. The MME114 is applied in the visited network packet ps (h) domain, and includes a storage unit 1142, a processing unit 1144, and a communication unit 1146. The MME114 further includes a first receiving module 1148, an establishing module 1150, and a first sending module 1152, where the establishing module 1148 specifically includes a second sending module 1154, a second receiving module 1156, and a notifying module 1158. The modules are configured to be executed by one or more processors (processing unit 1144 in this embodiment) to implement the invention. The modules 1148 to 1158 in the embodiments of the present invention are computer program segments for performing a specific function, and are stored in the storage unit 1142. Wherein:

a first receiving module 1148, configured to receive an rSRVCC pre-request message of a first mobility management entity mme (v)112 in a visited network packet ps (v) domain. In this embodiment, the resource request message is a request message of the first mme (v)112 responding to the MSC110 pre-request message; the MSC pre-request message is a request message sent by the MSC110 after knowing that the UE is connected to the BS in the CS domain and confirming that the UE can perform rSRVCC handover. The pre-request message also includes the number of the UE in the CS domain, etc.

The establishing module 1150, according to the pre-request message, pre-establishes an rSRVCC voice resource path. In this embodiment, after receiving the pre-request message, the ue sends a request to ims (h) in ps (h) to determine whether voice resources are available, and after obtaining an active response, notifies the interfaces to establish a connection tunnel, i.e., a voice resource path. It should be noted that, multiple connection tunnels may be established, and the quality of each connection tunnel may be detected. The establishing module 1148 specifically includes a second sending module 1154, a second receiving module 1156, and a notifying module 1158. A second sending module 1154, configured to send the received resource request message to a second IP multimedia system ims (h) in the ps (h) domain; a second receiving module 1156, configured to receive a response message of the ims (h), where the response message includes information about whether the ims (h) can provide voice resources; a notifying module 1158, configured to notify the second serving gateway sgw (h) and the second packet data gateway pgw (h) in the ps (h) domain to establish an rSRVCC voice resource path according to the response message.

A first sending module 1152, configured to send a notification message containing the voice resource path information to a mobile switching center MSC110 through the first mme (v)112, so as to provide the voice resource path information to a user equipment UE through the MSC110, so that the UE obtains voice resources according to the provided voice resource path. In this embodiment, after the voice resource path information is sent to the MSC110, the MSC110 will temporarily store the voice resource information and wait for the request packet of the UE, when the UE requests to switch from the CS domain to the PS domain, the UE provides the information to the UE, and the UE rapidly obtains the voice resource of the ims (h) through the eNB according to the voice resource path information, thereby reducing the voice delay, i.e. the time delay, of the rSRVCC handover.

Fig. 7 is a functional block diagram of the MSC110 according to another embodiment of the present invention. Fig. 8 is a flowchart of the operation of the MSC of fig. 7. The MSC110 includes a storage unit 1100, a processing unit 1102, and a signal transmission unit 1104. The MSC110 further includes a first sending module 1106, a first receiving module 1108, a saving module 1110, a second receiving module 1112, and a second sending module 1114. The modules are configured to be executed by one or more processors (processing unit 1102 in this embodiment) to implement the present invention. The modules 1106 to 1114 in the embodiments of the present invention are computer program segments for performing a specific function, and are stored in the storage unit 1100.

A first sending module 1106, configured to send an rSRVCC pre-request message to a mobility management entity MME 112, so that the MME establishes an rSRVCC voice resource path according to the pre-request message; of course, the sending of the pre-request message is premised on confirming that the UE supports the rSRVCC handover, i.e., the UE supports the CS domain to PS domain handover.

A first receiving module 1108, configured to receive a first notification message of the MME 112, where the first notification message includes the voice resource path information established by the MME. In this embodiment, after receiving the pre-request message from the first sending module 1106, the MME 112 will notify the SGW and the PGW to establish the voice resource path in advance, and after the establishment is completed, send the established path information to the local MSC110, and the local MSC receives the path information through the first receiving module 1108.

The saving module 1110 is configured to save the voice resource path information. In this embodiment, the saving module 1110 may be various memories, registers, and the like.

A second receiving module 1112, configured to receive a second notification message of the BS, where the second notification message includes third information that the UE requests rsrvs handover. Specifically, when the BS detects that the UE is about to perform handover, the BS sends a handover request packet, i.e., a second notification message, which is received by the MSC110 through the second receiving module 1112.

A second sending module 1114, configured to send the voice resource path information to the UE according to the second notification message, so that the UE obtains a voice resource through the voice resource path information. The second sending module 1114 sends the voice resource path information in the storing module 1110 to the UE, and the UE obtains the voice resource of the IMS through the eNB according to the voice resource path information, so as to reduce the voice delay of the rSRVCC handover, i.e. the delay in time.

Fig. 9 is a functional block diagram of the MSC110 according to another embodiment of the present invention. Fig. 10 is a flowchart of the operation of the MSC of fig. 9. The MSC110 includes a storage unit 1100, a processing unit 1102, and a signal transmission unit 1104. The MSC110 further includes a third receiving module 1116A, an obtaining module 1116B, a confirming module 1116C, a first sending module 1106, a first receiving module 1108, a saving module 1110, a second receiving module 1112, and a second sending module 1114, where the first sending module 1106 includes the third sending module 1106A and the fourth sending module 1106B, and the first receiving module 1108 further includes a fourth receiving module 1108A and a fifth receiving module 1108B. The modules are configured to be executed by one or more processors (processing unit 1102 in this embodiment) to implement the present invention. The modules 1106 to 1116 in the embodiments of the present invention are computer program segments for performing a specific function, and are stored in the storage unit 1100.

It should be noted that, the third receiving module 1116A, the obtaining module 1116B, and the confirming module 1116C are used to confirm whether the UE supports the rSRVCC handover at an earlier stage; in roaming state, there is a roaming procedure, e.g. from the visited network ps (v) domain to the home network ps (h) domain, thus involving a first mme (v)112 in the ps (v) domain and a second mme (h)114 in the ps (h) domain.

The third receiving module 1116A is configured to receive a third notification message from the BS, where the third notification message includes first information that the BS and the UE establish a connection.

The obtaining module 1116B is configured to obtain the second information of the UE through the HSS after receiving the third notification message.

The determining module 1116C is configured to determine whether the UE can perform rsrvs handover according to the second information.

A first sending module 1106, configured to send an rSRVCC pre-request message to a mobility management entity MME, where the first sending module 1106 includes a third sending module 1106A and a fourth sending module 1106B: a third sending module 1106A is configured to send an rSRVCC pre-request message to the first mme (v) to notify, by the first mme (v), a first serving gateway sgw (v) and a first packet data gateway sgw (v) in the ps (v) domain to establish an rSRVCC voice resource path; a fourth sending module 1106B is configured to send the first mme (v) an rSRVCC pre-request message to the second mme (h) to notify, via the second mme (h), a second serving gateway sgw (h) and a second packet data gateway sgw (h) in the ps (h) domain to establish an rSRVCC voice resource path.

A first receiving module 1108, configured to receive a first notification message of the MME, where the first notification message includes the voice resource path information established by the MME. The first receiving module 1108 further includes a fourth receiving module 1108A and a fifth receiving module 1108B: a fourth receiving module 1108A is configured to receive a fourth notification message of the first mme (v), where the fourth notification message includes the voice resource path information of SGW/pgw (v); the fifth receiving module 1108B is configured to receive a fifth notification message of the second mme (h) through the first mme (v), where the fifth notification message includes the voice resource path information of the SGW/pgw (h).

A saving module 1110, configured to save the voice resource path information received by the fourth receiving module 1108A and the fifth receiving module 1108B. In this embodiment, the saving module 1110 may be various memories, registers, and the like.

Fig. 11 is a flowchart of an rSRVCC handover method according to an embodiment of the present invention. It should be noted that, the embodiment of the present invention is mainly described with the MME 112, and when understanding the embodiment, reference may be made to the embodiment corresponding to fig. 4.

Step S210, receiving an rSRVCC pre-request message from the mobile switching center MSC 110. The pre-request message is a request message sent by the MSC110 after knowing that the UE is connected to the base station BS of the CS domain and confirming that the UE can execute rSRVCC handover; the pre-request message also includes number information of the UE in the CS domain.

Step S212, according to the pre-request message, establishing an rSRVCC voice resource path. In this embodiment, after receiving the pre-request message, the IMS in ps (v) and ps (h) sends a request to determine whether voice resources are available, and after obtaining an active response, notifies the interfaces to establish a connection tunnel, that is, a voice resource path. It should be noted that, multiple connection tunnels may be established, and the quality of each connection tunnel may be detected.

Step S214, sending a notification message including the voice resource path information to the MSC110, so as to provide the voice resource path information to the UE through the MSC110, so that the UE can obtain the voice resource according to the provided voice resource path. In this embodiment, after the voice resource path information is sent to the MSC110, the MSC temporarily stores the voice resource information and waits for a request packet of the UE, and when the UE requests to switch from the CS domain to the PS domain, the UE provides the voice resource information to the UE, and the UE rapidly obtains the voice resource of the IMS through the eNB according to the voice resource path information, thereby reducing the voice delay and the time delay of the rSRVCC handover.

Fig. 12 is a flowchart of an rSRVCC handover method according to another embodiment of the present invention. It should be noted that, in the embodiment of the present invention, the MME 112 in the ps (v) domain is mainly explained, and in understanding the embodiment, reference may be made to the embodiment corresponding to fig. 5.

Step S310, receives an rSRVCC pre-request message from the mobile switching center MSC 110.

Step S312, sending the pre-request message to the first IP multimedia system ims (v) in the ps (v) domain.

Step S314, receiving the response message of IMS (v), the response message includes the information whether the IMS (v) can provide voice resource.

When it is determined that the voice resource can be provided according to the information of step S314, step S316 is entered:

step S316, according to the response message, notifying the first serving gateway sgw (v) and the first packet data gateway pgw (v) in the ps (v) domain to establish an rSRVCC voice resource path.

When it is determined that the voice resource cannot be provided according to the information of step S314, the process proceeds to step S318:

step S318, sending the pre-request message to a second IP multimedia system IMS (h) in a domain PS (h) through a second mobility management entity MME (h) in the domain PS (h);

step S320, after the ims (h) sends a response message to the second mme (h), the first mme (v) notifies the second serving gateway sgw (h) and the second packet data gateway pgw (h) in the ps (h) domain to establish the rSRVCC voice resource path through the second mme (h).

After establishing the rSRVCC voice resource path in step S316 or S320, the process proceeds to step S322:

step S322, sending a notification message including the voice resource path information to the MSC110, so as to provide the voice resource path information to the UE through the MSC110, so that the UE can obtain the voice resource according to the provided voice resource path.

For clarity and clarity of embodiments of the present invention, a flow chart of operations in a specific environment, as shown in FIG. 13, is provided for reference. In addition, the above-mentioned S310 to S322 are only an example for explaining the present invention, and are not intended to limit the present invention. For example, in practice, the exclusion condition may be removed, and the voice resource paths are established in parallel in ps (v) and ps (h).

Fig. 14 is a flowchart of an rSRVCC handover method according to another embodiment of the present invention. It should be noted that, the embodiment of the present invention is mainly described in terms of the second mobility management entity, second mme (h)114, applied in the home network packet ps (h) domain, and in understanding the embodiment, reference may be made to the embodiment corresponding to fig. 6.

Step S410, receiving an rSRVCC pre-request message of the first mobility management entity mme (v)112 in the visited network packet ps (v) domain. The resource request message is a request message of the first MME (v)112 responding to the MSC110 pre-request message; the MSC110 pre-request message is a request message sent by the MSC110 after knowing that the UE is connected to the base station BS in the CS domain and confirming that the UE can perform rSRVCC handover.

After receiving the rSRVCC pre-request message, pre-establishing an rSRVCC voice resource path, the specific steps are as follows:

step S412, sending the pre-request message to a second IP multimedia system ims (h) in the ps (h) domain. In this embodiment, after receiving the pre-request message, ims (h) detects whether the visited network has available Voice resources, i.e. whether VOIP (Voice over Internet Protocol) service can be provided, and responds to MME114 with the detection result.

Step S414, receiving the response message of ims (h), where the response message includes information about whether the ims (h) can provide voice resources.

Step S416, according to the response message, notifying the second serving gateway sgw (h) and the second packet data gateway pgw (h) in the ps (h) domain to establish an rSRVCC voice resource path. In this embodiment, a plurality of rSRVCC voice resource paths may be established according to the number of interfaces between the swg (h) and the pgw (h).

Step S418, sending a notification MSC110 containing the voice resource path information through the first mme (v)112, so as to provide the voice resource path information to a user equipment UE through the MSC110, so that the UE can obtain a voice resource according to the provided voice resource path. In this embodiment, after the voice resource path information is sent to the MSC110, the MSC110 will temporarily store the voice resource information and wait for the request packet of the UE, when the UE requests to switch from the CS domain to the PS domain, the UE provides the information to the UE, and the UE rapidly obtains the voice resource of the ims (h) through the eNB according to the voice resource path information, thereby reducing the voice delay, i.e. the time delay, of the rSRVCC handover.

For clarity and clarity of embodiments of the present invention, a flow chart of operations in a specific environment, as shown in FIG. 15, is provided for reference.

Fig. 16 is a flowchart of an rSRVCC handover method according to another embodiment of the present invention. FIG. 17 is a flowchart illustrating a corresponding operation of the handover method of FIG. 16 in a system environment. It should be noted that, in the present embodiment, the MSC110 is mainly used for explanation, and in understanding the present embodiment, reference may be made to the embodiments corresponding to fig. 7 and 8.

Step S510, sending an rSRVCC pre-request message to an MME, so that the MME can establish an rSRVCC voice resource path according to the pre-request message. In this embodiment, the sending of the pre-request message is based on the premise that the UE supports the rSRVCC handover, that is, the UE supports the CS domain to PS domain handover.

Step S512, receiving a first notification message of the MME, where the first notification message includes the voice resource path information established by the MME. In this embodiment, after receiving the pre-request message, the MME notifies the SGW and the PGW to establish the voice resource path in advance, and feeds back the established voice resource path information after the establishment is completed.

Step S514, saving the voice resource path information. In this embodiment, memory saving may be used, or a register or the like may be used.

Step S516, receiving a second notification message of the BS, where the second notification message includes third information that the UE requests srvss handover. I.e. waiting for the rSRVCC handover request, specifically, when the BS detects that the UE is about to perform handover, the BS sends a handover request packet, i.e. a second notification message.

Step S518, sending the voice resource path information to the UE according to the second notification message, so that the UE can obtain the voice resource through the voice resource path information. That is, the voice resource path information is sent to the UE, and the UE can rapidly obtain the voice resource of the IMS through the eNB according to the voice resource path information, thereby reducing the voice delay of rSRVCC switching, namely the delay in time.

Fig. 18 is a flowchart of an rSRVCC handover method according to another embodiment of the present invention. FIG. 19 is a flowchart illustrating a corresponding operation of the handover method of FIG. 18 in a system environment. It should be noted that, in the present embodiment, the MSC110 is mainly used for explanation, and in understanding the present embodiment, reference may be made to embodiments corresponding to fig. 9 and 10.

In roaming state, there is a roaming procedure, such as from the visited network ps (v) domain to the home network ps (h) domain, and thus involves a first mme (v)112 in the ps (v) domain and a second mme (h)114 in the ps (h) domain, which aims to disclose the method for rSRVCC handover in roaming state.

Step S610, receiving a third notification message from the BS, wherein the third notification message includes first information for establishing connection between the BS and the UE;

step S612, after receiving the third notification message, obtaining second information of the UE through a Home Subscriber System (HSS);

step S614, according to the second information, determining whether the UE can execute rSRVSS handover.

Step S616, sending an rSRVCC pre-request message to the first mme (v) to notify the first serving gateway sgw (v) and the first packet data gateway sgw (v) in the ps (v) domain to establish an rSRVCC voice resource path through the first mme (v);

step S618, receiving a fourth notification message of the first mme (v), where the fourth notification message includes the voice resource path information of sgw (v)/pgw (v).

Step S620, sending the first mme (v) to send an rSRVCC pre-request message to the second mme (h) to notify the second serving gateway sgw (h) and the second packet data gateway sgw (h) in the ps (h) domain to establish an rSRVCC voice resource path through the second mme (h);

step S622, receiving a fifth notification message from the second mme (h) through the first mme (v), where the fifth notification message includes the voice resource path information of sgw (h)/sgw (h).

Step S624, saving the voice resource path information. In this embodiment, memory saving may be used, or a register or the like may be used.

Step S626, receiving a second notification message of the BS, where the second notification message includes third information that the UE requests srvss handover. I.e. waiting for the rSRVCC handover request, specifically, when the BS detects that the UE is about to perform handover, the BS sends a handover request packet, i.e. a second notification message.

Step S628, sending the voice resource path information to the UE according to the second notification message, so that the UE can obtain the voice resource through the voice resource path information.

It should be noted that, the execution conditions may be set before steps S620 and S622, and if step S618 fails to acquire the voice resource path information, steps S620 and S622 are executed.

The above-described embodiments do not limit the scope of the present invention. Any modification, equivalent replacement, and improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A reverse single radio voice call continuity (rSRVCC) handover method is applied to a first Mobility Management Entity (MME) (v) in a packet (PS (v)) domain of a visited network, and is characterized in that the method comprises the following steps:

receiving an rSRVCC pre-request message from a Mobile Switching Center (MSC);

establishing an rSRVCC voice resource path according to the pre-request message;

sending a notification message containing the voice resource path information to the MSC so as to provide the voice resource path information to User Equipment (UE) through the MSC, so that the UE can acquire voice resources according to the provided voice resource path;

wherein, the step of establishing an rSRVCC voice resource path according to the pre-request message specifically includes:

sending the pre-request message to a first IP multimedia system, ims, (v) in the ps (v) domain;

receiving a response message of the IMS (v), wherein the response message comprises information of whether the IMS (v) can provide voice resources or not;

and according to the response message, informing a first Service Gateway (SGW) (v) and a first packet data gateway (PGW) (v) in the PS (v) domain to establish an rSRVCC voice resource path.

2. The method of claim 1, wherein the pre-request message is a request message sent by the MSC after the MSC knows that the UE is connected to a base station BS in a CS domain and confirms that the UE can perform rSRVCC handover.

3. The method of claim 1, wherein the step of establishing an rSRVCC voice resource path according to the pre-request message further comprises:

sending the pre-request message to a second IP Multimedia System (IMS) (h) in a domain (PS) (h) through a second Mobility Management Entity (MME) (h) in the domain of a home network Packet (PS) (h);

after the ims (h) sends a response message to the second mme (h), the first mme (v) notifies the second serving gateway sgw (h) and the second packet data gateway pgw (h) in the ps (h) domain to establish the rSRVCC voice resource path through the second mme (h).

4. A reverse single radio voice call continuity (rSRVCC) handover method is applied to a second Mobility Management Entity (MME) in a home network Packet (PS) (h) domain, and is characterized by comprising the following steps:

receiving an rSRVCC pre-request message of a first mobility management entity MME (v) in a domain of a visited network packet PS (v);

pre-establishing an rSRVCC voice resource path according to the rSRVCC pre-request message;

sending a notification message containing the voice resource path information to a Mobile Switching Center (MSC) through the first MME (v), so as to provide the voice resource path information to a User Equipment (UE) through the MSC, and thus the UE can obtain voice resources according to the provided voice resource path;

wherein, the step of pre-establishing the rSRVCC voice resource path according to the resource request message specifically includes:

sending the pre-request message to a second IP multimedia system, ims, (h) in the ps (h) domain;

receiving a response message of the IMS (h), wherein the response message comprises information of whether the IMS (h) can provide voice resources or not;

and according to the response message, informing a second Service Gateway (SGW) (h) and a second packet data gateway (PGW) (h) in the PS (h) domain to establish the rSRVCC voice resource path.

5. The method of claim 4, wherein the resource request message is a request message of the first MME (v) in response to the MSC Pre-request message; the MSC pre-request message is a request message sent by the MSC after the MSC learns that the UE is connected with the base station BS of the CS domain and confirms that the UE can execute rSRVCC switching.

6. A reverse single radio voice call continuity (rSRVCC) handover method applied in a Mobile Switching Center (MSC), the method comprising:

sending an rSRVCC pre-request message to a Mobility Management Entity (MME), so that the MME establishes an rSRVCC voice resource path according to the pre-request message;

receiving a first notification message of the MME, wherein the first notification message comprises the voice resource path information established by the MME;

saving the voice resource path information;

receiving a second notification message of the BS, wherein the second notification message comprises third information that the UE requests rSRVSS handover;

sending the voice resource path information to the UE according to the second notification message so that the UE can acquire voice resources through the voice resource path information;

wherein the MME comprises a first mobility management entity MME (v) in the visited network packet PS (v) domain and a second mobility management entity MME (h) in the home network packet PS (h) domain; the step of sending the rSRVCC pre-request message to a mobility management entity MME, so that the step of the MME establishing an rSRVCC voice resource path according to the pre-request message specifically includes:

sending an rSRVCC pre-request message to the first mme (v) to notify, by the first mme (v), a first serving gateway sgw (v) and a first packet data gateway pgw (v) in the ps (v) domain to establish an rSRVCC voice resource path;

receiving a fourth notification message of the first MME (v), wherein the fourth notification message comprises the voice resource path information of SGW (v)/PGW (v).

7. The method of claim 6, wherein the step of sending the rSRVCC pre-request message to the mobility management entity MME further comprises a confirmation step, which specifically comprises:

receiving a third notification message from the BS, the third notification message including first information that the BS and the UE establish a connection;

after receiving the third notification message, acquiring second information of the UE through a Home Subscriber System (HSS);

and confirming whether the UE can execute rSRVSS switching or not according to the second information.

8. The method of claim 6, wherein the step of sending the rSRVCC pre-request message to a mobility management entity MME, such that the MME establishes an rSRVCC voice resource path according to the pre-request message, further comprises:

(v) sending an rSRVCC pre-request message to the second mme (h) by sending the first mme (v) to notify a second serving gateway sgw (h) and a second packet data gateway sgw (h) in the ps (h) domain to establish an rSRVCC voice resource path through the second mme (h);

receiving, by the first MME, (v) a fifth notification message of the second MME (h), the fifth notification message including the voice resource path information of SGW (h)/SGW (h).

9. A mobility management entity MME for use in a visited network packet ps (v) domain, the MME comprising:

a first receiving module, configured to receive a reverse single radio voice call continuity rSRVCC pre-request message from a mobile switching center MSC;

the establishing module is used for establishing an rSRVCC voice resource path according to the pre-request message, and the establishing module further comprises a second sending module, a second receiving module and a first notification module, wherein:

the second sending module is configured to send the pre-request message to a first IP multimedia system ims (v) in the ps (v) domain;

the second receiving module is configured to receive a response message of the ims (v), where the response message includes information about whether the ims (v) can provide voice resources;

the first notifying module is configured to notify the first serving gateway sgw (v) and the first packet data gateway pgw (v) in the ps (v) domain to establish an rSRVCC voice resource path according to the response message; and

a first sending module, configured to send a notification message including the voice resource path information to the MSC, so as to provide the voice resource path information to a user equipment UE through the MSC, so that the UE can obtain voice resources according to the provided voice resource path.

10. The MME of claim 9, wherein the pre-request message is a request message sent by the MSC after the MSC learns that the UE is connected to a base station BS in a CS domain, and confirms that the UE can perform rSRVCC handover.

11. The MME of claim 9, wherein the establishing module further comprises a third sending module and a second notifying module:

the third sending module is configured to send the pre-request message to a second IP multimedia system ims (h) in a home network packet ps (h) domain through a second mobility management entity mme (h) in the ps (h) domain;

the second notifying module is configured to notify, by the second mme (h), a second serving gateway sgw (h) and a second packet data gateway pgw (h) in the ps (h) domain to establish an rSRVCC voice resource path after the ims (h) sends a response message to the second mme (h).

12. A mobility management entity, MME, for application to a home network packet, ps (h), wherein the MME comprises:

a first receiving module, configured to receive an rSRVCC pre-request message of a first mobility management entity mme (v) in a visited network packet ps (v) domain;

the establishing module establishes an rSRVCC voice resource path in advance according to the pre-request message, and the establishing module further comprises a second sending module, a second receiving module and a notification module, wherein:

the second sending module is configured to send the received resource request message to a second IP multimedia system ims (h) in the ps (h) domain;

the second receiving module is configured to receive a response message of the ims (h), where the response message includes information about whether the ims (h) can provide voice resources;

the notifying module is configured to notify a second serving gateway sgw (h) and a second packet data gateway pgw (h) in the ps (h) domain to establish an rSRVCC voice resource path according to the response message; and

a first sending module, configured to send a notification message containing the voice resource path information to a mobile switching center MSC through the first mme (v), so as to provide the voice resource path information to a user equipment UE through the MSC, so that the UE obtains voice resources according to the provided voice resource path.

13. The MME of claim 12, wherein the resource request message is a request message for the first MME (v) in response to the MSC pre-request message; the MSC pre-request message is a request message sent by the MSC after the MSC learns that the UE is connected with the base station BS of the CS domain and confirms that the UE can execute rSRVCC switching.

14. A mobile switching center, MSC, comprising:

a first sending module, configured to send an rSRVCC pre-request message to a mobility management entity MME, so that the MME establishes an rSRVCC voice resource path according to the pre-request message;

a first receiving module, configured to receive a first notification message of the MME, where the first notification message includes the voice resource path information established by the MME;

the storage module is used for storing the voice resource path information;

a second receiving module, configured to receive a second notification message of the BS, where the second notification message includes third information that the UE requests srvss handover; and

a second sending module, configured to send the voice resource path information to the UE according to the second notification message, so that the UE obtains voice resources through the voice resource path information;

wherein the MME comprises a first mobility management entity MME (v) in the visited network packet PS (v) domain and a second mobility management entity MME (h) in the home network packet PS (h) domain; the first sending module comprises a third sending module and a fourth sending module, wherein:

the third sending module, configured to send an rSRVCC pre-request message to the first mme (v) to notify, by the first mme (v), a first serving gateway sgw (v) and a first packet data gateway sgw (v) in the ps (v) domain to establish an rSRVCC voice resource path;

the fourth sending module is configured to send, by the first mme (v), an rSRVCC pre-request message to the second mme (h) to notify, by the second mme (h), a second serving gateway sgw (h) and a second packet data gateway sgw (h) in the ps (h) domain to establish an rSRVCC voice resource path.

15. The MSC of claim 14, further comprising a third receiving module, an obtaining module, and an acknowledgement module, wherein:

the third receiving module is configured to receive a third notification message from the BS, where the third notification message includes first information for establishing a connection between the BS and the UE;

the acquiring module is used for acquiring second information of the UE through a Home Subscriber System (HSS) after receiving the third notification message;

and the confirming module is used for confirming whether the UE can execute rSRVSS switching or not according to the second information.

16. The MSC of claim 14, wherein the first transmitting module further comprises a fourth receiving module and a fifth receiving module, wherein:

the fourth receiving module is configured to receive a fourth notification message of the first mme (v), where the fourth notification message includes voice resource path information of an SGW/pgw (v);

the fifth receiving module is configured to receive a fifth notification message of the second mme (h) through the first mme (v), where the fifth notification message includes the voice resource path information of the SGW/pgw (h).

17. A communication system, comprising: a first mobility management entity MME (v), a second mobility management entity MME (h), a mobile switching center MSC, wherein:

the second MME (h) serves in a home network packet PS (h) domain and is used for receiving the rSRVCC pre-request message forwarded by the first MME (v); pre-establishing an rSRVCC voice resource path according to the resource request message; (v) sending a notification message containing the voice resource path information to the MSC via the first mme;

wherein, the first mme (v) is further configured to send the pre-request message to a first IP multimedia system ims (v) in the ps (v) domain according to the pre-request message; receiving a response message of the IMS (v), wherein the response message comprises information of whether the IMS (v) can provide voice resources or not; and according to the response message, informing a first Service Gateway (SGW) (v) and a first packet data gateway (PGW) (v) in the PS (v) domain to establish an rSRVCC voice resource path.

18. The system of claim 17, wherein the second mme (h) is further configured to send the pre-request message to a second IP multimedia system ims (h) in the ps (h) domain according to the pre-request message; receiving a response message of the IMS (h), wherein the response message comprises information of whether the IMS (h) can provide voice resources or not; and according to the response message, informing a second Service Gateway (SGW) (h) and a second packet data gateway (PGW) (h) in the PS (h) domain to establish the rSRVCC voice resource path.

19. The system according to any one of claims 17 to 18, further comprising an evolved node b eNB, wherein the UE acquires voice resources of an IP multimedia system IMS according to the voice resource path information after connecting to the eNB.