WO2011044834A1

WO2011044834A1 - Method and system for implementing circuit switched fallback in evolved packet system network

Info

Publication number: WO2011044834A1
Application number: PCT/CN2010/077676
Authority: WO
Inventors: 陶全军; 谢振华
Original assignee: 中兴通讯股份有限公司
Priority date: 2009-10-17
Filing date: 2010-10-12
Publication date: 2011-04-21
Also published as: CN102045803A; CN102045803B

Abstract

The present invention discloses a method for implementing Circuit Switched (CS) fallback in Evolved Packet System (EPS) network, which comprises: Mobility Management Entity (MME) receives CS fallback indication sent by a user terminal, and indicates Evolved Universal Terrestrial Radio Access Network (E-UTRAN) to switch the user terminal to CS circuit domain network; said E-UTRAN switches said user terminal to the CS circuit domain network by said MME and the Mobile Switching Center (MSC) co-registered when said user terminal accesses the EPS network; and said user terminal and the co-registered MSC transmit service data by said CS circuit domain network. The present invention also discloses a system for implementing CS fallback in EPS network. The present invention avoids the problem of long service access time caused by the location update which is needed in that the fallbacked target MSC is different from the co-registered MSC.

Description

System and method for implementing circuit switching fallback of evolved packet domain system network

TECHNICAL FIELD The present invention relates to the field of mobile communications, and in particular, to an evolved packet domain system for a terminal.

(Evolved Packet System, abbreviated as EPS) The circuit switching service is backed up to the Circuit Switched Fallback (CSFB).

Background technique

In order to maintain the strong competitiveness of the 3rd Generation Partnership Project (3GPP) in the field of mobile communications, 3GPP is currently working on the Packet Switched Core (PS Core). Network and the evolution of the Universal Mobile Telecommunication System (UMTS) Terrestrial Radio Access Network (UTRAN), the purpose of which is to make the evolved PS Core (Evolved PS Core, EPC for short) available. Higher transmission rate, shorter transmission delay, and support for evolved UTRAN (Evolved UTRAN, E-UTRAN for short), GSM EDGE radio access network (GSMRAN), where GSM is global Abbreviation for Global System for Mobile communications, EDGE is the Enhanced Data Rate for GSM Evolution (Acronym), UTRAN, Wireless Local Area Network (WLAN) and others. Non-3GPP access network Mobility management. This evolved mobile communication system is called an evolved packet domain system (Evolved Packet System, abbreviated as EPS). FIG. 1 is a structural diagram of a circuit in which a terminal performs a Circuit Switching (CS) service fallback CS network under the EPS network access in the prior art. The description of each entity shown in Figure 1 is as follows: User Equipment (UE) 101;

UTRAN 102, GSM/Universal Mobile Telecommunications System (UMTS) network radio access network, providing circuit domain And packet domain radio access resources;

E-UTRAN 103, an evolved radio access network, can provide higher uplink and downlink rates, lower transmission delay and more reliable wireless transmission; the network element included in E-UTRAN is an evolved base station (Evolved NodeB, abbreviated Providing radio resources for the access of the terminal for the eNodeB or the eNB); Serving GPRS Supporting Node (SGSN) 104 for the service of the General Packet Radio Service (GPRS); Service Gateway (Serving Gateway, Referred to as S-GW) 105, it is a user plane entity, responsible for user plane data routing processing; Mobility Management Entity (MME) 106, is a control plane entity, a server that temporarily stores user data, responsible for Manage and store UE context (such as UE/user identity, mobility management state, and user security parameters, etc.), assign a temporary identifier to the user, and be responsible for authenticating the user when the UE is camped in the tracking area or the network; Mobile Switching Center (MSC) 107; the MSC can also be The new functional entities in the R4 phase and thereafter, such as the MSC server (Server), are uniformly represented by the MSC/Visitor Location Register (VLR) in the present invention; Public Switched Telephone Network (PSTN) 108 , here refers to the fixed telephone network. When the UE accesses the EPS network, it notifies the MME to perform joint registration, and informs the Circuit Switching Fall Back (CSFB) capability. The MME sends a joint registration message to the MSC instead of the UE to initiate a joint registration. The MSC receives the joint registration message. If there is no user data, the user data is obtained from the Home Location Register (HLR).

2 is a schematic diagram of a call flow of a prior art terminal for implementing a CS service fallback CS network under EPS network access. The UE has been registered with the MME and the MSC in the EPS network. At this time, the UE initiates the CS service. The UE sends an enhanced service request message to the MME. The message carries the CSFB indication. After receiving the enhanced service request message, the MME notifies the UE to fall back through the E-UTRAN. UTRAN CS business. As shown in FIG. 2, the call initiation process mainly includes the following steps: Step S201: A UE sends an enhanced service request message to an MME, where the enhanced service request message carries a CSFB indication, where the CSFB indication is used to instruct the MME to perform circuit switching service fallback. S202, the MME sends a notification CSFB message to the E-UTRAN, where the CSFB message carries a CSFB indication, and indicates to the E-UTRAN that the UE needs to fall back to the UTRAN. In step S203, the E-UTRAN may obtain a measurement report from the UE, and determine the UE to fall back according to the measurement report. The specific cell to be obtained; Step S204, if the UE has a data service in the EPS network, the E-UTRAN triggers the packet domain handover procedure, and the data service is switched to the UTRAN, which is not described in detail in the present invention; Step S205: If the UE is in the EPS The network does not have a data service, the E-UTRAN notifies the UE to perform the fallback, and switches to the UTRAN. Step S206, after the handover succeeds, the UE sends a service request message to the MSC of the serving target access cell in the UTRAN; Step S207: If the MSC is the UE When the MSC is jointly registered in the EPS network, the MSC judges according to the service data of the user, receives the current service request, and returns service access to the UE. A message; (subsequent to the encryption and authentication process, which is not described in detail in the present invention); Step S208, if the MSC is not the MSC that the UE is jointly registered in the EPS network access in step S206, the MSC has no user data, the MSC Returning a service access reject message to the UE, informing the UE to initiate a location update procedure; Step S209, the UE re-initiating the location update process in the UTRAN; Step S210, the MSC obtains an authentication parameter from the HLR; Step S211, the MSC receives the authentication parameter; S212, the MSC notifies the UE to perform the authentication process; Step S213, after the authentication succeeds, the MSC initiates a location update request to the HLR; Step S214, the HLR notifies the source MSC to delete the user data; Step S215, the source MSC notifies the MME to delete the association relationship; Step S216, after the source MSC deletes the user data successfully, returns a deletion success message (delete response);

Step S217, the source MSC sends a delete response message to the HLR. Step S218: The HLR sends an insert user data request message to the MSC. Step S219, after the MSC inserts the user data successfully, returns an insert success message (insertion response) to the HLR;

Step S220, the HLR returns a location update response message to the MSC. Step S221: The MSC notifies the UTRAN to perform an encryption process. Step S222: The MSC returns a location update response message to the UE. The foregoing step S208-step S222 is the MSC dropped by the UE and the jointly registered MSC. Step S223: The UE initiates a call setup request to the MSC; Step S224, the MSC notifies the UTRAN to establish a terrestrial circuit and a radio resource, and allocates a service bearer;

Step S225, the MSC establishes an inter-office bearer to the PSTN. In the process of implementing the present invention, the inventor finds that: the E-UTRAN as described above determines the target cell that falls back according to the radio signal quality of the UE's measurement, and cannot guarantee that the MSC and the UE served by the target cell that the UE falls back are in the EPS. The MSCs that are jointly registered by the network access are the same MSC. When the MSC that is dropped by the UE is different from the MSC that is jointly registered, the UE needs to add the steps S208-S222 to initiate the call. The access time of the service is too long and the efficiency is low.

SUMMARY OF THE INVENTION The technical problem to be solved by the present invention is to provide a system and method for implementing circuit-switched fallback of an EPS network, so as to shorten the access time of the UE when the MSC that is dropped by the UE and the jointly registered MSC are not. In order to solve the above technical problem, the present invention first provides an evolved packet domain system.

(EPS) A method for implementing network circuit switching fallback, comprising: a mobility management entity (MME) receiving a circuit switched fallback indication sent by a user terminal, indicating that an evolved global mobile communication system terrestrial radio access network (E-UTRAN) puts the user The terminal switches to a circuit switched (CS) circuit domain network; the E-UTRAN switches the user terminal by using a mobile switching center (MSC) jointly registered by the MME and the user terminal when the EPS network accesses And to the CS circuit domain network; and the user terminal and the jointly registered MSC transmit service data through the CS circuit domain network. The CS circuit domain network includes a Global System for Mobile Communications Terrestrial Radio Access Network (UTRAN) or a GSM EDGE Radio Access Network (GERAN). The circuit switched fallback indication sent by the user terminal received by the MME is sent by the user terminal to the MME by using an enhanced service request message. The step of the E-UTRAN switching the user terminal to the CS circuit domain network by using the MME and the jointly registered MSC includes: the E-UTRAN, according to the MME, according to the user terminal The wireless measurement report determines the target cell to be handed over, and the target eNB is notified by the MME to the jointly registered MSC; the jointly registered MSC selects a target CS circuit domain network according to the target cell, and the adopted wireless resource Accessing parameters, and notifying the user terminal of the radio resource access parameter by using the E-UTRAN; and the user terminal switching to the target CS circuit domain network according to the radio resource access parameter. The wireless measurement report of the user terminal includes: the current wireless measurement report of the user terminal or the latest wireless measurement report saved by the E-UTRAN. The step of the jointly registered MSC selecting the target CS circuit domain network according to the target cell includes: the jointly registered MSC selecting a target MSC according to the target cell, and notifying the target cell and a required bearer type And the target MSC determines the target CS circuit domain network according to the target cell, and indicates the required allocated bearer type to the target CS circuit domain network. The step of obtaining the radio resource access parameter by the jointly registered MSC includes: after the target CS circuit domain network allocates radio bearer resources according to the required bearer type, the radio resource is used by the target MSC The access parameters are sent to the jointly registered MSC.

The step of the data includes: the user terminal and the jointly registered MSC establish a call by using a device message, and the user terminal or the jointly registered MSC establishes a bearer with the remote PSTN, and delivers the service data. In the step of the user terminal and the jointly registered MSC establishing a call by using the device message, the user terminal and the jointly registered MSC establish the call through the target CS circuit domain network. In order to solve the above technical problem, the present invention also provides an evolved packet domain system (EPS) network circuit switched fallback implementation system for dropping user terminals back to a circuit switched (CS) circuit domain network, including mobility management. An entity (MME), an evolved global mobile communication system terrestrial radio access network (E-UTRAN), and a mobile switching center (MSC), wherein: the MME is configured to: after receiving the circuit switched fallback indication sent by the user terminal Instructing the E-UTRAN to switch the user terminal to the CS circuit domain network; the E-UTRAN is configured to: jointly register the MSC by the MME and the user terminal when the EPS network accesses Switching the user terminal to the CS circuit domain network; the CS circuit domain network is configured to: transfer the user terminal and the jointly registered MSC Business data. The CS circuit domain network includes a Global System for Mobile Communications Terrestrial Radio Access Network (UTRAN) or a GSM EDGE Radio Access Network (GERAN). The E-UTRAN is configured to switch the user terminal to the CS circuit domain network by using an MSC jointly registered by the MME and the user terminal when the EPS network is accessed as follows: Determining, by the MME, the target cell to be handed over according to the radio measurement report of the user terminal, notifying the target cell to the MME; and notifying the user of the radio resource access parameter sent by the jointly registered MSC The MME is further configured to: forward the target cell notified by the E-UTRAN to the jointly registered MSC; and the jointly registered MSC is configured to: select the CS circuit domain network according to the target cell Transmitting, by the radio resource access parameter, the radio resource access parameter to the E-UTRAN; wherein the user terminal switches to the CS circuit domain network according to the radio resource access parameter. The system further includes: a target MSC, configured to: receive a required allocated bearer type notified by the jointly registered MSC, and the target cell, and determine the CS circuit domain network according to the target cell, Transmitting the required bearer type indication to the CS circuit domain network, and sending the radio resource access parameter sent by the CS circuit domain network to the jointly registered MSC; wherein the jointly registered MSC is configured according to The target cell selects the target MSC; the CS circuit domain network allocates the radio bearer resource according to the required bearer type, and sends the radio resource access parameter to the target MSC. The user terminal is further configured to: after establishing a call by using the device message by the jointly registered MSC, establishing a bearer with the remote PSTN, and transmitting the service data; or the jointly registered MSC is further configured to: After the terminal establishes a call through the device message, the terminal establishes a bearer with the remote PSTN, and delivers the service data. The call is established between the user terminal and the jointly registered MSC through the CS circuit domain network.

The technical solution of the present invention avoids the problem that the service access time caused by the location update is longer due to the difference between the target MSC and the joint registration MSC when the UE performs the CSFB, and the access efficiency is improved. Other features and advantages of the invention will be set forth in the description which follows, The objectives and other advantages of the invention may be realized and obtained by the structure particularly pointed in the appended claims.

The drawings are intended to provide a further understanding of the invention and are intended to be a part of the description of the invention. In the drawings: FIG. 1 is a network architecture diagram of a terminal implementing a CS service under an EPS network access according to the prior art; FIG. 2 is a schematic diagram of a prior art terminal implementing a CS service fallback CS network under an EPS network access; 3 is a schematic flow chart of a first embodiment of the present invention; FIG. 4 is a schematic flow chart of a second embodiment of the present invention; FIG. 5 is a flow chart of a third embodiment of the present invention; A schematic diagram of the process of the embodiment.

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings and embodiments, by which the present invention is applied to the technical means to solve the technical problems, and the realization of the technical effect can be fully understood and Implementation. It should be noted that, if not conflicting, the embodiments of the present invention and the various features in the embodiments may be combined with each other, and are all within the protection scope of the present invention. Additionally, the steps illustrated in the flowchart of the figures may be performed in a computer system, such as a set of computer-executable instructions, and, although the logical order is illustrated in the flowchart, in some cases, may be different The steps shown or described are performed in the order herein. Figure 3 is a schematic flow chart of the first embodiment of the method of the present invention. In this embodiment, the target UTRAN is within the jurisdiction of the MSC in which the user is jointly registered. The user terminal initiates a call on the EPS network, and the MME notifies the E-UTRAN to drop the user back to the UTRAN, and the target UTRAN is within the MSC jurisdiction of the user joint registration. As shown in FIG. 3, the embodiment mainly includes the following steps: Step S301: The UE accesses the E-UTRAN, and successfully registers with the MSC, and the user terminal initiates a call, and the UE sends an enhanced service request message to the MME through the E-UTRAN. The message carries a CSFB indication and a service request category; optionally, the UE may further carry a codec example table in the message;

Step S302: The MME sends a notification CSFB message to the E-UTRAN according to the CSFB indication in the enhanced service request message, to instruct the E-UTRAN to switch the user terminal to the CS circuit domain network. In this embodiment, the CS circuit domain network is UTRAN. In other embodiments, the CS circuit domain network is GERAN; Step S303, the E-UTRAN obtains the current wireless measurement report from the UE, or acquires the E-UTRAN to save the latest wireless measurement report; Step S304, E-UTRAN And selecting, according to the radio measurement report that is obtained in step S303, the target cell to be handed over, and sending a handover request message to the MME, where the message carries parameters such as a CSFB indication, a source cell identifier, and a target cell identifier; if the user terminal currently has a data service connection, The message carries the bearer identifier that needs to be switched. In step S305, after receiving the handover request message, the MME determines that the data service exists in the user terminal, and triggers the packet domain handover procedure. The present invention does not describe the procedure in detail. Step S306 The MME determines that the handover request message carries the CSFB indication, and sends a handover request message to the MSC jointly registered by the UE. The message carries the user identifier, target cell information, the CSFB indication, the service class table embodiment and a codec (if step S301 has been carried in the table Example codec); Step S307, after receiving the handover request message sent by the MME, the MSC determines that the handover request message carries the CSFB indication, and determines whether the CSFB service is allowed to be performed according to the user service data. If yes, the process proceeds to step S308, and if not, the handover is refused; Step S308, the MSC selects a target UTRAN according to the target cell information in the handover request message, and sends a handover request message to the target UTRAN. After receiving the handover request message, the target UTRAN allocates a radio bearer resource, and returns a handover response to the MSC. a message, the message carries the allocated radio resource access parameter; Step S309, the MSC receives the handover response message, and forwards the handover response message to the MME; Step S310, after receiving the handover response message, the MME passes the E-UTRAN The UE sends a handover command to notify the UE to switch to the target UTRAN. Step S311, the UE switches to the radio channel reserved by the target UTRAN according to the radio resource access parameter of the target UTRAN in the handover command, and the target UTRAN establishes a relationship between the UE and the MSC. After completing the handover operation, the UE encapsulates the call setup request message into a device message, The target UTRAN is sent to the MSC; wherein the call setup request message includes the called number; step S312, the MSC receives the device message sent by the target UTRAN, and unpacks the call setup request message, and determines the call authority of the user, if If the user is allowed to call, the call setup response message is encapsulated in the device message and sent to the UE to establish a call with the UE. Step S313, the MSC establishes a bearer with the remote PSTN according to the called number in the call setup request message in step S311. , passing business data.

4 is a schematic flow chart of a second embodiment of the method of the present invention. In this embodiment, the target UTRAN is not within the jurisdiction of the MSC in which the user is jointly registered. The user terminal initiates a call in the EPS network, and the MME notifies the E-UTRAN to drop the user terminal back to the CS circuit domain network (the CS circuit domain network is UTRAN in this embodiment, in other embodiments, may also be GERAN), and the target UTRAN is not in the user association. Registered within the jurisdiction of the MSC. As shown in FIG. 4, the embodiment mainly includes the following steps: Step S401 - Step S407, respectively, the same as step S301 - Step S307; wherein, the MSC in step S402, step S406 and step S407 is the source MSC, where the source MSC is For the UE The MSC is jointly registered by the EPS network access; in step S408, the source MSC selects the target MSC according to the target cell information in the received handover request message, and sends a mobile handover request (Mobile Application Part, MAP for short) to the target MSC. a message indicating that the required bearer type is included in the message, and further includes the target cell information. Step S409, the target MSC selects the target UTRAN according to the target cell information in the preliminary handover request MAP message, and sends a handover request message to the target UTRAN. The message indicates that there is a bearer type to be allocated; after receiving the handover request message, the target UTRAN allocates radio bearer resources according to the required bearer type indicated in the message, and returns a handover response message to the target MSC, the message And the target MSC receives the handover response message, and returns a preliminary handover response MAP message to the source MSC, where the message includes the received handover response message. Content, that is, the allocated radio resource access parameter; step S411, the source MSC receives the After the handover response MAP message, the handover response message is sent to the MME. Step S412, after receiving the handover response message, the MME sends a handover command to the UE through the E-UTRAN to notify the UE to switch to the target UTRAN. Step S413, the UE switches according to the handover. The radio resource access parameter of the target UTRAN in the command is switched to the radio channel reserved by the target UTRAN, and the target UTRAN establishes a tunnel between the UE and the target MSC; after the handover operation is completed, the target MSC is sent to the target MSC by using the target UTRAN. Completing the message; Step S414, the target MSC informs the MME of the handover completion message through the source MSC; Step S415, the UE encapsulates the call setup request message into a device message, and sends the message to the target MSC through the target UTRAN; Step S416, the target MSC receives the device After the message, the content of the device message, that is, the call setup request message, is encapsulated in the MAP message and sent to the source MSC. Step S417, the source MSC receives the MAP message sent by the target MSC, and obtains the packet. a call setup request message, the user call authority is judged, if the user is allowed to call, the call setup response message is encapsulated into a MAP message and sent to the target MSC; wherein the call setup request message includes the called number;

Step S418, after receiving the MAP message, the target MSC encapsulates the content of the message, that is, the call setup response message, in the device message, and sends the call to the UE to establish a call with the UE. Step S419, the source MSC according to the call setup request message in step S417. The called number establishes a bearer between the remote PSTNs and delivers service data.

Figure 5 is a flow chart showing the third embodiment of the method of the present invention. The CS circuit domain network in this embodiment is UTRAN. In other embodiments, it may also be GERAN. The called UTRAN is a called embodiment within the jurisdiction of the MSC in which the user is jointly registered. The user terminal receives the called page in the EPS network, and the user terminal sends an enhanced service request including the indicated CSFB to the MME through the E-UTRAN, and the MME notifies the E-UTRAN to drop the user terminal to the UTRAN, and the target UTRAN is jointly registered by the user. Within the jurisdiction. As shown in FIG. 5, the embodiment mainly includes the following steps: Step S501: The MSC receives a remote PSTN address initial request; Step S502: The MSC sends a paging request to the UE by using the MME; Step S503-Step S512, respectively, step S301 - Step S310; Step S513, the UE switches to the radio channel reserved by the target UTRAN according to the radio resource access parameter of the target UTRAN in the handover command, and the target UTRAN establishes a tunnel between the UE and the MSC; after completing the handover operation, Sending a handover complete message to the MSC by using the target UTRAN; Step S514, the UE sends a paging response message to the MSC by using the device message in the target UTRAN, and the packet response message is encapsulated in the device message and sent to the MSC; In an optional step, the MSC may serve as a sending occasion of the paging response message in step S508. In step S515, the MSC encapsulates the call setup request message in the device message, and sends the call to the UE through the target UTRAN. In step S516, the UE establishes a call setup response. The message is encapsulated in the device message, and sent to the MSC by the target UTRAN to establish a call with the MSC; Step S517, the called user returns a response message to the remote PSTN, connects the call, and delivers the service data.

Figure 6 is a flow chart showing the fourth embodiment of the method of the present invention. The CS circuit domain network in this embodiment is UTRAN. In other embodiments, it may also be GERAN. The target UTRAN is not a called embodiment within the jurisdiction of the MSC in which the user is jointly registered. The user terminal receives the called page in the EPS network, sends an enhanced service request carrying the indicated CSFB to the MME through the E-UTRAN, and the MME notifies the E-UTRAN to drop the user terminal to the UTRAN, and the target UTRAN is not in the MSC jurisdiction of the user joint registration. Inside. As shown in FIG. 6, the embodiment mainly includes the following steps: Step S601 - Step S609, respectively, step S501 - Step S509; wherein, the MSC in step S601, step S602, step S604, step S608, and step S609 is the source MSC Step S610: The source MSC selects a target MSC according to the target cell information in the received handover request message, and sends a preliminary handover request Mobile Application Part (MAP) message to the target MSC, where the message indicates that there is a requirement. The allocated bearer further includes the target cell information. Step S611: The target MSC selects the target UTRAN according to the target cell information in the handover request message, and sends a handover request message to the target UTRAN, where the message indicates the bearer type to be allocated. After receiving the handover request message, the target UTRAN allocates a radio bearer resource according to the required bearer type indicated in the message, and returns a handover response message to the target MSC, where the message carries the allocated radio resource access parameter; S612. After receiving the handover response message, the target MSC returns a preliminary handover response MAP message to the source MSC. The information includes the content of the received handover response message, that is, the allocated radio resource access parameter; Step S613, the source MSC returns a handover response message to the MME; Step S614, the MME sends a handover command to the UE through the E-UTRAN; The command includes the radio resource access parameter of the target UTRAN; step S615, the UE according to the radio resource access parameter of the target UTRAN in the handover command, Switching to the radio channel reserved by the target UTRAN, the target UTRAN establishes a tunnel between the UE and the MSC; after completing the handover operation, sending a handover complete message to the target MSC through the target UTRAN;

Step S616, the target MSC informs the MME of the handover completion message through the source MSC. Step S617, the UE sends a paging response message to the target MSC by using the device message in the target UTRAN; that is, the paging response message is encapsulated into the device message and sent to the MME. After the target MSC receives the packet, the content of the device message is encapsulated in the MAP message and sent to the source MSC. The steps S617 and S618 are optional steps, and the target MSC can also Step S608 is used as the sending occasion of the paging response message; Step S619, the source MSC encapsulates the call setup request message into the MAP message and sends the message to the target MSC; Step S620, the target MSC receives the MAP message, and the content in the message is established. The request message is encapsulated in the device message and sent to the UE;

Step S621, the UE encapsulates the call setup response message in the device message, and sends the call setup message to the target MSC through the target UTRAN. Step S622, the target MSC receives the device message, and encapsulates the content of the message, that is, the call setup response message, in the MAP message. The medium MSC is sent to establish a call with the UE; in step S623, the called party is connected, the response message is returned to the remote PSTN, the call is connected, and the service data is transmitted. With reference to the foregoing method embodiments shown in FIG. 3 to FIG. 6 , the embodiment of the implementation system for the EPS network circuit switching fallback in the present invention is mainly used to drop the user terminal back to the CS circuit domain network, including the MME, the E-UTRAN, and the like. MSC, where: the MME is configured to: after receiving the circuit switched fallback indication sent by the user terminal, instructing the E-UTRAN to switch the user terminal to the CS circuit domain network; the E-UTRAN is set to: pass the MME and The user terminal jointly registers the MSC when the EPS network accesses, and switches the user terminal to the CS circuit domain network; The CS circuit domain network is configured to: transmit service data between the user terminal and the jointly registered MSC. The CS circuit domain network includes a global mobile communication system terrestrial radio access network or a GSM EDGE radio access network. The E-UTRAN is further configured to: determine, according to the radio measurement report of the user terminal, the target cell to be handed over by the MME, and send a handover request message to the MME to notify the MME of the target cell; After the handover command sent by the MME, the radio resource access parameter of the CS circuit domain network (ie, the handover target network) in the handover command is notified to the user terminal; the MME is further configured to: the E-UTRAN The target cell notified by the handover request message is forwarded to the jointly registered MSC; the jointly registered MSC is configured to: select the CS circuit domain network according to the target cell, and interact with the CS circuit domain network to obtain the CS circuit domain. The radio resource access parameter allocated by the network for the handover, the radio resource access parameter is sent to the E-UTRAN; wherein, after receiving the handover command sent by the E-UTRAN, the user terminal is configured according to the handover command The radio resource access parameter is switched to the CS circuit domain network. The system may further include: a target MSC, configured to: receive a required allocated bearer type notified by the jointly registered MSC, and the target cell, and determine the CS circuit domain network according to the target cell, and allocate the required The bearer type is sent to the CS circuit domain network, and the radio resource access parameter sent by the CS circuit domain network is sent to the jointly registered MSC; wherein the jointly registered MSC is further set to: according to the target The cell selects the target MSC; the CS circuit domain network is further configured to: allocate the radio bearer resource according to the required bearer type, and send the radio resource access parameter to the target MSC. The user terminal is further configured to: after establishing a call by using the device message by the jointly registered MSC, establishing a bearer with the remote PSTN to transmit the service data; or the jointly registered MSC is further configured to: Establish call by device message After the call is made, a bearer is established with the remote PSTN, and the service data is delivered. The call is established between the user terminal and the jointly registered MSC through the CS circuit domain network. Obviously, those skilled in the art should understand that the above modules or steps of the present invention can be implemented by a general-purpose computing device, which can be concentrated on a single computing device or distributed over a network composed of multiple computing devices. Alternatively, they may be implemented by program code executable by the computing device, such that they may be stored in the storage device by the computing device, or they may be separately fabricated into individual integrated circuit modules, or they may be Multiple modules or steps are made into a single integrated circuit module. Thus, the invention is not limited to any specific combination of hardware and software. While the embodiments of the present invention have been described above, the described embodiments are merely for the purpose of understanding the invention and are not intended to limit the invention. Any modification and variation of the form and details of the invention may be made by those skilled in the art without departing from the spirit and scope of the invention. It is still subject to the scope defined by the appended claims.

Industrial Applicability The technical solution of the present invention avoids the problem that the service access time caused by the location update is longer due to the difference between the target MSC and the jointly registered MSC, and the access efficiency is improved. .

Claims

Claim

An implementation method for an evolved packet domain system (EPS) network circuit switched fallback, comprising: a mobility management entity (MME) receiving a circuit switched fallback indication sent by a user terminal, indicating an evolved global mobile communication system terrestrial wireless An access network (E-UTRAN) switches the user terminal to a circuit switched (CS) circuit domain network; the E-UTRAN is jointly registered by the MME and the user terminal when the EPS network is accessed. (MSC), switching the user terminal to the CS circuit domain network; and the user terminal and the jointly registered MSC transmitting service data through the CS circuit domain network.

2. The method of claim 1, wherein: said CS circuit domain network comprises a Global System for Mobile Communications Terrestrial Radio Access Network (UTRAN) or a GSM EDGE Radio Access Network (GERAN).

3. The method according to claim 1, wherein: the circuit switched fallback indication sent by the user terminal received by the MME is that the user terminal sends the enhanced service request message to the MME.

4. The method according to claim 1, wherein the step of the E-UTRAN switching the user terminal to the CS circuit domain network by using the MME and the jointly registered MSC comprises: the E-UTRAN Determining, by the MME, a target cell to be handed over according to the radio measurement report of the user terminal, and notifying the target cell by the MME; the jointly registered MSC according to the Target cell selects target CS circuit domain network, through redistribution a radio resource access parameter, and notifying, by the E-UTRAN, the radio resource access parameter to the user terminal; and the user terminal switching to the target CS circuit domain according to the radio resource access parameter The internet.

5. The method according to claim 4, wherein: the wireless measurement report of the user terminal comprises: a current wireless measurement report of the user terminal or a last wireless measurement saved by the E-UTRAN report.

The method of claim 4, wherein the step of the jointly registered MSC selecting a target CS circuit domain network according to the target cell comprises: the jointly registered MSC selecting a target MSC according to the target cell, and Notifying the target cell and the required assigned bearer type to the target MSC; and the target MSC determining the target CS circuit domain network according to the target cell, and indicating the required assigned bearer type to The target CS circuit domain network.

The method of claim 6, wherein the step of obtaining, by the jointly registered MSC, the radio resource access parameter comprises: the target CS circuit domain network allocating a radio bearer according to the required bearer type After the resource, the radio resource access parameter is sent by the target MSC to the jointly registered MSC.

8. The method according to claim 1, wherein the step of the user terminal and the jointly registered MSC transmitting service data through the target CS circuit domain network comprises: the user terminal and the jointly registered MSC being established by using a device message The user terminal or the jointly registered MSC establishes a bearer with the remote PSTN to deliver the service data.

9. The method according to claim 8, wherein the user terminal and the jointly registered MSC establish a call by using a device message, The call is established between the user terminal and the jointly registered MSC through the target CS circuit domain network.

10. An evolved packet domain system (EPS) network circuit switched fallback implementation system for dropping a user terminal back into a circuit switched (CS) circuit domain network, including a mobility management entity

(MME), an evolved global mobile communication system terrestrial radio access network (E-UTRAN), and a mobile switching center (MSC), wherein: the MME is configured to: after receiving the circuit switched fallback indication sent by the user terminal, Instructing the E-UTRAN to switch the user terminal to the CS circuit domain network; the E-UTRAN is configured to: jointly register the MSC by the MME and the user terminal when the EPS network is accessed, Switching the user terminal to the CS circuit domain network; the CS circuit domain network is configured to: transmit service data between the user terminal and the jointly registered MSC.

11. The system of claim 10, wherein: said CS circuit domain network comprises a Global System for Mobile Communications Terrestrial Radio Access Network (UTRAN) or a GSM EDGE Radio Access Network (GERAN).

12. The system according to claim 10, wherein: the E-UTRAN is an MSC configured to be jointly registered by the MME and the user terminal when the EPS network is accessed, in the following manner, to the user Switching to the CS circuit domain network: determining, by the MME, the target cell to be handed over according to the radio measurement report of the user terminal, notifying the target cell to the MME; and registering the joint The MME sends the radio resource access parameter to the user terminal; the MME is further configured to: forward the target cell notified by the E-UTRAN to the jointly registered MSC; and the jointly registered MSC is set as: Selecting the CS circuit domain network according to the target cell And the radio resource access parameter is sent to the E-UTRAN, where the user terminal switches to the CS circuit domain network according to the radio resource access parameter.

13. The system of claim 12, further comprising: a target MSC, configured to: receive a required assigned bearer type and the target cell notified by the jointly registered MSC, and determine according to the target cell The CS circuit domain network, the required allocation of the bearer type is indicated to the CS circuit domain network, and the radio resource access parameter sent by the CS circuit domain network is sent to the jointly registered MSC; The jointly registered MSC selects the target MSC according to the target cell; the CS circuit domain network allocates the radio bearer resource according to the required bearer type, and uses the radio resource access parameter Sent to the target MSC.

The system of claim 10, wherein: the user terminal is further configured to: after establishing a call by the jointly registered MSC by using a device message, establishing a bearer with the remote PSTN, and transmitting the service data; The jointly registered MSC is further configured to: after establishing a call by the user terminal through the device message, establish a bearer with the remote PSTN, and deliver the service data.

15. The system of claim 14, wherein: the call is established between the user terminal and the jointly registered MSC over the CS circuit domain network.