WO2015010516A1

WO2015010516A1 - Roaming processing method in circuit switched fallback service, and network element

Info

Publication number: WO2015010516A1
Application number: PCT/CN2014/080803
Authority: WO
Inventors: 刘竞翔; 梁爽; 余磊
Original assignee: 中兴通讯股份有限公司
Priority date: 2013-07-25
Filing date: 2014-06-26
Publication date: 2015-01-29
Also published as: CN104349302A

Abstract

A roaming processing method in a circuit switched fallback service, and a network element. The method comprises: an original mobility management unit in a packet switched (PS) domain receiving a paging request sent by a mobility management unit in a circuit switched (CS) domain; and when the original mobility management unit in the PS domain determines that a user equipment (UE) accesses a new mobility management unit in the PS domain, the original mobility management unit in the PS domain sending a notification message to the mobility management unit in the CS domain, the message carrying notification information used for notifying execution of a mobility management process in the PS domain.

Description

Roaming processing method and network element in circuit domain fallback service

The present invention relates to a system and method for handling roaming in the field of communications, and more particularly to roaming processing methods and network elements in a circuit domain fallback service (including a packet switched domain mobility management unit and a circuit switched domain mobile switching unit). Background technique

The SAE (System Architecture Evolution) network is a new generation wireless network technology developed by the 3GPP (3rd Generation Partnership Project) to replace the traditional circuit domain switching network. It includes LTE (Long Term Evolution) and EPC (evolved Packet Core). Its architecture is shown in Figure 1. The functions of each network element are described below.

User Equipment (UE): User equipment has access to UTRAN/GERAN (Universal Mobile Telecommunication System Radio Access Network/GSM EDGE Radio Access Network, GPRS wireless network, UTRAN Representing 3G, GERAN stands for 2G) and LTE two wireless networks. Due to capacity limitations and energy saving requirements, UEs can only reside in one wireless system (called Single Radio) at the same time. For example, when the UE camps on LTE, it cannot receive paging from UTRAN/GERAN. Message.

Evolved NodeB (eNodeB): Evolved wireless nodes can provide higher uplink and downlink rates, lower transmission delays, and more reliable wireless transmissions on the air interface than UTRAN. The eNodeB provides radio resources for the access of the terminal, and establishes an S1 control plane link with the core network MME.

Mobility Management Entity (MME) is a control plane entity that temporarily stores user data. It is responsible for managing and storing UE context (such as UE/user ID, mobility management status, user security parameters, etc.). The user is assigned a temporary identifier (GUTI), and the MME is responsible for authenticating the user when the user accesses the LTE. The SAE Gateway (System Architecture Evolution GW, SAE GW for short) is a user plane entity responsible for user plane data routing processing. The SAE GW is generally divided into a Serving Gateway GW and a Packet Data Network Gateway (PDN GW). The Serving GW is responsible for the mobility anchor between LTE and UMTS. In the idle state, downlink data triggers MME and SGSN paging. The PDN GW is responsible for UE access. The gateway function of the PDN (Packet Data Network) is to assign a user IP (Internet Protocol) address to the user. The PDN GW and the Serving GW may be combined in one physical entity.

The HSS (Home Subscriber Server) is used to store the subscription data of the user and record the MME name (MME NAME) where the user is located.

Figure 1 also shows the architecture of a traditional circuit domain switching network. The core network element has a Mobile Switching Center (MSC) and a Visitor Location Register (VLR). The MSC and the VLR are physically combined.

The 3G Radio Access Controller (RNC) or the Base Station Controller (BSC) is responsible for controlling and managing the user's wireless activities.

The traditional circuit domain switching network uses a home location register (Home Location Register,

HLR) Saves the user's subscription information and the address of the VLR. In the called call, the HLR can obtain the Mobile Subscriber Roaming Number (MSRN) from the VLR. In Figure 1, the HLR and HSS are served by one physical network element.

The Gateway Mobile Switching Center (GMSC) is used to route calls to the MSC where the user is located. When there is a call to the mobile subscriber, the GMSC obtains the subscriber's MSRN through the HLR, and then routes the call according to the MSRN.

The SG network element of the SAE and the VLR of the traditional circuit domain switching network are connected through the SGs interface.

The replacement of traditional circuit domain switching networks by SAE networks is a long-term trend. In this process, since the traditional circuit domain switching network has better wireless coverage and stable service, it is an effective supplement to the SAE network. When SAE is unable to provide satisfactory traditional voice services, it can instead provide services by traditional circuit domain switching networks. This mechanism of retreating to the traditional circuit domain switching network is called circuit intersection. Switch to Fallback Technology (CSFB, Circuit Switch Fallback). A UE that can fall back to a traditional circuit domain switching network for service is called a Dual Mode Single Radio UE. The CSFB technology establishes an SGs interface between the MME of the SAE and the VLR of the traditional circuit domain switching network. Through the interface, the MME can enable the UE roaming under LTE to trigger the location update process of the traditional circuit domain switching network, so that the UE registers in the traditional circuit domain switching network while the SAE is active. The process includes the following steps:

Step 201: The UE in the LTE is powered on or changes the Tracking Area (TA), initiates an ATTACH or a Tracking Area Update (TAU) operation; Step 202: The MME receives the above message and performs SAE Registration to the HSS;

Step 203: After the registration is successful, the MME derives the location area (LAI) of the UE in the traditional circuit domain switching network by using the tracking area where the UE is located, and locates the corresponding VLR, and sends the location by using the SGs interface. Update request to the VLR;

Step 204: If the VLR does not have user data, or the VLR considers that the user data is unreliable, the VLR sends a location update request to the HLR;

Step 205: The HLR will send an ISD (insert user data request) to the VLR, and the VLR records the user subscription data and returns a response.

Step 206: The HLR returns a success response of the location update, and records the number of the VLR where the user is located. Step 207: The VLR returns a location update complete message to the MME, and modifies the status of the SGs interface to be activated. As a network option, the message may carry a temporary mobile subscriber identity (TMSI, Temporary Mobile Subscriber Identities) allocated by the VLR to the UE.

After the user registers with the HLR, the SGs interface status of the user is marked as active on the MSC/VLR, so that when the called service is received, the MSC/VLR determines the status and pages the user through the SGs interface. The process is shown in Figure 3 and includes the following steps:

Step 301: After receiving the IAM (Initial Address Message) of the external network, the GMSC finds the called HLR according to the called MSISDN number (ie, the user's phone number), and sends an SRI (Send Routing Information) to the HLR. Information) request, with the user's MSISDN number; Step 302: The HLR finds the MSC/VLR number registered by the user according to the MSISDN number, and sends a PRN (Provide Roaming Number) request to the MSC/VLR. The MSC/VLR is the MSC registered by the UE from the LTE/EPC. VLR. The MSC/VLR allocates the temporary subscriber identity MSRN and returns it to the HLR. The MSRN uniquely identifies the MSC/VLR and the called UE; Step 303: The HLR returns an SRI response to the GMSC, with the MSRN;

Step 304: The GMSC then routes the call to the MSC/VLR according to the MSRN.

Step 305: The MSC/VLR checks that the status of the SGs interface of the user is activated, and initiates a CS paging process from the SGs to the MME. The MME then initiates a CS paging process within the LTE, and returns a service request to the MSC/VLR.

Step 306: The UE rolls back to the circuit domain, and initiates a paging response from the traditional circuit domain switching network. Step 307: If necessary, the MSC/VLR performs an access operation;

Step 308: The MSC/VLR sends a call setup request Setup to the UE.

Step 309: The MSC/VLR, the UE completes the remaining called establishment process.

For the above process, there is a possibility that the UE accesses another MME before receiving the paging request, and the UE initiates a tracking area update on the new MME. At this time, the original MME may remove the user because the user is or has already removed the The SGs interface paging message returns a failure response, which causes the call to be unsuccessful. The scenario consists of the following steps:

Step 401: The GMSC receives the IAM message and sends the SRI to the HLR, where the MSISDN number of the user is carried.

Step 402: The HLR sends a PRN request to the recorded MSC/VLR, and the MSC/VLR allocates the temporary user identity MSRN and returns it to the HLR, where the MSC/VLR is recorded as MSC/VLR1;

Step 403: The HLR returns an SRI response to the GMSC with the MSRN.

Step 404: The GMSC routes the call to the MSC/VLR1 according to the MSRN.

Step 405: The MSC/VLR1 checks that the status of the SGs interface of the user is activated, and sends an SGs interface to the MME1.

Step 406: The UE moves to the MME2 before receiving the paging message, and initiates tracking in the MME2. District update request;

Step 407: MME2 interacts with MME1 to acquire the context of the UE.

Step 408: MME1 returns a SGs interface paging reject message because the UE has or is leaving.

Step 409: The MSC/VLR1 receives the message, determines that the current call fails, and sends a release message to the GMSC.

In the above process, because the UE has been or is being removed, the paging of the SGs interface initiated by the MSC/VLR1 fails, and the secondary call cannot be established, causing loss to the customer, so it is necessary to consider optimization. Summary of the invention

The embodiments of the present invention provide a roaming processing method and a network element in a circuit domain fallback service, to solve the technical problem of roaming paging failure in the existing circuit domain fallback service.

The roaming processing method in the circuit domain fallback service of the embodiment of the present invention includes:

The original mobility management unit of the packet switched (PS) domain receives the paging request sent by the mobility management unit of the circuit switched (CS) domain;

The original mobility management unit of the PS domain determines that the user equipment (UE) accesses the new mobility management unit of the PS domain, and sends a message for notification to the mobility management unit of the CS domain, the message carrying to notify that the PS domain is currently being executed. Notification information for the mobile management process.

Optionally, when the new mobility management unit of the PS domain is registered to the new mobility management unit of the CS domain, the new mobility management unit of the PS domain sends an interface location update request to the new mobility management unit of the CS domain. The mobility management unit carrying the CS domain is to allocate identity information of the UE.

Optionally, the message for notification is a paging rejection message, and the notification information is represented by a cause value or a parameter.

Optionally, the mobility management process includes a PS domain location update procedure (TAU) or a handover procedure. In order to solve the above technical problem, the embodiment of the present invention further provides a roaming processing method in another circuit domain fallback service, where the method includes:

The mobility management unit of the CS domain receives the notification for the notification sent by the original mobility management unit of the PS domain. The message carries notification information for notifying that the mobile management process of the PS domain is currently being executed;

Optionally, when the new mobility management unit of the PS domain is registered to the mobility management unit of the CS domain, the mobility management unit of the CS domain continues to perform paging, including: the mobility management unit of the CS domain initiates to the PS domain. Interface paging for the new mobility management unit.

Optionally, when the new mobility management unit of the PS domain is registered to the mobility management unit of the CS domain, before the mobility management unit of the CS domain continues to page, the method further includes:

The mobility management unit of the CS domain receives an interface location update request sent by a new mobility management unit of the PS domain; or the mobility management unit of the CS domain starts a timer after receiving the message for notification, and is in a timed period An interface location update request sent by the new mobility management unit of the PS domain is received.

Optionally, when the new mobility management unit of the PS domain is registered to the new mobility management unit of the CS domain, the mobility management unit of the CS domain continues to paging, including: the mobility management unit of the CS domain notifies the new domain of the CS domain The mobility management unit completes paging to the UE.

Optionally, when the new mobility management unit of the PS domain is registered to the new mobility management unit of the CS domain, before the mobility management unit of the CS domain continues to page, the method further includes:

The mobility management unit of the CS domain receives a location cancel message of a new mobility management unit carrying a CS domain sent by a home location register (HLR); or

The mobility management unit of the CS domain starts the timer after receiving the message for notification, and receives a location cancellation message of the new mobility management unit carrying the CS domain sent by the home location register (HLR) within the timeout period.

The embodiment of the present invention further provides a mobility management unit of a packet switching (PS) domain, where the mobility management unit of the PS domain includes a paging request receiving module and a notification module, and the PS mobility management unit serves as a user in a circuit domain fallback service. When the device's PS domain is the original mobility management unit,

The paging request receiving module is configured to: receive a paging request sent by a mobility management unit of the CS domain; The notification module is configured to: when determining that the user equipment (UE) accesses the new mobility management unit of the PS domain, send a message for notification to the mobility management unit of the CS domain, where the message carries a notification to notify that the PS domain is currently being executed. Management process notification information.

Optionally, the mobility management process includes a PS domain location update procedure (TAU) or a handover procedure. In order to solve the above technical problem, the embodiment of the present invention further provides a mobility management unit of a CS domain, where the mobility management unit of the CS domain includes:

And a message receiving module, configured to: receive a message for notification sent by the original mobility management unit of the PS domain, where the message carries notification information for notifying that the mobility management process of the PS domain is currently being executed;

The paging module continues to be set to continue paging when it is determined that the mobility management process for the PS domain is complete. Optionally, when the new mobility management unit of the PS domain is registered to the mobility management unit of the CS domain, the resume paging unit is an interface page set to initiate a new mobility management unit to the PS domain.

Optionally, the mobility management unit of the CS domain further includes a location update management module, where the new mobility management unit of the PS domain is registered to the mobility management unit of the CS domain, and the location update management mode is set to: receive the PS domain. The interface location update request sent by the new mobility management unit; the resume paging module is configured to: start after the location update management module receives the interface location update request or receives the message for notification The interface location update request is received within the timeout period of the timer to continue paging.

Optionally, when the new mobility management unit of the PS domain is registered to the new mobility management unit of the CS domain, the resume paging unit is configured to notify the new mobility management unit of the CS domain to complete paging to the UE.

Optionally, the new mobility management unit of the PS domain is registered to the new mobility management unit of the CS domain, and the module is further configured to: receive a location cancellation message of the new mobility management unit carrying the CS domain sent by the home location register (HLR) The continuation paging module is configured to: receive the location cancel message within a time limit of a timer that is started after the message receiving module receives the location cancel message or receives the message for notification Continue to page. The method and the network element of the embodiment of the present invention, when the mobile management process of the PS domain is being executed, the original mobility management unit of the PS domain sends a message for notification to the mobility management unit of the CS domain, thereby causing the CS domain to move. The management unit knows that the mobile management process of the PS domain is currently being executed, and continues paging to make the call connected, which improves the call success rate. BRIEF abstract

1 is a framework of a related art SAE and a conventional circuit domain switching network;

2 is a process of registering a traditional circuit domain switching network by a user in LTE in the related art; FIG. 3 is a processing process of a user falling back to a traditional circuit domain switching network and receiving a traditional circuit domain switching network incoming call in LTE in the related art;

FIG. 4 is a flowchart of a process in which a UE moves to a new MME when a called service is paged, causing a call to fail;

5 is a flowchart of Embodiment 1 of a roaming processing method in a circuit domain fallback service according to the present invention, in which a UE moves to a new MME when a called service is paged, and a new MME initiates a location update to the original MSC/VLR, the original MSC. /VLR re-sends the process of paging on the new MME;

6 is a flowchart of Embodiment 2 of a roaming processing method in a circuit domain fallback service according to the present invention, in which a UE moves to a new MME when a called service is paged, and a new MME initiates a location update to a new MSC/VLR, the original MSC. /VLR transfers the call to the new MSC/VLR;

7 is a flowchart of Embodiment 3 of the roaming processing method in the circuit domain fallback service of the present invention, in which the HLR does not support the transmission of the MSC/VLR number, and the new and old MSC/VLRs transmit the number through the Send Identify process;

8 is a schematic diagram of Embodiment 4 of a roaming processing method in a circuit domain fallback service according to the present invention; FIG. 9 is a schematic diagram of Embodiment 5 of a roaming processing method in a circuit domain fallback service according to the present invention; FIG. 10 is a packet switching (PS) of the present invention. Schematic diagram of the module structure of the mobile management unit embodiment of the domain;

11 is a block diagram showing the structure of an embodiment of a mobility management unit of a CS domain according to the present invention. Preferred embodiment of the invention

The embodiments of the present invention mainly relate to a scenario in which a user equipment (UE) falls back to a circuit switched (CS) domain when roaming in a packet switched (PS) domain, where a PS domain mobility management unit (such as a mobility management entity (MME)) is mainly involved. CS domain mobility management unit (such as MSC/VLR).

It should be noted that the mobility management unit of the CS domain means the VLR. But in fact, the VLR and the MSC are generally combined into one network element.

The implementation of the technical solution will be further described in detail below with reference to the accompanying drawings. It should be noted that, in the case of no conflict, the features in the embodiments and the embodiments in the present application may be arbitrarily combined with each other.

Example 1

In the first embodiment, the PS domain mobility management unit is a mobility management entity (MME), and the CS domain mobility management unit is an MSC/VLR.

As shown in FIG. 5, in this embodiment, when the called cell is paged, the UE roams to the new MME, and the new MME initiates location update to the original MSC/VLR, and the original MSC/VLR re-sends to the new MME to page. Embodiment 1 of the roaming processing method in the circuit domain fallback service of the present invention includes the following steps:

Step 501: The GMSC receives the initial address message (IAM) message, and sends the SRI to the HLR, where the MSISDN number of the user is carried.

Step 502: The HLR sends a PRN request to the recorded MSC/VLR, and the MSC/VLR allocates the temporary user identity MSRN and returns it to the HLR.

In this embodiment, before the UE moves, the recorded MSC/VLR is recorded as MSC/VLR1, that is, the original mobility management unit of the packet switching (PS) domain.

Step 503: The HLR returns an SRI response to the GMSC, with the MSRN;

Step 504: The GMSC then routes the call to the MSC/VLR1 according to the MSRN;

Step 505: The MSC/VLR1 checks that the status of the SGs interface of the user is activated, and sends a paging request of the SGs interface to the MME1.

Step 506: The UE moves to the MME2 at this time, and initiates a tracking area update request in the MME2; the MME2 receives the tracking area update, requests the context of the UE from the MME1; and the MME1 returns the UE to the MME2. Context request; at this time, MME1 knows that the UE has moved to the coverage of MME2; MME1 returns a paging reject message to MSC/VLR1, and the paging reject message carries notification information for notifying that the mobility management flow of the PS domain is currently being executed. ;

The notification information may be represented by a cause value or a parameter. Of course, other messages or special messages can be used to implement the notification.

The MSC/VLR1 does not send a release message to the GMSC based on the notification.

Optionally, the MSC/VLR1 starts a timer to monitor whether to continue paging.

Step 507: The MME2 receives the tracking area update, sends an SGs interface location update request to the MSC/VLR1, and after receiving the MSC/VLR1, processes the location update, and returns the location update accept;

Step 508: The MSC/VLR1 initiates an SGs interface paging request to the MME2 according to the notification of the MME1 in step 506.

When the timer is started in step 506, if the location update request message is received in step 507, the MSC/VLR1 initiates a paging request to the SGs interface of the MME2, and if the location update request message is not received within the timeout period, the MSC /VLR1 sends a release message to the GMSC.

In order to ensure the call is successful, the timer can be started a predetermined number of times to extend the waiting time.

Step 509: After receiving the MME, the MME2 searches for the UE under LTE, and returns a service request to the MSC/VLR2.

Step 510: The UE falls back to the circuit domain, and initiates a paging response from the traditional circuit domain switching network. Step 511: If necessary, the MSC/VLR2 performs an access operation;

Step 512: The MSC/VLR2 sends a call setup request Setup to the UE.

Step 513: MSC/VLR2, the UE completes the remaining called establishment process.

Example 2

In the second embodiment, the PS domain mobility management unit is a mobility management entity (MME), and the CS domain mobility management unit is an MSC/VLR.

As shown in FIG. 6, in the second embodiment, when the called page is called, the UE roams to the new MME, and the new MME initiates a location update to the new MSC/VLR, and the original MSC/VLR transfers the call to the new MSC/VLR. MSC/VLR. The method 2 of the roaming processing method in the circuit domain fallback service of the present invention includes the following steps: Step 601: The GMSC receives the IAM message and sends the SRI to the HLR, where the MSISDN number of the user is carried.

Step 602: The HLR sends a PRN request to the recorded MSC/VLR, and the MSC/VLR allocates the temporary user identity MSRN and returns it to the HLR. The MSC/VLR is recorded as MSC/VLR1;

Step 603: The HLR returns an SRI response to the GMSC with the MSRN.

Step 604: The GMSC then routes the call to the MSC/VLR1 according to the MSRN;

Step 605: The MSC/VLR1 checks that the status of the SGs interface of the user is activated, and sends a paging request of the SGs interface to the MME1.

Step 606: The UE accesses the MME2, and initiates a tracking area update request in the MME2. The MME2 receives the tracking area update, and requests the context of the UE from the MME1. The MME1 returns the context request of the UE to the MME2, and the MME1 learns that the UE has moved to the MME2. Coverage; MME1 returns a paging reject message to the MSC/VLR1, the paging reject message carrying notification information for notifying that the mobility management procedure of the PS domain is currently being executed;

Optionally, the MSC/VLR1 starts a timer to monitor whether to continue paging.

Step 607: MME2 receives the tracking area update, and sends an SGs interface location update request to

MSC/VLR2;

Step 608: The MSC/VLR2 sends a location update message to the HLR, carrying the number of the MSC/VLR2;

Step 609: The HLR processes the location update request, inserts the user data into the MSC/VLR2, returns a location update success response, and the MSC/VLR2 returns the SGs interface location update to the MME2. Step 610: The HLR simultaneously sends a location cancel message to the MSC/VLR1. Carry the number of the MSC/VLR2; Step 611: The MSC/VLR1 receives the location cancellation message and the notification in step 606, stops paging to the original MME, uses the number addressing of the MSC/VLR2, and sends a request for providing a roaming number to the MSC/VLR2;

When the timer is started in step 606, if the location cancel message of step 611 is received within the time limit, the MSC/VLR1 sends a request for providing a roaming number to the MSC/VLR2, and if the location cancel message is not received within the time limit, The MSC/VLR1 sends a release message to the GMSC.

In order to ensure the call is successful, the timer can be started multiple times to extend the waiting time.

MSC/VLR1 may initiate a resume paging by sending a roaming number request to MSC/VLR2. Alternatively, MSC/VLR1 may also send a resume call processing message to the GMSC, which will reroute the call to MSC/VLR2; The call will be handled between the GMSC and MSC/VLR2. This process is a prior art known to those skilled in the art and will not be described herein.

It can be understood that, as long as the mobile management unit of the CS domain sends a message, the new mobile management unit directly or indirectly notifies the CS domain to page the UE, thereby completing the purpose of the call, and the present invention moves the CS domain. Messages sent by the management unit are not limited.

Step 612: MSC/VLR2 returns a new roaming number MSRN2;

Step 613: The MSC/VLR1 routes the call to the MSC/VLR2 through the MSRN2. Step 614: The MSC/VLR2 performs paging on the SGs interface. After receiving the MME2, the MME2 searches for the UE under LTE, and returns a service request to the MSC/VLR2.

Step 615: The UE falls back to the circuit domain, and initiates a paging response from the traditional circuit domain switching network. Step 616: If necessary, the MSC/VLR2 performs an access operation;

Step 617: The MSC/VLR2 sends a call setup request Setup to the UE.

Step 618: MSC/VLR2, the UE completes the remaining called establishment process.

Example 3

In the third embodiment, the HLR does not support the forwarding of the MSC/VLR2 number, and the transmission of the MSC/VLR2 is implemented by the transmission identification request between the MSC/VLR2 and the MSC/VLR1. As shown in FIG. 7, Embodiment 3 of the roaming processing method in the circuit domain fallback service of the present invention includes the following steps: Step 701: The GMSC receives the IAM message and sends the SRI to the HLR, where the MSISDN number of the user is carried.

Step 702: The HLR sends a PRN request to the recorded MSC/VLR, and the MSC/VLR allocates the temporary user identity MSRN, and returns it to the HLR, where the MSC/VLR is recorded as MSC/VLR1;

Step 703: The HLR returns an SRI response to the GMSC with the MSRN.

Step 704: The GMSC then routes the call to the MSC/VLR1 according to the MSRN.

Step 705: The MSC/VLR1 checks that the status of the SGs interface of the user is activated, and sends a paging request of the SGs interface to the MME1.

Step 706: The UE accesses the MME2, and initiates a tracking area update request at the MME2. MME2 receives the tracking area update, requests the context of the UE from MME1; MME1 returns the context request of the UE to MME2, at which time MME1 knows that the UE has moved to the coverage of MME2; MME1 returns a paging reject message to MSC/VLR1, the seeking The call rejection message carries notification information for notifying that the mobility management process of the PS domain is currently being executed;

The MSC/VLR1 does not send a release message to the GMSC based on the notification. Optionally, the MSC/VLR1 starts a timer to monitor whether to continue paging.

Step 707: The MME2 receives the tracking area update, and sends an SGs interface location update request to the MSC/VLR2, where the MSC/VLR1 carries the identifier assigned by the UE, such as TMSI.

Step 708: The MSC/VLR2 performs a location update process, and sends a Send Identify Request to the MSC/VLR1, where the TMSI is used, and carries the MSC/VLR2 number;

Step 709: After receiving the MSC/VLR1, record the MSC/VLR2 number and return a response; Step 710: The MSC/VLR2 sends a location update message to the HLR;

Step 711: The HLR processes the location update request, inserts the user data into the MSC/VLR2, returns a location update success response, and the MSC/VLR2 returns the SGs interface location update to the MME2; Step 712: The HLR sends a location cancel message to the MSC/VLR1;

Step 713: The MSC/VLR1 receives the location cancel message, stops the paging to the original MME according to the notification in step 706, uses the number of the recorded MSC/VLR2 to address, and sends a roaming number request to the MSC/VLR2;

When the timer is started in step 706, if the location cancel message of step 713 is received within the time limit, the MSC/VLR1 sends a request for providing a roaming number to the MSC/VLR2. If the location cancel message is not received within the time limit, the MSC /VLR sends a release message to the GMSC.

Step 714: The MSC/VLR2 returns a new roaming number MSRN2;

Step 715: The MSC/VLR1 routes the call to the MSC/VLR2 through the MSRN2.

Step 716: The MSC/VLR2 performs paging on the SGs interface, and after receiving the MME2, the MME2 searches for the UE under LTE, and returns a service request to the MSC/VLR2.

Step 717: The UE falls back to the circuit domain, and initiates a paging response from the traditional circuit domain switching network. Step 718: If necessary, the MSC/VLR2 performs an access operation;

Step 718: The MSC/VLR2 sends a call setup request Setup to the UE.

Step 710: MSC/VLR2, the UE completes the remaining called establishment process.

The above embodiments 1-3 are also applicable to the process in which the UE initiates a location update request to the MSC/VLR 2 when connecting to the new MME2. At this time, the PS domain performs a handover process instead of a location update process, and the difference between the two is reflected in step 506 (606, 706). The differences are as follows:

In step X06, the UE is currently performing handover of the PS domain due to the location shift. The MME1 receives the handover request initiated by the base station, and determines that it needs to reselect an MME, which is assumed to be MME2. The MME1 returns a paging reject message to the MSC/VLR1, indicating that the UE is performing the mobility management procedure of the PS domain. The MSC/VLR1 does not send a release message to the GMSC according to the indication. Optionally, the MSC/VLR1 starts a timer to monitor whether to continue paging. The MME1 performs a subsequent PS domain handover procedure. After the PS domain handover (Handover, HO) is completed, the UE initiates a location update request through the MME2. The subsequent steps of FIG. 5 to FIG. 7 are respectively performed according to different situations, and the steps are similar to those described above, and are not described again. The present invention is also applicable to the case where the MME discovers that the UE accesses the PS domain mobility management unit, that is, the SGSN of the GERAN/UTRAN. In this case, the SGSN is a new mobility management unit of the PS domain, and the original mobility management unit of the PS domain, that is, the MME. The MSC/VLR can also be notified by message.

In addition, considering the saving of network resources, the message for notification can be extended to the Gs interface of the SGSN and the MSC/VLR, that is, when the SGSN is processing the mobility management procedure, the MSC/VLR is notified. After receiving the MSC/VLR, it may choose to initiate CS domain paging immediately or wait for subsequent retransmission joint paging according to different network modes.

The method of the present invention is described below from the perspective of the mobility management unit of the PS domain and the original mobility management unit of the CS domain:

Example 4

As shown in FIG. 8, the fourth embodiment of the roaming processing method in the circuit domain fallback service of the present invention includes: Step 801: The original mobility management unit of the packet switched (PS) domain receives the mobile management unit of the circuit switched (CS) domain. Paging request

When the new mobility management unit of the PS domain registers with the new mobility management unit of the CS domain, the new mobility management unit of the PS domain carries the CS in the interface location update request sent by the new mobility management unit of the CS domain. The mobility management unit of the domain allocates identification information of the UE.

Step 802: The original mobility management unit of the PS domain determines that the user equipment (UE) accesses the new mobility management unit of the PS domain, and sends a message for notification to the mobility management unit of the CS domain, where the message is carried to notify that the current execution is being performed. Notification information for the mobile management process of the PS domain.

The mobility management process includes a PS Domain Location Update Process (TAU) or a handover procedure.

The message for notification is a paging rejection message, and the notification information is represented by a cause value or a parameter.

Example 5

As shown in FIG. 9, the fifth embodiment of the roaming processing method in the circuit domain fallback service of the present invention includes: Step 901: The mobility management unit of the CS domain receives a message for notification sent by the original mobility management unit of the PS domain, The message carries notification information for notifying that the mobile management process of the PS domain is currently being executed; Step 902: The mobility management unit of the CS domain determines to continue paging when the mobility management process of the PS domain is completed.

When the new mobility management unit of the PS domain registers with the mobility management unit of the CS domain, the mobility management unit of the CS domain continues to page that the mobility management unit of the CS domain initiates new mobility management to the PS domain. Interface paging of the unit.

When the new mobility management unit of the PS domain registers with the new mobility management unit of the CS domain, the mobility management unit of the CS domain continues to page that the mobility management unit of the CS domain notifies the new mobility management unit of the CS domain to complete Paging to the UE.

When the new mobility management unit of the PS domain is registered to the new mobility management unit of the CS domain,

Before the mobile management unit of the CS domain continues to page, the method further includes:

As described above, the message for notification is a paging rejection message, and the notification information is represented by a cause value or a parameter.

In order to implement the foregoing method, the embodiment of the present invention further provides a mobility management unit of a packet switched (PS) domain, as shown in FIG. 10, when the original mobility management unit of the PS domain of the user equipment in the circuit domain fallback service is used, The mobile management unit of the PS domain includes:

a paging request receiving module, configured to receive a paging request sent by a mobility management unit of the CS domain; The notification module is configured to: when determining that the user equipment (UE) accesses the new mobility management unit of the PS domain, send a message for notification to the mobility management unit of the CS domain, where the message carries a notification to notify that the PS domain is currently being executed. Notification information for the mobile management process.

Optionally, when the mobility management unit of the PS domain is used as a new mobility management unit of the PS domain of the user equipment in the circuit domain fallback service and is registered to the new mobility management unit of the CS domain, the location update management module is further configured to: An interface location update request sent to the new mobility management unit of the CS domain, where the identifier information of the UE is carried.

Preferably, the message is a paging reject message, and the notification information is represented by a cause value or a parameter.

Optionally, the mobility management process includes a PS domain location update procedure (TAU) or a handover procedure. In order to implement the foregoing method, the embodiment of the present invention further provides a mobility management unit of the CS domain. As shown in FIG. 11, the mobility management unit of the CS domain includes:

The message receiving module is configured to: receive a message for notification sent by the original mobility management unit of the PS domain, where the message carries notification information for notifying that the mobility management process of the PS domain is currently being executed; and the paging module is set to: The paging is continued when it is determined that the mobility management process of the PS domain is completed. Optionally, when the new mobility management unit of the PS domain is registered to the mobility management unit of the CS domain, the resume paging module is configured to: initiate an interface paging to a new mobility management unit of the PS domain.

Optionally, the mobility management unit of the CS domain further includes a location update management module, where the new mobility management unit of the PS domain is configured to receive a new mobility management unit of the PS domain when registering to the mobility management unit of the CS domain. The transmitted interface location update request; the resume paging module receives the timer within a time period after the location update management module receives the interface location update request or receives the message for notification The interface location update request continues to page.

Optionally, when the new mobility management unit of the PS domain is registered to the new mobility management unit of the CS domain, the resume paging module is configured to notify the new mobility management unit of the CS domain to complete paging to the UE.

Optionally, the new mobility management unit of the PS domain is registered to the new mobility management unit of the CS domain, and the module is further configured to: receive a location cancellation message of the new mobility management unit carrying the CS domain sent by the home location register (HLR) The continuation paging module is set to a timing of a timer that is started after the message receiving module receives the location cancel message or receives the message for notification The page is not received until the location cancellation message is received.

The method and the network element of the embodiment of the present invention, when the mobile management process of the PS domain is being executed, the original mobility management unit of the PS domain sends a message for notification to the mobility management unit of the CS domain, thereby causing the CS domain to move. The management unit knows that the mobile management process of the PS domain is currently being executed, and continues paging to make the call connected, which improves the call success rate.

The embodiment of the present invention further provides a computer program, including program instructions, when the program instruction is executed by the mobility management unit, so that the mobility management node can perform the method of the embodiment of the present invention.

Embodiments of the present invention also provide a carrier carrying the above computer program.

One of ordinary skill in the art will appreciate that all or a portion of the above steps may be accomplished by a program instructing the associated hardware, such as a read-only memory, a magnetic disk, or an optical disk. Alternatively, all or part of the steps of the above embodiments may also be implemented using one or more integrated circuits (using an FPGA or an ASIC chip). Correspondingly, each module/unit in the above embodiment may be implemented in the form of hardware or in the form of a software function module. The invention is not limited to any specific form of combination of hardware and software.

The above is only a preferred embodiment of the present invention, and of course, the present invention may be embodied in various other embodiments without departing from the spirit and scope of the invention. Corresponding changes and modifications are intended to be included within the scope of the appended claims.

Industrial applicability

The embodiment of the present invention enables the mobility management unit of the CS domain to know that the mobile management process of the PS domain is currently being performed, and continues paging to make the call connected, thereby improving the call success rate.

Claims

claims

1. A roaming processing method in circuit domain fallback service, the method includes:

The original mobility management unit in the packet switching (PS) domain receives the paging request sent by the mobility management unit in the circuit switching (CS) domain;

The original mobility management unit of the PS domain determines that the user equipment (UE) has accessed the new mobility management unit of the PS domain, and sends a notification message to the mobility management unit of the CS domain. The message carries a notification message that is currently being used. Notification information for executing the mobility management process of the PS domain.

2. The method of claim 1, further comprising: when the new mobility management unit of the PS domain registers with the new mobility management unit of the CS domain, the new mobility management unit of the PS domain registers with the CS domain The new mobility management unit sends an interface location update request, wherein the mobility management unit carrying the CS domain assigns the identification information of the UE.

3. The method of claim 1, wherein: the message used for notification is a paging rejection message, and the notification information is represented by a cause value or a parameter.

4. The method of claim 1, wherein: the mobility management process includes a PS domain location update process (TAU) or a handover process.

5. A roaming processing method in circuit domain fallback service, the method includes:

The mobility management unit of the circuit-switched (CS) domain receives a message for notification sent by the original mobility management unit of the packet-switched (PS) domain, where the message carries notification information for notifying that the mobility management process of the PS domain is currently being executed;

6. The method of claim 5, wherein: when the new mobility management unit of the PS domain registers with the mobility management unit of the CS domain, continuing paging by the mobility management unit of the CS domain includes: the CS The mobility management unit of the domain initiates an interface paging to the new mobility management unit of the PS domain.

7. The method of claim 5, wherein: when the new mobility management unit of the PS domain registers with the mobility management unit of the CS domain, before the mobility management unit of the CS domain continues paging, the Methods also include:

The mobility management unit of the CS domain receives the interface location update request sent by the new mobility management unit of the PS domain; or the mobility management unit of the CS domain starts a timer after receiving the message for notification, and at the scheduled time The interface location update request sent by the new mobility management unit of the PS domain is received.

8. The method of claim 5, wherein: when the new mobility management unit of the PS domain registers with the new mobility management unit of the CS domain, the mobility management unit of the CS domain continuing paging includes: the CS domain The mobility management unit notifies the new mobility management unit of the CS domain to complete paging the UE.

9. The method of claim 5, wherein: when the new mobility management unit of the PS domain registers with the new mobility management unit of the CS domain, and before the mobility management unit of the CS domain continues paging, the method further includes :

The mobility management unit of the CS domain receives the location cancellation message sent by the home location register (HLR) carrying the new mobility management unit of the CS domain; or

The mobility management unit of the CS domain starts a timer after receiving the notification message, and receives a location cancellation message carrying a new mobility management unit of the CS domain sent by the home location register (HLR) within the timer.

10. The method of claim 5, wherein: the message used for notification is a paging rejection message, and the notification information is represented by a cause value or a parameter.

11. A mobility management unit in the packet switching (PS) domain. The mobility management unit in the PS domain includes a paging request module and a notification module, where:

When the PS mobility management unit serves as the original mobility management unit of the PS domain of the user equipment in the circuit domain fallback service, the paging request module is configured to: receive the paging request sent by the mobility management unit of the CS domain;

The notification module is configured to: when determining that the user equipment (UE) accesses a new mobility management unit of the PS domain, send a message for notification to the mobility management unit of the CS domain, and the message carries a notification that the PS domain is currently being executed. Notification information for the mobile management process.

12. The mobility management unit of the PS domain according to claim 11, wherein: the message used for notification is a paging rejection message, and the notification information is represented by a cause value or a parameter.

13. The PS domain mobility management unit according to claim 11, wherein: the mobility management process includes a PS domain location update process (TAU) or a handover process.

14. A mobility management unit in a circuit switched (CS) domain. The mobility management unit in the CS domain includes:

A message receiving module, which is configured to: receive a message for notification sent by the original mobility management unit of the Packet Switching (PS) domain, where the message carries notification information for notifying that the mobility management process of the PS domain is currently being executed; and

Continue paging module, which is set to: continue paging when it is determined that the mobility management process of the PS domain is completed.

15. The mobility management unit of the CS domain according to claim 14, wherein: the continued paging module is configured to: when a new mobility management unit of the PS domain registers with the mobility management unit of the CS domain, initiate a call to the PS Interface paging for the domain's new mobility management unit.

16. The mobility management unit of the CS domain according to claim 14, the mobility management unit of the CS domain further comprising a location update management module, which is configured to: register the new mobility management unit of the PS domain to the CS domain When the mobile management unit of the PS domain receives the interface location update request sent by the new mobility management unit of the PS domain; the continued paging module is configured to: when the location update management module receives the interface location update request or receives the Paging is continued only after the interface location update request is received within the timer period of the timer started after the notification message.

17. The mobility management unit of the CS domain as claimed in claim 14, wherein: the continued paging module is configured to: notify the CS when the new mobility management unit of the PS domain registers with the new mobility management unit of the CS domain. The new mobility management unit of the domain completes paging of the UE.

18. The mobility management unit of the CS domain according to claim 14, wherein: the new mobility management unit of the PS domain is registered to the new mobility management unit of the CS domain, and the mobility management unit of the CS domain serves as the original CS domain. When the mobile management unit is a mobile management unit, the message receiving module is also configured to: receive the location cancellation message of the new mobile management unit carrying the CS domain sent by the home location register (HLR); The continued paging module is configured to: receive the location cancellation message within a time period of a timer started after the message receiving module receives the location cancellation message or receives the message for notification. Continue paging.

19. A computer program, including program instructions, which when executed by a mobile management unit, enable the mobile management unit to execute the method described in any one of claims 1-10.

20. A carrier carrying the computer program of claim 19.