WO2012167467A1

WO2012167467A1 - Processing method, mobile management entity and system for circuit switched domain service to return to conventional network

Info

Publication number: WO2012167467A1
Application number: PCT/CN2011/076884
Authority: WO
Inventors: 陈中平; 吴问付; 张艳平
Original assignee: 华为技术有限公司
Priority date: 2011-07-06
Filing date: 2011-07-06
Publication date: 2012-12-13
Also published as: WO2012167521A1

Abstract

The present invention relates to a processing method, mobile management entity (MME) and system for a circuit switched domain service to return to a conventional network. The method includes: an MME receiving an extension service request message sent from user equipment; the MME retaining the local IP access public data network (LIPA PDN) connection of the user equipment, which user equipment only has one LIPA PDN connection and the user equipment is within a non-local IP access (LIPA) authorization area; the MME sending indication information to an evolved UMTS (universal mobile telecommunications system) terrestrial radio access network (E-UTRAN), which indication information indicates that the E-UTRAN moves the user equipment to another network; and the MME releasing the LIPA PDN connection. The method can ensure that before the MME sends the indication information to the E-UTRAN, the user equipment will not be forced to reinitiate an attachment flow due to being separated, thus ensuring that the CSFB will not be interrupted and improving the service experience of the user.

Description

Method for processing circuit switched domain services to return to traditional networks, mobile management entities and systems

The present invention relates to the field of communications technologies, and in particular, to a method, a mobility management entity, and a system for processing a circuit switched domain service back to a legacy network. Background technique

LIPA (Local IP Access) is a data offloading technology based on the HeNB (Home evolved Node B) network. The UE (User Equipment) can directly access other IP devices in the home or enterprise network through the HeNB without traversing the user plane of the mobile operator network. Compared with the carrier's core network, this part of the service is directly The traffic is offloaded from the HeNB, thereby reducing the load and transmission costs of the core network. When a user uses a LIPA service, the UE needs to establish a PDN (Public Data Network) connection for this purpose, which is called a Local IP Access Public Data Network (LIPA PDN) connection. In addition, LIPA does not support mobility, that is, there is a regional restriction. When the network device discovers that the UE leaves the authorized area of LIPA, the network device will release (similar to delete, deactivate) the LIPA PDN connection.

CSFB (CS Fallback, CS Service Return to Traditional Network; CS, Circuit Switched Domain, Circuit Switched Domain) technology was proposed to reuse existing CS services in an EPS (Evolved Packet System) network. The user equipment is registered in the EPS network by performing a joint attach to the MSC (Mobile Switch Center) of the circuit domain. When the CS service needs to be performed, the user equipment returns to the second generation mobile communication according to the requirements of the EPS network (The 2nd Generation; Abbreviation: 2G) / The third generation mobile communication (The 3rd Generation; referred to as: 3G) The network completes the CS service.

The prior art has at least the following problems:

In the case where the user equipment has only one LIPA PDN connection, when the mobility management entity (Mobility) Management Entity, referred to as: MME) When CSFB is discovered, the CSFB is interrupted after the user equipment leaves the LIPA authorized area, thus affecting the user experience. Summary of the invention

The embodiment of the present invention provides a method, an MME, and a system for processing a circuit switched domain service to return to a legacy network, and solves the problem that when the MME performs CSFB, the user equipment leaves the network device when the user equipment has only one LIPA PDN connection. After the LIPA authorized zone, CSFB was forced to interrupt the issue.

Embodiments of the present invention provide a method for processing a circuit switched domain service back to a legacy network, including:

Receiving, by the MME, an extended service request message sent by the user equipment, where the extended service request message is used to indicate that the service of the CSFB is performed;

The MME retains a LIPA PDN connection of the user equipment, the user equipment has only one LIPA PDN connection and the user equipment is in a non-LIPA authorized area;

The MME sends indication information to the E-UTRAN, the indication information instructing the E-UTRAN to move the user equipment to other networks;

The MME releases the LIPA PDN connection.

An embodiment of the present invention further provides an MME, including:

a receiving module, configured to receive an extended service request message sent by the user equipment, where the extended service request message is used to indicate that the CSFB service is performed;

a reservation module, configured to reserve a LIPA PDN connection of the user equipment, the user equipment has only one LIPA PDN connection and the user equipment is in a non-LIPA 4 authorized area;

a sending module, configured to send indication information to the E-UTRAN, where the indication information indicates that the E-UTRAN moves the user equipment to another network;

A release module that is used to release the LIPA PDN connection.

Embodiments of the present invention also provide a system for processing CSFB, including E-UTRAN and MME; when the MME sends indication information to the E-UTRAN, instructing the E-UTRAN to move the user equipment to other networks, the E-UTRAN moves the user equipment to the other network.

In the embodiment of the present invention, when the user equipment has only one LIPA PDN connection, when the MME performs CSFB, it finds that the user equipment leaves the LIPA authorized area, and then sends the indication information to the E-by retaining the LIPA PDN connection of the user equipment. The UTRAN indicates that the user equipment is moved to another network, and then the LIPA PDN connection is released, which ensures that before the MME sends the indication information to the E-UTRAN, the user equipment does not cause the user equipment to re-initiate the attach procedure because it is separated, thereby ensuring CSFB will not be interrupted, improving the user's business experience. DRAWINGS

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the embodiments or the description of the prior art will be briefly described below. Obviously, the drawings in the following description are only It is a certain embodiment of the present invention, and other drawings can be obtained from those skilled in the art without any inventive labor.

1 is a schematic flowchart of a method according to Embodiment 1 of the present invention;

2 is a schematic flowchart of a method according to Embodiment 2 of the present invention;

3 is a schematic flowchart of a method according to Embodiment 3 of the present invention;

4 is a schematic structural diagram of a first MME according to Embodiment 4 of the present invention;

FIG. 5 is a schematic structural diagram of a second MME according to Embodiment 4 of the present invention;

FIG. 6 is a schematic structural diagram of a third MME according to Embodiment 4 of the present invention;

FIG. 7 is a schematic structural diagram of a fourth MME according to Embodiment 4 of the present invention;

FIG. 8 is a schematic structural diagram of a system according to Embodiment 5 of the present invention. detailed description

The technical solutions in the embodiments of the present invention are clearly and completely described in the following with reference to the accompanying drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and Not all embodiments. All other embodiments obtained by a person of ordinary skill in the art based on the embodiments of the present invention without any inventive effort are within the scope of the present invention.

The serial numbers of the following embodiments of the present invention are merely for the description, and do not represent the advantages and disadvantages of the embodiments.

Network Architecture

General Packet Radio Service (GPRS) / Universal Mobile Telecommunications System (UMTS) is defined by the 3rd Generation Partnership Project (3GPP) organization. A mobile communication network includes a radio access network (RAN) and a core network (Core Network: CN). The CN is logically divided into a Circuit Switched Domain (CS) domain and a Packet Switched Domain (PS) domain. The CS domain mainly handles voice services, and the PS domain mainly handles packet services. The signaling plane control entity of the CS domain is a Mobile Switch Center (MSC)/Visitor Location Register (VLR), and the signaling plane control entity of the PS domain is a serving GPRS support node (Serving) GPRS Support Node; Abbreviation: SGSN), SGSN and MSC/VLR can be connected through Gs interface.

In order to meet the challenges of wireless broadband technology and maintain the leading edge of 3GPP networks, 3GPP has developed a Long Term Evolution (LTE) program and defined a new mobile communication network architecture under the guidance of the evolution plan. The architecture is flatter than the current GPRS/UMTS, and only the packet domain is reserved, so it can be called an Evolved Packet System (EPS) network.

The core network of the evolved packet system network mainly includes a Mobility Management Entity (MME), a Serving Gateway (S-GW), and a Packet Data Network Gateway (referred to as a Packet Data Network Gateway). : P-GW ) Three logical functions. The access network of the evolved packet system network is an evolved UMTS Territorial Radio Access Network (E-UTRAN). In the following embodiments, the evolved packet network is referred to as an E-UTRAN network, where E-UTRAN The physical network element may be an eNB (evolved Node B) or an HeNB.

Business scene

In order to provide CS services to UEs in an E-UTRAN network, an architecture for connecting to CS over an E-UTRAN network is introduced. The MME is connected to the MSC of the CS through the SGs interface, and the CS service is provided to the UE in the E-UTRAN network.

Under the above architecture, the UE first initiates an EMM (EPS mobility management) joint process in the E-UTRAN network, for example: a combined attach procedure or a joint tracking area/location area update process ( Combined TA/LA Updating Procedure ). Through the joint process, the MME and the MSC create an SGs association for the UE. For the Mobile Originating (MO) process: First, the UE sends an EXTENDED SERVICE REQUEST message to the MME. Second, the MME instructs the E-UTRAN to switch the UE to another network (for example, a 2G network or a 3G network); The UE eventually returns to the other network to execute the caller. For the called procedure, that is, the MSC receives a Mobile Terminated (MT): First, the MSC sends a paging message to the MME through the SGs interface; second, the MME performs CS paging on the UE through the E-UTRAN network; After the CS paging message, the caller is returned from the E-UTRAN to the other network by a similar calling process.

In the E-UTRAN network, the UE accesses through the HeNB. The UE can use the LIPA service to directly access other IP devices in the home or enterprise network. In a specific implementation, the HeNB is configured with a local gateway (Local Gateway, L-GW for short) or the HeNB is bound to an L-GW. In fact, the UE accesses other IPs in the home or enterprise network through the L-GW. equipment. When the UE uses the LIPA service, it needs to establish a LIPA PDN connection. When the UE leaves the authorized area of the LIPA, it needs to release (similarly, delete, deactivate) the LIPA PDN connection. In the following embodiments, the UE leaves the HeNB, for example, from the HeNB to the eNB, and the UE is considered to have left the LIP A authorized area.

When the UE has only one LIPA PDN connection, if the UE is handed over from the HeNB to the eNB, whether the UE is the calling or the called, the extended service request message sent to the MME is CSFB, and the MME finds that the UE leaves the HeNB, and the LIP is released. A PDN connection, causing the UE to be separated, the current CS service Forced to terminate, affecting the user's business experience.

Based on the foregoing scenario, the embodiment of the present invention solves the problem that CSFB is forced to be interrupted after the user equipment leaves the LIPA authorized area when the MME performs CSFB in the case that the user equipment has only one LIPA PDN connection, as follows:

Embodiment 1

Embodiment 1 of the present invention provides a method of processing CSFB. The method does not release the LIPA PDN connection temporarily when the user equipment has only one LIPA PDN connection and the user equipment is in the non-LIP A authorized area, but waits for a suitable time to release the LIPA PDN connection, ensuring that the user equipment moves to other networks. At the same time, it can guarantee the principle that LIPA PDN connection does not support mobility.

FIG. 1 is a schematic flowchart of a method provided in Embodiment 1, as shown in FIG. 1, the specific process is as follows:

101: receiving an extended service request message of the user equipment;

The MME receives an extended service request message sent by the user equipment, and the extended service request message is used to indicate the service of the CSFB.

102: retain the LIPA PDN connection of the user equipment;

The MME retains the LIPA PDN connection of the user equipment, where the user equipment has only one LIPA PDN connection and the user equipment is in a non-LIP A authorization area;

103: Send indication information to the E-UTRAN, where the indication information indicates that the E-UTRAN moves the user equipment to another network;

The MME sends indication information to the E-UTRAN, which indicates that the E-UTRAN moves the user equipment to other networks.

104: Release the LIPA PDN connection.

Wherein, the method is performed by the MME.

The extended service request message may be initiated based on the calling process or may be initiated based on the called process.

The user equipment is in the non-LIP A authorized area, where the user equipment leaves the HeNB supporting the LIPA PDN connection of the user equipment, and may be handover to the eNB or handover to another HeNB, etc. Wait. In general, the HeNB and the L-GW are bound together, and the HeNB can learn the L-GW address (generally the IP address). The HeNB reports the LG W address in the process of establishing the association (S1 association) with the MME each time. To the MME, for example, the HeNB reports the Initial User Message (Surface) message to the MME through the Initial UE message (L-GW address). The MME will save the L-GW address for the first time, and then the MME will obtain the L again. - GW address, the MME checks whether the L-GW address changes according to the saved L-GW address. If the L-GW changes (eg, moves from one HeNB to another HeNB) or does not receive the L-GW address (eg, from one The HeNB moves to another eNB. Generally, the eNB does not configure or bind one L-GW, which means that the UE leaves the HeNB.

The LIPA PDN connection of the user equipment is reserved. When the user equipment has only one LIPA PDN connection and the user equipment is in the non-LIP A authorization area, the LIPA PDN connection only for the user equipment is not released.

In the prior art, when the user equipment has only one LIPA PDN connection and the user equipment is in a non-LIPA authorized area, the MME releases the LIPA PDN connection, and the MME separates the user equipment because only one LIPA PDN connection is released. Specifically, the MME sends a Service Reject message to the user equipment, and the message indicates implicit separation. After the user equipment receives the service rejection message, if the reason for the rejection in the message indicates implicit separation, the user equipment will re-initiate. The attach process causes CSFB to be interrupted.

Therefore, retaining the LIPA PDN connection of the user equipment can prevent the user equipment from re-initiating the attach procedure because it is separated, thus ensuring that CSFB will not be interrupted.

Optionally, the LIPA PDN connection of the user equipment is reserved, including one or any combination of the following manners: Method 1: Setting a flag in the UE context (UE Context) (for example: LIPA PDN connection needs to be deactivated, ie LIPA PDN need deactivated flag), used to indicate that the UE's LIPA PDN connection needs to be released, and retains the LIPA PDN connection indicated by the flag that needs to be released.

The flag is used to indicate that the LIPA PDN connection of the UE needs to be released, that is: the LIPA PDN connection is not temporarily released, but the LIPA PDN connection is released after step 103. Preferably, after the user equipment context release request (UE Context Release Request) message is received, the LIP A PDN connection may also be released.

Therefore, further, releasing the LIPA PDN connection includes: releasing a LIPA PDN connection indicated by the release flag that needs to be released. Preferably, releasing the LIPA PDN connection comprises: releasing the LIPA PDN connection indicated to be released after the user equipment release request message is received.

Manner 2: Set a timer, which is used to control the lifetime of the LIPA PDN connection and keep the LIPA PDN connection that is controlled by the timer.

The timer is used to control the lifetime of the LIPA PDN connection. When the timer does not time out, there is no other release condition (for example, a certain message is received and the LIPA PDN connection is released). The LIPA PDN connection can still be reserved for the current connection. When the timer expires, it indicates that the LIPA PDN should be released.

Specifically, 1) when the timer does not time out and the user equipment context release request message is not received, the LIPA PDN connection is temporarily not released; 2) when the timer does not time out, the user equipment context is released. After the message is requested, the LIPA PDN connection is released; 3) When the timer expires, the LIPA PDN connection is released.

Therefore, further, releasing the LIPA PDN connection includes:

1) When the timer expires, release the LIPA PDN connection that is controlled by the timer; or 2) When the timer does not time out, after receiving the user equipment context release request message, release the timer LIPA PDN connection that controls the time to live.

It should be understood by those skilled in the art that, by way of example of the above two modes, an equivalent modification of the above two modes may also be implemented to implement a LIPA PDN connection that retains the user equipment.

In general, the indication information can be included in the message to be sent. The message of this embodiment may be a UE Initial Context Setup Request message or a User Equipment Context Modification Request message (UE Context Modification).

The indication information may specifically be a CS Fallback Indicator information returned by the CS service or other information used to instruct the E-UTRAN to move the user equipment to another network. Interest.

Further, the method further includes: the E-UTRAN moving the user equipment to another network.

The other network may be a 2G network or a 3G network. As the technology develops, other networks may also appear, which are not limited herein.

When the E-UTRAN moves the user equipment to other networks, the E-UTRAN may initiate a Packet Switched Domain Switching (PS HO) process to move the user equipment to other networks, and may also initiate the non-PS HO to move the user equipment to other The internet.

When the E-UTRAN moves the user equipment to other networks in PS HO mode, the E-UTRAN sends a Handover Required message to the MME. After the MME receives the handover request message of the E-UTRAN, the LIPA PDN connection does not support handover from the source network to the target network due to the LIPA-based processing principle. Therefore, the E-UTRAN handover request is rejected, and the MME sends a handover rejection ( Handover Reject) message, after which the UE needs to return to other networks autonomously.

In order to enable the E-UTRAN to assist the UE to return to other networks, the handover request message sent by the MME may include indication information indicating that the E-UTRAN moves the user equipment to the other network in a non-PS HO manner, and is used to indicate the E-UTRAN. Move user devices to other networks in a non-PS HO manner.

In the above process, there is an unnecessary PS HO process, which wastes network resources and reduces the efficiency of user equipment moving to other networks. In order to prevent the E-UTRAN from initiating the PS HO process to move the user equipment to other networks, saving network resources, and improving the efficiency of the user equipment moving to other networks, the indication information in step 103 may indicate that the E-UTRAN uses the user equipment as a non-PS HO. The way to move to other networks.

Therefore, further, sending the indication information to the E-UTRAN, the indication information indicating that the E-UTRAN moves the user equipment to the other network comprises: sending the indication information to the E-UTRAN, the indication information is used to indicate that the E-UTRAN will be the user The device moves to other networks in a non-PS HO manner.

The indication information specifically includes:

1) Non-packet switched domain switching mode for CSFB indication (CS Fallback without PS HO Indicator information, used to instruct the E-UTRAN to move the user equipment to other networks in a non-PS HO manner. or,

2) CS Fallback Indicator information and method information.

The CS Fallback Indicator is used to instruct the E-UTRAN to move the user equipment to other networks, and the mode information is used to indicate that the CSFB is performed in a manner other than the PS HO. or,

3) CS Fallback Indicator information, E-UTRAN Radio Access Bearer (E-UTRAN Radio Access Bearer, E-RAB) information and LIP A indication information.

The E-RAB information includes a radio access bearer list, and the list records contents such as ID and QoS corresponding to each E-RAB; LIPA indication information (eg, relationship identifier, Correlation ID), used to indicate the E-RAB Is the E-RAB associated with LIPA PDN. The E-UTRAN senses that only one E-RAB needs to be created, and the E-RAB is the LIPA PDN-related E-RAB, and the CSFB of the user equipment is performed in a non-PS HO manner.

Similarly, the indication information indicating that the E-UTRAN moves the user equipment to the other network in a non-PS HO manner may be included in the UE Initial Context Setup Request message, the UE device context tampering request message (UE Context) Modification ) or Switch Handover Reject message.

Further, the method further includes: E-UTRAN moves the user equipment to other networks in a non-PS HO manner.

The release of the LIPA PDN connection may be performed after receiving the user equipment context release request message.

In this embodiment, when the user equipment has only one LIPA PDN connection, when the MME performs the CSFB and finds that the user equipment leaves the LIP A authorized area, the LIPA PDN connection is not immediately released, but the indication information is sent to the E first. - UTRAN, instructing the E-UTRAN to move the user equipment to other networks, and then releasing the LIPA PDN connection, ensuring that the user equipment does not cause the user equipment to re-initiate the attach procedure because the MME sends the indication information to the E-UTRAN. , thus ensuring that CSFB will not be interrupted, improving the user's business experience. Embodiment 2

2 is a schematic flow chart of a method provided by Embodiment 2 of the present invention. As shown in Figure 2, the specific process ^ mouth:

201: The MME sends a CS page to the UE.

Specifically, the MME receives the paging request (Paging Request) message sent by the MSC, and the current UE is in an idle (Idle) state, that is, the UE does not have a signaling connection with the MME, and the MME sends a paging message to the UE, in particular, The core domain (CN Domain) in the call message is set to CS, which is used to indicate that the current page is a CS page.

202: The UE sends an extended service request message to the MME.

Specifically, when the UE senses that the CS is called, or the UE currently has a calling service, the UE sends an extended service request message to the MME, where the extended service request message includes a service type cell, and the service type cell It is set to "Calling CSFB (mobile originating CS fallback)", which is used to indicate the calling service that is currently CSFB, or the service type cell is set to "Called CSFB (mobile terminating CS fallback)", which is used to indicate that it is currently CSFB's called business. At this time, the UE has only one LIPA PDN connection.

203: The MME reserves a LIP A PDN connection of the user equipment.

Specifically, the MME learns that the current service type is called the CSFB service or the called CSFB service. If the MME finds that the UE has left the HeNB, the LIPA PDN connection is not released at this time.

Not releasing the LIPA PDN connection here means temporarily not releasing the LIPA PDN connection and waiting for a suitable time to release the LIPA PDN connection.

Optionally, the LIPA PDN connection of the user equipment is reserved, including one or any combination of the following manners: Method 1: Setting a flag in the context of the UE (for example: a LIPA PDN connection needs to be deactivated, ie, a LIPA PDN need deactivated flag ), indicating that the LIPA PDN connection of the UE needs to be released, and retaining the LIPA PDN connection indicated by the flag that needs to be released.

The flag is used to indicate that the LIPA PDN connection of the UE needs to be released, that is: the LIPA PDN connection is not temporarily released, but the LIPA PDN connection is released after step 204 (this Releasing the LIPA PDN connection after step 204 does not mean that the LIPA PDN connection is released immediately after the completion of step 204.

Preferably, the LIPA PDN connection may also be released after receiving the user equipment context release request message.

Since the MME does not release the only LIPA PDN connection of the UE, the MME does not separate the UE, so the MME does not return a Service Reject message indicating the implicit separation to the UE, and the UE does not re-initiate. The attachment process caused the CS service to be interrupted.

204: The MME sends a user equipment initialization context setup request message/user equipment context modification request message to the E-UTRAN;

Specifically, when the MME does not establish an S1 connection with the E-UTRAN, the MME sends a User Equipment Initialization Context Setup Request message to the E-UTRAN. When the MME and the E-UTRAN have created an S1 connection, the MME sends the user equipment context modification to the E-UTRAN. The request message, the user equipment initialization context setup request message or the user equipment context modification request message includes indication information (eg, CSFB indication information, ie, CS Fallback Indicator message), for indicating that the E-UTRAN moves the UE to the 2G/3G network.

205: E-UTRAN sends user equipment context modification request message/user equipment context modification Response message to the MME;

When the E-UTRAN moves the UE to the 2G/3G network in the PS HO manner, step 206 is performed, otherwise step 208 is performed.

206: The E-UTRAN sends a handover request message to the MME.

Specifically, when the UE is moved to the 2G/3G network in the manner of PS HO, the E-UTRAN sends a Handover Required message to the MME.

After the MME receives the handover request message sent by the E-UTRAN,

207: The MME sends a handover reject message to the E-UTRAN.

Specifically, since the UE leaves the HeNB and the corresponding LIP A PDN connection has not been released, the LIPA PDN connection does not support switching from the source network to the target network at this time according to the LIPA-based processing principle. Therefore, the current UE has only one LIPA. In case the PDN is connected and cannot be switched to the target network, the MME sends a Handover Reject message to the E-UTRAN for rejecting the E-UTRAN handover request.

Since the handover request of the E-UTRAN is rejected, the UE needs to return to the 2G/3G network autonomously. In order to improve the service efficiency, the indication information may be included in the handover rejection message (for example, the non-packet switched domain handover mode performs CSFB indication information, that is, CS. Fallback without PS HO Indicator information), the indication information is used to indicate that the E-UTRAN moves the UE to the 2G/3G network in a non-PS HO manner, and the specific form of the indication information is not limited herein.

Step 208 does not depend on step 206, step 207, that is, when the E-UTRAN moves the UE to the 2G/3G network in a non-PS HO manner, step 206 and step 207 are skipped, and step 208 is directly executed.

208: The process in which the E-UTRAN moves the UE to the 2G/3G network;

The E-UTRAN moves the UE to the 2G/3G network in a non-PS HO manner, for example: E-UTRAN triggers the RRC (Radio Resource Control) connection release (RRC Connection Release) process between the UE and the UE The E-UTRAN network moves to the 2G/3G network. Specifically, if both the UE and the network support the "RC connection release with the multi-cell system information for reselection to 2G/3G (RRC connection release with redirection and Multi Cell System Informatin) To 2G/3G) " , then E-UTRAN triggers "RC connection release with redirection to 2G/3G", and ^ ^{1 corresponds to} at least one physical cell identifier, information, and cell The system information informs the UE that the UE can quickly return to the 2G/3G network according to the information, access a suitable cell, and establish an air interface connection.

It will be understood by those skilled in the art that there are other non-PS HO ways to move the UE to the 2G/3G network, which is not limited herein.

209: The UE performs a CS service.

Specifically, after the step 208, the UE returns the 2G/3G network from the E-UTRAN, and performs a related process of the CS service, for example, the UE returns a Paging Response message to the MSC.

210: The E-UTRAN sends a user equipment context release request message to the MME.

The step 210 and the step 208 have no timing relationship, and the step 210 may be started simultaneously with the step 208, or may be performed after the step 208 is started.

211: The MME releases the LIP A PDN connection.

Wherein, step 211 has no timing relationship with step 208, and step 211 may be performed before step 208, concurrently with step 208, or after step 208 begins execution;

Step 211 and step 210 also have no timing relationship, and step 211 may start execution before step 210 or begin execution after step 210.

Preferably, step 211 is performed after step 210 to ensure that the LIP A PDN connection is released after CSFB begins execution.

Specifically, when a flag is set in the context of the UE, the flag is used to indicate that the LIP A PDN connection of the UE needs to be released, and the LIPA PDN connection indicated by the flag needs to be released is released; After the user equipment context release request message, the LIPA PDN connection indicated by the flag that needs to be released is released.

When a timer is set for the UE's LIPA PDN connection, which is used to control the lifetime of the LIPA PDN connection, 1) when the timer has not timed out, after the user equipment context release request message is received, the timer is released. The LIPA PDN connection; or, 2) when the timer expires Next, release the LIPA PDN connection.

In this embodiment, when the user equipment has only one LIPA PDN connection, when the MME performs the CSFB and finds that the user equipment leaves the LIP A authorized area, the LIPA PDN connection is not immediately released, but the E-UTRAN is first executed. The CSFB related operation moves the UE to the 2G/3G network, and then releases the LIPA PDN connection, which ensures that before the MME sends the indication information to the E-UTRAN, the user equipment does not cause the user equipment to re-initiate the attach procedure because it is separated, thereby ensuring that the user equipment does not initiate the attach procedure due to the separation. CSFB will not be interrupted, improving the user's business experience.

Embodiment 3

FIG. 3 is a schematic flow chart of a method according to Embodiment 3 of the present invention. As shown in Figure 3, the specific process ^ mouth:

301: The MME sends a CS page to the UE.

302: The UE sends an extended service request message to the MME.

303: The MME reserves a LIPA PDN connection of the user equipment.

Not releasing the LIPA PDN connection here means temporarily not releasing the LIPA PDN connection and waiting Release the LIPA PDN connection at a suitable time.

Wherein, the flag is used to indicate that the LIPA PDN connection of the UE needs to be released, that is: the LIPA PDN connection is not temporarily released, but the LIPA PDN connection is released after step 304 (referred to hereafter after step 304) Releasing the LIPA PDN connection does not mean that the LIPA PDN connection is released as soon as step 304 is completed.

Preferably, the LIPA PDN connection may be released after receiving the user equipment context release request message.

Specifically, 1) when the timer does not time out and the user equipment context release request message is not received, the LIPA PDN connection is temporarily not released; 2) when the timer does not time out, the user equipment context release request is received. After the message, the LIPA PDN connection is released; 3) When the timer expires, the LIPA PDN connection is released.

Since the MME does not release the only LIPA PDN connection of the UE, the MME does not separate the UE, so the MME does not return a Service Reject message indicating that the implicit separation is indicated to the UE, and the UE does not re-initiate the attachment. The process caused the CS business to be interrupted.

304: The MME sends a user equipment initialization context setup request message/user equipment context modification request message to the E-UTRAN; The user equipment initialization context setup request message/user equipment context modification request message includes indication information, which is used to indicate that the E-UTRAN moves the user equipment to the 2G/3G network in a non-PS HO manner. For example, the indication information may include:

1) The CS Fallback without PS HO Indicator message is used to instruct the E-UTRAN to move the user equipment to the 2G/3G network in a non-PS HO manner. Or,

2) CS Fallback Indicator information and method information.

The CS Fallback Indicator is used to instruct the E-UTRAN to move the user equipment to the 2G/3G network, and the mode information is used to indicate that the CSFB is performed in a manner other than the PS HO. or,

The above examples are not limitations on the indication information. It will be appreciated by those skilled in the art that other indication information can be used to instruct the E-UTRAN to move the user equipment to the 2G/3G network in a non-PS HO manner.

Specifically, when the UE is in the idle state, the MME sends a user equipment initialization context setup request message to the E-UTRAN. When the UE is in the connected state, the MME sends a user equipment context modification request message to the E-UTRAN, and the user equipment initializes the context establishment. The request message or user equipment context modification request message contains indication information for instructing the E-UTRAN to move the UE to the 2G/3G network in a non-PS HO manner.

305: The E-UTRAN sends a user equipment context modification request message/user equipment context modification response message to the MME. Since the E-UTRAN learns that the UE moves to the 2G/3G network in the non-PS HO mode after the step 304, the E-UTRAN does not send the handover request message to the MME, thereby saving network resources and improving the user equipment to move to the 2G. The effect of the efficiency of the /3G network.

306: E-UTRAN moves the UE to the 2G/3G network in a non-PS HO manner;

The E-UTRAN moves the UE to the 2G/3G network in a non-PS HO manner, for example: E-UTRAN triggers the RRC (Radio Resource Control) connection release (RRC Connection Release) process between the UE and the UE The E-UTRAN network moves to the 2G/3G network. Specifically, if both the UE and the network support the "RC connection release with the multi-cell system information for reselection to 2G/3G (RRC connection release with redirection and Multi Cell System Informatin) To 2G/3G) " , then E-UTRAN triggers "RRC connection release with redirection to 2G/3G", and ^ ¹ at least one physical cell mark, information and cell corresponding The system information informs the UE that the UE can quickly return to the 2G/3G network according to the information, access a suitable cell, and establish an air interface connection.

307: The UE performs a CS service.

Specifically, after step 306, the UE returns from the E-UTRAN to the 2G/3G network, and performs a related process of the CS service, for example, the UE returns a Paging Response message to the MSC.

308: E-UTRAN sends a user equipment context release request message to the MME;

The step 308 and the step 306 have no timing relationship, and the step 308 can be started simultaneously with the step 306, or can be executed after the step 306 is started.

309: The MME releases the LIP A PDN connection.

Wherein, step 309 has no timing relationship with step 306, and step 309 can be performed before step 306, simultaneously with step 306, or after step 306 begins execution;

There is also no timing relationship between step 309 and step 308. Step 309 may begin execution before step 308 or begin execution after step 308. Preferably, step 309 is performed after step 308 to ensure that the LIP A PDN connection is released after CSFB begins execution.

When a timer is set for the UE's LIPA PDN connection, which is used to control the lifetime of the LIPA PDN connection, 1) when the timer has not timed out, after the user equipment context release request message is received, the timer is released. The LIPA PDN connection; or, 2) release the LIPA PDN connection when the timer expires.

In this embodiment, when the user equipment has only one LIPA PDN connection, when the MME performs the CSFB and finds that the user equipment leaves the LIP A authorized area, the LIPA PDN connection is not immediately released, but the E-UTRAN is first indicated. Non-PS HO mode performs CSFB related operations to move the UE to the 2G/3G network, and then release the LIPA PDN connection, which ensures that the user equipment does not cause the user equipment to be re-initiated because it is separated before the MME sends the indication information to the E-UTRAN. The attach process is initiated to ensure that CSFB is not interrupted, improving the user's business experience.

Embodiment 4

FIG. 4 is a schematic structural diagram of an MME provided in this embodiment. As shown in FIG. 4, the MME specifically includes:

The receiving module 401 is configured to receive an extended service request message sent by the user equipment.

The retaining module 402: is configured to reserve a LIPA PDN connection of the user equipment, where the user equipment has only one LIPA PDN connection and the user equipment is in a non-LIP A authorized area;

The sending module 403 is configured to send the indication information to the E-UTRAN, where the indication information indicates that the E-UTRAN moves the user equipment to another network;

Release module 405: Used to release the LIPA PDN connection.

Optionally, as shown in FIG. 5, the reservation module 402 includes: The marking module 402a is configured to set a flag in the context of the user equipment, the flag is used to indicate that the LIPA PDN connection needs to be released;

The first reservation module 402b is configured to retain the LIPA PDN connection that needs to be released as indicated by the flag.

Correspondingly, the release module 405 is specifically configured to release the LIPA PDN connection indicated by the mark that needs to be released.

Optionally, as shown in FIG. 6, the reservation module 403 includes:

The timer module 402aa is configured to set a timer, which is used to control the lifetime of the LIPA PDN connection;

The second reservation module 402bb is configured to reserve the LIPA PDN connection during the lifetime.

Correspondingly, the releasing module 405 is specifically configured to release the LIPA PDN connection when the timer expires; or

The releasing module 405 is specifically configured to release the LIPA PDN connection after receiving the user equipment context release request message when the timer does not time out.

Optionally, the sending module 403 is specifically configured to send a user equipment initialization context establishment request message or a user equipment context modification request message, where the user equipment initialization context establishment request message or the user equipment context modification request message includes indication information, where the indication information is used. Instruct E-UTRAN to move the user equipment to other networks.

Optionally, the sending module 403 is specifically configured to send indication information, where the indication information is used to indicate that the E-UTRAN moves the user equipment to other networks in a non-PS HO manner.

Optionally, the sending module 403 is specifically configured to send the indication information to the E-UTRAN, where the indication information includes CS Fallback without PS HO Indicator information, where the CS Fallback without PS HO Indicator information indicates that the E-UTRAN uses the user equipment as a non-PS HO. Move to other networks.

Optionally, the sending module 403 is specifically configured to send the indication information to the E-UTRAN, where the indication information includes CS Fallback Indicator information and mode information, where the mode information is used to indicate that the E-UTRAN moves the user equipment to the non-PS HO manner. Other networks. Optionally, the sending module 403 is specifically configured to send the indication information to the E-UTRAN, where the indication information includes CS Fallback Indicator information, E-UTRAN Radio Access Bearer (E-RAB) information, and LIPA indication information; In connection with indicating that the E-RAB is connected to the LIPA PDN, the user equipment is to be moved to other networks in a non-PS HO manner.

Optionally, the sending module 403 is specifically configured to send a user equipment initialization context establishment request message, a user equipment context modification request message, or a handover rejection message, where the user equipment initialization context establishment request message, the user equipment context modification request message, or the handover rejection message includes Instructing information, the indication information is used to instruct the E-UTRAN to move the user equipment to other network in a non-PS HO manner.

Further, as shown in FIG. 7, the MME provided in this embodiment further includes:

The first receiving module 404 is configured to receive a user equipment context release request message. After the first receiving module receives the user equipment context release request message, the trigger release module 405 starts to work.

The other network in this embodiment may be a 2G network or a 3G network. Other technologies may be used as the other technologies, which are not limited herein.

In the case that the user equipment has only one LIPA PDN connection, when the MME performs the CSFB, the MME does not immediately release the LIPA PDN connection after the user equipment leaves the LIP A authorized area, but first indicates the E- The UTRAN performs the C SFB related operation to move the UE to another network, and then releases the LIPA PDN connection, which ensures that before the MME sends the indication information to the E-UTRAN, the user equipment does not cause the user equipment to re-initiate the attach procedure because it is separated, thereby It ensures that CSFB will not be interrupted, which improves the user's business experience.

Embodiment 5

This embodiment provides a system for processing CSFB. As shown in FIG. 8, the system includes:

MME 501 and E-UTRAN 502, MME 501 is the MME of any of the embodiments 4; the MME is configured to receive an extended service request message sent by the user equipment, where the extended service request message is used to indicate that the CSFB service is performed; when the MME 501 sends the indication information to E-UTRAN 502, when E-UTRAN 502 is instructed to move the user equipment to other networks, E-UTRAN 502 moves the user equipment Go to other networks.

Further, when the MME 501 sends the indication information to the E-UTRAN 502, indicating that the E-UTRAN 502 moves the user equipment to the other network in a non-PS HO manner, the E-UTRAN 502 moves the user equipment to the other network in a non-PS HO manner.

The other network in this embodiment may be a 2G or a 3G network. Other technologies may be used as the technology evolves.

In the case of the system of the present embodiment, when the user equipment has only one LIPA PDN connection, when the MME performs CSFB, it finds that the user equipment leaves the LIP A authorized area, and does not immediately release the LIPA PDN connection, but first indicates E- The UTRAN performs the C SFB related operation to move the UE to another network, and then releases the LIPA PDN connection, which ensures that before the MME sends the indication information to the E-UTRAN, the user equipment does not cause the user equipment to re-initiate the attach procedure because it is separated, thereby It ensures that CSFB will not be interrupted, which improves the user's business experience.

In summary, in the embodiment of the present invention, when the user equipment has only one LIPA PDN connection, when the MME performs the CSFB, it finds that the user equipment leaves the LIPA authorized area, and does not immediately release the LIPA PDN connection, but first Instructing the E-UTRAN to perform CSFB related operations to move the UE to other networks, and then releasing the LIPA PDN connection, can ensure that the user equipment does not cause the user equipment to re-initiate the attach procedure because the MME sends the indication information to the E-UTRAN. , thus ensuring that CSFB will not be interrupted, improving the user's business experience. Further, the MME instructs the E-UTRAN to perform CSFB related operations to move the UE to other networks in a non-PS HO manner, which improves the efficiency of the user equipment switching to other networks.

It will be understood by those of ordinary skill in the art that the drawings are only a schematic representation of one embodiment, and the modules or processes in the drawings are not necessarily required to practice the invention.

Those skilled in the art can understand that the modules in the embodiment can be distributed in the MME of the embodiment according to the embodiment. The modules of the above embodiments may be combined into one module, or may be further split into a plurality of sub-modules.

One of ordinary skill in the art can understand that all or part of the steps of the above method embodiments are implemented. The foregoing program may be stored in a computer readable storage medium, and when executed, the program includes the steps of the foregoing method embodiment; and the foregoing storage medium includes: ROM, RAM A variety of media that can store program code, such as a disk or an optical disk.

It should be noted that the above embodiments are only for explaining the technical solutions of the present invention, and are not intended to be limiting; although the present invention has been described in detail with reference to the foregoing embodiments, it will be understood by those skilled in the art that: The technical solutions described in the foregoing embodiments are modified, or some of the technical features are replaced by equivalents; and the modifications or substitutions do not deviate from the spirit of the technical solutions of the embodiments of the present invention. range.

Claims

Claim

A method for processing a circuit switched domain service back to a legacy network (CSFB), the method comprising:

The mobility management entity (MME) receives an extended service request message sent by the user equipment, where the extended service request message is used to indicate the service of the CSFB;

The MME retains a local IP access public data network (LIPA PDN) connection of the user equipment, the user equipment has only one LIPA PDN connection and the user equipment is in a non-local IP access (LIPA) authorization area;

The MME sends indication information to an evolved UMTS (Universal Mobile Telecommunications System) Terrestrial Radio Access Network (E-UTRAN), the indication information instructing the E-UTRAN to move the user equipment to another network;

The MME releases the LIP A PDN connection.

2. The method of claim 1 wherein:

The MME retains the LIPA PDN connection of the user equipment, including: the MME setting a flag in the context of the user equipment, the flag is used to indicate that the LIPA PDN connection needs to be released; and the MME retains the requirement indicated by the marking The released LIPA PDN connection;

The MME releases the LIP A PDN connection, including: the MME releases the LIPA PDN connection indicated by the flag and needs to be released.

The method of any one of the preceding claims, wherein the MME before receiving the LIPA PDN connection further comprises: the MME receiving a user equipment context release request message sent by the E-UTRAN.

4. The method of claim 1 wherein:

The MME retains the LIPA PDN connection of the user equipment, including:

Setting, by the MME, a timer, where the timer is used to control a lifetime of the LIPA PDN connection; and the MME retains the LIPA PDN connection in the lifetime;

The MME releases the LIP A PDN connection, including: When the timer expires, the MME releases the LIPA PDN connection; or, when the timer does not time out, the MME releases the LIPA after receiving the user equipment context release request message. PDN connection.

The method according to any one of claims 1-4, wherein: the MME sends the indication information to the E-UTRAN, where the indication information indicates that the E-UTRAN moves the user equipment to another network, including:

Sending, by the MME, a user equipment initialization context establishment request message or a user equipment context modification request message, the user equipment initialization context establishment request message or the user equipment context modification request message includes indication information, where the indication information indicates that the E-UTRAN will User devices move to other networks.

The MME sends indication information to the E-UTRAN, the indication information instructing the E-UTRAN to move the user equipment to other networks in a non-packet switched domain handover (PS HO ) manner.

The method according to claim 6, wherein the MME sends the indication information to the E-UTRAN, and the indication information indicates that the E-UTRAN moves the user equipment to another network in a non-PS HO manner. Includes:

The MME sends the indication information to the E-UTRAN, where the indication information includes a CS Fallback without PS HO Indicator information, and the CS Fallback without PS HO Indicator information indicates that the E-UTRAN will The user equipment moves to other networks in a non-PS HO manner; or

The MME sends the indication information to the E-UTRAN, where the indication information includes a CS Fallback Indicator information and mode information, where the mode information is used to indicate that the E-UTRAN is in a non-PS HO manner. The user equipment is moved to another network; or

The MME sends indication information to the E-UTRAN, where the indication information includes CS Fallback Indicator information, E-UTRAN radio access bearer (E-RAB) information, and LIP A indication information; the LIP A indication information is used to indicate that the E-RAB is related to the LIPA PDN connection, and is to be non-PS HO The way to move the user equipment to other networks.

The method according to claim 6 or 7, wherein the MME sends the indication information to the E-UTRAN, the indication information instructing the E-UTRAN to move the user equipment to other non-PS HO manners. Network, including:

And the MME sends a user equipment initialization context establishment request message, a user equipment context modification request message, or a handover rejection message, where the user equipment initialization context establishment request message, the user equipment context modification request message, or the handover rejection message includes indication information, where the indication is The information indicates that the E-UTRAN moves the user equipment to other networks in a non-PS HO manner.

9. An MME, comprising:

a receiving module, configured to receive an extended service request message sent by the user equipment, where the extended service request message is used to indicate that the service of the CSFB is performed;

a reservation module, configured to reserve a LIPA PDN connection of the user equipment, where the user equipment has only one LIPA PDN connection and the user equipment is in a non-LIPA authorized area;

a release module for releasing the LIPA PDN connection.

10. The MME of claim 9, wherein:

The reservation module includes: a marking module, configured to set a mark in a context of the user equipment, the mark is used to indicate that the LIPA PDN connection needs to be released; and the first retention module is configured to reserve the mark indication The LIPA PDN connection that needs to be released;

The release module is specifically configured to release the LIPA PDN connection indicated by the mark that needs to be released.

The MME according to claim 9 or 10, wherein the MME further comprises: a first receiving module, configured to receive a user equipment context release request sent by the E-UTRAN Message

The release module releases the LIPA PDN connection after the first receiving module receives the user equipment context release request message.

12. The MME of claim 9, wherein:

The reservation module includes: a timer module, configured to set a timer, where the timer is used to control a lifetime of the LIPA PDN connection; and a second retention module, configured to reserve the LIPA PDN during the lifetime Connection

The releasing module is specifically configured to: when the timer expires, release the LIPA PDN connection; or, specifically, when the timer is not timed out, after receiving the user equipment context release request message , release the LIPA PDN connection.

13. The MME of any of claims 9-12, wherein:

The sending module is configured to send a user equipment initialization context establishment request message or a user equipment context modification request message, where the user equipment initialization context establishment request message or the user equipment context modification request message includes indication information, where the indication information indicates E - UTRAN moves the user equipment to other networks.

14. The MME of any of claims 9-12, wherein:

The sending module is specifically configured to send the indication information to the E-UTRAN, where the indication information indicates that the E-UTRAN moves the user equipment to another network in a non-PS HO manner.

15. The MME of claim 14 wherein:

The sending module is specifically configured to send the indication information to the E-UTRAN, where the indication information includes CS Fallback without PS HO Indicator information, where the CS Fallback without PS HO Indicator information indicates that the E-UTRAN uses the user equipment as a non-PS HO's way to move to other networks; or,

Specifically, the method is used to send the indication information to the E-UTRAN, where the indication information includes CS Fallback Indicator information and mode information, where the mode information is used to indicate that the E-UTRAN moves the user equipment to another network in a non-PS HO manner; or, Specifically, the indication information is sent to the E-UTRAN, where the indication information includes CS Fallback Indicator information, E-UTRAN Radio Access Bearer (E-RAB) information, and LIPA indication information, where the indication information is used to indicate the 5 -1 in 8 is associated with the 1^1? PDN connection, and the user equipment is to be moved to other networks in a non-PS HO manner.

16. The MME according to claim 14 or 15, wherein

The sending module is specifically configured to send a user equipment initialization context establishment request message, a user equipment context modification request message, or a handover rejection message, where the user equipment initialization context establishment request message, the user equipment context modification request message, or the handover rejection message includes an indication. Information, the indication information indicates that the E-UTRAN moves the user equipment to other network in a non-PS HO manner.

A system for processing CSFB, comprising: an E-UTRAN and an MME according to any one of claims 9-16;

The E-UTRAN is configured to: when the MME sends indication information to the E-UTRAN, instructing the E-UTRAN to move the user equipment to another network, moving the user equipment to another network.

18. The system of claim 17 wherein:

The E-UTRAN is specifically configured to: when the MME sends indication information to the E-UTRAN, indicating that the E-UTRAN moves the user equipment to another network in a non-PS HO manner, in a non-PS HO manner User devices move to other networks.