WO2010020196A1 - Method and device for processing circuit switched domain service in the isr scene - Google Patents

Abstract

A method and device for processing circuit switched domain service in the ISR scene, the method comprises that a mobility management entity determines the interface information of a mobile switching center; the mobility management entity transmits a message to the mobile switching center to establish a SGs interface association if the mobility management entity determines that the mobile switching center does not establish the SGs interface association. The devices includes an interface information determining unit for determining the interface information of the mobile switching center; a SGs interface establishing unit for transmitting a message to the mobile switching center to establish a SGs interface association when the mobile switching center is determined not to establish the SGs interface association.

Description

 The invention relates to a circuit switching domain service processing method and device in an ISR scenario. The application is filed on August 21, 2008, and the application number is 200810210066.8. The invention name is "an ISR scenario circuit switching domain service processing method and device". The priority of the Chinese Patent Application, the entire contents of which is incorporated herein by reference. Technical field

 The present invention relates to the field of mobile communication network technologies, and in particular, to a circuit switching domain service processing method and apparatus in an ISR scenario.

Background technique

 GPRS/UMTS is a mobile communication network defined by the 3GPP organization and has been widely deployed. It includes two parts: Radio Access Network (RAN) and Core Network (CN). The CN is logically divided into a Circuit Switched Domain (CS) and a Packet Switched Domain (PS). CSi or mainly handles voice services, and the PS domain mainly handles packet services. As shown in FIG. 1 , the signaling plane control entity of the CS domain is a Mobi le Switch Center/Visitor Location Register (MSC/VLR), and the signaling plane control entity of the PS domain is a serving GPRS. The Serving GPRS Support Node (SGSN), the SGSN and the MSC/VLR can be connected through the Gs interface. The Gateway GPRS Support Node (GGSN) and the GPRS Support Node SGSN are connected by Gn.

 In order to meet the challenges of wireless broadband technology and maintain the leading edge of the 3GPP network, 3GPP developed the Long Term Evolution (LTE) at the end of 2004. Under the guidance of the evolution plan, the architecture of the new mobile communication network is defined. This architecture is flatter than the current GPRS/UMTS, and only the packet domain is reserved, so it can be called evolved packet system (EPS). .

As shown in Figure 2, the core network of the wireless evolved network mainly includes three logical functions: MME, Serving SAE Gateway, and PDN SAE Gateway. The solid E is the mobility management entity and is responsible for the network connection. Incoming Service (NAS) signaling and NAS signaling encryption and roaming, tracking, assigning user temporary identity, etc., which correspond to the control plane portion of the current SGSN system SGSN. The Serving Gateway (S-GW) is responsible for the local mobility anchor and the mobility anchors within the 3GPP system and the lawful interception related information; P匪Gateway (P-GW) is responsible for policy enforcement and charging and lawful interception related functions.

 Since many services of the operator are running in the circuit domain of GPRS/UMTS, in order to reuse the existing CS service in the EPS network, a method of connecting to the CS domain core network through the EPS network is proposed, as shown in FIG. The E in the EPS network is connected to the MSC of the traditional CS core network through a Gs-like interface (SGs).

 In this architecture, when the user equipment (User Equipment, UE) is ready to initiate the MO (Mobile Originating) service, the UE needs to first go to the GPRS/UMTS network, select a 2G/3G cell to camp, and then Launch M0 business. When the mobile switching center (MSC) receives a terminal (MT, Mobile Terminated) service, the MSC sends a paging message to the MME through the SGs interface, and the MME pages the UE through the EPS network, and the UE receives the paging message. After paging the message, it is necessary to first go to the GPRS/UMTS network, select a 2G/3G cell to camp, and then complete the subsequent processing of the MT service. Therefore, the architecture and processing method can be called "CS fallback" (CS service returns to traditional network processing).

 In the existing 3GPP protocol (TS 23.272), if an SGs interface association has been established for the UE in the LTE network, the short message service (SMS) of the CS domain is delivered to the UE through the PS domain. Specifically, the MSC notifies the MME to page the UE through the SGs interface, the MME sends a paging message to the UE, the UE receives the paging message, and responds to the paging transition to the connected state, and the MSC transmits the short message to the MME through the SGs interface, and the solid E passes through NAS signaling is passed to the UE.

 The short message service (SMS) in the 2G/3G network is delivered to the UE through the CS domain. Specifically, the MSC notifies the SGSN to page the UE through the Gs interface, and the SGSN sends a paging message (message indicating CS paging) to the UE, and the UE switches to the CS domain in response to the paging, and connects to the MSC through the A/Iu_CS interface.

One requirement for an evolved network is to implement Idle mode signaling reduction (also known as Signaling saving or signaling restriction in idle mode, referred to as ISR) function, mainly to reduce the mobility management process of UEs in idle mode between different access networks (such as reducing Inter between GERAN/UTRAN and EUTRAN) 3GPP Access System Mobility in Idle State Processing). At present, the solution of the Idle mode signaling reduction mechanism between the 3GPP access networks is a dual registration mechanism, that is, the UE is registered in two different access networks, so that the UE in the idle mode moves between the two access networks. The Inter 3GPP Access System Mobility process, such as the inter-system RAU/TAU process, will not be triggered.

 In the scenario of an ISR, the MSC maintains only one of the SGs interface association or the Gs interface association.

 If the MSC keeps the SGs interface association and the current UE resides in the GERAN/UTRAN network, the MSC receives the service of the CS, and sends a message through the SGs interface to trigger the solid E paging UE. The message also needs to indicate the CS service type at this time. The MME finds that the ISR has been started, and then selects a suitable paging message (CS domain paging or PS domain paging) according to the service type of the CS domain in the network, and also needs to send a message to trigger the association with the ISR. The SGSN pages the UE, and the paging message transmitted on the S3 interface instructs the SGSN to send the paging message of the CS domain to the UE (because it is a CS domain service, if the UE resides in the GERAN/UTRAN network, it needs to be from the CS The domain completes the business). The UE receives the CS domain paging message sent by the SGSN, and can perform a Gs interface processing mechanism to return a Paging Response message to the MSC/VLR to complete subsequent processing of the CS service.

 If the MSC maintains the Gs interface association and the current UE resides in the LTE network, the MSC receives the service of the CS, and sends a message through the Gs interface to trigger the SGSN to page the UE. Based on the assumption that the Gs interface is not upgraded, the message cannot indicate this time. The CS service type only triggers the SGSN to send a CS paging message to the UE. If the SGSN finds that the ISR has been started, the paging message (CS domain paging) is sent to the UE in the network, and the UE needs to send a message to trigger the fixed E paging UE associated with the ISR establishment. The paging message indicates that the solid E sends a paging message of the CS domain to the UE. The UE receives the CS domain paging message sent by the MME, and can perform the CS Fallback processing mechanism, switch to the GERAN/UTRAN network, and return a Paging Response message to the MSC/VLR to complete the subsequent processing of the CS service.

In the process of implementing the present invention, the inventor finds that the disadvantage of the prior art is that when the network side provides the CS domain service to the user equipment, the solid E knows that it is a CS domain after receiving the paging message transmitted by the SGSN. The service, when the UE responds to the paging in the LTE network, will perform CS Fa l lback handover to the GERAN/UTRAN network, which complicates the service processing of the CS domain.

Summary of the invention

 The embodiment of the invention provides a circuit switching domain service processing method in an ISR scenario, which can ensure the processing of the CS service in the LTE network.

 The technical solution of the circuit switching domain service processing method in the ISR scenario is as follows: A circuit switching domain service processing method in an ISR scenario, including:

 The mobility management entity determines interface information of the mobile switching center;

 If the mobility management entity determines that the mobile switching center does not establish an SGs interface association, the mobility management entity sends a message to the mobile switching center to establish an SGs interface association.

 The following describes a technical solution for processing a circuit switched domain service in an ISR scenario:

 A circuit switching domain service processing method in an ISR scenario, including:

 The user equipment learns the interface information of the current mobile switching center;

 The user equipment knows the network in which it is currently located;

 The user equipment determines whether to perform the establishment of the SGs interface association process or the execution of the SGs interface association process.

 The embodiment of the invention further provides a circuit switching domain service processing device in an ISR scenario, which can ensure the processing of the CS service in the LTE network.

 The technical solution of the circuit switching domain service processing device in the ISR scenario is as follows: A circuit switching domain service processing device in an ISR scenario, including:

 An interface information determining unit, configured to determine interface information of the mobile switching center;

 The SGs interface establishing unit is configured to: when the interface information determining unit determines that the mobile switching center does not establish an SGs interface association, send a message to the mobile switching center to establish an SGs interface association.

In the embodiment of the present invention, the circuit switching domain service processing apparatus in the ISR scenario may also adopt the following technical solutions: A circuit switching domain service processing apparatus in an I SR scenario, comprising:

 An interface information acquiring unit, configured to acquire interface information of the current mobile switching center;

 a network information acquiring unit, configured to determine a network where the device is currently located;

 The SGs interface processing unit is configured to determine, according to the interface information acquired by the interface information acquiring unit and the network determined by the network information acquiring unit, whether to perform an association process for establishing an SGs interface, or to perform an SGs interface association process.

DRAWINGS

 1 is a schematic diagram of a GPRS/UMTS network architecture in the prior art;

 2 is a schematic diagram of a wireless evolved network architecture (non-roaming scenario) in the prior art;

 3 is a schematic diagram of an EPS network architecture in the prior art;

 4 is a flowchart of a method for processing a CS service in an SR scenario according to an embodiment of the present invention;

 5 is a flowchart of determining, by a mobility management entity, a Gs interface or an SGs interface of a mobile switching center according to an embodiment of the present invention to maintain a Gs interface association, where the mobility management entity sends a message to the mobile switching center to establish an association of an SGs interface. ;

 FIG. 6 is a schematic diagram of an embodiment of the present invention, when the mobility management entity determines that the information of the Gs interface or the SGs interface of the mobile switching center is that the maintained SGs interface has been released, the mobility management entity sends a message to the mobile switching center to establish an SGs interface association. Flow chart

 FIG. 7 is a flow chart of another method for processing a circuit switched domain service in an ISR scenario according to an embodiment of the present invention;

 FIG. 8 is a flowchart of an embodiment of determining, according to an already existing association, whether to initiate establishment of an association of an SGs interface according to an association already existing in an embodiment of the present invention;

 FIG. 9 is a block diagram of a circuit switching domain service processing apparatus in an SR scenario according to an embodiment of the present invention; FIG. 10 is a block diagram showing a circuit switching domain service processing apparatus in an SR scenario according to an embodiment of the present invention;

11 is a block diagram showing a circuit switching domain service processing apparatus in an I SR scenario according to another embodiment of the present invention; 12 is a block diagram showing a circuit switching domain service processing apparatus in an ISR scenario according to still another embodiment of the present invention;

 FIG. 13 is a block diagram showing a circuit switching domain service processing apparatus in an ISR scenario according to still another embodiment of the present invention.

detailed description

 The present invention aims to provide a method for processing a circuit switched domain service in an ISR scenario, which can ensure the processing of CS services in an LTE network. The embodiments of the present invention will be described in detail below with reference to the accompanying drawings. Other embodiments may be derived from these descriptions without undue creative effort.

 Referring to FIG. 4, a method for processing a circuit switched domain service in an ISR scenario according to an embodiment of the present invention includes the following steps:

 S10. The mobility management entity determines interface information of the mobile switching center.

 The interface information of the mobile switching center MSC includes information related to the SGs interface or the Gs interface maintained by the MSC. For example, the MSC maintains the SGs interface association or the Gs interface association, or does not maintain any association (such as once maintained). The SGs interface association has been released, but no new SGs interface association or Gs interface association has been established.

 S20. If the mobility management entity determines that the mobile switching center does not establish an SGs interface association, the mobility management entity sends a message to the mobile switching center to establish an SGs interface association.

 The determining, by the mobility management entity, that the mobile switching center does not establish an SGs interface association includes: the mobility management entity determines that the interface information of the mobile switching center is to maintain the Gs interface association, or the mobility management entity learns that the SGs interface association maintained by the mobile switching center is released. .

In the embodiment of the present invention, a circuit switching domain service processing method in an ISR scenario, where a mobility management entity determines interface information of a mobile switching center; and if the mobility management entity determines that the mobile switching center does not establish an SGs interface association, the mobility management entity performs the mobile switching The center sends a message to establish an SGs interface association. In this way, in the ISR scenario, the UE maintains the SGs interface association in the LTE network, and the MSC receives the CS. The service sends a message to the UE through the SGs interface, and the UE indicates the specific CS service type. The UE completes the CS domain service through the PS domain in the LTE network, for example, completes the short message service of the CS domain, instead of You need to perform CS Fallbak to switch to the GERAN/UTRAN network, and then complete the CS domain service through the circuit domain. This ensures the CS service processing in the LTE network, simplifies the service processing of the CS domain, and reduces the delay of the CS service.

 Embodiment 1

 FIG. 5 is a flowchart of an embodiment in which the mobility management entity determines that the information of the Gs interface or the SGs interface of the mobile switching center is to maintain the Gs interface association, and the mobility management entity sends a message to the mobile switching center to establish an association of the SGs interface. .

 The signaling process is described as follows:

 1: The UE has performed a (GPRS/IMSI) joint attachment of the packet domain and the circuit domain, ie the MSC has maintained the Gs interface association. The MSC receives an Initial Address Message (I AM) or a Forward Short Message.

 2: The MSC/VLR sends a paging message Page message (IMSI, VLRTMSI, Location Inf or mat ion) to the SGSN through the Gs interface.

 3a: The SGSN accepts paging messages from the MSC/VLR. The SGSN sends a CS domain indicator to its Radio Network Subsystem/Base System (RNS/BSS).

 3b: The RNS/BSS delivers a paging message to the UE.

 4a: If the UE camps on the GERAN/UTRAN network, it receives a paging message of the circuit domain, initiates cell reselection, and accesses the circuit domain. Send the circuit domain paging response to the RNS/BSS.

 4b: The RNS/BSS forwards the paging response to the MSC/VLR.

 4c: The MSC/VLR receives the circuit domain paging response CS paging response message, and performs a short message service (SMS MT process) process.

5a: If the ISR is active and the UE is in the idle state, the SGSN forwards the circuit domain paging CS Paging message transmitted from the MSC/VLR to the MN 8 with which the ISR association is established. Conversely, the SGSN does not forward the paging message to the MME with which the ISR association is established. 5b: The MME accepts the CS domain paging message forwarded by the SGSN. The MME learns that it is a CS domain service at this time. The MME receives the CS domain paging message forwarded by the SGSN, and the EM establishes an SGs interface with the MSC to provide the CS service to the user.

 If the user equipment is in the idle mode, the mobility management entity in the long term evolution network sends a packet switched domain paging message to the user equipment; after the user equipment normally responds to the packet switched domain paging message; the mobility management entity Proactively sending a message to the mobile switching center to establish an SGs interface association of the mobile switching center. Specifically, if the UE is in the idle mode, the MME sends a PS domain indicator (PS domain indicator) to the eNodeB that it occupies. The eNodeB is the serving eNodeB of the area where the TA list associated with the UE is recorded by the MME, and then the steps are performed. 5c.

 If the user equipment is in an active state, the mobility management entity in the long term evolution network actively sends a message to the mobile switching center to establish an SGs interface association of the mobile switching center. Specifically, if the UE is in an active state and the ISR has been started, the MME actively sends a message to the MSC to establish an SGs interface association. That is, step 6b is executed at this time.

 5c: The eNodeB delivers a paging message to the UE.

 6a: The UE performs a service request procedure as a paging response of the PS domain, and sends a Service Request message to the MME.

 6b: The solid E determines that the SGs interface association is not established at this time, and the UE resides in the network at this time, and the E E initiates the process to establish an SGs interface association.

 The MME determines that the SG s interface is not established at this time. The MME can learn that the MSC keeps the Gs interface association between the MGC and the SGSN according to the CS domain paging message forwarded by the SGSN, instead of the SGs interface association, or For example, the solid E is informed that the SGs interface association has been released according to the notification message sent from the mobile switching center or the serving GPRS support node. In this embodiment, the CS paging message forwarded by the serving GPRS support node (SGSN) is received from the S3 interface according to the mobility management entity, thereby determining that the SGs interface association is not established.

 The MME initiates the process establishment. The specific establishment methods of the SG s interface association are as follows:

1) The MME initiates a location update request (Location Update Request (new LAI, IMSI, MME address, Location Update Type, forwarding indicate)) The message is sent to the MSC to re-establish the SGs interface association for the UE. The MSC saves the address of the MME. The forwarding indicating indicates that the MSC forwards the CS domain service indication to the LTE network. This cell is an optional cell. If it does not carry the message, when the MSC establishes an SGs interface association, the CS domain service is automatically transferred to the LTE network.

 2) The MME sends a Service Request (new LAI, MME address, Service Type) message to the MSC to re-establish the SGs interface association for the UE. The MSC saves the address of the solid E. The Service Type instructs the MSC to forward the CS domain service indication to the LTE network. This cell is an optional cell. If it does not carry the message, the MSC establishes the SGs interface association and automatically transfers the CS domain service to the LTE network.

 3) The MME initiates a new message (for example: Resume SGs Request Resume SGs Request (new LAI, IMSI, MME address)) to the MSC. The MSC saves the address of the solid E and forwards the CS domain service indication to the LTE network.

 6c: The MSC saves the SGs interface association, and sends the buffered short message (short message service) or the paging message of the CS domain (other CS domain services) to the MME. If the MSC has changed, the MSC also needs to allocate the circuit to the user. The domain temporary identifier is sent to the MME and sent by the MME to the UE. The specific response is handled as follows:

 1) Location Update Accept (VLR TMSI, CS paging indication). If it is a short message service, the MSC cached short message needs to be included in this message. If it is another service, the message carries a similar cell such as CS paging indication, which is used to indicate that the UE needs to perform CS Fallback return circuit domain. This message corresponds to a Location Update Request message (the MME cannot determine if the MSC has changed).

2) Location Update Accept (VLR TMSI), this message corresponds to the MME sending a Location Update Request message (the MME cannot determine if the MSC has changed). If it is a short message service, the MSC buffered short message needs to be included in the downlink joint data (Downlink Unitdata) message and sent to the MME. If it is another service, the MSC sends a CS paging message to the MME again, and the UE needs to perform CS Fallback return. Circuit area.

 3) Resume SGs Response (VLR TMSI, CS paging indication). If it is a short message service, the MSC cached short message needs to be included in this message. If it is another service, the message carries a similar cell such as CS paging indication, which is used to indicate that the UE needs to perform CS Fallback return circuit domain. This message corresponds to the MME sending a Resume SGs Request message.

 4) If it is a short message service, the MSC buffered short message needs to be included in the Downlink Unitdata message. If it is another service, the MSC sends a CS paging message to the MME, and the UE needs to execute the CS Fallback return circuit domain. If the MSC changes, it is also necessary to bring the newly assigned VLR TMSI to the solid 8.

 6d: The MME receives the reply message on the interface of the MSC SGs, and needs to transmit the received short message to the UE through the NAS message. If the MSC has changed, the VLR TMSI allocated by the New MSC needs to be delivered to the UE, if the MSC transmits It is a CS paging message, then the MME also needs to deliver the CS paging message to the UE. The specific processing is as follows:

 1) Solid E delivers the short message to the UE via the NAS message (Downlink NAS Transport). If the VLR TMSI is received, it is also included in the message. If the MSC passes the CS paging message or the received message carries the CS paging indicator, the MME also needs to include the CS paging message or the CS paging indicator in the message and deliver it to the UE.

 2) Solid E delivers the short message to the UE via the NAS message (Downlink NAS Transport). If the VLR TMSI is received, it is also included in the message. If the MSC passes the CS paging message or receives an indication that the message carries the CS paging indicator, then the MME needs to pass the CS paging as a separate message to the UE. If the VLR TMSI is received, the VLR TMSI can also be carried to the UE by being carried in the CS paging message (because the paging message of the connected state at this time can directly locate the user).

3) If the MSC passes the CS paging message or the received message carries the CS paging indicator, then the solid E needs to pass the CS paging as a separate message. UE. If the VLR TMSI is received, the VLR TMSI carries the interaction message between the network side and the UE through the subsequent CS fal lback process to the UE, and specifically carries the VLR TMSI to the UE through the PS HO CO solid AND or NACC message.

 4) If the VLR TMSI is received, the VLR TMSI is carried therein and sent to the UE through a new NAS message.

 6e: If the UE still needs to reply to the MME after receiving the short message, the UE replies with a del ivery report compressed in the NAS message (Uplink NAS Transport) to the MME.

 6f: The MME forwards the delivery report and sends it back to the MSC in the Upl ink Unitdata message. In addition, if the UE receives a similar indication such as CS paging or CS paging indicator, the CS fal lback process needs to be performed. Before this, the UE needs to reply to the network side as a response.

 In the embodiment of the present invention, the circuit switching domain service processing method in the ISR scenario, when the mobility management entity determines that the interface information of the mobile switching center is to maintain the Gs interface association, the mobility management entity sends a message to the mobile switching center to establish an SGs interface association. . In this way, in the ISR scenario, the UE maintains the SGs interface association in the LTE network, and the MSC receives the service of the CS, and sends a message through the SGs interface to trigger the MME to page the UE. The message indicates the specific CS service type, and the UE is in the LTE. In the network, the services of the CS domain are completed through the PS domain, for example, the short message service of the CS domain is completed, and the CS Fallbak is not required to be switched to the GERAN/UTRAN network, and the CS domain service is completed through the circuit domain, thereby ensuring CS in the LTE network. The processing of the service simplifies the business process processing of the CS domain and reduces the delay of the CS service.

 Embodiment 2

 In this embodiment, after the mobility management entity learns that the SGs interface association maintained by the mobile switching center is released, the message is sent to the mobile switching center to establish an association of the SGs interface.

The mobility management entity determines that the interface information of the mobile switching center is that when the SGs interface association has been released, the information about the SGs interface has been released on the solid E setting. For example, setting the special identifier indicates that the SGs interface association has been released. Or the interface state can be set in the context to indicate that the SGs interface association has been released, etc.; when the mobility management entity learns that the user equipment is in After the active state, the message is sent to the mobile switching center according to the special identifier, and an SGs interface association is established. The following is an example of setting a special identifier on the MME as an example.

 Figure 6 is a flow chart showing an embodiment in which the mobility management entity determines that the interface information of the mobile switching center is maintained when the SGs interface association has been released, and the mobility management entity sends a message to the mobile switching center to establish an SGs interface association.

 The signaling process is described as follows:

 A: The mobility management entity can learn from the notification message sent by the mobile switching center or the serving GPRS support node that the SGs interface association has been released, and thereby determine that the information of the Gs interface or the SGs interface of the mobile switching center is maintained. The SGs interface association has been released.

 Al: The MSC sends a message to notify E, and the SGs interface association has been released. The UE is required to send a message to the MSC to re-establish the SGs interface association after detecting that the UE is in an active state. The process of re-establishing the association of the SGs interface may be: setting a special identifier of the mobility management entity in the long-term evolution network, and detecting the state of the user equipment; after the mobility management entity detects that the user equipment is in an active state, according to the The special identifier sends a message to the mobile switching center to establish an SGs interface association. The mobility management entity in the long-term evolution network may also set a special identifier. After receiving the activation message initiated by the user, the mobility management entity may The special identifier sends a message to the mobile switching center to establish an SGs interface association.

 A2: The SGSN sends a message to notify the MME that the SGs interface association has been released. The UE is required to send a message to the MSC to re-establish the SGs interface association after detecting that the UE is in an active state. The process of re-establishing the association of the SGs interface includes: setting a special identifier in the mobility management entity in the long-term evolution network, and detecting the state of the user equipment; after the mobile management entity detects that the user equipment is in an active state, according to the special The identity sends a message to the mobile switching center to establish an SGs interface association.

 B: Determine that the user equipment is in an active state according to the service request initiated by the UE, and thereby initiate establishment of an SGs interface association.

Bl: The UE of the ISR actively initiates a service in the E-UTRAN, and sends a service request message to the solid E. At this time, the solid E detects that the user equipment is in an active state, and then establishes an SGs interface association according to the identifier described in A; B2: The solid E sends a message to the MSC to establish an SGs interface association. The processing method is as follows:

 1) The MME initiates an SGs interface association with the MME to initiate an SGs interface association for the UE. The MSC saves the address of the MME.

 2) The MME initiates a new message (for example, the recovery SGs request Resume SGs Request (new LAI, IMSI, MME address)) to the MSC. The MSC saves the address of the solid E and forwards the CS domain service indication to the LTE network.

 B3: The MSC replies to the response message to the MN. If the MSC has changed, the MSC also needs to send the circuit domain temporary identifier VLR TMS I assigned to the user to the MME, and the reply processing is as follows:

 1) Location Update Accept (VLR TMS I) message. This message corresponds to the Location Update Request message sent by the MME (the MME cannot determine if the MSC has changed).

 2) Resume the SGs Response (VLR TMS I) message. This message corresponds to the Resume SGs Request message sent by the MME.

 B4: The solid E adds the newly allocated circuit domain temporary identifier VLR TMSI to the UE. The specific processing method is as follows: If the VLR TMSI is received, the VLR TMSI is carried in a new NAS message or through an existing NAS message. Give the UE.

 C: Determine that the user equipment is in an active state according to the service request message initiated by the UE in response to the network side, and thereby initiate establishment of an SGs interface association.

 Cl, C2, C3: After receiving the Downlink Data Notification message sent by the S-GW on the S11 interface, the MME sends a paging message to the UE if the UE is in an idle state. After the UE responds to the SR message normally, the E is based on A. Said to describe the special identity to send a message to the MSC, establish an SGs interface association (execution B description).

 D: This scenario corresponds to the description and embodiment of the UE in the idle state. The processing of the UE in the connected state in Embodiment 1 is independent of the description of this embodiment.

The subsequent processing is the same as that of the first embodiment, and details are not described herein again. It should be understood that the above processing for the MME is equally applicable to the SGSN.

 In the embodiment of the present invention, the circuit switching domain service processing method in the ISR scenario, when the mobility management entity determines that the interface information of the mobile switching center is that the maintained SGs interface association has been released, the mobility management entity sends a message to the mobile switching center. Establish an SGs interface association. In this way, in the ISR scenario, the UE maintains the SGs interface association in the LTE network, and the MSC receives the service of the CS, and sends a message through the SGs interface to trigger the MME to page the UE. The message indicates the specific CS service type, and the UE is in the LTE. In the network, the services of the CS domain are completed through the PS domain, for example, the short message service of the CS domain is completed, and the CS domain is not required to be switched to the GERAN/UTRAN network, and the service of the CS domain is completed through the circuit domain, thereby ensuring the LTE network. The processing of the CS service simplifies the business process processing of the CS domain and reduces the delay of the CS service.

 As shown in FIG. 7, the embodiment of the present invention further provides a circuit switching domain service processing method in an ISR scenario, including the following steps:

 S 701. The user equipment learns interface information of the current mobile switching center.

 5702. The user equipment knows the network where the user is currently located;

 S703: The user equipment determines whether to perform the process of establishing an association relationship between the SGs interface or the process of maintaining the association of the SGs interface.

 In the embodiment of the present invention, the circuit switching domain service processing method in the ISR scenario, the user equipment learns the interface information of the current mobile switching center and the network where the user is currently located; and then the user equipment determines whether to perform the establishment of the SGs interface association process or the execution of the SGs interface. In the ISR scenario, the UE maintains the SGs interface association in the LTE network, and the MSC receives the service of the CS, and the SGs interface sends a message to trigger the MME to advertise the UE, and the message indicates the specific CS service type. The UE completes the CS domain service through the PS domain in the LTE network, for example, completes the short message service of the CS domain, and does not need to perform the CS Fa l lbak handover to the GERAN/UTRAN network, and then complete the CS domain service through the circuit domain. Therefore, the processing of the CS service in the LTE network is guaranteed, the service flow processing of the CS domain is simplified, and the delay of the CS service is reduced.

In step S701, the user equipment is informed that the interface information of the current mobile switching center may be: the network side notifies the user equipment of the current mobile switching center interface information, or is set by the user. The UE can learn the interface information of the current mobile switching center. For example, the UE can initiate the joint registration according to the GERAN/UTRAN network, and then learns that the Gs interface association is established. When the UE initiates the joint registration in the E-UTRAN network flow, the UE learns the established Is the SGs interface association.

 The steps of the circuit switching domain service processing method in the foregoing ISR scenario are as follows:

 S701a) If the user equipment is informed that the MSC remains associated with the Gs interface of the SGSN, for example, when the user equipment is currently in the GERAN/UTRAN network, the network notifies the user equipment MSC to remain associated with the Gs interface of the SGSN.

 S702a) When the user equipment experiences network migration, the user equipment knows that it is in the long term evolution network. S703a) The user equipment is associated with the Gs interface of the SGSN and the user is currently in the long term evolution network, and the user equipment determines to perform the process of establishing an SGs interface association. For example, if the UE initiates the joint location update, the MSC establishes an SGs interface with the solid E. Association.

 The steps of the circuit switching domain service processing method in the foregoing ISR scenario may also be specifically:

 S701A) If the user equipment determines that the MSC maintains an association with the SGs interface of the fixed E, for example, when the user initiates the joint location update in the long term evolution network, the user determines the SGs interface maintained on the MSC.

 S702A) When the user migrates to the network, the user equipment learns that it returns to the GERAN/UTRAN network. S703A) the user equipment is associated with the SGs interface of the MN and the user is currently in the GERAN/UTRAN network, and the user equipment determines to perform the maintenance. SGs interface association process. For example, the user equipment does not need to initiate a joint location update, that is, if the Gs interface association is not established, the SGs interface association continues to be saved on the MSC.

 In another embodiment of the present invention, a circuit switching domain service processing method in an I SR scenario includes the following steps:

 S 801. The user equipment learns interface information of the current mobile switching center.

 S802. The user equipment sets an identifier or an internal state according to the interface information.

 5803. The user equipment knows the network where it is currently located;

The user equipment determines whether to perform the process of establishing an SGs interface association process or the SGs interface association process according to the identifier or the internal state and the network that the user is currently located. The user equipment setting identifier or the internal state is mainly used to indicate that the UE is in the network migration. When the user equipment knows the network in which the user is located, the UE determines whether to perform the process of establishing the SGs interface association process, or performs the SGs interface association process.

 The specific expression may be: the identifier or the internal status may be a flag flag, or the identifier or the internal status may be an "SGs Association needed" cell or the like. For example, the UE sets a flag bit flag, such as "SGs Establishment Flag". When the network side notifies the UE to activate the ISR, if the UE senses that the MSC maintains the Gs interface association, the UE needs to set the SGs Establishment Flag to be "needed". This means that when the UE returns to the LTE network, it needs to perform the process of establishing the association of the SGs interface. When the network side informs the UE to activate the ISR, if the UE senses that the MSC maintains the SGs interface association, the UE needs to set the SGs Establishment Flag to be "not needed" (for example: when the joint TA/LA update process is successfully completed, the UE sets its SGs Establishment Flag is "not needed"). That is to say, when the UE returns to the GERAN/UTAN network, it does not need to perform the process of establishing a Gs interface association, but continues to maintain the SGs interface association.

 The usage of the cell "SGs Association needed" is similar to the above. When the network side informs the UE to activate the ISR, if the UE senses that the MSC maintains the Gs interface association, the UE needs to set the "SGs Association needed" or set the cell value to a valid value, which means that when the UE returns to the LTE network The process of establishing an association of the SGs interface needs to be performed. When the network side informs the UE to activate the ISR, if the UE senses that the MSC maintains the SGs interface association, the UE needs to set "SGs Association not needed" or "SGs Association needed" to take an invalid value. That is to say, when the UE returns to the GERAN/UTAN network, it does not need to perform the process of establishing a Gs interface association, but continues to maintain the SGs interface association.

 Figure 8 is a flow chart showing an embodiment of determining whether to initiate establishment of an SGs interface association according to an already existing association in the state in which the ISR is activated.

 The signaling process is described as follows:

Scenario A: The SGs interface association between the MSC and the solid E has been established. The UE accesses the GERAN/UTRAN network from the LTE network, establishes an ISR, and establishes a Gs interface association process. Al: The UE initiates a route update request, indicating a joint location update in the message.

 A2a, A2b, and A2c: The process of context interaction between the SGSN and the MME establishes an ISR association. The A2c message informs the MME to enable ISR.

 A3a, A3b: The SGSN informs the MSC to perform the location update process. In this process, the Gs interface association is established, and the SGs interface association recorded by the MSC is replaced by the Gs interface association at this time.

 A4: The SGSN sends a Routing Area Update Accept message to the UE.

 The message carries the cell "ISR", "SGs Association needed". The ISR indicates that the UE activates the ISR. The purpose of the "SGs Association needed" similar cell is to indicate that the UE is active on the premise of the ISR. If the UE returns to the LTE network, the UE needs to immediately initiate a joint tracking area update procedure to establish the MSC. SGs interface association between MMEs (the TAU Request message carries "CS fallback indicator"). If the ISR is not activated, the SGSN does not need to pass the "SGs Association needed" to the UE in the message.

 The status of the "SGs Association needed" similar cell may also be set by the UE itself (the UE may perceive whether the MSC has an SGs interface association or a Gs interface association, because the establishment of the SGs association or the establishment of the Gs association is a UE-initiated association. Registration (attachment process or location update process) - Implemented by the joint registration process of PS and CS. If joint registration is not performed, the related association cannot be established). Specifically, the UE may notify the UE to activate the ISR. If the UE learns that the MSC maintains the association with the Gs interface of the SGSN, the UE needs to set the status to be “SGs”.

Association needed" (or set "SGs Association needed" to be valid), the purpose is to indicate that if the ISR is activated, if it returns to the LTE network, it needs to immediately initiate a joint tracking area update procedure to establish the MSC and MME. Inter-SGS interface association (TAU Request message carries "CS fallback indicator").

There is also a processing method in which: the UE sets a message by itself, and the purpose is to indicate that if the UE returns to the LTE network on the premise of the ISR activation, the UE needs to immediately initiate a joint tracking area update procedure for establishing the E and the MSC. The SGs interface is associated (the "CS fallback indicator" is carried in the TAU Request message). For example: The UE sets a flag bit flag, such as "SGs Establishment Flag", When the network side informs the UE to activate the ISR, if the MSC maintains the Gs interface association, the UE needs to set the SGs Establishment Flag to be "needed". If the UE returns to the LTE network, the UE needs to initiate the joint tracking immediately. The area update procedure is used to establish an SGs interface association between the solid E and the MSC.

 Scenario B: The Gs interface association is established and the ISR is activated. The UE accesses the LTE network from the GERAN/UTRAN network to establish a process associated with the SGs interface.

 B1: According to the process described in scenario A, a Gs interface association is established between the MSC and the SGSN, and the ISR is activated. The UE accesses the LTE network from the GERAN/UTRAN network, and initiates a tracking area location update request.

 B2a, B2b: The E-notifies the MSC to perform the location update process. In this process, the SGs interface association is established. The Gs interface association recorded by the MSC is replaced by the SGs interface association at this time. That is: establish an SGs interface association.

 B 3: The MME sends a Tracking Area Update Accept message to the UE.

 The message carries the cell "ISR", "SGs Association not needed". The ISR indicates that the UE activates the ISR. The purpose of the "SGs Association not needed" similar cell is to indicate that the UE is active on the premise of the ISR. If it returns to the GERAN/UTRAN network, it does not need to immediately initiate a joint routing area update procedure to establish. The Gs interface between the MSC and the SGSN is associated. If the ISR is not activated, the solid E does not need to pass the "SGs Association not needed" to the UE in the message.

 The status of the "SGs Association not needed" similar cell can also be set by the UE itself (the UE can sense whether the MSC has an SGs interface association or a Gs interface association). When the network side notifies the UE to activate the ISR, if the MSC maintains the SGs interface association, the UE needs to set the status to "SGs Association not needed" (or set "SGs Association needed" to be invalid), in order to indicate activation in the ISR. On the premise, if you return to the GERAN/UTRAN network, you do not need to immediately initiate a joint routing area update procedure to establish the Gs interface association between the MSC and the SGSN.

There is also a processing method in which: the UE sets a message, and the purpose is to indicate that if the ISR is activated, if the GERAN/UTRAN network is returned, the combined routing area update process does not need to be initiated immediately to establish a Gs interface association. For example: The UE sets a flag f lag , such as " SGs Establi shment Flag", when the network side informs the UE to activate the ISR, if the MSC maintains the SGs interface association, the UE needs to set the SGs Establishment Flag to "not needed", meaning that when the joint TA/LA update process is successfully completed, The UE sets its SGs Establishment Flag to "not needed".

 In summary, the MSC needs to maintain the SGs interface association in the state of ISR activation. If the Gs interface association is maintained, the UE needs to establish an SGs interface association between the MSC and the solid E to return to the LTE network. If the MSC has maintained the SGs interface association, it will be processed according to the normal procedure.

 In the embodiment of the present invention, the circuit switching domain service processing method in the ISR scenario, the user equipment learns the interface information of the current mobile switching center and the network where the user is currently located; and then the user equipment determines whether to perform the establishment of the SGs interface association process or the execution of the SGs interface. The association process, that is, if the user equipment determines that it is in the GERAN/UTRAN network, and the MSC maintains the Gs interface association, when the user equipment returns to the long-term evolution network, initiates establishment of an SGs interface association between the MSC and the solid E; In the long term evolution network and the MSC maintains the SGs interface association, when the user equipment returns to the GERAN/UTRAN network, the Gs interface association between the MSC and the SGSN is not initiated. In this way, in the ISR scenario, the MSC maintains the SGs interface association in the LTE network, and the MSC receives the service of the CS, and sends a message through the SGs interface to trigger the MME to page the UE. The message indicates the specific CS service type, and the UE is in the LTE. In the network, the services of the CS domain are completed through the PS domain, for example, the short message service of the CS domain is completed, and the CS Fallbak is not required to be switched to the GERAN/UTRAN network, and the service of the CS domain is completed through the circuit domain, thereby ensuring CS in the LTE network. The processing of the service simplifies the business process processing of the CS domain and reduces the delay of the CS service.

 As shown in FIG. 9, the embodiment of the present invention further provides a circuit switching domain service processing apparatus 500 in an ISR scenario, including:

 The interface information determining unit 510 is configured to determine interface information of the mobile switching center.

 The SGs interface establishing unit 520 is configured to send a message to the mobile switching center to establish an SGs interface association when the interface information determining unit 510 determines that the mobile switching center does not establish an SGs interface association.

In this way, in the ISR scenario, the UE keeps the SGs interface associated in the LTE network, and the MSC receives The CS service sends a message to the MME to advertise the UE through the SGs interface. The message indicates the specific CS service type. The UE completes the CS domain service through the PS domain in the LTE network, for example, completing the short message service of the CS domain. It is not necessary to perform CS Fa l lbak handover to the GERAN/UTRAN network, and then complete the CS domain service through the circuit domain, thereby ensuring the processing of the CS service in the LTE network, simplifying the service processing of the CS domain, and reducing the delay of the CS service. .

 As shown in FIG. 10, in an embodiment of the present invention, the interface information determining unit 510 includes:

 The message receiving module 510a is configured to receive a CS paging message forwarded by the serving GPRS support node, and the interface determining module 510b is configured to determine, according to the message received by the message receiving module 51 Oa, whether the mobile switching center establishes an SGs interface association.

 As shown in FIG. 11, in another embodiment of the present invention, the interface information determining unit 510 includes:

 The interface information obtaining module 510A is configured to obtain information that the SGs interface association has been released by the mobile switching center;

 The identifier setting module 510B is configured to set an identifier indicating that the SGs interface association has been released. The SGs interface establishing unit 520 includes:

 a user equipment status obtaining module 520A, configured to acquire whether the user equipment is in an active state;

The SGs interface establishing module 520B is configured to: after the user equipment status obtaining module 520A learns that the user equipment is in an active state, according to the identifier that is set by the identifier setting module, indicating that the SGs interface association has been released, to the mobile switching center Send a message to establish an SGs interface association.

 In one embodiment of the invention the device is a mobility management entity.

In the embodiment of the present invention, the circuit switching domain service processing apparatus 500 in the ISR scenario, when the interface information determining unit 510 determines that the mobile switching center does not establish an SGs interface association, the SGs interface establishing unit 520 sends a message to the mobile switching center to establish an SGs interface association. . In this way, in the ISR scenario, the UE maintains the SGs interface association in the LTE network, and the MSC receives the service of the CS, and sends a message through the SGs interface to trigger the MME to page the UE. The message indicates the specific CS service type, and the UE is in the LTE. Through the network through PS The domain completes the services of the CS domain, for example, completing the short message service of the CS domain without performing CS execution.

Fa l lbak switches to the GERAN/UTRAN network, and then completes the CS domain service through the circuit domain, thereby ensuring

The processing of the CS service in the LTE network simplifies the service processing of the CS domain and reduces the delay of the CS service.

 As shown in FIG. 12, the embodiment of the present invention further provides another circuit switching domain service processing apparatus 600 in an ISR scenario, including:

 The interface information acquiring unit 610 is configured to acquire interface information of the current mobile switching center, and the network information acquiring unit 620 is configured to determine a network where the device is currently located;

 The SGs interface processing unit 630 is configured to determine, according to the interface information of the current mobile switching center determined by the interface information acquiring unit 610 and the network that the device is currently determined by the network information acquiring unit 620, that is performed to initiate the establishment. The SGs interface association process, or the execution of the SGs interface association process.

 In the embodiment of the present invention, the circuit switching domain service processing device in the ISR scenario, the interface information acquiring unit acquires the interface information of the current mobile switching center, the network information acquiring unit determines the network where the device is currently located, and the SGs interface processing unit according to the interface information. Obtaining, by the acquiring unit, the interface information and the network determined by the network information acquiring unit, determining whether to perform an initiation of establishing an SGs interface association process, or performing an SGs interface association process. In this way, in the ISR scenario, the UE maintains the SGs interface association in the LTE network, and the MSC receives the service of the CS, and sends a message through the SGs interface to trigger the fixed E paging UE. The message indicates the specific CS service type, and the UE is in the UE. The LTE network completes the services of the CS domain through the PS domain, for example, completes the short message service of the CS domain, and does not need to perform the CS Fa l lbak handover to the GERAN/UTRAN network, and then completes the service of the CS domain through the circuit domain, thereby ensuring LTE. The processing of the CS service in the network simplifies the service flow processing of the CS domain and reduces the delay of the CS service.

 As shown in FIG. 13, in another embodiment of the present invention, the apparatus further includes an identifier setting unit 625, configured to perform identifier setting according to the interface information and the network information.

 In one embodiment of the invention the device is a user equipment.

In the embodiment of the present invention, the circuit switching domain service processing apparatus 600 in the ISR scenario, the interface information acquiring unit 610 acquires the interface information of the current mobile switching center, and the network information acquiring unit 620 determines the loading. The SGs interface processing unit 630 determines, according to the interface information acquired by the interface information acquiring unit and the network determined by the network information acquiring unit, whether to perform the process of establishing an SGs interface association process or performing maintenance. SGs interface association process. In this way, in the ISR scenario, the UE keeps the SGs interface associated in the LTE network, and the MSC receives the service of the CS.

 The SGs interface sends a message to trigger the fixed E paging UE, and the message indicates the specific CS service type. The UE completes the CS domain service through the PS domain in the LTE network, for example, completes the short message service of the CS domain, and does not need to pass the message. The CS Fa l lbak is switched to the GERAN/UTRAN network, and the CS domain service is completed through the circuit domain, thereby ensuring the processing of the CS service in the LTE network, simplifying the service processing of the CS domain, and reducing the delay of the CS service.

 It should be noted that those skilled in the art can understand that all or part of the process of implementing the above embodiments may be completed by a computer program indicating related hardware, and the program may be stored in a computer readable storage medium. Wherein, the program, when executed, may include the flow of an embodiment of the methods as described above. The storage medium may be a magnetic disk, an optical disk, a Read-Only Memory (ROM), or a Random Acces Memory (RAM).

 The above is only the specific embodiment of the present invention, but the scope of the present invention is not limited thereto, and any person skilled in the art can easily think of changes or substitutions within the technical scope of the present invention. It should be covered by the scope of the present invention. Therefore, the scope of the invention should be determined by the scope of the claims.

Claims

Claim  A circuit switching domain service processing method in an ISR scenario, comprising: a mobility management entity determining interface information of a mobile switching center;  If the mobility management entity determines that the mobile switching center does not establish an SGs interface association, the mobility management entity sends a message to the mobile switching center to establish an SGs interface association.  2. The circuit switching domain service processing method in the ISR scenario according to claim 1, wherein the mobility management entity determines that the mobile switching center does not establish an SGs interface association:  The mobility management entity determines that the interface information of the mobile switching center is to maintain the Gs interface association, or the mobility management entity learns that the SGs interface association maintained by the mobile switching center is released.  The method for processing a circuit switched domain service in an ISR scenario according to claim 2, wherein the mobility management entity determines that the interface information of the mobile switching center is to maintain the association of the Gs interface as follows: The GPRS supports the CS paging message forwarded by the node, and the mobility management entity determines that the interface information of the mobile switching center is to maintain the Gs interface association.  The method for processing a circuit switched domain service in an ISR scenario according to claim 2, wherein the mobility management entity learns that the association of the SGs interface maintained by the mobile switching center is released: the mobility management entity moves from the mobile switching center or In the notification message sent by the serving GPRS support node, it is learned that the SGs interface association maintained by the mobile switching center is released.  The method for processing a circuit switched domain service in an ISR scenario according to claim 3, wherein when the mobility management entity receives a CS paging message forwarded by a serving GPRS support node, the mobility management entity The mobile switching center sends a message, and the establishing the SGs interface association includes: if the user equipment is in the idle mode, the mobility management entity in the long term evolution network sends the packet switched domain paging message to the user equipment;  The user equipment is responsive to the packet switched domain paging message;  The mobility management entity sends a message to the mobile switching center to establish an SGs interface association of the mobile switching center; or If the user equipment is in an active state, the mobility management entity in the long term evolution network The mobile switching center sends a message to establish an SGs interface association of the mobile switching center.  6. The circuit switching domain service processing method in an I SR scenario according to claim 4, wherein:  If the mobility management entity learns that the SGs interface association is released by the mobile switching center, the mobile management entity sends a message to the mobile switching center, and the establishing the SGs interface association includes:  The mobility management entity in the long term evolution network sets information indicating that the SGs interface association has been released; after the mobile management entity learns that the user equipment is in an active state, according to the information indicating that the SGs interface association has been released, the mobile exchange is performed. The center sends a message to establish an SGs interface association.  The method for processing a circuit switched domain service in an ISR scenario according to claim 6, wherein after the mobile management entity learns that the user equipment is in an active state, the information indicating that the SGs interface association has been released is Sending a message to the mobile switching center, and establishing an SGs interface association specifically includes:  After receiving the service request sent by the user equipment, the mobility management entity sends a message to the mobile switching center according to the information indicating that the SGs interface has been released, and establishes an SGs interface association; or  After the user equipment responds to the paging message sent by the network side, the mobility management entity sends a message to the mobile switching center according to the information indicating that the SGs interface has been released, and establishes an SGs interface association.  8. The method of processing a circuit switched domain service in an ISR scenario according to claim 1, wherein the mobility management entity sends a message to the mobile switching center, and the association of establishing an SGs interface is specifically:  The mobility management entity initiates a location update request message to the mobile switching center, and the mobile switching center establishes an SGs interface association, or  The mobility management entity sends a service request message to the mobile switching center, and the mobile switching center establishes an SGs interface association, or  The mobility management entity initiates a new message to the mobile switching center, and the mobile switching center establishes an SGs interface association. A circuit switching domain service processing method in an ISR scenario, the method includes: the user equipment learns interface information of a current mobile switching center; The user equipment knows the network in which it is currently located;  The user equipment determines whether to perform the establishment of the SGs interface association process or the execution of the SGs interface association process.  The method for processing a circuit switched domain service in an ISR scenario according to claim 9, wherein the method specifically includes:  The user equipment learns that the mobile switching center remains associated with the Gs interface of the serving GPRS support node; the user equipment knows that it is in the long term evolution network;  The user equipment determines to perform the process of establishing an SGs interface association.  The method for processing a circuit switched domain service in an ISR scenario according to claim 9, wherein the method specifically includes:  The user equipment learns that the mobile switching center remains associated with the S G s interface of the mobility management entity; the user equipment knows that it is in the GERAN/UTRAN network;  The user equipment determines to perform the keep SGs interface association process.  The method for processing a circuit switched domain service in an ISR scenario according to claim 9, wherein the user equipment learns that the interface information of the current mobile switching center is specifically:  The network side notifies the interface information of the current mobile switching center of the user equipment, or the user equipment knows the interface information of the current mobile switching center.  The method for processing a circuit switched domain service in an ISR scenario according to claim 9, wherein after the user equipment learns the interface information of the current mobile switching center, the method further includes: setting identifier or status information;  The process of determining whether to perform the establishment of the SGs interface association process or the process of maintaining the SGs interface association is as follows:  The user equipment determines whether to perform the process of establishing an SGs interface association process or the SGs interface association process according to the identifier or the status information and the network where the user equipment is currently located. A circuit switching domain service processing apparatus in an I SR scenario, comprising: an interface information determining unit, configured to determine interface information of a mobile switching center; The SGs interface establishing unit is configured to: when the interface information determining unit determines that the mobile switching center does not establish an SGs interface association, send a message to the mobile switching center to establish an SGs interface association.  The apparatus for processing a circuit switching domain in an I SR scenario according to claim 14, wherein the interface information determining unit comprises:  The message receiving module is configured to receive a CS paging message forwarded by the serving GPRS support node, and the interface determining module is configured to determine, according to the message received by the message receiving module, whether the mobile switching center establishes an SGs interface association.  The apparatus for processing a circuit switching domain in an ISR scenario according to claim 14, wherein the interface information determining unit comprises:  An interface information obtaining module, configured to obtain information that the SGs interface association has been released by the mobile switching center;  An identifier setting module, configured to set an identifier indicating that the SGs interface association has been released.  The apparatus for processing a circuit switched domain in an I SR scenario according to claim 16, wherein the SGs interface establishing unit includes:  a user equipment status obtaining module, configured to acquire whether the user equipment is in an active state;  The SGs interface establishing module is configured to send a message to the mobile switching center according to the identifier that the SGs interface association has been released according to the identifier set by the identifier setting module after the user equipment state obtaining module learns that the user equipment is in an active state. Establish SGs interface association.  The circuit switching domain service processing apparatus in the I SR scenario according to any one of claims 14 to 17, wherein the device is a mobility management entity.  A circuit switching domain service processing apparatus in an ISR scenario, comprising: an interface information acquiring unit, configured to acquire interface information of a current mobile switching center;  a network information acquiring unit, configured to determine a network where the device is currently located; The SGs interface processing unit is configured to determine, according to the interface information acquired by the interface information acquiring unit and the network determined by the network information acquiring unit, whether to perform an SGs interface association process or a SGs interface association process. The apparatus for processing a circuit switched domain in an ISR scenario according to claim 19, wherein the device further comprises an identifier setting unit, configured to perform identifier setting according to the interface information.  The device for processing a circuit switched domain in an ISR scenario according to claim 19 or 20, wherein the device is a user equipment.