CN101662756A - Voice continuous call switching method and system and mobile service switching center - Google Patents

Abstract

The embodiment of the present invention discloses a voice continuity call switching method, including: receiving an SR VCC switching request message carrying emergency call indication information; learning that the current SR VCC switching request is an emergency call according to the switching request message; executing the emergency call SR VCC switching, switching from the current network side to the target network side. Correspondingly, the embodiment of the present invention also discloses a network system for voice continuity call switching, a mobile service switching center, a mobile management entity and a GPRS service support point. The solution provided by the invention enables the mobile service switching center MSC to know that the current call is an emergency call SR VCC, so that the current call is routed to the IMS domain to complete voice call anchoring, and finally realize the emergency call SR VCC switch.

Description

Method, system and mobile service switching center for voice continuity call switching

technical field

The invention relates to the technical field of communication, in particular to a method and system for voice continuity call switching, a mobile management entity, a GPRS service support point and a mobile service switching center.

Background technique

In order to enhance the competitiveness of future networks, 3GPP is studying a new evolved network, including the evolved UMTS Terrestrial Radio Access Network (E-UTRAN, Evolved UMTS Terrestrial Radio Access Network), which is used to realize all functions related to the wireless of the evolved network ; Mobility Management Entity (MME, Mobility Management Entity), responsible for the mobility management of the control plane, including user context and mobility status management, assigning user temporary identity, etc.; Serving Gateway entity (SGW, ServingGateway), is the 3GPP access network The user plane anchor point between the 3GPP access network and the non-3GPP access network terminates the interface of E-TURAN; the packet data network gateway entity (PGW, Packet Data Network Gateway) is the user plane anchor point between the 3GPP access network and the non-3GPP access network, terminating and external packet Data network (PDN, Packet DataNetwork) interface, etc.

3GPP introduces the voice call continuity (Voice Call Continuity, VCC) application in the IP-based multimedia subsystem (IMS) domain in the network to realize the voice call between the CS domain and the PS domain of the terminal (User Equipment, UE) continuity. When the UE performs VCC services, the MME sends a message to notify the Mobile Services Switching Center (MSC) to perform single-system access voice continuity call (Single Radio VCC, SR VCC) service switching, and the MSC transfers the ongoing voice services Route to IMS domain for handover.

In the process of realizing the present invention, the inventor finds that there are at least the following problems in the prior art:

In the SR VCC call processing technology, at present, there is no technology to realize the emergency call SR VCC service.

Contents of the invention

The technical problem to be solved by the embodiments of the present invention is to provide a method and system for SR VCC call switching, a mobile management entity, a GPRS service support point, and a mobile service switching center, so that the MSC can know that the current call is an emergency call SR VCC, thereby completing the emergency call. Call SR VCC processing.

In order to solve the above technical problems, an embodiment of the present invention provides a method for voice continuity call switching, including:

Receive a single access system voice continuity SR VCC switching request message carrying emergency call indication information;

According to the switching request message, it is known that it is currently an emergency call SR VCC switching request;

Perform emergency call SR VCC switching from the current network side to the target network side.

The embodiment of the present invention also provides a method, including:

When it is judged that the current call is an emergency call SR VCC, the emergency call SR VCC is processed;

During the processing of the emergency call SRVCC, the VDN or STN-SR used to complete the emergency call SR VCC switching is acquired.

Correspondingly, an embodiment of the present invention also provides a network system, including:

The mobility management entity or the GPRS service support point is used to send a handover request message carrying emergency call indication information;

The mobile service switching center is used to receive the SR VCC switching request message that carries the emergency call indication information, and when it is learned that the current switching request is an emergency calling SR VCC switching request according to the switching request message, perform the emergency calling SR VCC switching, from the current network side Switch to the target network side.

The embodiment of the present invention also provides a network system, including a mobility management entity or a GPRS service support point,

The mobile management entity or the GPRS service support point is used to determine that the current call is an emergency call, and perform emergency call SR VCC processing, and obtain the VDN used to complete the emergency call SR VCC switching during the process of emergency call SR VCC processing or STN-SR.

The embodiment of the present invention also provides a mobile service switching center, including:

The receiving unit is used to receive the SR VCC switching request message carrying the emergency call indication information;

A processing unit, configured to perform emergency call SR VCC service switching according to the SR VCC switching request message of the emergency call indication information.

The embodiment of the present invention also provides a device, including:

Judging unit, used to judge whether the current call is an emergency call SR VCC;

The sending unit is used to send the emergency call SR VCC switching request message carrying the emergency call indication information to the mobile service switching center when the judging unit judges that the current call is an emergency call SR VCC.

Implementing the embodiment of the present invention has the following beneficial effects:

The embodiment of the present invention informs the mobile service switching center that the current call is an emergency call SR VCC by sending emergency call indication information, so that the mobile service switching center can process according to the emergency call SR VCC flow, and route the current emergency call to the IMS domain to complete the voice call. Call switching processing meets the requirements of the terminal and the network side.

Description of drawings

FIG. 1 is a schematic diagram of a network system architecture for illustrating an embodiment of the present invention;

Fig. 2 is the flow chart of the method for realizing the SR VCC switching of emergency call in the first embodiment of the present invention;

Fig. 3 is the flow chart of the method for realizing the R VCC switching of the emergency call of the second embodiment of the present invention;

Fig. 4 is an example of realizing the SR VCC switching of an emergency call according to Embodiment 2 of the present invention;

Fig. 5 is the flow chart of the method for realizing the SR VCC switching of the emergency call of the third embodiment of the present invention;

Fig. 6 is an example that realizes the SR VCC switching of emergency call according to the embodiment of the present invention of Fig. 5;

Fig. 7 is another example that realizes the SR VCC switching of emergency call according to the embodiment of the present invention of Fig. 5;

FIG. 8 is a schematic structural diagram of a network system according to an embodiment of the present invention;

FIG. 9 is a schematic structural diagram of a mobile service switching center according to an embodiment of the present invention;

Fig. 10 is a schematic structural diagram of a mobile network entity according to an embodiment of the present invention.

Detailed ways

The present invention will be described in further detail below in conjunction with the accompanying drawings.

FIG. 1 is a schematic diagram illustrating the architecture of a network system implementing an embodiment of the present invention. Referring to FIG. 1, the network system architecture includes an evolved UMTS Terrestrial Radio Access Network (E-UTRAN, Evolved UMTSTerrestrial Radio Access Network), a radio access network (GERAN), and a universal terrestrial radio access network (UTRAN). Mobility Management Entity (MME, Mobility Management Entity), responsible for the mobility management of the control plane, including user context and mobility state management, assigning temporary user IDs, etc.; Serving Gateway entity (SGW, Serving Gateway), is the 3GPP access network The user plane anchor point between the 3GPP access network and the non-3GPP access network terminates the interface of E-TURAN; the packet data network gateway entity (PGW, Packet DataNetworkGateway) is the user plane anchor point between the 3GPP access network and the non-3GPP access network, terminating and external packet data network (PDN, Packet Data Network) interface. The policy and charging rule functional entity (PCRF, Policy and Charging Rule Function) is used for policy control decision and flow charging control function. The Home Subscriber Server (HSS, Home Subscriber Server) is used to store user subscription information.

The embodiment of the present invention takes the network system in FIG. 1 as an example to illustrate how the network side assists the UE in switching from the eUTRAN network to the CS domain of UTRAN/GERAN when the UE initiates an emergency call SRVCC on the eUTRAN network side. The MSC in the embodiment of the present invention learns that the current call is an emergency call SR VCC according to the received emergency call indication information, thereby completing the subsequent emergency call SR VCC processing flow.

FIG. 2 is a flowchart of a method for implementing SR VCC switching of an emergency call according to Embodiment 1 of the present invention. As shown in Figure 2, the method includes steps:

S201. Receive an SR VCC switching request message carrying emergency call indication information;

In this embodiment, the UE sends a measurement report to the source-side access system eUTRAN. If the source-side eUTRAN determines that the target network side supports the SR VCC capability, the eUTRAN sends a handover request message to notify the MME, and the message carries an SR VCC indication (SR VCC indication ) parameter is used to indicate SR VCC switching. Correspondingly, the MME can know whether the current call is an emergency call SR VCC according to the received emergency call indication information sent by the UE, or the MME can know whether the current call is an emergency call according to whether the Qos corresponding to the voice bearer in the current call is an emergency call QoS, or It may be that the MME learns whether the current call is an emergency call according to whether the access point name (Access Point Name, APN) corresponding to the bearer belongs to an emergency APN (Emergency APN). If the current call is an emergency call to SR VCC, the MME knows that it needs to be handed over according to the received handover request message carrying the SR VCC indication parameter, and sends the SR VCC handover request message carrying the emergency call indication information to the MSC, so that the MSC knows the current need Perform emergency call SR VCC switching processing.

Similarly, when switching from High Speed Packet Access (HSPA) VOIP to the CS domain of UTRAN/GERAN, it may be that the GPRS service support point (Serving GPRSSupporting Node, SGSN) completes the corresponding sending of emergency call indication information to MSC process.

S202. According to the handover request message, it is learned that the current handover request of the emergency call SR VCC is performed, and the emergency call SR VCC is switched, and switched from the current network side to the target network side;

In this embodiment, the MSC learns that SR VCC handover processing is currently required based on receiving the handover request message, and learns that the current call is an emergency call from the emergency call indication information carried in the handover request message, and needs to perform SR VCC handover processing for the emergency call.

In this embodiment, the MSC sends handover information carrying emergency call indication information to the target network side to inform the need to perform emergency call SR VCC handover. After receiving the above information, the target network side prepares for emergency call resources and returns corresponding response information. to MSC. The MSC completes call routing and anchors to the IMS domain, and sends a handover instruction to the UE, prompting the UE to handover from the current network side to the target network side (for example, GERAN or UTRAN).

3 is a flowchart of a method for implementing SR VCC switching of an emergency call according to Embodiment 2 of the present invention. As shown in Figure 3, the method includes steps:

S301. Receive an SR VCC switching request message carrying emergency call indication information;

In this embodiment, the SR VCC handover request message carrying the emergency call indication information comes from the MME/SGSN, and the manner in which the handover request message carries the emergency call indication information includes the following:

1. The message carries an Emergency Indication parameter;

Two, the message type is a special message type, such as an emergency call message type (EmergencyForward relocation Req);

3. When the MME/SGSN knows that the current call is an emergency call, it carries an empty VCC Domain Switching Number (VDN) or SRVCC Session Switching Number (STN-SR) in the handover request message to inform the MSC that the current call is an emergency call ;

4. Expand the indicator bit in the information element in the message to inform the MSC that the current call belongs to an emergency call. Here, VDN or STN-SR can be expanded, and other existing information elements can also be expanded to make it carry an emergency call indication. For example, changing a VDN or STN-SR into an extended VDN or an extended STN-SR means that there is an indication bit to indicate that the call is an emergency call.

S302. According to the SR VCC switching request message, it is learned that the switching request of the SR VCC is currently an emergency call;

In this embodiment, the MSC learns that the SR VCC handover process needs to be performed according to receiving the handover request message from the MME or SGSN, and at the same time learns from the emergency call indication information carried in the handover request message that the current call is an emergency call, and an emergency call needs to be made. SR VCC switching process.

S303. Send handover information carrying the emergency call indication information to the target network side, so as to notify the target network side that the current call is an emergency call SR VCC handover.

In this embodiment, the MSC does not necessarily have to send the emergency call indication information to notify the target network side, and may also set a high priority when learning that the current call is an emergency call SR VCC, so as to realize corresponding emergency call SR VCC processing.

S304. During the SRVCC switching process of the emergency call, obtain the current VDN or STN-SR, and route the call to the IMS domain according to the current VDN or STN-SR;

In the normal SR VCC process, the MSC does not need to send a MAP Subscriber Location Report message to the GMLC or E-RUA to report specific location information and obtain routing information. During the emergency call SR VCC processing, when the MSC knows that the current emergency call is, it needs to send a message to the GMLC/LRF or E-RUA to report the location information and obtain the routing information, so as to route the current emergency call to the IMS domain. For example, the MSC sends a user location report request message to the GMLC/E-RUA, and the GMLC sends a user location report response message carrying a VDN or STN-SR, and the MSC learns the VDN or STN-SR according to the received user location report corresponding message.

Optionally, the MSC may also receive the current VDN or STN-SR sent by the MME or SGSN during the emergency call SR VCC switching process, and switch from the current network side to the target network according to the current VDN or STN-SR side. The acquisition of the current VDN or STN-SRDE may be provided by the domain handover function entity DTF, E-RAU or GMLC/LRF of the IMS domain during the handover process of the UE.

S305. The UE switches from the current network side to the target network side.

The embodiment of the present invention informs the mobile service switching center that the current call is an emergency call by carrying the emergency indication information, so that the mobile service switching center can process the SRVCC switching according to the SRVCC flow of the emergency call, thus meeting the requirements of the terminal and the network side.

Fig. 4 is an example of implementing SR VCC switching of an emergency call according to Embodiment 2 of the present invention. As shown in Figure 4, when the UE is handed over from the eUTRAN network to the target UTRAN/GERAN network, the MME on the network side sends the emergency call indication information to the MSC, and the MSC judges the emergency call SRVCC process according to the emergency call indication information, and then completes the subsequent steps Emergency call SRVCC processing flow. The methods include:

Step 401, UE sends a measurement report to the source-side access system eUTRAN;

Step 402, if the eUTRAN on the source side judges that the target side network supports the SR VCC capability, the eUTRAN sends a Handvoer Required message to notify the source side MME, and the message carries Source to TargetTransparent Container and SRVCC indication parameters;

Step 403a, sending a Forward relocation Req message to the MSC on the source side;

Here, the MME distinguishes whether it is a voice bearer or a non-voice bearer according to the QCI (QoS Class identifier) parameter in QoS. Whether the corresponding access point name (Access Point Name, APN) belongs to the emergency APN (Emergency APN) to know whether the current call is an emergency call. If the current call is an emergency call SR VCC, the MME sends a Forward relocation request message (Forward relocation Req) to the MSC according to the SR VCC indication information sent by eUTRAN. The message carries the Emergency Indication parameter to indicate that the current call is an emergency call. The Emergency Indication parameter Mainly, the MME is used to inform the MSC that the current session (there may be multiple sessions in the future, so the indication may be for one of the sessions) is an emergency call. The message also carries parameters such as VDN, MSISDN, Source to Target Transparent Container, and MM Context.

Step 403b, the MSC sends a Prepare HO Req message to the target MSC, the message carries an Emergency Indication parameter to the target MSC, and notifies the target MSC to prepare for emergency call resources;

In step 403c, the MSC on the target side initiates a CS relocation process. The MSC on the target side sends a RelocationRequest message, which carries the Source to Target Transparent Container parameter and the Emergency Indication parameter to the radio network subsystem (Radio Network System) on the target side, and notifies the RNS on the target side to prepare emergency call resources;

Step 404a, MME sends a Forward Relocation Req message to the target SGSN, initiates PS relocation, and carries Source to Target Transparent Container and MM Context in the message;

Step 404b, SGSN sends a Relocation Request message, which carries Source to TargetTransparent Container.

Step 405a, the RNS on the target side coordinates to allocate PS and CS resources, and sends a Relocation RequestAcknowledge message to the SGSN on the target side, and the message carries Target to Source TransparentContainer.

Step 405b, the SGSN on the target side sends a Forward Relocation Response message, which carries a Target to Source Transparent Container message to the source-side MME.

In the embodiment of the present invention, steps 404a, 404b, 405a and 405b are executed when the target network supports Dual Transfer Mode PS handover (DTM/PSHO) and there is currently a non-voice bearer.

Step 406a, the RNS on the target side sends a Relocation Request Acknowledge message, which carries the Target to Source Transparent Container to the MSC on the target side.

Step 406b, Target MSC sends Prepare HO Response message to MSC Server.

Step 406c, establishing a circuit connection between the MSC on the target side and the MGW associated with the MSC server.

Step 407a, MSC learns that the current call is an emergency call according to the Emergency indication parameter obtained in step 3a, and then sends a Map Subscriber Location Report Request message to the GMLC/LRF, and the message carries information such as IMSI, IMEI, MSISDN, and VMSC address.

Step 407b, GMLC/LRF sends a Map Subscriber Location Report Response message to the MSC at the source side.

In step 408, the MSC at the source side initiates a domain handover to the IMS domain, and updates the access leg. At this time, voice packets are sent and received from the CS domain.

Step 409, the MSC on the source side sends a Forward Relocation Response message to the MME on the source side, and the message carries Target to Source Transparent Container.

Step 410, the source-side MME sends a Handover Command message to the source-side eUTRAN, and the message carries Target to Source Transparent Container.

Step 411, eUTRAN sends a Handover from eUTRAN Command message to the UE, prompting the UE to switch to the target domain.

In step 412, the UE switches to the target domain, and the switching is completed.

In the embodiment of the present invention, a method for obtaining a VDN or STN-SR in the emergency call SR VCC service is also provided, and the VDN or STN-SR is used to complete the processing of emergency call SR VCC switching.

The above method includes the steps of:

When it is judged that the current call is an emergency call SR VCC, the emergency call SR VCC is processed;

Here, the MME or SGSN can know whether the current call is an emergency call according to the received emergency call indication information sent by the UE, or know whether the current call is an emergency call according to whether the QoS corresponding to the voice bearer in the current call is an emergency call QoS, or Whether the current call is an emergency call is learned according to whether the Access Point Name (APN) corresponding to the voice bearer belongs to an emergency APN (Emergency APN).

During the processing of the emergency call SR VCC, obtain the VDN or STN-SR for completing the emergency call SR VCC switching;

Among them, the current VDN or STN-SR can be acquired during the process of establishing an emergency call, or during the SR VCC switching process of an emergency call, and the acquisition methods include the following:

1. When the MME/SGSN determines that the current call is an emergency call, it sends a request message (such as a location information request message) to the emergency remote user agent E-RUA or gateway mobile location center GMLC, and the E-RUA or GMLC/LRF sends A response message carrying the current VDN or STN-SR (correspondingly, a location information response message) is sent to the MME/SGSN;

2. The DTF in the IMS domain sends the latest VDN or STN-SR to the UE (if the VDN or STN-SR changes during the call, the DTF will send the changed VDN or STN-SR to the UE); the UE will receive Send the latest VDN or STN-SR to MME/SGSN.

Here, the UE may send an IMS domain signaling 200 OK message to the DTF, and the DTF sends the current VDN or STN-SR to the UE. It can also be that after the UE is registered in the IMS domain, the UE interacts with the DTF to obtain the VDN during the anchoring process of the SR VCC service. When the VDN changes, the DTF sends the changed VDN to the UE by itself.

3. The UE obtains the latest VDN or STN-SR from the GMLC/LRF or E-RUA through the USSD function, and then the UE sends the latest VDN or STN-SR to the MME through the access network for the MME to send the latest VDN when switching Or the STN-SR is brought to the MME/SGSN.

Since the emergency call is related to the specific physical location, the VDN or STN-SR obtained by the MSC is also related to the specific physical location. Sr. The current VDN or STN-SR is used to inform the MSC during the SR VCC switching process, so that the MSC can complete the emergency call SR VCC switching, thereby effectively realizing the emergency call SR VCC service.

5 is a flowchart of a method for implementing SR VCC switching of an emergency call according to Embodiment 3 of the present invention. In the embodiment of the present invention, it includes how to obtain the VDN or STN-SR of the current call, so as to complete the SR VCC switching process of the emergency call. As shown in Figure 5, the method includes:

S501. When it is determined that the current call is an emergency call SR VCC, perform emergency call SR VCC processing;

S502. During the processing of the emergency call SR VCC, obtain the VDN or STN-SR used to complete the emergency call SR VCC switching;

Here, the MME obtains the current VDN or STN-SR before the emergency call SRVCC service switching request.

S503. Send switching request information carrying emergency call indication information, and perform emergency call SR VCC switching according to the switching request information;

Here, when the MME knows that the current call is an emergency call and executes the SR VCC handover process according to the received Handover Required message sent by eUTRAN, it sends a handover request message carrying emergency call indication information to the MSC to notify the MSC that the current call is an emergency call. Call SR VCC switch. The manner in which the handover request message carries the emergency call indication information may refer to the manner in which the handover request message carries the emergency call indication information in the SRVCC call handover method in Embodiment 2 of the present invention.

S504. During the SR VCC switching process of an emergency call, receive the current VDN or STN-SR sent by the MME, and route the current call to the IMS according to the current VDN or STN-SR, so as to realize the communication from the current network side Switch to the target network side.

Optionally, in this embodiment, it is also possible that the MSC executes the SR VCC switching of the emergency call according to the switching request message. The switching request message carries the current VDN or STN-SR. The current VDN or STN-SR routes the current call to the IMS, so as to realize handover from the current network side to the target network side.

In the embodiment of the present invention, the above-mentioned MME function can also be implemented by the SGSN. Similarly, when switching from High Speed Packet Access (HSPA) VOIP to the CS domain of UTRAN/GERAN, the SGSN can complete the corresponding The process of sending emergency call indication information to MSC.

Since the emergency call is related to the specific physical location, the VDN or STN-SR obtained by the MSC is also related to the specific physical location. This embodiment obtains the VDN or STN-SR of the current emergency call and informs the MSC, so that the MSC can Complete the emergency call SR VCC switching, thereby effectively realizing the emergency call SR VCC service.

FIG. 6 is an example of a method for implementing a voice continuity emergency call SR VCC in a single access system according to Embodiment 3 of the present invention. As shown in Figure 6, the method includes:

Step 601, UE sends measurement report to eNodeB;

Step 602, eUTRAN sends a Handover Required message to notify the source-side MME, and the message carries Source to Target Transparent Container and SRVCC indication parameters;

Step 603a, when the MME learns that the current call is an emergency call, it sends a location information request message Location information Request to the GMLC/LRF, and the message carries information such as IMSI and MSISDN;

The premise of sending this message is that there is an interface between the MME and the GMLC/LRF.

Step 603b, GMLC/LRF sends a location information response message Location informationResponse message to MME, the message carries the current VDN or STN-SR;

Step 604a: According to the SRVCC indication parameter sent by eUTRAN, the MME sends a Forward relocation Req message to the MSC on the source side, and the message carries the VDN or STN-SR obtained in step 3 and the Emergency indication, and MSISDN, Source to Target Transparent Container, MM Context and other parameters;

Step 604b, when the MSC determines that the current call is an emergency call according to the received message, it sends a Prepare HO Req message carrying emergency indication information to the target MSC;

In step 604c, the MSC on the target side initiates a CS relocation process. The MSC on the target side sends a RelocationRequest message carrying the Source to Target Transparent Container to the RNS on the target side. After receiving the information, the target RNS immediately allocates resources to continue the subsequent CS relocation process;

Step 605a, the target side RNS sends a Relocation Request Acknowledge message, carrying the Target to Source Transparent Container to the target side MSC;

Step 605b, Target MSC sends Prepare Handover Response message to MSC Server.

Step 605c, establishing a circuit connection between the MSC on the target side and the MGW associated with the MSC server;

Step 606a, MSC judges that it is an emergency call according to the emergency indication sent in step 604a, and then sends a Map Subscriber Location Report Request message to GMLC/LRF, carrying information such as IMSI, IMEI, MSISDN, VMSC address in the message;

Step 606b, GMLC/LRF sends a Map Subscriber Location Report Response message to the MSC at the source side;

Step 607 to step 611 are the same as step 408 to step 412 in FIG. 4 .

Fig. 7 is another example of the method for realizing the voice continuity emergency call SR VCC in the single access system according to the third embodiment of the present invention. After the UE anchors the call in the IMS domain, the DTF will bring the latest VDN or STN-SR information to the UE, and the UE will then send the latest VDN or STN-SR to the MME through the access network to prepare for the latest VDN during handover. Or STN-SR to MSC. As shown in Figure 7, the method includes:

Step 701. During the establishment of an emergency call, if SRVCC is to be implemented, the voice call initiated by the UE must be anchored in the IMS domain. When the UE anchors the voice call in the IMS domain, the DTF of the IMS domain will use the latest VDN or STN -SR is sent to the UE (if the VDN or STN-SR changes during the call, the DTF will send the changed VDN or STN-SR to the UE.);

Step 702, UE receives the latest VDN or STN-SR, and sends it to MME;

Here, the MME will bring the latest VDN or STN-SR to the MSC during the subsequent SR VCC handover process to prepare for the subsequent SR VCC handover.

Next, complete the flow process of SR VCC call handover as shown in steps 4 to 11 in Figure 6.

Correspondingly, the embodiment of the present invention also provides a network system for SR VCC call switching, so as to perform emergency call SR VCC switching according to the received emergency call indication information.

FIG. 8 is a schematic structural diagram of a network system for SR VCC call switching according to an embodiment of the present invention. Referring to FIG. 8 , it includes: a network system 1, which includes a mobile service switching center MSC10, a mobility management entity MME20, and an IMS domain 30; and an access network 2, which includes a current network side 21 and The target network side 22; the network system 1 includes:

The mobility management entity MME20 is configured to send an SR VCC handover request message carrying emergency call indication information.

The mobile service switching center MSC10 is used to receive the SRVCC switching request message carrying the emergency call indication information, and when it is learned that the current switching request is an emergency call SR VCC according to the switching request message, it executes the emergency call SR VCC switching, from the current network The side switches 21 to the target network side 22 .

In the embodiment of the present invention, the mobility management entity MME20 is used to inform the mobile service switching center 10 that the current call is an emergency call SR VCC by carrying emergency call indication information in the SR VCC handover request message sent to the mobile service switching center 10. The switching of the emergency call indication information in the switching request message includes the following:

1. The message carries emergency call indication information to indicate that the current call is an emergency call;

2. The message type is an emergency call message type to indicate that the current call is an emergency call;

3. The VDN or STN-SR in the message is empty to indicate that the current call is an emergency call;

4. The information element in the message becomes an extended information element carrying an indication bit to indicate that the current call is an emergency call.

In the embodiment of the present invention, the mobile service switching center 10 is further configured to send handover information carrying the emergency call indication information to the target network side 22, so as to notify the target network side 22 that the current emergency call SR VCC switching.

The embodiment of the present invention informs the mobile service switching center 10 that the current call is an emergency call by carrying the emergency indication information, so that the mobile service switching center 10 can process it according to the emergency call SR VCC process, thus meeting the requirements of the terminal and the network side.

In the embodiment of the present invention, the network system 1 may further include: a gateway mobile location center or an emergency remote user agent, which is used to send the current VDN or STN-SR to the MSC10.

Here, the mobile service switching center 10 sends specific location request information to the gateway mobile location center or the emergency remote user agent, and the gateway mobile location center or the emergency remote user agent sends specific location response information to the mobile service switching center to 10, The specific location response message carries the VDN or STN-SR, and the MSC routes the call to the IMS domain according to the current VDN or STN-SR, so as to implement handover from the current network side 21 to the target network side 22 .

In the embodiment of the present invention, the MME20 of the network system 1 is also used to obtain the current VDN or STN-SR and send it to the mobile service switching center 10, and the mobile service switching center is used to obtain the current VDN or STN-SR according to the current VDN or STN-SR - SR, routing the call to the IMS domain 30 according to the current VDN or STN-SR, so as to implement handover from the current network side 21 to the target network side 22 .

Similarly, when switching from HSPA VOIP to the CS domain of UTRAN/GERAN, the SGSN may complete the corresponding process of sending emergency call indication information to the MSC.

The network system of the embodiment of the present invention carries emergency indication information when switching the request to inform the mobile service switching center 10 that the current call is an emergency call, so that the mobile service switching center can process the SRVCC switch according to the emergency call SRVCC flow, satisfying the requirements of the terminal and the network side. The SR VCC emergency call service needs.

Now according to the network system of Embodiment 1 of the present invention, the emergency call SR VCC switching process is exemplified as follows:

The UE sends a measurement report to the source-side access system eUTRAN. If the source-side eUTRAN judges that the target-side network supports the SR VCC capability, eUTRAN sends a Handvoer Required message to notify the source-side MME. The message carries Source to Target Transparent Container and SRVCC indication parameters.

The MME can know whether the current call is an emergency call SR VCC according to the received emergency call indication information sent by the UE, or the MME can know whether the current call is an emergency call according to whether the QoS corresponding to the voice bearer in the current call is an emergency call QoS, or the MME According to whether the Access Point Name (APN) corresponding to the voice bearer belongs to the Emergency APN (Emergency APN), it is learned whether the current call is an emergency call. If the current call is an emergency call, the MME sends a forward relocation request message (Forward relocation Req) to the MSC according to the SR VCC indication information sent by eUTRAN, and the message carries the Emergency Indication parameter to indicate that the current call is an emergency call, and the Emergency Indication parameter It is mainly used by the MME to inform the MSC that the current session (there may be multiple sessions in the future, so the indication may be for one of the sessions) is an emergency call. The message also carries parameters such as VDN, MSISDN, Source to Target Transparent Container, and MM Context.

When the MSC determines that the current call is an emergency call based on the received information, it sends a Prepare HO Req message to the target MSC, which carries the Emergency Indication parameter to the target MSC, and notifies the target MSC to prepare emergency call resources.

The MSC on the target side initiates the CS relocation procedure. The MSC on the target side sends a Relocation Request message, which carries the Source to Target Transparent Container parameter and EmergencyIndication information to the RNS on the target side, and notifies the RNS on the target side to prepare emergency call resources;

The RNS on the target side sends a location relocation confirmation message Relocation Request Acknowledge, which carries the Target to Source Transparent Container to the MSC on the target side. The MSC on the target side sends a Prepare Handover Response message to the MSC 10 on the source side after receiving the location migration confirmation message. The MSC10 at the source side initiates a circuit connection to the MSC at the target side, and establishes a circuit connection between the MSC at the target side and the MSC10 at the source side.

The MSC judges that the current call is an emergency call according to the Emergency indication parameter carried in the forwarding handover request message received, so it sends a Map Subscriber LocationReport Request message to the GMLC/LRF, and the message carries IMSI, IMEI, MSISDN, VMSCaddress, etc. information. GMLC/LRF sends Map Subscriber Location Report Response message to MSC10 on the source side. After the MSC learns the location information of the current calling user, it initiates a domain switch to the IMS domain and updates the access leg. At this time, voice packets are sent and received from the CS domain.

MSC sends Forward Relocation Response message to MME, carrying Target to Source Transparent Container in the message. MME2 sends a Handover Command message to the eUTRAN on the source side, and the message carries Target to Source Transparent Container. eUTRAN sends a Handover from eUTRAN Command message to the UE, prompting the UE to switch to the target domain.

In the embodiment of the present invention, another network system embodiment is provided, and the network system can obtain the VDN or STN-SR in the emergency call SRVCC service. The network system includes a mobile management entity or a GPRS service support point, and the mobile management entity or the GPRS service support point is used to determine that the current call is an emergency call SR VCC, and perform emergency call SR VCC processing, and when performing an emergency call SR During VCC processing, obtain the VDN or STN-SR used to complete the emergency call SR VCC handover. In the embodiment of the present invention, the mobility management entity or GPRS service support point obtains the current VDN or STN-SR, and sends the current VDN or STN-SR to the mobile service switching center when performing SR VCC switching, so that the MSC According to the current VDN or STN-SR, the current call is routed to the IMS domain to realize the handover from the current network side to the target network side.

Optionally, in the embodiment of the present invention, the network system further includes: the emergency remote user agent E-RUA or the gateway mobile location center GMLC.

The mobility management entity or GPRS service support point: when learning that the current call is an emergency call, send a request message (such as a location request message) to the emergency remote user agent E-RUA or gateway mobile location center GMLC;

After receiving the request message, the emergency remote user agent E-RUA or gateway mobile location center GMLC sends a response message carrying the current VDN or STN-SR (correspondingly, a location response message) to the mobility management entity Or GPRS service support point.

Optionally, in this embodiment of the present invention, the network system further includes: a domain function entity DTF and a terminal UE. During the establishment of an emergency call SR VCC, the domain function entity DTF sends the latest VDN or STN-SR Send to the terminal, if the VDN or STN-SR changes during the call, the DTF will send the changed VDN or STN-SR to the UE;

Here, the UE may send an IMS domain signaling 200 OK message to the DTF, and the DTF sends the current VDN or STN-SR to the UE. It can also be that after the UE is registered in the IMS domain, the UE interacts with the DTF to obtain the VDN during the anchoring process of the SR VCC service. When the VDN changes, the DTF sends the changed VDN to the UE by itself.

The terminal sends the received current VDN or STN-SR to the mobility management entity or GPRS service support point.

Optionally, in the embodiment of the present invention, the network system further includes: GMLC or E-RUA and a terminal,

The terminal is used to obtain the current VDN or STN-SR from the GMLC or E-RUA through the unstructured supplementary data USSD service, and send the current VDN or STN-SR to the mobility management entity or GPRS service support point.

After obtaining the current VDN or STN-SR, the MME/SGSN sends the current VDN or STN-SR to the MSC during the emergency call SR VCC handover process to implement SRVCC emergency call processing and switch from the current network side to the target network side.

Since the emergency call is related to the specific physical location, the VDN or STN-SR obtained by the MSC is also related to the specific physical location. This embodiment notifies the MSC by obtaining the VDN or STN-SR of the current call, so that the MSC can more effectively implement Emergency call SR VCC.

Correspondingly, the embodiment of the present invention also provides a mobile service switching center. Referring to Fig. 9, the mobile service switching center 10 includes:

The receiving unit 101 is configured to receive the SR VCC switching request message carrying the emergency call indication information;

The processing unit 103 is configured to process according to the SR VCC switching message of the emergency call indication information, and execute the emergency call SR VCC switching.

The MSC in the embodiment of the present invention can realize the emergency call SR VCC service, and complete the voice continuity between the circuit domain/CS domain and the packet domain/PS domain.

Correspondingly, an embodiment of the present invention also provides a device. Referring to FIG. 10, the device includes: a judging unit 201, configured to judge whether the current call is an emergency call SR VCC; and a sending unit 202, configured to When the unit 201 determines that the current call is an emergency call SR VCC, it sends an emergency call SR VCC switching request message carrying emergency call indication information to the mobile service switching center.

In this embodiment, the manner in which the emergency call SR VCC switching request message sent by the sending unit 202 carries the emergency call indication information includes the following:

carrying emergency call indication information in the message to indicate that the current call is an emergency call;

The message type is an emergency call message type to indicate that the current call is an emergency call;

The VDN or STN-SR is empty in the message to indicate that the current call is an emergency call;

The information element in the message is an extended information element carrying an indication bit to indicate that the current call is an emergency call.

The device in the embodiment of the present invention may be a mobility management entity, and may also be a GPRS service support point SGSN. The mobility management entity in the embodiment of the present invention can provide MSC with information indicating that the current call is an emergency call, so that the network system can realize the emergency call SR VCC. The SGSN, when switching from High Speed Packet Access (HSPA) VOIP to the CS domain of UTRAN/GERAN, can be a GPRS service support point (Serving GPRS Supporting Node, SGSN) to complete the corresponding emergency call indication Information to the MSC process. In the embodiment of the present invention, the device may further include: an information obtaining unit 203, configured to obtain the current VDN or STN-SR of the emergency call SR VCC, and the sending unit 202 is also configured to send the current VDN or The STN-SR is sent to the mobile service switching center. Wherein, the information obtaining unit 203 obtains the VDN or STN-SR of the current call including the following methods:

When knowing that the current call is an emergency call, send a request message to the emergency remote user agent E-RUA or the gateway mobile location center GMLC, and then receive the response message carrying the VDN or STN-SR sent by the E-RUA or GMLC/LRF ;

Here, for example, the information acquiring unit 203 sends a location information request message to the GMLC, and the GMLC returns a corresponding location information response message carrying the VDN or STN-SR.

Receive the current VDN or STN-SR sent by the terminal, the current VDN or STN-SR is sent to the terminal by the DTF of the IMS domain;

Receive the VDN or STN-SR sent from the terminal.

Here, during the SRVCC emergency call processing, the UE obtains the latest VDN or STN-SR from the GMLC/LRF or E-RUA through the USSD function, and then the UE sends the latest VDN or STN-SR to the MME through the access network for future use. The MME brings the latest VDN or STN-SR to the MME during handover.

The device in the embodiment of the present invention can provide the VDN or STN-SR for the MSC to complete the switching of the emergency call SR VCC, so that the network system can realize the emergency call SR VCC service.

Finally, those of ordinary skill in the art can understand that all or part of the steps in the method of the above-mentioned embodiments can be completed by hardware related to program instructions, and the associated program can be stored in a computer-readable storage medium. When the program is executed, , including all or part of the following steps:

receiving a handover request message carrying emergency call indication information;

According to the handover request message, it is learned that the handover request of the emergency call SR VCC is currently performed, and the handover of the emergency call SR VCC is performed to switch from the current network side to the target network side.

It should be noted that the present invention is not limited to the SR VCC service for emergency calls implemented on the network architecture provided in the embodiments, and any network system capable of implementing VCC services can be regarded as capable of implementing the SR VCC service for emergency calls; Correspondingly, the present invention is not limited to the switching of the emergency call SR VCC from the eUTRAN network to the UTRAN network or the GERAN network given in the embodiment, and may also be other networks.

The above description is a preferred embodiment of the present invention, and it should be pointed out that for those skilled in the art, without departing from the principle of the present invention, some improvements and modifications can also be made, and these improvements and modifications are also considered Be the protection scope of the present invention.

Claims (21)

1. A method for voice continuity call switching, comprising: Receive a single access system voice continuity SR VCC switching request message carrying emergency call indication information; According to the handover request message, it is known that it is currently an emergency call SR VCC handover request, and the emergency call SR VCC handover is performed to switch from the current network side to the target network side. 2. The method according to claim 1, wherein the manner in which the handover request message carries emergency call indication information includes one of the following: The switching request message carries an emergency call parameter to indicate that the current call is an emergency call; The switch request message type is a special message type to indicate that the current call is an emergency call; The voice continuity VCC domain switching number VDN or SR VCC session switching number STN-SR in the switching request message is empty to indicate that the current call is an emergency call; The information element of the switching request message is extended with an indication bit to indicate that the current call is an emergency call. 3. The method according to claim 1, further comprising: when the mobile management entity or the GPRS service support point determines that the current call is an emergency call SR VCC, sending the emergency call indication information carrying SR VCC switching request message; the mobile management entity or GPRS service support point determines that the current call is an emergency call SR VCC, including one of the following methods: Knowing that the current call is an emergency call SR VCC according to the emergency call indication information from the terminal; Whether the current call is an emergency call SR VCC according to whether the QoS corresponding to the voice bearer in the current call is an emergency call Qos; Whether the current call is an emergency call is learned according to whether the corresponding access point name APN bearer in the current call belongs to the emergency APN. 4. The method according to claim 1, further comprising: Sending SRVCC handover information carrying the emergency call indication information to the target network side. 5. The method according to any one of claims 1 or 4, wherein the switching request message carries the current VDN or STN-SR, and the emergency call SR VCC switching is performed from the current network side to the target Network side, including: When performing emergency call SR VCC switching, switch from the current network side to the target network side according to the current VDN or STN-SR. 6. The method according to any one of claims 1 or 4, characterized in that the performing emergency call SR VCC switching from the current network side to the target network side includes: During the emergency call SRVCC switching process, the current VDN or STN-SR is obtained, and the current network side is switched to the target network side according to the current VDN or STN-SR. 7. The method according to claim 6, wherein said acquiring the current VDN or STN-SR comprises: receiving the message carrying the current VDN or STN-SR sent by the emergency remote user agent E-RUA or the gateway mobile location center GMLC; or Receive the current VDN or STN-SR sent by the mobility management entity or GPRS service support point. 8. A method, characterized in that it comprises: When it is judged that the current call is an emergency call SR VCC, the emergency call SR VCC is processed; During the processing of the emergency call SR VCC, the VDN or STN-SR used to complete the emergency call SR VCC switching is obtained. 9. The method according to claim 8, characterized in that the acquiring the VDN or STN-SR used to complete the emergency call SR VCC switching includes one of the following methods: Receiving a response message carrying the current VDN or STN-SR sent by the emergency remote user agent E-RUA or the gateway mobile location center GMLC; Receive the VDN or STN-SR obtained from the domain switching function DTF from the terminal; Receive the VDN or STN-SR obtained from the GMLC or E-RUA by the terminal through the unstructured supplementary data USSD service. 10. A network system, characterized by comprising: The mobile management entity or GPRS service support point is used to send the SR VCC handover request message carrying the emergency call indication information; The mobile service switching center is used to receive the SR VCC switching request message carrying the emergency call indication information, and when it is learned that the switching request is currently an emergency calling SR VCC according to the switching request message, perform the emergency calling SRVCC switching, from the current network side Switch to the target network side. 11. The network system according to claim 10, characterized in that: The mobile service switching center is further configured to send SRVCC handover information carrying the emergency call indication information to the target network side. 12. The network system according to claim 10 or 11, further comprising: Gateway Mobile Location Center GMLC or Emergency Remote User Agent E-RUA, used to send VDN or STN-SR to the mobile services switching center; The mobile service switching center is configured to switch from the current network side to the target network side according to the VDN or STN-SR. 13. The network system according to claim 10 or 11, characterized in that: The mobility management entity or GPRS service support point is also used to obtain a VDN or STN-SR and send it to the mobile service switching center; The mobile service switching center is further configured to switch from the current network side to the target network side according to the VDN or STN-SR. 14. A network system, comprising a mobile management entity or a GPRS service support point, characterized in that: When the mobile management entity or GPRS service support point is used to determine that the current call is an emergency call SRVCC, it performs emergency call SR VCC processing, and during the emergency call SR VCC processing process, obtains the VDN or VDN used to complete the emergency call SR VCC handover STN-SR. 15. The network system according to claim 14, further comprising emergency remote user agent E-RUA or gateway mobile location center GMLC, characterized in that: The mobility management entity or GPRS service support point is also used to send a location information request message to the E-RUA or GMLC; The E-RUA or GMLC is configured to send a location information response message carrying the current VDN or STN-SR to the mobility management entity or GPRS service support point according to the received location information request message. 16. The network system according to claim 14, further comprising a domain function entity DTF and a terminal, characterized in that: The domain function entity DTF is used to send the current VDN or STN-SR to the terminal; The terminal is configured to send the received current VDN or STN-SR to the mobility management entity or GPRS service support point. 17. The network system according to claim 14, further comprising GMLC and terminal, or E-RUA and terminal, characterized in that: The terminal is used to obtain the current VDN or STN-SR from the GMLC or E-RUA through the unstructured supplementary data USSD service, and send the current VDN or STN-SR to the mobility management entity or GPRS service support point. 18. A mobile service switching center, comprising: The receiving unit is used to receive the SR VCC switching request message carrying the emergency call indication information; A processing unit, configured to perform emergency call SR VCC switching according to the SR VCC switching request message carrying the emergency call indication information. 19. A device, characterized in that it comprises: Judging unit, used to judge whether the current call is an emergency call SR VCC; The sending unit is used to send the emergency call SR VCC switching request message carrying the emergency call indication information to the mobile service switching center when the judging unit judges that the current call is an emergency call SR VCC. 20. The device according to claim 19, further comprising: An information acquisition unit, configured to acquire the current VDN or STN-SR of the emergency call SR VCC; The sending unit is further configured to send the current VDN or STN-SR to the mobile service switching center. 21. The device according to claim 19, characterized in that the device is a mobility management entity or a GPRS service support point.

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