WO2010105525A1

WO2010105525A1 - Optimizing method for handover, handover device and system

Info

Publication number: WO2010105525A1
Application number: PCT/CN2010/070877
Authority: WO
Inventors: 胡伟华
Original assignee: 华为技术有限公司
Priority date: 2009-03-19
Filing date: 2010-03-05
Publication date: 2010-09-23
Also published as: CN101841836A

Abstract

An optimizing method for handover, handover device and system are provided by the present invention embodiments. In said method, a user plane handover of a service control system is initiated first, after the user plane handover for the service control system is accomplished and a response message is returned, a radio air interface handover for a mobile terminal is further initiated according to the response message. Application of the present invention can shorten the voice interruption time effectively during the handover process of single radio access voice call continuity, and improve the service experience of users.

Description

The present invention claims to be submitted to the Chinese Patent Office on March 19, 2009, and the application number is 200910129232.6. The invention is entitled "A Switching Optimization Method, Switching Device and System" Chinese Patent Priority of the application, the entire contents of which are incorporated herein by reference. Technical field

The present invention relates to the field of communications technologies, and in particular, to a handover optimization method, a handover apparatus, and a system. Background technique

Currently, the 3rd Generation Partnership Project (3GPP) is working on a new Evolved Packet System (EPS) to enhance the competitiveness of the future network. The Evolved Universal Mobile Telecommunications System Territorial Radio Access Network (E-UTRAN) has high contention, high data rate, low latency, and most data packets. Optimization and other characteristics.

And the existing Global System for Mobile Communications/Enhanced Data Rate Global System for Mobile Communications (LTE), GSM/EDGE Radio Access Network (UTRAN, Universal Mobile Telecommunications System Territorial Radio Access Network) In contrast, the core network (C, Core Network) of E-UTRAN only includes a packet switched domain (PS) network, and all services including voice are carried in a packet domain network; and the core network of GERAN and UTRAN includes a packet domain. The network and circuit domain (CS) circuit, and the packet domain network is used to carry Internet Protocol (IP) services, and the circuit domain network is used to carry voice services. In addition, in E-UTRAN, in order to facilitate control services and charging, an IP Multimedia Subsystem (IMS) needs to be deployed, and all services carried in the packet domain network are controlled by the IMS.

Since the deployment process of the E-UTRAN is gradual, it is inevitable that the operator operates the E-UTRAN and the existing GERAN/UTRAN simultaneously. Hybrid deployment of different radio access networks necessarily requires support for handover between different radio access networks, namely E-UTRAN and Switching between GERAN/UTRAN. It can be seen from the above description that all services in the E-UTRAN, including voice services, are carried in the packet domain network and are controlled by the IMS. The voice services in the GERAN/UTRAN are carried in the circuit domain network, so that the voice service is continuous. Therefore, it is necessary to ensure that mobile users can smoothly switch between the GERAN/UTRAN circuit domain network and the E-UTRAN when using voice services. In order to meet this requirement, 3GPP defines a handover procedure of Single Radio Voice Call Continuity (SRVCC).

The SRVCC handover procedure includes wireless air interface switching and IMS domain user plane switching. The wireless air interface switching process can be divided into two phases, a preparation phase and a handover phase. The process of user plane switching in the IMS domain involves a session transmission and a remote user plane update process. In the SRVCC handover process defined by the current 3GPP, the preparation process of the wireless air interface switching is started, and the user plane switching of the IMS domain is initiated, and the two are performed in parallel. When the wireless air interface switching is initiated or the remote user plane of the IMS domain is updated, the user voice service is interrupted until the wireless air interface switching and the remote user plane update of the IMS domain are completed, and the user voice service is restored. In the process of user plane switching in the IMS domain, the mobile switching center (MSC) server first needs to initiate a session transmission process to the IMS domain to trigger the switching of the user plane of the IMS domain. Since the MSC server needs to trigger the signaling route to the IMS domain through the intelligent service mode, the process of initiating the session transmission takes a long time, which causes the user plane switching process of the entire IMS domain to take a long time (up to the second level), thereby causing the SRVCC handover process. The voice interruption time is long (up to the second level), which seriously affects the user's business body. Summary of the invention

The embodiment of the invention provides an optimization method, a switching device and a system for switching, which can effectively shorten the voice interruption time of the SRVCC handover process and improve the service experience of the user.

To achieve the above objective, the embodiment of the present invention provides the following technical solutions:

An embodiment of the present invention provides an optimization method for handover, including:

Initiating user plane switching of the service control system;

Receiving a user plane handover completion response message returned by the service control system;

Initiating wireless air interface switching of the mobile terminal according to the response message.

The embodiment of the invention provides a switching device, including:

a first triggering unit, configured to initiate a user plane switching of the service control system; An acquiring unit, configured to receive a user plane handover complete response message sent by the service control system, where the second triggering unit is configured to initiate wireless air interface switching of the mobile terminal according to the response message. The embodiment of the invention further provides a switching system, including:

a switching device, configured to initiate a user plane handover of the service control system, and receive a user plane handover completion response message sent by the service control system; and the response message initiates a wireless air interface switch of the mobile terminal;

And a service control system, configured to perform user plane switching according to the trigger of the switching device, and return a user plane handover complete response message to the switching device.

Compared with the prior art, the embodiment of the present invention preferentially completes the user plane switching of the service control system, and then performs the wireless air interface switching of the mobile terminal. The user plane switching of the service control system is preferentially completed, so that the mobile terminal that has not performed the wireless air interface switching still keeps the voice stream uninterrupted for a long time (mainly the time of the early session transmission phase of the user plane switching of the service control system), thereby Effectively shorten the voice interruption time in the single wireless access voice call continuity switching process, and improve the user's service experience. DRAWINGS

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings to be used in the embodiments will be briefly described below. Obviously, the drawings in the following description are only some of the present invention. For the embodiments, those skilled in the art can obtain other drawings according to the drawings without any creative work.

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

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

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

4 is a schematic flowchart of a method for optimizing handover according to Embodiment 4 of the present invention;

FIG. 5 is a schematic flowchart of a method for optimizing handover according to Embodiment 5 of the present invention;

6 is a schematic flowchart of a method for optimizing handover according to Embodiment 6 of the present invention;

7 is a schematic flowchart of a method for optimizing handover according to Embodiment 7 of the present invention;

FIG. 8 is a schematic structural diagram of a switching apparatus according to Embodiment 8 of the present invention; FIG.

FIG. 9 is a schematic structural diagram of a handover system according to Embodiment 9 of the present invention. detailed description

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

Embodiment 1:

Referring to FIG. 1, FIG. 1 is a schematic flow chart of a method for optimizing handover according to an embodiment of the present invention. As shown in FIG. 1, the method may include the steps of:

Step 101: Initiating user plane switching of the service control system;

Specifically, the MSC server may initiate a session transmission to the service control system to trigger remote user plane update of the service control system.

Specifically, the communication control system may instruct the communication remote end to send the voice service to the designated media gateway, thereby implementing remote user plane update.

The service control system is mainly used for controlling, charging, and the like, including the voice. In the E-UTRAN, the service control system may be an IP multimedia subsystem.

Step 102: Receive a user plane handover complete response message returned by the service control system. Specifically, after the user plane switch of the service control system is completed, a response message may be returned to the MSC server to indicate that the user plane handover is completed.

Step 103: Initiate wireless air interface switching of the mobile terminal according to the response message.

After receiving the user plane handover complete response message returned by the service control system, the MSC server may send a forward transport response message carrying the transparent container cell of the target side to the source side to the mobility management entity;

After receiving the preamble migration response message sent by the MSC server, the mobility management entity sends a handover command message carrying the target side to the source side transparent container cell to the source side access network device (such as the base station node eNodeB of the E-UTRAN);

After receiving the handover command message, the source side access network device sends a handover command message to the mobile terminal that needs to be handed over to the source side access network, and commands the mobile terminal to switch from the source side access network to the target side network.

(such as switching to GERAN/UTRAN).

The method provided by the embodiment of the present invention may be performed before step 103, or step 103 is performed. At the same time, or after performing step 103, the MSC server instructs the media gateway to forward the received downlink voice service to the target mobile switching center through a pre-established circuit connection between the media gateway and the target mobile switching center. . When the mobile terminal completes the process of switching from the source side access network to the target side network, the voice service can be resumed. In this way, the time of the voice interruption mainly includes the transmission time of several signaling messages in the network and the time of the wireless air interface switching of the mobile terminal, and the total time of the voice interruption is about 200 ms, which is similar to the traditional circuit domain switching.

The method provided by the embodiment of the present invention may also receive, by the MSC server, the voice stream media surface information sent by the mobility management entity in advance, and send the voice stream media surface information to the media gateway; And receiving the received downlink voice service according to the voice streaming media plane information, and transmitting the downlink voice service to the mobile terminal.

After the mobile terminal completes the wireless air interface switching, the MSC server may instruct the media gateway to stop encoding the received downlink voice service according to the voice streaming media plane information, and send the downlink voice service to the mobile terminal; and at the same time, command the media gateway to receive the downlink. The voice service is forwarded to the target side MSC through a pre-established circuit connection between the media gateway and the target side MSC, and the downlink voice service is sent by the target side MSC to the target side network device (such as the base station node) to the switched The mobile terminal of the target side network enables the mobile terminal to resume voice service.

In this way, the mobile terminal that has not performed the wireless air interface switching can keep the voice service uninterrupted during the user plane switching process of the service control system. In this way, the time of the voice interruption mainly includes the time of the wireless air interface switching of the mobile terminal and the transmission time of several signaling messages in the network, and the total time of the voice interruption is about 200 ms, which is similar to the traditional circuit domain switching.

The method provided by the embodiment of the present invention may also receive, by the MSC server, the voice stream media surface information sent by the mobility management entity in advance, and send the voice stream media surface information to the media gateway; Transmitting the received downlink voice service according to the voice stream media surface information, and transmitting the received downlink voice service to the mobile terminal, and passing the received downlink voice service through a pre-established circuit between the media gateway and the target side mobile switching center. The connection is forwarded to the target side mobile switching center.

After the mobile terminal completes the wireless air interface switching, the media gateway stops encoding the received downlink voice service according to the voice streaming media information, and sends the received downlink voice service to the mobile terminal.

In this way, during the user plane switching of the service control system, the wireless space has not been performed yet. The port-switched mobile terminal can keep the voice service uninterrupted at all times, and the time of the voice interruption only includes the time of the wireless air interface switching of the mobile terminal, further shortening the voice interruption time.

The method for optimizing the handover provided by the first embodiment of the present invention is described above. The embodiment of the present invention preferentially completes the user plane switching of the service control system, and then performs the wireless air interface switching of the mobile terminal, thereby implementing the SRVCC handover process. Further shorten the voice interruption time and enhance the user's business experience.

Embodiment 2:

Referring to FIG. 2, FIG. 2 is a schematic flowchart of a method for optimizing a handover according to Embodiment 2 of the present invention. The second embodiment of the present invention introduces the present invention by taking the SRVCC handover from the source side access network E-UTRAN to the target side network GERAN, and the target side network GERAN does not support dual transfer mode (DTM, Dual Transfer Mode) or PS handover. An optimization method for switching provided by the embodiment, as shown in FIG. 2, the method may include:

1. Receiving the measurement report sent by the mobile terminal, and the source-side access network E-UTRAN device determines to trigger the handover to the target side network GERAN.

The source side access network E-UTRAN device may be a base station node eNodeB of the source side access network E-UTRAN.

2. The source side access network E-UTRAN device sends a handover request message Handover Required (the message carries the target cell or base station identifier, the source side to the target side transparent container) to the mobility management entity MME; and the source side access network E- The UTRAN device instructs the MME that this handover is an SRVCC handover.

3. According to the SRVCC handover indication of the source-side access network E-UTRAN device, the MME identifies the existing voice bearers based on the bearer's Quality Class Identity (QCI), and then initiates the PS from the target MSC server only for these voice bearers. Domain to CS domain switching.

The MME sends a forward retransmission request message Forward Relocation Request (the request message carries the session transmission number, the mobile phone number, the source side to the target side transparent container, and the mobility management context) to the MSC server.

The MSC server is selected by the MME according to the target cell or the base station identifier carried in the received handover request message; the session transmission number and the mobile phone number are used as part of the user subscription data, and are downloaded to the MME when the user attaches the E-UTRAN. The mobility management context contains the security context of the circuit domain and other related information. The circuit domain security context is that the MME is based on the user. The key information in E-UTRAN is derived.

4. The MSC server initiates a cross-MSC handover procedure, and sends a pre-handover request message to the target MSC. Prepare Handover Requests

5. The target MSC and the target base station exchange handover request and acknowledgement messages to perform resource allocation.

6. The target MSC sends a pre-handover response message to the MSC server, and the MSC server establishes a circuit connection between the target MSC and the media gateway MGW.

7. The MSC server initiates the session transmission by using the session transmission number. For example, the MSC server may send an ISUP IAM message to the IMS domain, or send an invitation message to the IMS domain. Subsequently, the standard IMS service continuity process is applied to perform session transmission. During the process of updating the remote user plane, the IMS updates the communication remote user plane information to the media gateway MGW, so that the downlink voice service is switched to

The MSC server may send a downlink voice service from the remote end of the communication to the target MSC through the circuit connection during the foregoing circuit connection establishment process or initiate a session transmission, and the MGW may simultaneously receive the connection from the circuit. The incoming voice service is forwarded to the remote end of the communication.

It should be noted that, in this case, only the downlink data from the remote end of the communication may pass through the MGW, and the mobile terminal sends the uplink data or the E-UTRAN through the source side access network. The communication remote end described herein refers to the communication peer end of the mobile terminal.

8. The IMS domain completes the session transmission and the remote user plane update, and returns a response message.

Corresponding to step 7, the response message may be an ANUP message of the ISUP, or a SIP 200 OK message. When the MSC server receives the response message, the remote end of the communication has sent the downlink voice stream to the MGW associated with the MSC server. If the MSC server has commanded the corresponding MGW to enable the circuit connection between the MGW and the target MSC to forward the uplink and downlink data, the downlink voice stream will further reach the target MSC.

9. After receiving the response message returned in step 8, the MSC server sends a forward retransmission response message Forward Relocation Response (the message carries the target side to the source side transparent container cell) to the MME. The MME protects the bearers that may be non-voiced and have no reserved bandwidth requirements. 10. The MME sends a handover command message Handover Command (the message carries the target side to the source side transparent container cell) to the source side access network E-UTRAN device.

11. Source-side access network The E-UTRAN device sends a handover command message from the E-UTRAN Handover from E-UTRAN Command to the mobile terminal, and commands the mobile terminal to switch to the target side.

12. The mobile terminal switches to access the target side network, and the target side network detects the mobile terminal access. If the MSC server forwards the uplink and downlink data during the circuit connection establishment process in the foregoing step 6 or in the connection in step 7, the uplink and downlink voice streams are restored. For example, after the voice stream is restored, the uplink voice flow is: starting from the mobile terminal, passing through the target side network device, the target mobile switching center, the mobile switching center server/multimedia gateway, the IP multimedia subsystem, and finally reaching the communication. remote.

13. If the mobile terminal still has other non-voice services before the handover, the mobile terminal starts a suspend process, and notifies the target SGSN to send a suspension request to the MME. The MME returns a pending response to the target SGSN, and the response message contains the mobility management of the user and the suspended bearer context.

14. The target side network base station detects the terminal access, and sends a handover complete message Handover Complete to the target MSC.

15. The target MSC notifies the MSC server that the handover is complete.

16. In order to be compatible with the fixed network system, the target MSC may notify the MSC server to reply to the message. If the MSC server forwards the uplink and downlink data during the circuit connection establishment process in the foregoing step 6 or the connection connection in the step 7, in the above step 15 or step 16, the MSC server instructs the corresponding MGW to enable the connection between the MGW and the target MSC. The circuit connection forwards the uplink and downlink data. The upstream and downstream voice services were restored. For example, after the voice stream is restored, the uplink voice flow is: starting from the mobile terminal, passing through the target side network device, the target mobile switching center, the mobile switching center server/multimedia gateway, the IP multimedia subsystem, and finally reaching the communication. remote.

17. The MSC server sends a Forward Relocation Complete message to the MME, notifying that the mobile terminal has switched to the target side. The MME sends a Forward Relocation Complete Acknowledge to the MSC server for confirmation. If necessary, the MSC server can perform an update location process to the Home Subscriber Server (HSS)/Home Location Register (HLR) to obtain data such as subscription information of the user.

After the voice call ends, if the mobile terminal remains in the target side network GERAN, the mobile terminal initiates a route update process to resume the suspended packet service.

In the embodiment of the present invention, the start and end time of the voice service interruption is the T part in FIG. 2, that is, the downlink voice service is switched from the communication remote end to the MGW to start the interruption (because the downlink voice service arrives at the MGW at this time, the target MSC is further reached). However, the mobile terminal cannot be reached, and the mobile terminal has not switched to the target side network under the target MSC. The voice service is restored until the mobile terminal switches to the target side network. The delay of this process mainly includes several signaling messages in the network. The delay and the delay of the wireless air interface switching of the mobile terminal are less than 400ms, which is similar to the current interrupt circuit delay of 200ms in the traditional circuit domain switching, so that the voice interruption time of the SRVCC switching process can be effectively shortened and improved. The user's business experience.

Embodiment 3:

Referring to FIG. 3, FIG. 3 is a schematic flowchart of a method for optimizing a handover according to Embodiment 3 of the present invention. The third embodiment of the present invention provides an SRVCC handover from the source side access network E-UTRAN to the target side network UTRAN or GERAN, and the target side network UTRAN or GERAN supports PS handover as an example, and describes a handover provided by the embodiment of the present invention. The optimization method, as shown in Figure 3, can include:

1. Receiving the measurement report sent by the mobile terminal UE, the source side access network E-UTRAN device determines to trigger the handover to the target side network GERAN or UTRAN.

2. The source-side access network E-UTRAN device sends a handover request message Handover Required (the message carries the target cell or base station identifier, the source side to the target side transparent container) to the MME; and the source side access network E-UTRAN device indicates the MME This switch is an SRVCC switch.

According to the SRVCC handover indication of the E-UTRAN device of the source side access network, the MME identifies the existing voice bearer based on the service level identifier of the bearer, and initiates a handover to the target MSC server and the target SGSN respectively. 3. The MME initiates a PS to CS handover procedure for the voice bearer, and sends a forward retransmission request message Forward Relocation Request (the message carries the session transmission number, the mobile phone number, the source side to the target side transparent container, and the mobility management context) to the MSC server. .

The MSC server is selected by the MME according to the target cell or the base station identifier carried in the received handover requirement message. The session transmission number and the mobile phone number are downloaded as part of the user subscription data to the MME when the user attaches to the source side access network E-UTRAN; the mobility management context includes the security context of the circuit domain and other related information; The security context is derived by the MME based on the key information of the user in the E-UTRAN.

5. The target MSC and the target base station exchange migration request and acknowledgement messages, and perform resource allocation for circuit domain handover.

6. While performing step 3 above, the MME initiates a handover to the target SGSN for the non-voiced packet domain bearer, and the MME sends a forward relocation request message Forward Relocation Request (the message carries the source side to the target side transparent container, the mobility management context ) to the target SGSN.

7. Target The SGSN sends a migration request message Relocation Request (which carries the source side to the target side transparent container) to the target side network device (such as the target side network UTRAN or GERAN base station RNS) to allocate resources for the packet domain handover. The target side network device coordinates the CS handover and the PS handover request, allocates resources, and returns a migration request acknowledgement message Relocation Request Acknowledge to the target SGSN, confirming the packet domain handover.

8. Target The SGSN sends a forward transmission response message Forward Relocation Response (the message carries the target side to the source side transparent container) to the MME.

9. Parallel to the above steps, after performing step 5, the target MSC sends a pre-handover response message, Prepare Handover Response, to the MSC server, which establishes a circuit connection between the target MSC and the media gateway MGW.

10. The MSC server initiates session transmission by using the session transmission number. For example, the MSC server may send an ISUP IAM message to the IMS domain or send an invitation message to the IMS domain. Subsequently, a standard IMS service continuity procedure is applied to perform session transmission, and during the process of updating the remote user plane, the communication remote end updates the peer user plane information to the media gateway MGW. The MSC server may, during the foregoing circuit connection establishment process or initiate a session transmission, command the corresponding MGW to enable the circuit connection between the MGW and the target MSC to forward the uplink and downlink data, that is, the MGW passes the downlink voice service from the remote end of the communication through the The circuit connection is further sent to the target MSC, and the uplink voice service received from the circuit connection is forwarded to the remote end of the communication.

It should be noted that, in practice, only downlink data from the remote end of the communication may pass through the MGW, and the mobile terminal accesses the network through the E-UTRAN if it sends uplink data.

11. The IMS domain completes the session transmission and the remote user plane update, and returns a response message.

Corresponding to step 10, the response message may be an ANUP message of the ISUP or a SIP 200 OK message. When the MSC receives the response message, the remote end of the communication has switched the downlink voice stream to the MGW associated with the MSC server. If the MSC server has commanded the corresponding MGW to enable the circuit connection between the MGW and the target MSC to forward the uplink and downlink data, the downlink voice service will further reach the target MSC.

12. After receiving the response message returned in step 11, the MSC server sends a forward retransmission response message Forward Relocation Response (the message carries the target side to the source side transparent container cell) to the MME.

13. The MME synchronizes the handover preparation process of the two domains, and sends a handover command message Handover Command (the message carries the target side to the source side transparent container cell) to the source side access network E-UTRAN device.

14. Source-side access network The E-UTRAN device sends a handover command message from the E-UTRAN Handover from E-UTRAN Command to the mobile terminal, and commands the mobile terminal to switch to the target side network GERAN or UTRANe

15. The mobile terminal switches access to the target side network GERAN or UTRAN, and the target side network GERAN or UTRAN detects the access of the mobile terminal.

If the MSC server has already performed data during the establishment of the foregoing circuit connection or the initiation of the session transmission, then the uplink and downlink voice services are restored. For example, after the voice stream is restored, the uplink voice flow is: starting from the mobile terminal, passing through the target side network device, the target mobile switching center, the mobile switching center server/multimedia gateway, the IP multimedia subsystem, and finally reaching the communication. remote. 16. The target side network device detects the access of the mobile terminal, and sends a migration complete message Relocation Complete to the target MSC.

17. Target The MSC notifies the MSC server that the handover is complete.

18. In order to be compatible with the fixed network system, the target MSC may notify the MSC server to reply to the message. If the MSC server is in the process of establishing the foregoing circuit connection or initiating the session transmission, the MSC server instructs the corresponding MGW to enable the circuit connection between the MGW and the target MSC to forward the uplink and downlink data in step 17 or 18.

19. The MSC server sends a pre-transmission complete message Forward Relocation Complete to the MME, and notifies the MME that the mobile terminal has switched to the target side. The MME sends a pre-transmission complete confirmation message Forward Relocation Complete Acknowledge to the MSC server for confirmation.

If necessary, the MSC server can perform an update location process to the HSS/HLR to obtain data such as the user's subscription information.

20. Parallel to the above step 16, the packet domain handover is also completed, and the target side network device sends a migration complete message Relocation Complete to the target SGSN.

21. The target SGSN sends a pre-transmission complete message Forward Relocation Complete to the MME, notifying the MME that the mobile terminal has switched to the target side. The MME sends a pre-transmission complete confirmation message Forward Relocation Complete Acknowledge to the SGSN for confirmation.

22. Target The SGSN updates the bearer information of the monthly service gateway Serving Gateway or Packet Data Network Gateway.

In the embodiment of the present invention, the start and end time of the voice service interruption is the T part in the figure, that is, the downlink voice service is switched from the communication remote end to the MGW to start the interruption (because the downlink voice service arrives at the MGW at this time, and further reaches the target MSC, However, the mobile terminal cannot be reached, and the mobile terminal has not switched to the target side network under the target MSC. The voice service is restored until the mobile terminal switches to the target side network. The delay of this process mainly includes several signaling messages in the network. The delay of the wireless air interface switching between the delay and the mobile terminal is less than 400ms, which is similar to the current interrupt circuit delay of 200ms in the traditional circuit domain switching, so that the voice interruption time of the SRVCC switching process can be effectively shortened, and the user is improved. Business experience.

Embodiment 4: Referring to FIG. 4, FIG. 4 is a schematic flowchart diagram of a method for optimizing handover according to Embodiment 4 of the present invention. The fourth embodiment of the present invention provides an SRVCC handover from the source-side access network E-UTRAN to the target-side network GERAN, and the target-side network GERAN does not support DTM or PS handover. Method, as shown in FIG. 4, the method may include:

1. Receiving the measurement report sent by the mobile terminal UE, the source side access network E-UTRAN device determines to trigger the handover to the target side network GERAN.

2. Source-side access network The E-UTRAN device sends a handover request message Handover Required (the message carries the target cell or base station identity, the source side to the target-side transparent container) to the MME. At the same time, the source side access network E-UTRAN device indicates to the MME that this handover is an SRVCC handover.

3. According to the SRVCC handover indication of the source-side access network E-UTRAN device, the MME identifies the existing voice bearers based on the service level identifier of the bearer, and then initiates the switching of the PS domain to the CS domain to the target MSC server only for these voice bearers.

The MME sends a forward retransmission request message Forward Relocation Request (the message carries the session transmission number, the mobile phone number, the source side to the target side transparent container, the mobility management context, and the media side information of the voice stream) to the MSC server.

The MSC server is selected by the MME according to the target cell or the base station identifier carried in the received handover request message; the session transmission number and the mobile phone number are part of the user subscription data, and the user access source side access network E-UTRAN When downloaded to the MME; the mobility management context contains the security context of the circuit domain and other relevant information. The circuit domain security context is derived by the MME based on the key information of the user in the source side access network E-UTRAN.

The media plane information of the voice stream can be derived from the user plane information of the voice bearer saved by the MME. For example, according to the downlink traffic flow template (TFT, Traffic Flow Template) of the voice bearer, the mobile terminal receives the media plane information of the downlink voice stream, such as a port. The IP address, the differentiated service code point (DSCP) value, or the like, or the bearer information of the downlink voice stream received by the SGW from the saved voice bearer user plane information; or may be received by the mobile terminal. The media plane information of the downlink voice stream is reported to the MME, including an IP address, a port, a DSCP value, and a media stream coding mode. The methods reported include, but are not limited to: 1) After the mobile terminal establishes the voice bearer successfully, it immediately reports the media surface information of the current voice stream of the MME;

2) according to the source side access network E-UTRAN device determines to initiate the handover, not only informs the MME of the need to switch, but also informs the mobile terminal that the handover is about to be performed, and the mobile terminal reports the media plane information of the current voice stream to the MME;

3) When the source-side access network E-UTRAN device decides to initiate the handover, it first interacts with the mobile terminal to obtain the media plane information of the current voice stream, and then includes the media plane information of the current voice stream in the handover required message. !^^;

4) After receiving the handover request message of the access network E-UTRAN device, the MME interacts with the mobile terminal, and requests the mobile terminal to report the media plane information of the current voice stream.

7. The MSC server initiates the session transmission by using the session transmission number. For example, the MSC server may send an ISUP IAM message to the IMS domain, or send an invitation message to the IMS domain. Then, the standard IMS service continuity process is applied to perform session transmission. In the process of updating the remote user plane, the communication remote end updates the downlink user plane information to the media gateway MGW, so that the downlink voice service is switched to

The MSC server notifies the media face information of the voice stream of the corresponding MGW in the foregoing process of initiating a cross-MSC handover procedure or circuit connection establishment.

Corresponding to step 7, the response message may be an ISAM message of the ISUP, or a SIP 200 OK message. When the MSC receives the response message, the remote end of the communication has sent the downlink voice service to the media gateway associated with the MSC server, and the media gateway MGW encodes the received downlink voice service according to the media plane information provided by the foregoing MSC server, and The encoded downlink voice service is further routed and forwarded. Here, if the MSC server provides the mobile terminal received by the MME, If the media plane information of the downlink voice stream or the downlink voice stream received by the mobile terminal obtained by the MME from the saved voice bearer user plane information, the downlink voice service will be first routed to the packet data gateway (PGW), and then through the service gateway ( SGW), the source-side access network E-UTRAN device arrives at the mobile terminal; if the MSC server provides the downlink voice streaming media information received by the SGW from the saved voice-bearing user plane information, the downlink voice service is The media gateway is directly sent to the SGW through the GTP tunnel, and then reaches the mobile terminal through the source-side access network E-UTRAN device.

9. After receiving the foregoing response message, the MSC server sends a forward retransmission response message Forward Relocation Response (the message carries the target side to the source side transparent container cell) to the ^^^^. The MME reserves for bearers that may be non-voiced and that do not have reserved bandwidth requirements.

10. The MME sends a handover command message Handover Command (the message carries the target side to the source side transparent container cell) to the source side access network E-UTRAN device.

11. Access network The E-UTRAN device sends a Handover from E-UTRAN Command message to the mobile terminal, and commands the mobile terminal to switch to the target side network GERAN.

12. The mobile terminal switches to access the target side network GERAN, and the target side network GERAN detects the mobile terminal access.

14. The target side network device detects the mobile terminal access, and sends a handover complete message Handover Complete to the target MSC.

15. The target MSC notifies the MSC server that the handover is complete.

16. In order to be compatible with the fixed network system, the target MSC may notify the MSC server to reply to the message. In the above step 15 or 16, the MG server instructs the corresponding MGW to enable the circuit connection between the MGW and the target MSC to forward the uplink and downlink data, that is, the MGW further transmits the downlink voice service from the remote end of the communication to the target MSC through the circuit connection. (There is no longer sent to the SGW/PGW), and the uplink voice service received from the circuit connection is forwarded to the remote end of the communication, so that the uplink and downlink voice service flows are switched to the target side.

17. The MSC server sends a forward relocation complete message Forward Relocation Complete to the MME, and notifies the MME that the mobile terminal has switched to the target side. The MME sends the pre-migration to complete The message Forward Relocation Complete Acknowledge is given to the MSC server for confirmation. If necessary, the MSC server can perform an update location process to the HSS/HLR to obtain data such as subscription information of the user.

After the voice call ends, if the mobile terminal remains in the GERAN access network, the mobile terminal initiates a route update procedure to resume the suspended packet service.

In this embodiment, the start and end time of the voice interruption is the T part in FIG. 4, that is, the mobile terminal receives the handover command from the source side access network E-UTRAN, until the mobile terminal switches to the target side network GERAN, and The MSC server receives the notification from the target MSC, and notifies the MGW to switch the downlink voice service to the target side MSC. Compared with the foregoing embodiment 2 and the third embodiment, the embodiment of the present invention does not cause the voice service to be interrupted during the user handover process of the IMS domain, because the downlink voice service is forwarded to the SGW or the PGW by the MGW and further sent. For the mobile terminal, the uplink data is still sent directly to the IMS domain by the mobile terminal. Therefore, the delay of this process is further optimized, which is similar to the current interrupt circuit delay of 200 ms in the traditional circuit domain switching, thereby effectively shortening the voice interruption time of the SRVCC handover process and improving the user experience. Embodiment 5:

Referring to FIG. 5, FIG. 5 is a schematic flowchart of a method for optimizing a handover according to Embodiment 5 of the present invention. In the fifth embodiment of the present invention, an SRVCC handover from a source-side access network E-UTRAN to a target-side network UTRAN or GERAN, and a target-side network UTRAN or GERAN support PS handover is taken as an example to describe a handover provided by an embodiment of the present invention. The optimization method, as shown in Figure 5, can include:

According to the SRVCC handover indication of the E-UTRAN device of the source side access network, the MME is based on the bearer The service level identifier identifies the existing voice bearer and initiates a handover to the target MSC server and the target SGSN, respectively.

3. The MME initiates a PS to CS handover procedure for the voice bearer, and sends a forward retransmission request message Forward Relocation Request (the message carries the session transmission number, the mobile phone number, the source side to the target side transparent container, the mobility management context, and the voice stream. Media side information) to the MSC server.

The MSC server is selected by the MME according to the target cell or the base station identifier carried in the received handover request message; the session transmission number and the mobile phone number are part of the user subscription data, and the user access source side access network E-UTRAN The time is downloaded to the MME; the mobility management context contains the security context of the circuit domain and other related information; the circuit domain security context is derived by the MME based on the key information of the user in the EPS system.

The media plane information of the voice stream may be derived by using the user plane information of the voice bearer saved by the MME. For example, according to the downlink TFT of the voice bearer, the mobile terminal receives the media plane information of the downlink voice stream, such as a port, an IP address, a DSCP value, or the like, or Acquiring the bearer information of the downlink voice stream received by the SGW from the saved voice bearer user plane information; or the mobile terminal may report the media plane information of the downlink voice stream to the MME, including the IP address, port, DSCP, and media stream coding. Ways, etc. The specific method for reporting is described in the foregoing third embodiment, and the embodiment is not repeated here.

5. The target MSC and the target base station exchange handover request and acknowledgement messages, and perform resource allocation for circuit domain handover.

7. The target SGSN sends a migration request message Relocation Request (the message carries the source side to the target side transparent container) to the target side network device (such as the target side network GERAN or the base station RNS of the UTRAN) to allocate resources for the packet domain handover. The target side network device coordinates the CS handover and the PS handover request, allocates resources, and returns a migration request acknowledgement message Relocation Request Acknowledge to the target SGSN to confirm the packet domain handover. 8. The target SGSN sends a forward retransmission response message Forward Relocation Response (the message carries the target side to the source side transparent container) to the MME.

10. The MSC server initiates session transmission by using the session transmission number. For example, the MSC server may send a message ISUP IAM to the IMS domain, or send an invitation message to the IMS domain. Then, the standard IMS service continuity process is applied to perform session transmission. In the process of updating the remote user plane, the communication remote end updates the downlink user plane information to the media gateway MGW, so that the downlink voice service is switched to

Corresponding to step 10, it may be an ANUP message of ISUP, or a SIP 200 OK message. When the MSC receives the response message, the remote end of the communication has switched the downlink voice service to the media gateway MGW associated with the MSC server. The media gateway MGW encodes and further routes the received downlink voice service according to the media plane information provided by the foregoing MSC server. Here, if the MSC server provides the media plane information of the downlink voice stream reported by the mobile terminal received by the MME or the downlink voice stream received by the mobile terminal obtained by the MME from the saved voice bearer user plane information, the downlink voice service will be first Routing to the packet data gateway (PGW), and then passing through the serving gateway (SGW) and the source side access network E-UTRAN device to the mobile terminal; if the MSC server provides the SGW obtained by the MME from the saved voice bearer user plane information After receiving the downlink voice streaming media information, the downlink voice service is directly sent by the media gateway to the SGW through the GTP tunnel, and then reaches the mobile terminal through the source-side access network E-UTRAN device.

12. After receiving the foregoing response message, the MSC server sends a forward retransmission response message Forward Relocation Response (the message carries the target side to the source side transparent container cell) to the MME.

13. The MME synchronizes the handover preparation process of the two domains, and sends a handover command message Handover Command (the message carries the target side to the source side transparent container cell) to the source side access network E-UTRAN device. 14. The source side access network E-UTRAN device sends a Handover from E-UTRAN Command message to the mobile terminal, and commands the mobile terminal to switch to the target side network GERAN or UTRANe.

16. The target side network device detects the access of the mobile terminal, and sends a migration complete message Relocation Complete to the target MSC.

17. Target The MSC notifies the MSC server that the handover is complete.

18. In order to be compatible with the fixed network system, the target MSC may notify the MSC server to reply to the message. In the above step 17 or 18, the MSC server instructs the corresponding MGW to enable the circuit connection between the MGW and the target MSC to forward the uplink and downlink voice service, that is, the MGW further transmits the downlink voice service from the remote end of the communication to the target through the circuit connection. The MSC (not sent to the SGW/PGW) forwards the uplink voice service received from the circuit connection to the remote end of the communication, so that the uplink and downlink voice service flows are switched to the target side.

22. Target The SGSN updates the bearer information of the Serving Gateway or Packet Data Network Gateway.

In the above two embodiments, the start and end time of the voice interruption is the T part in the figure, that is, the handover command is received from the terminal, leaving the source E-UTRAN access network, and the mobile terminal accesses the target radio access network, the MSC server. Receive the notification from the target MSC, and notify the MGW to switch the downlink voice service flow to the target side. Until now. Compared with the first embodiment, the remote update of the IMS domain does not cause a voice interruption, because the downlink voice stream is forwarded to the SGW or the PGW by the MGW and further sent to the terminal, and the uplink data is still directly sent by the terminal to the remote end. . Therefore, the delay of this process is further optimized. Basically, like the traditional handover, the delay is about 200ms, which ensures the user's consistent service experience and can fully meet the requirements of the operator.

In this embodiment, the start and end time of the voice interruption is the T part in FIG. 5, that is, the mobile terminal receives the handover command from the source side access network E-UTRAN until the mobile terminal switches to the target side network GERAN or UTRAN. And the MSC server receives the target MSC notification, and notifies the MGW to switch the downlink voice service to the target side MSC. In the embodiment of the present invention, the voice service is not interrupted during the user handover process of the IMS domain, because the downlink voice service is forwarded to the SGW or the PGW by the MGW and further sent to the mobile terminal, and the uplink data is still directly sent by the mobile terminal. To the IMS domain. Therefore, the delay of this process is further optimized, which is similar to the current interrupt circuit delay of 200 ms in the traditional circuit domain switching, so that the voice interruption time of the SRVCC handover process can be effectively shortened, and the user experience is improved.

Example 6:

Referring to FIG. 6, FIG. 6 is a schematic flowchart of a method for optimizing handover according to Embodiment 6 of the present invention. The sixth embodiment of the present invention provides an SRVCC handover from the source-side access network E-UTRAN to the target-side network GERAN, and the target-side network GERAN does not support DTM or PS handover. Method, as shown in FIG. 6, the method may include:

In the present embodiment, steps 1 to 7 are the same as steps 1 to 7 in the fourth embodiment, and the embodiment is not repeated here.

Corresponding to step 7, it can be an ANUP message of ISUP, or a SIP 200 OK message. When the MSC receives the response message, the remote end of the communication has sent the downlink voice service to the media gateway associated with the MSC server.

The media gateway MGW forwards the received downlink voice service through two paths, one is sent to the target MSC through a circuit connection with the target MSC, and the other is based on the media plane information, coding and further routing and forwarding provided by the foregoing MSC server. . Here, if the MSC server provides the media plane information of the downlink voice stream reported by the mobile terminal received by the MME or the MME saves from The voice carries the downlink voice stream received by the mobile terminal obtained in the user plane information, and the downlink voice service is first routed to the packet data gateway (PGW), and then sequentially passes through the serving gateway (SGW) and the source side access network E-UTRAN device. Arriving at the mobile terminal; if the MSC server provides the downlink voice streaming media information received by the SGW from the saved voice bearer user plane information, the downlink voice service is directly sent by the media gateway to the SGW through the GTP tunnel, and then The source side access network E-UTRAN device arrives at the mobile terminal.

10. The MME sends a handover command message Handover Command message (the message carries the target side to the source side transparent container letter) to the source side access network E-UTRAN device.

11. The source side access network The E-UTRAN device sends a handover command message from the E-UTRAN Handover from E-UTRAN Command to the mobile terminal, and commands the mobile terminal to switch to the target side network GERANe

12. The mobile terminal switches to access the target side network GERAN, and the target side network GERAN detects the mobile terminal access. At this point, the voice service of the mobile terminal has been switched to the target side network.

14. The target side network device detects the access of the mobile terminal, and sends a handover complete message Handover Complete to the target MSC.

15. The target MSC notifies the MSC server that the handover is complete.

16. In order to be compatible with the fixed network system, the target MSC may notify the MSC server to reply to the message. In the above step 15 or 16, the MSC server instructs the corresponding media gateway MGW to stop forwarding the downlink voice service to the SGW or the PGW, that is, the downlink voice service is forwarded only through the circuit connection with the target MSC.

17. The MSC server sends a forward relocation complete message Forward Relocation Complete to the MME, and notifies the MME that the mobile terminal has switched to the target side. The MME sends a Forward Relocation Complete Acknowledge to the MSC server for confirmation. If necessary, the MSC server can perform an update location process to the HSS/HLR to obtain data such as subscription information of the user.

After the voice call ends, if the mobile terminal remains in the target side network GERAN, the mobile terminal initiates a route update procedure to resume the suspended packet service.

In the embodiment of the present invention, the MSC server instructs the MGW to encode the received downlink voice service according to the voice stream media surface information, and routes the data to the mobile terminal to ensure that the voice service of the mobile terminal is not interrupted during the user plane handover in the IMS domain. The MGW is instructed to forward the received downlink voice service to the target side MSC through a pre-established circuit connection between the MGW and the target side MSC, so that the start and end time of the voice service interruption of the mobile terminal is only the T in FIG. In part, the voice service interruption time is only the air interface switching time of the mobile terminal. Compared with the foregoing embodiment 2 to the fifth embodiment, the embodiment of the present invention can further effectively shorten the voice service interruption time of the SRVCC handover process, and improve the user. Business experience.

Example 7:

Referring to FIG. 7, FIG. 7 is a schematic flowchart of a method for optimizing handover according to Embodiment 7 of the present invention. The seventh embodiment of the present invention provides an SRVCC handover from the source side access network E-UTRAN to the target side network UTRAN or GERAN, and the target side network UTRAN or GERAN supports PS handover as an example, and describes a handover provided by the embodiment of the present invention. The optimization method, as shown in FIG. 7, the method may include:

In this embodiment, steps 1 to 10 are the same as steps 1 to 10 in the fifth embodiment, and the embodiment is not repeated here.

Corresponding to step 10, it may be an ANUP message of ISUP, or a SIP 200 OK message. When the MSC receives the response message, the remote end of the communication has switched the downlink voice service to the media gateway MGW associated with the MSC server. The media gateway MGW forwards the received downlink voice service through two paths, one is sent to the target MSC through a circuit connection with the target MSC, and the other is based on the media surface information of the voice stream provided by the foregoing MSC server, coding and Further route forwarding. Here, if the MSC server provides the media plane information of the downlink voice stream reported by the mobile terminal received by the MME or the downlink voice stream received by the mobile terminal obtained by the MME from the saved voice bearer user plane information, the downlink voice service will be first Routing to the packet data gateway (PGW), and then The service gateway (SGW) and the source-side access network E-UTRAN device arrive at the mobile terminal; if the MSC server provides the downlink voice streaming media information received by the SGW from the saved voice bearer user plane information, the downlink The voice service is directly sent by the media gateway to the SGW through the GTP tunnel, and then reaches the mobile terminal through the source-side access network E-UTRAN device.

17. Target The MSC notifies the MSC server that the handover is complete.

18. In order to be compatible with the fixed network system, the target MSC may notify the MSC server to reply to the message. In the foregoing step 17 or 18, the MSC server instructs the corresponding media gateway MGW to stop forwarding the downlink voice service to the SGW or the PGW, that is, the downlink voice service is forwarded only through the circuit connection with the target MSC.

21. The target SGSN sends a pre-transmission complete message Forward Relocation Complete to The MME, the MME mobile terminal has switched to the target side. The MME sends a Forward Relocation Complete Acknowledge to the current SGSN for confirmation.

In the embodiment of the present invention, the MSC server instructs the MGW to encode the received downlink voice service according to the voice stream media surface information, and routes the data to the mobile terminal to ensure that the voice service of the mobile terminal is not interrupted during the user plane handover in the IMS domain. And instructing the MGW to forward the received downlink voice service to the target side MSC through a pre-established circuit connection between the MGW and the target side MSC, so that the start and end time of the voice service interruption of the mobile terminal is only the T in FIG. In part, the voice service interruption time is only the air interface switching time of the mobile terminal. Compared with the foregoing embodiment 2 to the fifth embodiment, the embodiment of the present invention can further effectively shorten the voice service interruption time of the SRVCC handover process, and improve the user. Business experience.

Example 8:

Please refer to FIG. 8. FIG. 8 is a schematic structural diagram of a switching apparatus according to Embodiment 8 of the present invention. The switching device provided by the embodiment of the present invention can be used as an independent device for optimizing SRVCC switching, and can also be used as a part of the MSC server, so that the MSC server can optimize the SRVCC switching. As shown in FIG. 8, the switching device may include:

The first triggering unit 801 is configured to initiate a user plane switching of the service control system.

The obtaining unit 802 is configured to receive a user plane handover complete response message sent by the service control system, where the second triggering unit 803 is configured to initiate wireless air interface switching of the mobile terminal according to the response message. The service control system is mainly used for controlling, charging, and the like, including the voice. The service control system in the E-UTRAN may specifically be an IP multimedia subsystem.

Preferably, the first triggering unit 801 may specifically initiate a session transmission to the service control system, so that the service control system triggers a remote user plane update.

Preferably, the second triggering unit 803 may specifically send, according to the response message, a pre-migration response message carrying a transparent container cell of the target side to the source side to the mobility management entity;

After receiving the preamble migration response message sent by the second triggering unit 803, the mobility management entity sends a handover command carrying the target side to the source side transparent container cell to the source side access network device (such as the base station node eNodeB of the E-UTRAN). Message After receiving the handover command message, the source-side access network device sends a handover command message to the mobile terminal in the source-side access network that needs to be handed over, and commands the mobile terminal to switch from the source-side access network to the target side network.

(such as switching to GERAN/UTRAN).

As shown in FIG. 8, the switching apparatus provided by the embodiment of the present invention may further include:

The first control unit 804 is configured to: pass the received downlink voice service to the MGW to pass the

A pre-established circuit connection between the MGW and the target side MSC is forwarded to the target side MSC.

Specifically, the first control unit 804 may be specifically used before the second triggering unit 803 initiates wireless air interface switching of the mobile terminal; or when the second triggering unit 803 initiates wireless air interface switching of the mobile terminal; or in the second After the triggering unit 803 initiates the wireless air interface switching of the mobile terminal, the MGW is instructed by the MGW to forward the received downlink voice service to the target side MSC through a pre-established circuit connection between the MGW and the target side MSC.

When the mobile terminal completes the process of switching from the source side access network to the target side network, the voice service can be resumed immediately. In this way, the time of interruption of the voice service mainly includes the transmission time of several signaling messages in the network and the time of the wireless air interface switching of the mobile terminal, and the total interruption time of the voice service is about 200 ms, which is similar to the traditional circuit domain switching.

The second control unit 805 is configured to: before the second triggering unit 803 initiates the wireless air interface switching of the mobile terminal, receive the voice streaming media surface information sent by the MME, and send the voice streaming media surface information to the MGW;

The MGW encodes the received downlink voice service according to the voice stream media surface information, and routes the signal to the mobile terminal.

Specifically, when the voice streaming media information is reported by the mobile terminal to the MME, or the MME receives the received voice bearer user plane information and is received by the mobile terminal, the MGW receives the voice streaming media information according to the information. The downlink voice service is encoded, and the encoded voice service is first routed to the packet data gateway, and then passes through the serving gateway and the source side access network device to reach the mobile terminal; or, when the voice streaming media information MME is saved from The MGW receives the received downlink voice service according to the voice stream media surface information, and routes the encoded voice service directly to the service gateway through the GTP tunnel, when the voice gateway is received by the service gateway. Then, the source side access network device reaches the mobile terminal. After the mobile terminal completes the wireless air interface switching, the second control unit 805 may instruct the MGW to stop encoding the received downlink voice service according to the voice streaming media plane information, and route the data to the mobile terminal; and then command the MGW only The received downlink voice service is forwarded to the target side MSC through a pre-established circuit connection between the MGW and the target side MSC, and the target side MSC passes the downlink voice service through the target side network device (such as a base station node). The mobile terminal that has switched to the target side network is sent so that the mobile terminal can resume the voice service.

In this way, the mobile terminal that has not performed the wireless air interface switching can keep the voice service uninterrupted during the user plane switching process of the service control system. The time of voice interruption mainly includes the time of wireless air interface switching of the mobile terminal and the transmission time of several signaling messages in the network. The total voice interruption time is about 200ms, which is similar to the traditional circuit domain switching.

In addition, the second control unit 805 may be further configured to: before the second triggering unit 803 initiates the wireless air interface switching of the mobile terminal, instruct the MGW to encode the received downlink voice service according to the voice streaming media plane information, And transmitting to the mobile terminal; and instructing the MGW to forward the received downlink voice service to the target mobile switching center through a circuit connection established in advance by the MGW and the target side MSC.

After the mobile terminal completes the wireless air interface switching, the second control unit 805 may instruct the MGW to stop encoding the received downlink voice service according to the voice streaming media information, and send the received downlink voice service to the mobile terminal; The downlink voice service is forwarded only to the target side MSC through the circuit connection established by the MGW and the target side MSC, and the downlink voice service is sent by the target side MSC to the target side through the target side network device (such as the base station node). The mobile terminal of the network enables the mobile terminal to resume voice service.

In this way, during the user plane switching process of the service control system, the mobile terminal that has not performed the wireless air interface switching can keep the voice service uninterrupted, and the time of the voice interruption is only the time of the wireless air interface switching of the mobile terminal, further shortening the voice. Interruption time.

It should be noted that, FIG. 8 is only a schematic structural diagram of an embodiment of an optimal switching device provided by an embodiment of the present invention. A person skilled in the art may know that the first control unit 804 may specifically, before or after the second trigger unit 803 initiates the wireless air interface switching of the mobile terminal, the MGW will pass the received downlink voice service through the MGW. And the circuit connection established in advance with the target side MSC is forwarded to the target side MSC, so above the base of FIG. A person skilled in the art can also obtain a schematic diagram of other different switching device structures, which are not limited herein.

The above describes the switching device provided in the eighth embodiment of the present invention. The switching device provided by the embodiment of the present invention preferentially completes the user plane switching of the service control system, and then performs the wireless air interface switching of the mobile terminal, thereby implementing the SRVCC. The handover process further shortens the voice interruption time and enhances the user's service experience.

Example 9:

Referring to FIG. 9, FIG. 9 is a schematic structural diagram of a handover system according to Embodiment 8 of the present invention. As shown in FIG. 9, the switching system can include:

The switching device 901 is configured to initiate user plane switching of the service control system, receive a user plane handover complete response message sent by the service control system, and initiate a wireless air interface switch of the mobile terminal according to the response message;

The service control system 902 is configured to perform user plane switching according to the trigger of the switching device, and return a user plane handover complete response message to the handover optimization device.

The switching device 901 provided by the embodiment of the present invention is the same as the switching device provided in the eighth embodiment, and the specific structure is not repeated herein;

The service control system provided by the embodiment of the present invention may specifically be an IP Multimedia Subsystem (IMS). As shown in FIG. 9, the switching system may further include:

Media gateway 903 and target side mobile switching center 904;

The circuit connection is pre-established between the media gateway 903 and the target mobile switching center 904. Preferably, the switching device 901 is further configured to: before initiating the wireless air interface switching of the mobile terminal according to the response message, The media gateway 903 forwards the received downlink voice service to the target mobile switching center 904 through a pre-established circuit connection between the media gateway 903 and the target mobile switching center 904.

In this way, when the mobile terminal completes the wireless air interface switching, the voice service can be resumed immediately. In this way, the time of voice interruption mainly includes the transmission time of several signaling messages in the network and the time of wireless air interface switching of the mobile terminal, and the total time of voice interruption is about 200 ms, which is similar to the traditional circuit domain switching.

Preferably, the switching device 901 is further configured to initiate a mobile terminal according to the response message. Receiving the voice streaming media information sent by the mobility management entity, and transmitting the voice streaming media information to the media gateway 903; the media gateway 903 receives the voice streaming media information according to the information The downlink voice service is encoded and transmitted to the mobile terminal.

Specifically, the media gateway 903 may encode the received downlink voice service according to the voice stream media surface information, and route the encoded voice service to the packet data gateway, and then pass through the service gateway and the source side access network. The device arrives at the mobile terminal;

Alternatively, the media gateway 901 may encode the received downlink voice service according to the voice streaming media plane information, and directly route the encoded voice service to the serving gateway, and then reach the mobile terminal through the source side access network device.

After the mobile terminal completes the wireless air interface switching, the switching device 901 may instruct the media gateway 903 to stop encoding the received downlink voice service according to the voice streaming media information, and send the downlink voice service to the mobile terminal. Meanwhile, the media gateway 903 is commanded to receive The incoming downlink voice service is forwarded to the target side mobile switching center 904 through a pre-established circuit connection between the media gateway 903 and the target side mobile switching center 904, and the downlink voice service is passed by the target side mobile switching center 904 through the target side. A network device (such as a base station node) is sent to the mobile terminal that has switched to the target side network, so that the mobile terminal can resume the voice service.

In this way, the mobile terminal that has not performed the wireless air interface switching during the user plane switching process of the service control system 902 can keep the voice service uninterrupted at all times. Thus, the time of voice interruption mainly includes the time of the wireless air interface switching of the mobile terminal and the transmission time of several signaling messages in the network, and the total time of the voice interruption is about 200 ms, which is similar to the traditional circuit domain switching.

Preferably, the switching device 901 is further configured to: before the wireless air interface switching of the mobile terminal is initiated according to the response message, receive voice streaming media information sent by the mobility management entity, and send the voice streaming media information The media gateway 903 is configured to encode the received downlink voice service according to the voice stream media surface information, and send the received downlink voice service to the mobile terminal, and pass the received downlink voice service to the media gateway 903. A pre-established circuit connection with the target side mobile switching center 904 is forwarded to the target side mobile switching center 904.

After the mobile terminal completes the wireless air interface switching, the media gateway 903 stops encoding the received downlink voice service according to the voice streaming media plane information, and sends the received downlink voice service to the mobile terminal.

In this way, the service control system 902 has not performed wireless during the user plane switching process. The mobile terminal switching can maintain the voice service uninterrupted at all times, and the time of the voice interruption only includes the time of the wireless air interface switching of the mobile terminal, further shortening the voice interruption time.

It should be noted that the dotted lines are connected between the units shown in FIG. 9. The dotted line connection may indicate that the units are connected by the assistance of other network devices, or that the units are directly connected. .

The foregoing describes a handover system provided by Embodiment 9 of the present invention. The optimization system provided by the embodiment of the present invention can preferentially complete the user plane switching of the service control system, and then further perform the wireless air interface switching of the mobile terminal, thereby implementing The SRVCC handover process further shortens the voice interruption time and enhances the user's service experience.

A person skilled in the art can understand that all or part of the steps of implementing the above method embodiments may be completed by using hardware related to program instructions, and the foregoing program may be stored in a computer readable storage medium, and the program is executed when executed. The foregoing storage device includes the following steps: The foregoing storage medium includes: a read-only memory (ROM), a random access memory (RAM), a magnetic disk, or an optical disk, and the like, which can store program codes.

The above description of the method for optimizing the handover, the switching device and the system provided by the embodiment of the present invention is only for helping to understand the method of the present invention and its core idea; meanwhile, it is for those skilled in the art. The present invention is not limited by the scope of the present invention.

Claims

Claim

A method for optimizing a handover, comprising:

Initiating user plane switching of the service control system;

2. The method of claim 1 wherein the service control system is a network protocol multimedia subsystem.

The method according to claim 1, wherein the sending, by the response message, the wireless air interface switching of the mobile terminal comprises:

Sending, by the response message, a pre-migration response message carrying a transparent container cell of the target side to the source side to the mobility management entity; after receiving the pre-migration response message, the mobility management entity commands the source-side access network Initiating air interface switching, the source side access network commands the mobile terminal to switch from the source side access network to the target side network.

The method according to any one of claims 1 to 3, wherein the method further comprises:

The commanded media gateway forwards the received downlink voice service to the target mobile switching center through a pre-established circuit connection between the media gateway and the target side mobile switching center.

The method according to any one of claims 1 to 3, wherein, before the initiating the wireless air interface switching of the mobile terminal according to the response message, the method further includes:

Receiving voice streaming media information sent by the mobility management entity;

Transmitting the voice streaming media surface information to the media gateway;

The media gateway encodes the received downlink voice service according to the voice stream media surface information, and sends the downlink voice service to the mobile terminal.

The method according to claim 5, wherein the method further comprises: the mobility management entity receiving the downlink voice streaming media information reported by the mobile terminal; or the mobility management entity carrying the user plane information from the saved voice Obtaining downlink voice streaming media information received by the mobile terminal; or

The mobility management entity obtains downlink voice streaming media information received by the serving gateway from the saved voice bearer user plane information.

The method according to claim 5, wherein the media gateway encodes the received downlink voice service according to the voice stream media surface information, and sends the message to the mobile terminal, including: when the voice stream media The face information is reported by the mobile terminal to the mobility management entity, or when the voice streaming media information is the voice streaming media surface information received by the mobile terminal from the saved voice bearer user plane information. The media gateway encodes the received downlink voice service according to the voice stream media surface information, and routes the encoded voice service to the packet data gateway, and then passes through the service gateway and the source side access network device to reach the mobile terminal. ;

Or, when the voice streaming media surface information is the voice streaming media surface information received by the service gateway that is acquired by the mobility management entity from the saved voice bearer user plane information, the media gateway receives the voice streaming media surface information according to the The downlink voice service is encoded, and the encoded voice service is directly routed to the serving gateway through the GTP tunnel, and then reaches the mobile terminal through the source side access network device.

The method according to claim 5, wherein the method further comprises: after the mobile terminal completes the wireless air interface switching, instructing the media gateway to stop performing the downlink voice service according to the voice streaming media surface information. Encoded and sent to the mobile terminal;

The method according to claim 5, wherein the method further includes: before the sending, by the response message, the wireless air interface switching of the mobile terminal, the method further includes:

The method according to claim 9, wherein the method further comprises: after the mobile terminal completes the wireless air interface switching, instructing the media gateway to stop performing the downlink voice service according to the voice streaming media surface information. Encoded and sent to the mobile terminal.

11. A switching device, comprising:

a first triggering unit, configured to initiate a user plane switching of the service control system;

An acquiring unit, configured to receive a user plane handover complete response message sent by the service control system, where the second triggering unit is configured to initiate wireless air interface switching of the mobile terminal according to the response message.

The switching device according to claim 11, wherein the second triggering unit is specifically configured to send, according to the response message, a transparent carrying target side to a source side to the mobility management entity. a pre-migration response message of the container cell, so that after the mobility management entity receives the pre-migration response message, the source-side access network initiates an air interface switch, and the source-side access network commands the mobile terminal to access from the source side. The network switches to the target side network.

The switching device according to any one of claims 11 to 12, further comprising:

The first control unit is configured to instruct the media gateway to forward the received downlink voice service to the target mobile switching center through a pre-established circuit connection between the media gateway and the target side mobile switching center.

a second control unit, configured to: before the initiating the wireless air interface switching of the mobile terminal, receive the voice streaming media information sent by the mobility management entity, and send the voice streaming media surface information to the media gateway, so that the media gateway is configured according to the media gateway The voice streaming media surface information encodes the received downlink voice service and sends the received downlink voice service to the mobile terminal.

The switching device according to claim 14, wherein the second control unit is further configured to: after the mobile terminal completes the wireless air interface switching, instruct the media gateway to stop receiving the received information according to the voice streaming media information. The downlink voice service is encoded and sent to the mobile terminal. The commanded media gateway forwards the received downlink voice service to the target mobile switching center through a pre-established circuit connection between the media gateway and the target mobile switching center. .

The switching device according to claim 14, wherein the second control unit is further configured to: before initiating the wireless air interface switching of the mobile terminal, command the media gateway to pass the received downlink voice service to the media gateway. A pre-established circuit connection with the target-side mobile switching center is forwarded to the target-side mobile switching center.

The switching device according to claim 16, wherein the second control unit is further configured to: after the mobile terminal completes the wireless air interface switching, instruct the media gateway to stop receiving the received information according to the voice streaming media information The downlink voice service is encoded and transmitted to the mobile terminal.

18. A switching system, comprising:

a switching device, configured to initiate a user plane switching of the service control system, and receive a user plane handover completion response message sent by the service control system; and the response message initiates a wireless air interface of the mobile terminal Switch

The switching system according to claim 18, wherein the switching system comprises: a media gateway and a target side mobile switching center;

The switching device is further configured to: before the responding message initiates the wireless air interface switching of the mobile terminal, instruct the media gateway to pre-establish the received downlink voice service between the media gateway and the target side mobile switching center. The circuit connection is forwarded to the target side mobile switching center; the media gateway is configured to pre-establish a circuit connection according to the command of the switching device and the target side mobile switching center.

The switching system according to claim 19, wherein the switching device is further configured to receive the voice streaming media information sent by the mobility management entity before initiating the wireless air interface switching of the mobile terminal according to the response message. And transmitting the voice streaming media information to the media gateway, so that the media gateway encodes the received downlink voice service according to the voice streaming media surface information, and sends the received downlink voice service to the mobile terminal.

The switching system according to claim 20, wherein the switching device is further configured to: after the mobile terminal completes the wireless air interface switching, instruct the media gateway to stop receiving the received downlink voice according to the voice streaming media surface information. The service is encoded and sent to the mobile terminal.