Disclosure of Invention
The invention aims to at least solve one of the technical problems in the prior art, and provides a call switching method and a call switching system, which can effectively improve the call switching efficiency of a dual-card dual-standby terminal.
In order to achieve the above object, the present invention provides a call handover method, including: when the signal intensity of a first SIM card in a called call state is judged to be smaller than a preset threshold value and the network format of the first SIM card is not switchable, a dual-card dual-standby terminal sends a call switching request to a first called mobile switching center server corresponding to the first SIM card in the called call state, wherein the call switching request comprises a telephone number of a second SIM card to be switched;
the first called mobile switching center server sends a call switching request to a calling mobile switching center server corresponding to the calling SIM card;
and the calling mobile switching center server switches the call to the second SIM card according to the call switching request.
Optionally, before the dual-card dual-standby terminal sends a call handover request to a first called mobile switching center server corresponding to the first SIM card in the called call state, the method further includes:
the dual-card dual-standby terminal judges whether the signal intensity of a first SIM card in a called call state is smaller than a preset threshold value or not, and judges whether the network type of the first SIM card is switchable or not if the signal intensity of the first SIM card is smaller than the preset threshold value.
Optionally, before the dual-card dual-standby terminal determines whether the signal strength of the first SIM card in the called call state is smaller than a preset threshold, the method further includes:
the calling mobile switching center server sends a first call request to a first called mobile switching center server and sends a call establishing command to a calling media gateway;
the calling media gateway creates a calling state object according to the call establishing command and sends the information of the calling state object to the calling mobile switching center server;
the first called mobile switching center server sends the first call request to a first SIM card and sends a call establishing command to a first called media gateway;
the first called media gateway creates a first called state object according to the call establishing command and sends the information of the first called state object to the first called mobile switching center server;
the calling mobile switching center server sends the information of the calling state object to the first called mobile switching center server, so that the first called mobile switching center server forwards the information of the calling state object to the first called media gateway;
and the first called mobile switching center server sends the information of the first called state object to the calling mobile switching center server, so that the calling mobile switching center server forwards the information of the first called state object to the calling media gateway, and the first called media gateway establishes connection with the calling media gateway.
Optionally, the switching, by the calling mobile switching center server, the call to the second SIM card according to the call switching request specifically includes:
the calling mobile switching center server sends a second call request to a calling gateway office mobile switching center server according to the call switching request, wherein the second call request comprises the telephone number of the second SIM card;
a calling gateway mobile switching center server sends a call establishing command to a calling gateway media gateway so as to establish connection between the calling gateway media gateway and the calling media gateway;
the calling gateway mobile switching center server sends a second call request to a second called gateway mobile switching center server corresponding to the second SIM card;
the second called gateway mobile switching center server sends a call establishing command to a second called gateway media gateway so that the second called gateway media gateway can establish connection with the calling gateway media gateway;
the second called gateway mobile switching center server sends a second call request to a second called mobile center server corresponding to the second SIM card;
the second called mobile switching center server sends the second call request to a second SIM card and sends a call establishing command to a second called media gateway so that the second called media gateway can establish connection with the second called gateway office media gateway;
and the calling mobile switching center server sends a connection releasing request to the first called mobile switching center server and switches the call to the second SIM card, wherein the connection releasing request is used for releasing the connection between the calling media gateway and the first called media gateway.
Optionally, the sending, by the mobile switching center server of the calling gateway office, a call establishment command to the media gateway of the calling gateway office, so that the establishing of the connection between the media gateway of the calling gateway office and the media gateway of the calling gateway specifically includes:
the media gateway of the calling gateway creates a state object of the calling gateway according to the call establishing command and sends the information of the state object of the calling gateway to a mobile switching center server of the calling gateway;
the calling mobile switching center server sends the information of the calling state object to a calling gateway office mobile switching center server, so that the calling gateway office mobile switching center server forwards the information of the calling state object to a calling gateway office media gateway;
and the calling gateway mobile switching center server sends the information of the calling gateway state object to the calling mobile switching center server so that the calling mobile switching center server forwards the information of the calling gateway state object to the calling media gateway.
Optionally, the sending, by the second called gateway office mobile switching center server, a call establishment command to the second called gateway office media gateway, so that the second called gateway office media gateway establishes a connection with the calling gateway office media gateway specifically includes:
the second called gateway office media gateway creates a second called gateway office state object according to the call establishing command and sends the information of the second called gateway office state object to the second called gateway office mobile switching center server;
the calling gateway mobile switching center server sends the information of the calling gateway state object to a second called gateway mobile switching center server, so that the second called gateway mobile switching center server forwards the information of the calling gateway state object to a second called gateway media gateway;
and the second called gateway mobile switching center server sends the information of the second called gateway state object to the calling gateway mobile switching center server, so that the calling gateway mobile switching center server forwards the information of the second called gateway state object to the calling gateway media gateway.
Optionally, the sending, by the second called mobile switching center server, the second call request to the second SIM card and sending a call establishment command to the second called media gateway, so that the establishing, by the second called media gateway and the second called gateway office media gateway, the connection specifically includes:
the second called media gateway creates a second called state object according to the call establishing command and sends the information of the second called state object to the second mobile switching center server;
the second called gateway mobile switching center server sends the information of the second called gateway state object to the second called mobile switching center server, so that the second called mobile switching center server forwards the information of the second called gateway state object to a second called media gateway;
the second called mobile switching center server sends the information of the second called state object to the second called gateway office mobile switching center server, so that the second called gateway office mobile switching center server forwards the information of the second called state object to the second called gateway office media gateway.
In order to achieve the above object, the present invention further provides a call switching system, including:
the dual-card dual-standby terminal is used for sending a call switching request to a first called mobile switching center server corresponding to a first SIM card in a called call state when the signal intensity of the first SIM card in the called call state is judged to be smaller than a preset threshold value and the network format of the first SIM card is not switchable, wherein the call switching request comprises the telephone number of a second SIM card to be switched;
the first called mobile switching center server is used for sending a call switching request to a calling mobile switching center server corresponding to the calling SIM card;
and the calling mobile switching center server is used for switching the call to the second SIM card according to the call switching request.
Optionally, the method further comprises: a calling media gateway and a first called media gateway;
the calling mobile switching center server is specifically configured to send a first call request to a first called mobile switching center server, send a call establishment command to a calling media gateway, send information of a calling state object to the first called mobile switching center server, and forward the information of the first called state object to the calling media gateway, so that the first called media gateway establishes a connection with the calling media gateway;
the calling media gateway is used for creating information of a calling state object according to the call establishing command and sending the information of the calling state object to the calling mobile switching center server;
the first called mobile switching center server is specifically configured to send a first call request to a first SIM card, send a call establishment command to a first called media gateway, forward information of the calling state object to the first called media gateway, and send information of the first called state object to the calling mobile switching center server;
the first called media gateway is used for creating a first called state object according to the call establishing command and sending the information of the first called state object to the first called mobile switching center server.
Optionally, the method further comprises: a calling gateway mobile switching center server, a second called gateway mobile switching center server and a second called mobile switching center server;
the calling mobile switching center server is further configured to send a second call request to a calling gateway office mobile switching center server according to the call switching request, where the second call request includes a phone number of the second SIM card, send a connection release request to a first called mobile switching center server and switch a call to the second SIM card, and the connection release request is used for releasing a connection between the calling media gateway and the first called media gateway;
the calling gateway mobile switching center server is used for sending a call establishing command to a calling gateway media gateway so as to establish connection between the calling gateway media gateway and the calling media gateway and sending a second call request to a second called gateway mobile switching center server corresponding to the second SIM card;
the second called gateway office mobile switching center server is used for sending a call establishing command to a second called gateway office media gateway so as to establish connection between the second called gateway office media gateway and the calling gateway office media gateway and sending a second call request to a second called mobile center server corresponding to the second SIM card;
and the second called mobile switching center server is used for sending the second call request to a second SIM card and sending a call establishing command to a second called media gateway so as to establish connection between the second called media gateway and the second called gateway office media gateway.
The invention has the following beneficial effects:
according to the call switching method provided by the invention, when the dual-card dual-standby terminal judges that the signal intensity of the first SIM card in the called call state is smaller than the preset threshold value and the network type of the first SIM card can not be switched, the dual-card dual-standby terminal sends the call switching request to the first called mobile switching center server, the first called mobile switching center server sends the call switching request to the calling mobile switching center server corresponding to the calling SIM card, and the calling mobile switching center server switches the call to the second SIM card according to the call switching request, so that the call switching efficiency of the dual-card dual-standby terminal can be effectively improved.
Detailed Description
In order to make those skilled in the art better understand the technical solution of the present invention, the following clear and complete description of the technical solution of the present invention is made with reference to the accompanying drawings, and it is obvious that the described embodiments are a part of the embodiments of the present invention, and not all embodiments. All other embodiments, which can be obtained by a person skilled in the art without any inventive step based on the embodiments of the present invention, are within the scope of the present invention.
Example one
Fig. 1 is a schematic flow chart of a call handover method according to an embodiment of the present invention, as shown in fig. 1, the method includes:
step 101, the dual-card dual-standby terminal judges whether the signal intensity of the first SIM card in the called call state is smaller than a preset threshold value, if so, step 102 is executed; if not, go to step 101.
102, the dual-card dual-standby terminal judges whether the network type of the first SIM card can be switched, if so, the step 101 is executed; if not, go to step 103.
Step 103, the dual-card dual-standby terminal sends a call switching request to a first called mobile switching center server corresponding to the first SIM card in the called call state, where the call switching request includes a phone number of a second SIM card to be switched.
And step 104, the first called mobile switching center server sends a call switching request to a calling mobile switching center server corresponding to the calling SIM card.
And 105, the calling mobile switching center server switches the call to the second SIM card according to the call switching request.
In the call switching method provided by this embodiment, when the dual-card dual-standby terminal determines that the signal intensity of the first SIM card in the called call state is smaller than the preset threshold and the network type of the first SIM card is not switchable, the dual-card dual-standby terminal sends a call switching request to the first called mobile switching center server, the first called mobile switching center server sends the call switching request to the calling mobile switching center server corresponding to the calling SIM card, and the calling mobile switching center server switches the call to the second SIM card according to the call switching request, so that the call switching efficiency of the dual-card dual-standby terminal can be effectively improved.
Example two
Fig. 2 is a schematic flow chart of a call handover method according to a second embodiment of the present invention, and as shown in fig. 2, the method includes:
step 201, the calling mobile switching center server sends a first call request to the first called mobile switching center server, and sends a call establishing command to the calling media gateway.
A calling subscriber dials the number of a first SIM card of the dual-card dual-standby terminal through a calling SIM, a calling Mobile Switching Center server corresponding to the calling SIM card learns that a Mobile Switching Center server (MSC Server) corresponding to the first SIM card is a first called Mobile Switching Center server through a Home Location Register (HLR), and sends a first call request to the first called Mobile Switching Center server. The first call request represents that the calling SIM card requests to establish a call with the first SIM card.
Specifically, the calling SIM card belongs to the calling mobile switching center server, and the first SIM card belongs to the first called mobile switching center server. A Media Gateway (MGW) corresponding to the calling mobile switching center server is the calling Media Gateway.
Step 202, the calling media gateway creates a calling state object according to the call establishing command and sends the information of the calling state object to the calling mobile switching center server.
Specifically, an RTP (Real-time Transport Protocol) mode is set, the voice information of the calling state object is set, the voice information includes jitter buffer related content and a voice compression algorithm, and a Real-time Transport Protocol (RTP) mode is set, and the mode of the calling state object is set to a transceiving mode. The information of the caller status object includes at least an RTP (Real-time Transport Protocol) port number, an IP address, and a voice compression algorithm. The calling state object corresponds to the calling media gateway.
Step 203, the first called mobile switching center server sends the first call request to the first SIM card and sends a call establishing command to the first called media gateway.
Step 204, the first called media gateway creates a first called state object according to the call establishing command and sends the information of the first called state object to the first called mobile switching center server.
The setting mode of the first called status object can be described with reference to the setting mode of the calling status object in step 202. The first called state object corresponds to the first called media gateway.
Step 205, the calling mobile switching center server sends the information of the calling status object to the first called mobile switching center server, so that the first called mobile switching center server forwards the information of the calling status object to the first called media gateway.
Step 206, the first called mobile switching center server sends the information of the first called state object to the calling mobile switching center server, so that the calling mobile switching center server forwards the information of the first called state object to the calling media gateway, and the first called media gateway establishes connection with the calling media gateway.
The establishing of the connection between the first called media gateway and the calling media gateway comprises: the first called media gateway and the calling media gateway need to adopt the same real-time transmission protocol port number and the same voice compression algorithm for communication.
Specifically, the first SIM card accepts the first call request, the first called media gateway establishes RTP connection with the calling media gateway, and the calling SIM of the calling subscriber establishes a call with the first SIM card of the dual-card dual-standby terminal.
Step 207, the dual-card dual-standby terminal judges whether the signal intensity of the first SIM card in the called call state is smaller than a preset threshold, if so, step 208 is executed; if not, go to step 207.
The dual-card dual-standby terminal monitors the signal intensity of the first SIM card in real time. The preset threshold value can be set according to the actual application scene.
Step 208, the dual-card dual-standby terminal judges whether the network type of the first SIM card is switchable, if so, step 207 is executed; if not, go to step 209.
Such as: and when the signal intensity of the first SIM card is smaller than a preset threshold value under the 4G network system, judging whether the first SIM card can be switched to the 3G network system. And when the signal intensity of the first SIM card is smaller than a preset threshold value under the 3G network system, judging whether the first SIM card can be switched to the 2G network system. When the signal strength of the first SIM card in the 2G network system is smaller than the preset threshold, the network system of the first SIM card is not switchable, and step 209 is executed.
Specifically, if the dual-card dual-standby terminal determines that the network type of the first SIM card is switchable, the network type of the first SIM card is switched so that the first SIM card continues to keep talking with the calling SIM card.
Step 209, the dual-card dual-standby terminal sends a call switching request to a first called mobile switching center server corresponding to the first SIM card in the called call state, where the call switching request includes a phone number of a second SIM card to be switched.
In this embodiment, the dual-card dual-standby terminal is provided with a first SIM card and a second SIM card.
Step 210, the first called mobile switching center server sends a call switching request to the calling mobile switching center server corresponding to the calling SIM card.
Step 211, the calling mobile switching center server switches the call to the second SIM card according to the call switching request.
The step of switching the call to the second SIM card by the calling mobile switching center server according to the call switching request is as follows: the calling SIM card disconnects the call connection with the first SIM card and establishes the call connection with the second SIM card. Preferably, the time point when the calling SIM card disconnects the call connection with the first SIM card is the same as the time point when the calling SIM card establishes the call connection with the second SIM card, and the calling SIM card seamlessly switches the call from the first SIM card to the second SIM card.
Specifically, step 211 includes the following steps:
step 211a, the calling mobile switching center server sends a second call request to the calling gateway office mobile switching center server according to the call switching request, where the second call request includes the phone number of the second SIM card.
The calling gateway mobile switching center server is a gateway mobile switching center server (GMSC) corresponding to the calling SIM card.
Specifically, the calling mobile switching center server learns that the call switching request corresponds to the first SIM card and that the first SIM card has opened the automatic call switching service through the home location register, and acquires an operator corresponding to the second SIM card through a phone number of the second SIM card included in the call switching request.
Step 211b, the calling gateway mobile switching center server sends a call establishing command to the calling gateway media gateway, so that the calling gateway media gateway establishes connection with the calling media gateway.
Specifically, the media gateway of the calling gateway creates a state object of the calling gateway according to the call establishing command and sends information of the state object of the calling gateway to the mobile switching center server of the calling gateway. And the calling mobile switching center server sends the information of the calling state object to a calling gateway office mobile switching center server so that the calling gateway office mobile switching center server forwards the information of the calling state object to a calling gateway office media gateway. And the calling gateway mobile switching center server sends the information of the calling gateway state object to the calling mobile switching center server so that the calling mobile switching center server forwards the information of the calling gateway state object to the calling media gateway.
The setting mode of the calling gateway status object can be described with reference to the setting mode of the calling status object in step 202. The calling gateway state object corresponds to the calling gateway media gateway. The establishing connection between the calling gateway office media gateway and the calling media gateway comprises the following steps: the calling gateway office media gateway and the calling media gateway need to adopt the same real-time transmission protocol port number and the same voice compression algorithm for communication.
Step 211c, the calling gateway mobile switching center server sends a second call request to a second called gateway mobile switching center server corresponding to the second SIM card.
The second call request represents that the calling SIM card requests to establish a call connection with the second SIM card. The second called gateway mobile switching center server is a gateway mobile switching center server corresponding to the second SIM card.
Step 211d, the second called gateway office mobile switching center server sends a call establishment command to the second called gateway office media gateway, so that the second called gateway office media gateway establishes a connection with the calling gateway office media gateway.
Specifically, the second called gateway office media gateway creates a second called gateway office state object according to the call establishing command and sends information of the second called gateway office state object to the second called gateway office mobile switching center server. And the calling gateway mobile switching center server sends the information of the calling gateway state object to a second called gateway mobile switching center server, so that the second called gateway mobile switching center server forwards the information of the calling gateway state object to a second called gateway media gateway. And the second called gateway mobile switching center server sends the information of the second called gateway state object to the calling gateway mobile switching center server, so that the calling gateway mobile switching center server forwards the information of the second called gateway state object to the calling gateway media gateway.
The setting mode of the second called gateway status object can be described by referring to the setting mode of the calling status object in step 202. The second called gateway state object corresponds to the second called gateway media gateway. The establishing connection between the second called gateway media gateway and the calling gateway media gateway comprises the following steps: the second called gateway media gateway and the calling gateway media gateway need to adopt the same real-time transmission protocol port number and the same voice compression algorithm for communication.
And step 211e, the second called gateway mobile switching center server sends the second call request to the second called mobile center server corresponding to the second SIM card.
Step 211f, the second called mobile switching center server sends the second call request to the second SIM card, and sends a call establishment command to the second called media gateway, so that the second called media gateway establishes a connection with the second called gateway office media gateway.
Specifically, the second called media gateway creates a second called state object according to the call establishing command and sends information of the second called state object to the second mobile switching center server. The second called gateway mobile switching center server sends the information of the second called gateway state object to the second called mobile switching center server, so that the second called mobile switching center server forwards the information of the second called gateway state object to the second called media gateway. The second called mobile switching center server sends the information of the second called state object to the second called gateway office mobile switching center server, so that the second called gateway office mobile switching center server forwards the information of the second called state object to the second called gateway office media gateway.
The setting mode of the second called status object can be described by referring to the setting mode of the calling status object in step 202. The second called state object corresponds to a second called media gateway. The establishing of the connection between the second called media gateway and the second called gateway office media gateway comprises: the second called media gateway and the second called gateway office media gateway need to adopt the same real-time transmission protocol port number and the same voice compression algorithm for communication.
Step 211g, the calling mobile switching center server sends a connection release request to the first called mobile switching center server and switches the call to the second SIM card, where the connection release request is used for the calling media gateway to release the connection with the first called media gateway.
Specifically, the second SIM card accepts the second call request, the calling mobile switching center server sends a connection release request to the first called mobile switching center server, and the calling media gateway releases the connection with the first called media gateway. And the calling gateway office media gateway establishes connection with the calling media gateway, the second called gateway office media gateway establishes connection with the calling gateway office media gateway, and the second called media gateway establishes connection with the second called gateway office media gateway, so that the calling SIM of the calling user establishes communication with the second SIM card of the dual-card dual-standby terminal.
It should be noted that any state object described in the present embodiment may be understood as a non-empty context.
In the call switching method provided by this embodiment, when the dual-card dual-standby terminal determines that the signal intensity of the first SIM card in the called call state is smaller than the preset threshold and the network format of the first SIM card is not switchable, the calling mobile switching center server switches the call to the second SIM card according to the call switching request, and the dual-card dual-standby terminal can automatically switch to the call between the second SIM card and the calling SIM card without disconnecting the current call between the first SIM card and the calling SIM card, so that the call switching efficiency of the dual-card dual-standby terminal can be effectively improved, and further the user experience of the dual-card dual-standby terminal user is improved.
EXAMPLE III
Fig. 3 is a schematic structural diagram of a call switching system according to a third embodiment of the present invention, and as shown in fig. 3, the system includes: the dual-card dual-standby terminal comprises a dual-card dual-standby terminal 1, a first called mobile switching center server 2 and a calling mobile switching center server 3.
The dual-card dual-standby terminal 1 is used for sending a call switching request to a first called mobile switching center server 2 corresponding to a first SIM card in a called call state when the signal intensity of the first SIM card in the called call state is judged to be smaller than a preset threshold value and the network format of the first SIM card is not switchable, wherein the call switching request comprises a telephone number of a second SIM card to be switched. The first called mobile switching center server 2 is configured to send a call handover request to the calling mobile switching center server 3 corresponding to the calling SIM card. The calling mobile switching center server 3 is configured to switch the call to the second SIM card according to the call switching request.
The call switching system provided in the third embodiment is used to implement the call switching method provided in the first embodiment.
In the call switching system provided in this embodiment, the dual-card dual-standby terminal is configured to send a call switching request to the first called mobile switching center server when it is determined that the signal intensity of the first SIM card in the called call state is smaller than the preset threshold and the network type of the first SIM card is not switchable, the first called mobile switching center server is configured to send the call switching request to the calling mobile switching center server corresponding to the calling SIM card, and the calling mobile switching center server is configured to switch a call to the second SIM card according to the call switching request.
Example four
Fig. 4 is a schematic structural diagram of a call switching system according to a fourth embodiment of the present invention, and as shown in fig. 4, the system includes: the dual-card dual-standby terminal comprises a dual-card dual-standby terminal 1, a first called mobile switching center server 2 and a calling mobile switching center server 3.
The dual-card dual-standby terminal 1 is used for sending a call switching request to a first called mobile switching center server 2 corresponding to a first SIM card in a called call state when the signal intensity of the first SIM card in the called call state is judged to be smaller than a preset threshold value and the network format of the first SIM card is not switchable, wherein the call switching request comprises a telephone number of a second SIM card to be switched. The first called mobile switching center server 2 is configured to send a call handover request to the calling mobile switching center server 3 corresponding to the calling SIM card. The calling mobile switching center server 3 is configured to switch the call to the second SIM card according to the call switching request.
Further, the dual-card dual-standby terminal 1 is further configured to determine whether the signal intensity of the first SIM card in the called call state is smaller than a preset threshold, and if it is determined that the signal intensity of the first SIM card is smaller than the preset threshold, determine whether the network system of the first SIM card is switchable.
Further, the system further comprises: a calling media gateway 4 and a first called media gateway 5.
The calling mobile switching center server 3 is specifically configured to send a first call request to the first called mobile switching center server 2, send a call establishment command to the calling media gateway 4, send information of a calling state object to the first called mobile switching center server 2, and forward the information of the first called state object to the calling media gateway 4, so that the first called media gateway 5 establishes a connection with the calling media gateway 4. The calling media gateway 4 is configured to create information of a calling state object according to the call establishment command and send the information of the calling state object to the calling mobile switching center server 3. The first called mobile switching center server 2 is specifically configured to send a first call request to the first SIM card, send a call establishment command to the first called media gateway 5, forward the information of the calling state object to the first called media gateway 5, and send the information of the first called state object to the calling mobile switching center server 3. The first called media gateway 5 is configured to create a first called status object according to the call establishment command and send information of the first called status object to the first called mobile switching center server 2.
Further, the system further comprises: a calling gateway mobile switching center server 6, a second called gateway mobile switching center server 7, a second called mobile switching center server 8, a calling gateway media gateway 9, a second called gateway media gateway 10 and a second called media gateway 11.
The calling mobile switching center server 3 is further configured to send a second call request to the calling gateway office mobile switching center server 6 according to the call handover request, where the second call request includes a phone number of the second SIM card, send a connection release request to the first called mobile switching center server 2, and switch a call to the second SIM card, where the connection release request is used for releasing a connection between the calling media gateway 4 and the first called media gateway 5. The calling gateway mobile switching center server 6 is configured to send a call establishment command to the calling gateway media gateway 9, so that the calling gateway media gateway 9 establishes a connection with the calling media gateway 4, and send a second call request to the second called gateway mobile switching center server 7 corresponding to the second SIM card. The second called gateway office mobile switching center server 7 is configured to send a call establishment command to a second called gateway office media gateway 10, so that the second called gateway office media gateway 10 establishes a connection with the calling gateway office media gateway 9, and sends a second call request to a second called mobile center server 8 corresponding to the second SIM card. The second called mobile switching center server 8 is configured to send the second call request to a second SIM card, and send a call establishment command to a second called media gateway 11, so that the second called media gateway 11 establishes a connection with the second called gateway office media gateway 10.
Further, the calling gateway media gateway 9 is specifically configured to create a calling gateway status object according to the call establishment command and send information of the calling gateway status object to the calling gateway mobile switching center server 6. The calling mobile switching center server 3 is specifically configured to send the information of the calling state object to the calling gateway mobile switching center server 6, so that the calling gateway mobile switching center server 6 forwards the information of the calling state object to the calling gateway media gateway 9. The calling gateway mobile switching center server 6 is specifically configured to send information of the calling gateway state object to the calling mobile switching center server 1, so that the calling mobile switching center server 1 forwards the information of the calling gateway state object to the calling media gateway 4.
Further, the second called gateway office media gateway 10 is specifically configured to create a second called gateway office state object according to the call establishment command and send information of the second called gateway office state object to the second called gateway office mobile switching center server 7. The calling gateway mobile switching center server 6 is specifically configured to send information of a calling gateway state object to the second called gateway mobile switching center server 7, so that the second called gateway mobile switching center server 7 forwards the information of the calling gateway state object to the second called gateway media gateway 10. The second called gateway mobile switching center server 7 is specifically configured to send information of a second called gateway state object to the calling gateway mobile switching center server 6, so that the calling gateway mobile switching center server 6 forwards the information of the second called gateway state object to the calling gateway media gateway 9.
Further, the second called media gateway 11 is specifically configured to create a second called status object according to the call establishment command and send information of the second called status object to the second mobile switching center server 8. The second called gateway mobile switching center server 7 is specifically configured to send information of the second called gateway state object to the second called mobile switching center server 8, so that the second called mobile switching center server 8 forwards the information of the second called gateway state object to the second called media gateway 11. The second called mobile switching center server 8 is specifically configured to send information of the second called state object to the second called gateway office mobile switching center server 7, so that the second called gateway office mobile switching center server 7 forwards the information of the second called state object to the second called gateway office media gateway 10.
The call switching system provided in the fourth embodiment is used to implement the call switching method provided in the second embodiment.
In the call switching system provided in this embodiment, the dual-card dual-standby terminal is configured to send a call switching request to the first called mobile switching center server when it is determined that the signal intensity of the first SIM card in the called call state is smaller than the preset threshold and the network type of the first SIM card is not switchable, the first called mobile switching center server is configured to send the call switching request to the calling mobile switching center server corresponding to the calling SIM card, and the calling mobile switching center server is configured to switch a call to the second SIM card according to the call switching request.
It will be understood that the above embodiments are merely exemplary embodiments taken to illustrate the principles of the present invention, which is not limited thereto. It will be apparent to those skilled in the art that various modifications and improvements can be made without departing from the spirit and substance of the invention, and these modifications and improvements are also considered to be within the scope of the invention.