WO2010115379A1

WO2010115379A1 - Method and system for call establishment in process of handover access

Info

Publication number: WO2010115379A1
Application number: PCT/CN2010/071660
Authority: WO
Inventors: 曹舜; 王丽涛; 茅非
Original assignee: 中兴通讯股份有限公司
Priority date: 2009-04-09
Filing date: 2010-04-09
Publication date: 2010-10-14
Also published as: CN101860926A; CN101860926B

Abstract

The invention provides a method for call establishment in the process of handover access. When a mobile station (MS) implements the handover during a call, if the mobile switching center (MSC) judges after the handover, the MS and the called party thereof belong to a same base station controller (BSC), the MSC sends a message carrying the local call identifier to inform said BSC. Said BSC establishes the local switching for the MS and the called party thereof. Before the handover, said local call identifier has been allocated to the BSC which the MS and the called party thereof belong to. The invention further provides a system for call establishment in the process of handover access. The method of the invention establishes the local switching for the two parties of the call which after the handover belong to the same BSC, and directly transmits the user plane information of the two parties of the call without through the core network, thus the waste of transmission resources is reduced.

Description

Call establishment method and system in the process of cutting in

Technical field

The present invention relates to the field of mobile communications, and in particular to a call setup method and system in a hand-in process.

Background technique

In the existing Global System for Mobile Communications (GSM), the Mobile Switching Center (MSC) and the Base Station Controller (BSC) are used. A interface communicates (A port can be carried in Time Division Multiplexing (TDM), and can also be carried in IP. For the case where A port is carried in IP, we call it IPA), and mobile terminal (Mobile Station) The MS and the base station (BS) communicate with each other through the air interface Um interface. In addition, the BS and the BSC are connected through the Abis interface.

The MS may switch during the call, including BSC internal switching and BSC external cutting. Among them, the MS may switch between BTSs, small areas, and channels under one BSC during the call, which we call BSC internal handover, referred to as internal handover. The MS may also switch from the coverage of one BSC to the coverage of another BSC during a call, which we call BSC external hand-in.

The internal switching process of GSM, the process when IPA is shown in Figure 1. The external splicing process of GSM BSC, as shown in Figure 2, is used for users to cut from one BSC to another. Currently in GSM, during the chaining process, each call is assigned a subscriber identity during the assignment of port A, whether it is a TDM call or an IP call.

Currently, in the internal handover process of GSM, a user plane path from the BSC to the Media Gateway (MGW) is established, and the user planes of both parties of the call are connected through the MGW to the user plane of the calling party. In the external BSC handover process of GSM, the user plane path from the BSC to the MGW will be established, and the user planes of both parties of the call will be connected through the MGW to the user plane path of the BSC where the calling party is located. During the internal handover process, when both parties are in the same BSC, and when the externally-cut MS is in the same BSC after the handover, the BSC first transmits the user plane to the MGW, and the MGW then The case where the user plane is transmitted back to the original BSC, as shown in FIG. 3, causes waste of transmission resources.

Summary of the invention

The invention provides a call establishment method and system in the process of cutting in, which reduces waste of transmission resources. In order to solve the above problem, the present invention provides a call setup method in a hand-in process. When a mobile terminal performs handover during a call, the mobile switching center determines whether the mobile terminal and its calling party belong to the same base station controller after the handover. Sending a message carrying the local call identifier to the base station controller, the base station controller establishing a local exchange for the mobile terminal and its calling party, the local call identifier being assigned to the mobile terminal and the Call the base station controller where the other party is located.

The method may further include: when the base station controller notifies the mobile terminal that the mobile terminal and the calling party belong to the same base station controller, the base station controller further determines whether the local exchange can be established, and sends a local exchange when determining that the local exchange can be established. The mobile switching center can establish information to the mobile switching center; after receiving the local exchange configurable information, the mobile switching center selects the opportunity to send a local exchange establishment command to the base station controller, and the base station controller is the mobile terminal after receiving the local exchange establishment command. Establishing a local exchange with the calling party; wherein, the step of establishing a local exchange for the mobile terminal and its calling party is: establishing a local switched internal user plane link for the mobile terminal and its calling party.

The foregoing method may further have the following feature: the handover is an internal handover of the base station controller, and the method further includes: before the handover, the mobile switching center receives the internal handover request message; and the message carrying the local call identifier includes an internal handover command, where The internal handover command carries the local call identifier;

The local exchange configurable information includes: a handover complete message, where the handover complete message carries a local exchange to establish an identifier;

The mobile switching center selects the opportunity to send the local exchange after receiving the local exchange configurable information. The step of establishing a command to the base station controller comprises: after receiving the handover complete message with the local exchange establishable identity, the mobile switching center sends a local exchange setup command to the base station controller.

The foregoing method may further have the following feature: the handover is external to the base station controller; the message carrying the local call identifier includes: a handover request message, where the handover request message carries a local call identifier;

The local exchange establishable information includes: a handover completion message, where the handover completion message carries a local exchange to establish an identifier;

The step of the mobile switching center selecting a timing to send a local exchange setup command to the base station controller after receiving the local exchange configurable information comprises: after the mobile switching center receives the handover completion message with the local exchange identifiable identifier Send a local exchange setup command to the base station controller.

The method may further include: after the base station controller establishes a local exchange internal user plane link, and further sends a local exchange completion message to the mobile switching center, after the mobile switching center receives the local exchange completion message, The user plane path of the mobile terminal and its calling party from the base station controller to the mobile switching center.

The foregoing method may further have the following feature: the base station controller determines whether a local exchange can be established according to the following manner: the base station controller searches, according to the local call identifier, whether there is a call that matches the local call identifier, and if yes, Can establish local exchanges;

The local call identifier is a unique serial number, or the local call identifier is a call identifier Call ID or a circuit identifier CIC of the calling party.

The method may further include: before transmitting the handover complete message to the mobile switching center: the base station controller assigns the mobile terminal with the same channel type and voice version as the calling party, or the base station controls The channel matches the channel type and voice version of the mobile terminal and its calling party by TC conversion.

The method may further include: before transmitting the handover completion message to the mobile switching center: the base station controller allocates, to the mobile terminal, a channel type and a voice version supported by the mobile terminal and its calling party, and The calling party initiates an internal handover to switch to the channel type and voice version; or

The base station controller allocates the same channel type and the same as the calling party to the mobile terminal Voice version; or

The base station controller matches the channel type and the voice version of the mobile terminal and its calling party by TC conversion.

The present invention also provides a mobile switching center that supports call setup in a hand-in process. The mobile switching center is configured to: when the mobile terminal performs handover during a call, determine whether the mobile terminal and its calling party belong to the same base station after the handover The controller, if yes, transmitting a message carrying the local call identifier to the base station controller, wherein the local call identifier has been assigned to the mobile terminal and the base station controller where the caller is located before the handover;

After receiving the local exchange configurable information sent by the base station controller, the timing is selected to send a local exchange setup command to the base station controller.

The present invention further provides a base station controller supporting call setup in a hand-in process, wherein the base station controller is configured to determine whether a local exchange can be established after the mobile exchange center knows that the mobile terminal and its calling party belong to the same base station controller. When it is determined that a local exchange can be established, sending a local exchange can establish information to the mobile switching center;

A local switched internal user plane link is established for the mobile terminal and its calling party upon receipt of the local exchange setup command sent by the mobile switching center.

The base station controller may further have the following feature, the base station controller is configured to determine whether a local exchange can be established by: the base station controller searching, according to the local call identifier, whether there is a call matching the local call identifier If yes, it is determined that the local exchange can be established; wherein the local call identifier is a unique serial number, or the local call identifier is a call identifier Call ID or a circuit identifier CIC of the calling party.

The present invention also provides a call setup system in a hand-in process, the system comprising a base station controller and a mobile switching center, wherein

The mobile switching center is configured to determine, when the mobile terminal performs handover during a call, whether the mobile terminal and its calling party belong to the same base station controller after the handover, and if yes, send a message carrying the local call identifier to notify the base station The controller, the local call identifier is assigned to the mobile terminal and a base station controller where the calling party is located before the handover;

The base station controller is configured to notify the mobile terminal after the handover is received by the mobile switching center When the calling party belongs to the same base station controller, a local exchange is established for the mobile terminal and its calling party.

The above system may also have the following features, the base station controller is further configured to determine whether the local exchange can be established when the mobile switching center informs the handover that the mobile terminal and the calling party belong to the same base station controller, Sending a local exchange when establishing a local exchange can establish information to the mobile switching center;

The mobile switching center is further configured to, after receiving the local exchange configurable information sent by the base station controller, select a timing to send a local exchange establishment command to the base station controller;

The base station controller is arranged to establish a local exchange for the terminal and its calling party by: establishing a local switched internal user plane link for the mobile terminal and its calling party after receiving the local exchange setup command.

The above system may also have the following features: the base station controller is configured to determine whether a local exchange can be established by: the base station controller searching for a call matching the local call identifier according to the local call identifier, if If yes, it is judged that local exchange can be established;

In the handover process, the local exchange is established for both parties of the call that belong to the same BSC after the handover, and the user plane information of both parties of the call is directly transmitted through the core network, thereby reducing the waste of transmission resources.

BRIEF abstract

1 is an internal switching process in the prior art;

2 is a BSC external cutting process in the prior art;

3 is a schematic diagram of an access network and a core network transmitting a user plane in an internal handover or an external handover in the prior art;

4 is a schematic diagram of a user plane transmitted by an access network and a core network after performing a local switching function;

Figure 5 is an optimization of the internal handover command and the handover completion message during the internal handover process. Signaling flow chart;

6 is a flow chart in which the MSC informs the BSC to make a local call by means of a local call identifier during the internal handover process, and the BSC determines that a local exchange can be established and returns a handover to the MSC to carry the local exchange to establish an identifier;

FIG. 7 is a flow chart of the MSC establishing a local call setup command to the BSC after the local exchange can establish an identity by the local exchange, and the BSC establishes a local exchange; FIG. 8 is a process in which the MSC passes the internal handover process. The local call identifier informs the BSC of the local call that the two parties talk to each other, and the BSC determines that the TC can be used to establish a local exchange and the MSC is returned to the handover completion to carry the flow chart of the local exchange establishable identity;

FIG. 9 is a signaling flow chart for optimizing the hand-in request message during the external handover process of the BSC; FIG. 10 is a local call in which the MSC informs the BSC to each other through the local call identifier during the external handover process of the BSC, and the BSC determines that the local call can be established. Exchanging and returning to the MSC a request for a response to carry a local exchange to establish an identity;

FIG. 11 is a flow chart of the BSC establishing a local exchange after the local exchange can establish an identity by the local exchange to learn that the local call can be established, and then initiate a local call setup command to the BSC;

12 is a local call in which the MSC informs the BSC to talk to each other through the local call identifier during the external handover process of the BSC. After the BSC initiates an internal handover to the calling party, the BSC determines that the local exchange can be established and the MSC returns a request for the handover. The local exchange can be established. Flow chart of the identification;

FIG. 13 is a local call in which the MSC informs the BSC to talk to each other through the local call identifier during the external handover process of the BSC, and the BSC determines that the callable party initiates an internal handover judgment to establish a local exchange and returns a handover request response to the MSC, where the local exchange can establish an identity. Flow chart

14 is a flow chart of the BSC initiating a local call setup command to the BSC after the local exchange can establish an identity to learn that the local call can be established by the local exchange, and the BSC establishes a local call by initiating internal handover to the caller;

15 is a flow chart in which the MSC informs the BSC to talk to each other through the local call identifier during the external handover process of the BSC, and the BSC determines that the TC can be used to establish a local exchange and return a handover request response to the MSC, which carries a flow chart of the local exchange establishable identity. Preferred embodiment of the invention

The preferred embodiments of the present invention are described with reference to the accompanying drawings, and the preferred embodiments of the present invention are intended to illustrate and explain the invention.

The central idea of the present invention is that for a mobile terminal that performs handover (including internal handover and external handover) during a call, if the mobile terminal and its calling counterpart are in the same BSC after handover, local establishment is established for the mobile terminal and its calling party. Switching, realizing the function of local call local exchange, as shown in FIG. 4, for the call under the same BSC, the user plane information of both parties of the call is directly transmitted through the core network, thereby reducing the waste of transmission resources.

In the present invention, in addition to the existing protocol specification function, the MSC needs to identify the calling parties when the call is established, to indicate that this is a pair of calls, which we call a local call identifier, and the local call identifier can use a unique water flow. The number indicates that it can also be marked by the Calling Identifier or CIC (Chip Identifier) of the calling party. The former can be uniformly allocated when the call is established; the latter's Call Identifier, which is the original Call ID (for The flag bears the A port call on the IP Transport, and the latter's CIC (Circuit Identity Codec), which is the original circuit identifier (used to mark the A port call carried on the TDM Transport). When receiving the Internal Handover Required message or sending a Handover Request message, the MSC determines whether the call is a local call with the calling party. The determining method belongs to the prior art, and if so, the internal switching command ( The Internal Handover Command message or the hand-in request message is used to identify an identifier for identifying a local call, the identifier being used to inform the BSC that the call is a local call with another call under the BSC.

The following two cases are explained, internal switching and external cutting.

(1) Internal switching

The present invention provides a method for processing call information, which is specifically as follows.

When receiving the Internal Handover Required message, the MSC needs to determine whether the MS is in the same BSC as the calling party. The judgment algorithm belongs to the prior art. If it is found to be a local call, it is sent to the MSC. BSC internal switching command (Internal Handover Command) The local call identifier used to identify the local call, which is used to inform the BSC that the call is a local call with another call under the BSC.

If the unique serial number is used as the local call identifier, in the call setup process (refer to the call setup before the handover), the local call identifier needs to be sent to the BSC where the calling party is located, so that the BSC can perform internal handover when switching. The local call identifier in the command finds the calling party. If Call Identify is used as the local call identifier, the local call identifier may or may not be carried when the call is established. When switching, the BSC finds the call partner through the local call identifier in the internal handover command. The local call identifier is assigned to the base station controller of the calling party of the mobile terminal before the handover.

The BSC learns that the call is a local call with another call through the local call identifier in the internal handover command. The BSC searches for the other party in the call according to the local call identifier, and determines whether the local exchange can be established. If there is a call matching the local call identifier, the local exchange can be established. If the local exchange can be established, the handover to the MSC is completed ( The Handover Complete message carries the local exchange to establish information (such as carrying a local exchange to establish an identity).

After receiving the handover complete message with the local exchange identifiable identity, the MSC considers that the BSC can establish a local exchange for the pair of calls, and the MSC can send a local exchange setup command to the BSC.

After receiving the local exchange setup command, the BSC establishes a local exchange internal user plane link and returns a local exchange completion message to the MSC.

After receiving the local exchange completion message, the MSC considers that the local call completes the preparation of the local exchange, and can use the local exchange to remove the user plane path from the BSC to the MSC.

Embodiment 1

According to an embodiment of the present invention, a method is provided. When an internal handover is performed, both parties of the call are served by the same BSC. During the internal handover, the MSC informs the BSC that the MS and its calling party are both by the BSC. Provide services. This process is an optimization of the existing internal switching process.

As shown in Figure 6, 7, includes:

Step 601: The MSC receives an internal handover request message.

Step 602, the MSC determines whether the call is a local call, if it is found to be a local call, step 603 is performed, otherwise, step 604 is performed; Step 603, the MSC sends an internal handover command to the BSC, the internal handover command carries the local call identifier, step 605;

In the process of establishing the calling and called calls, the MSC determines whether the call is a local call. If the local call is found, the MSC uses the local call identifier to identify the local call identifier, which is a unique serial number. Assignment at call setup (the service BSC that has been sent to both parties to the call in the assignment message at the time of call setup).

Step 604, the MSC sends an internal handover command to the BSC, the internal handover command does not carry the local call identifier, step 605;

Step 605, after receiving the internal switching command, the BSC determines whether there is a local call identifier in the internal switching command, if yes, step 606 is performed, otherwise, step 608 is performed;

Step 606: The BSC searches for a call that matches the local call identifier carried in the internal handover command for all the calls. If yes, go to step 607. Otherwise, go to step 608. Step 607: The BSC considers that the call and the internally switched call are Two local calls to each other. When the BSC allocates a channel type and a voice version for an internally switched call, it allocates the same channel type and voice version as the channel type and voice version of the calling party to facilitate local exchange. The BSC carries the local exchange identifiable identifier in the handover complete message replied to the MSC, and performs step 701;

Step 608: The BSC considers that the call is not a local call, and the handover completion message sent to the MSC does not carry the local exchange to establish the identifier, and step 701 is performed. Step 701: The MSC receives the handover complete message.

Step 702, the MSC determines whether there is a local exchange identifiable identifier in the handover complete message, if yes, step 703 is performed, otherwise, step 706 is performed;

Step 703: The MSC considers that the BSC can establish a local exchange for the pair of calls, and the MSC can send a local exchange setup command to the BSC.

Step 704: After receiving the local exchange establishment command, the BSC establishes a local exchange internal user plane link, and returns a local exchange completion message to the MSC.

Step 705: After receiving the local exchange completion message, the MSC considers that the local call is ready for local exchange, and may use local exchange to remove the user from the BSC to the MSC. Face passage, end.

Step 706, executing the existing process, and ending.

Embodiment 2

According to an embodiment of the present invention, a method is further provided. When a call is internally switched, both parties of the call are served by the same BSC. During the internal handover, the MSC informs the BSC that the MS and its calling party are both The services provided by the BSC. This process is an optimization of the existing internal switching process.

Specifically, in the process of establishing the calling and called calls, the MSC determines whether the call is a local call, and if it is found to be a local call, the local call identifier is used for identification, and the local call identifier is a Call Identifier of the calling party. The Call Identifier here is the original Call ID (used to mark the A port call carried on the IP Transport).

If the two parties are in a local call after the internal handover is completed, the MSC carries the local call identifier in the internal handover command sent to the BSC.

After receiving the internal handover command, the BSC searches for all the calls for the call that matches the local call identifier carried in the call. If yes, the BSC considers that the call and the internally switched call are two local calls for mutual call. When assigning a channel type and a voice version to an internally switched call, the BSC allocates the same channel type and voice version as the channel type and voice version of the calling party to facilitate local exchange. The BSC carries a local exchange establishable identity in the handover complete message replied to the MSC.

The signaling flow chart is shown in Figure 5, and the implementation flow chart is shown in Figure 6 and Figure 7. Embodiment 3

According to an embodiment of the present invention, a method is further provided for the BSC that the internal handover command is used to learn that the internal handover user and the calling party belong to the local call, but cannot directly allocate the same channel type and voice version as the original call. Establish local exchange. If the BSC has internal TC resources, the BSC performs voice conversion through the internal TC to achieve the internal handover condition. This process is an optimization of the existing internal intersection process.

Specifically, the BSC learns that the internally switched call forms a local call with an existing call in the BSC by using the method in the first embodiment or the second embodiment, but cannot allocate the same channel type and the same as the calling party user to the internally switched user. Voice version. However, the BSC has available TC resources, and the channel type and voice version of both parties of the call can be matched by TC conversion. The BSC carries the local exchange establishable identity in the handover complete message replied to the MSC.

After receiving the local exchange setup command, the BSC establishes a local switched internal user plane link (via TC conversion) and returns the local exchange completion message to the MSC. The TC conversion starts after the user plane is established, and ends when the user plane is removed.

The signaling flow chart is shown in Figure 5, and the implementation flow chart is shown in Figure 8 and Figure 7.

(2) External cutting

The present invention further provides a method for processing call information. Specifically, the MSC needs to determine whether the MS is in a local call with the calling party after the MS successfully cuts into the BSC before sending the Handover Request message. The local call identifier is used to notify the BSC of the call, and the local call identifier is used to identify the local call, and the local call identifier is added to the cut request message sent to the BSC. Another call under the BSC is a local call.

Wherein, if the unique serial number is used as the local call identifier, during the call setup process (refer to Before the handover is established, the MSC needs to send the local call identifier to the BSC where the calling party is located, so that when the handover is performed, the BSC finds the calling party by the local call identifier in the hand-in request message. If CIC or Call Identify is used as the local call identity, the local call identity may be sent or not sent to the calling and called BSC when the call is established. When switching, the BSC finds the calling party by the local call identifier in the hand-in request message.

The BSC learns that the call is a local call with another call by cutting in the local call identifier in the request message. The BSC internally searches for the calling party according to the local call identifier, and determines whether the local exchange can be established. If there is a call matching the local call identifier, the local exchange can be established. If the local exchange can be established, the handover to the MSC is completed ( The Handover Complete message carries the local exchange to establish information (such as carrying a local exchange to establish an identity).

After receiving the hand-in completion message with the local exchange identifiable identity, the MSC considers that the BSC can establish a local exchange for the pair of calls, and the MSC can send a local exchange setup command to the BSC.

Embodiment 4

According to an embodiment of the present invention, a method is provided for the MSC to inform the BSC that the MS and its calling party are both in the external hand-in process when the calling party cuts in from outside the BSC and the calling party is served by the same BSC. It is a service provided by the BSC. This process is an optimization of the existing BSC external hand-in process.

Specifically, in the process of establishing the calling and called calls, the MSC identifies the call by using a local call identifier, which is a unique serial number, which is allocated when the call is established (allocation message at the time of call setup) The service has been sent to both parties (BSC).

If the two parties are local calls after the completion of the handover, the MSC carries the local call identifier in the hand-in request message sent to the BSC.

After receiving the hand-in request message, the BSC searches for all calls to see if it exists and carries it. The local call identifies the matching call. If it exists, the BSC considers that the call is external to the BSC and the two calls are called. When assigning a channel type and a voice version to an externally handed-in call, the BSC allocates the same channel type and voice version as the channel type and voice version of the calling party to facilitate local exchange. The BSC carries the local exchange to establish an identity in the hand-in completion message replied to the MSC.

After receiving the local exchange establishment command, the BSC establishes a local exchange internal user plane link and returns a local exchange completion message to the MSC.

The signaling flow chart is shown in Figure 9, and the implementation flow chart is shown in Figure 10 and Figure 11.

Embodiment 5

According to an embodiment of the present invention, a method is further provided for the MSC to inform the BSC that the MS and its calling party are both in the external hand-in process when the calling party is cut in from outside the BSC and both parties are calling through the same BSC. It is a service provided by the BSC. This process is an optimization of the existing BSC external hand-in process.

Specifically, in the process of establishing the calling and called calls, the MSC identifies the call by using the local call identifier, where the local call identifier can be the CIC or Call Identifier of the calling party, where CIC (Circuit Identity Codec) The original circuit identifier (used to mark the A port call carried on the TDM Transport), here the Call Identifier, which is the original Call ID (used to mark the A port call carried on the IP Transport).

After receiving the hand-in request message, the BSC searches for all the calls for the call that matches the local call identifier carried in the call. If there is a call, the BSC considers that the call and the call that is externally cut by the BSC are two local calls that call each other. BSC assigns channel type and language to externally handed-in calls In the sound version, the same channel type and voice version as the calling party's channel type and voice version are assigned to facilitate local exchange. The BSC carries the local exchange to establish an identity in the hand-in completion message replied to the MSC.

Embodiment 6

According to an embodiment of the present invention, a method is further provided for the BSC to learn, by the hand-in request message, that the externally handed-in user and the calling party belong to the local call, but cannot directly allocate the same channel type and voice version as the original call. A local exchange is established, at which time the BSC achieves the condition of internal handover by internally switching the original call. This process is an optimization of the existing BSC external hand-in process and channel allocation algorithm.

Specifically, the BSC learns that the externally handed-in call forms a local call with an existing call in the BSC by using the method in the fourth embodiment or the fifth embodiment, but the externally cut-in user cannot be assigned the same channel type as the existing user. Voice version, but there are other channel types and voice versions supported by the MSs of both parties. The BSC allocates the channel type and the voice version supported by both parties to the externally-cut user, and initiates an internal handover to the existing user (that is, the calling party of the externally-cut user) to switch to the channel type and the voice version, thereby Establish a local exchange. The BSC carries the local exchange to establish an identity in the hand-in completion message replied to the MSC. The subsequent steps are the same as those in the fourth and fifth examples.

The signaling flow chart is shown in Figure 9, and the implementation flow chart is shown in Figure 12 and Figure 11.

Example 7 According to an embodiment of the present invention, a method is further provided for the BSC to learn, by the hand-in request message, that the externally handed-in user and the calling party belong to the local call, but cannot directly allocate the same channel type and voice version as the original call. The local exchange is established. At this time, the BSC considers that the local call can be established and carries the local exchange establishable identifier in the handover completion message sent to the MSC, and completes the local exchange through internal handover after receiving the local exchange establishment command of the MSC. This process is an optimization of the existing BSC external hand-in process and channel allocation algorithm.

Specifically, the BSC learns that the externally handed-in call forms a local call with an existing call in the BSC by using the method in the fourth embodiment or the fifth embodiment, but the externally cut-in user cannot be assigned the same channel type as the existing user. Voice version, but there are other channel types and voice versions supported by the MSs of both parties. The BSC allocates a channel type and a voice version supported by both parties to the externally handed-in user, and the BSC carries the local exchange identifiable identifier in the hand-in completion message replied to the MSC.

After receiving the local exchange setup command, the BSC initiates an internal handover to the original call (i.e., the caller of the externally handed-in user) to switch to the channel type and voice version used by the external hand-in user, thereby establishing a local exchange. The BSC then establishes a local switched internal user plane link for the externally handed in user and its calling party, and returns the local exchange completion message to the MSC.

The signaling flow chart is shown in Figure 9, and the implementation flow chart is shown in Figure 13 and Figure 14.

Example eight

According to an embodiment of the present invention, a method is further provided for the BSC to learn that the externally handed-in user and the calling party belong to the local call through the hand-in request message, but cannot directly allocate the same channel type and voice version as the original call. Establish local exchange. If the BSC has internal TC resources, the BSC performs voice conversion through the internal TC to achieve the internal handover condition. This process is an optimization of the existing BSC external hand-in process. Specifically, the BSC learns that the externally handed-in call forms a local call with an existing call in the BSC by using the method in the fourth embodiment or the fifth embodiment, but the externally cut-in user cannot be assigned the same channel type as the existing user. Voice version. However, the BSC has available TC resources, and the channel type and voice version of both parties of the call can be matched by TC conversion. The BSC carries the local exchange to establish an identity in the hand-in completion message replied to the MSC.

After receiving the local exchange setup command, the BSC establishes a local switched internal user plane link (via TC conversion) and returns the local exchange completion message to the MSC.

The signaling flow chart is shown in Figure 9, and the implementation flow chart is shown in Figure 15 and Figure 11.

Example nine

The present invention also provides a base station controller supporting call setup during a hand-in process, wherein the base station controller is configured to determine whether a local exchange can be established after the mobile exchange center knows that the mobile terminal and its calling party belong to the same base station controller. Sending a local exchange can establish information to the mobile switching center when it is determined that a local exchange can be established;

The above base station controller is configured to determine whether a local exchange can be established by: The base station controller searches for a call that matches the local call identifier according to the local call identifier, and if yes, determines that a local exchange can be established; wherein the local call identifier is a unique serial number, or the local The call identifier is the calling party's identification Call ID or CIC.

The present invention also provides a call setup system in a hand-in process, including a base station controller and a mobile switching center, where

The mobile switching center is configured to notify the base station controller by sending a message carrying a local call identifier when the mobile terminal and the calling party belong to the same base station controller after the mobile terminal performs the handover during the call. The local call identifier is assigned to the mobile terminal and the base station controller where the caller is located before the handover; and is further configured to send the local exchange setup after receiving the local exchange configurable information sent by the base station controller. Commanding to the base station controller; the base station controller is configured to establish a local exchange for the mobile terminal and its calling party when the mobile switching center informs the handover that the mobile terminal and its calling party belong to the same base station controller. Further, when it is determined that the mobile terminal and the calling party thereof belong to the same base station controller after receiving the handover, the mobile terminal determines whether the local exchange can be established, and sends a local exchange to establish information when determining that the local exchange can be established. The mobile switching center establishes a local exchange for the mobile terminal and its calling party after receiving the local exchange establishment command.

Determining, by the base station identifier, whether there is a call matching the local call identifier according to the local call identifier, and if yes, establishing a local exchange;

The local call identifier is a unique serial number, or the local call identifier is a call identity Call ID or circuit identifier CIC of the calling party.

It should be noted that, if not conflicting, the various embodiments of the present invention and the various features of the embodiments may be combined with each other, and are all within the scope of the present invention. Additionally, the steps illustrated in the flowchart of the figures may be performed in a computer system, such as a set of computer-executable instructions, and, although the logical order is illustrated in the flowchart, in some cases, may be different The steps shown or described are performed in the order herein.

Industrial applicability

Compared with the prior art, the present invention is a call double belonging to the same BSC after handover in the handover process. The local exchange is established, and the user plane information of both parties of the call is directly transmitted through the core network, thereby reducing the waste of transmission resources.

Claims

Claim

A method for establishing a call during a handover process, comprising: when a mobile terminal performs handover during a call, the mobile switching center determines whether the mobile terminal and its calling party belong to the same base station controller after the handover, and if yes, sends the bearer The local call identifier informs the base station controller that the base station controller establishes a local exchange for the mobile terminal and its calling party, and the local call identifier is assigned to the mobile terminal and its calling party before the handover. Base station controller.

2. The method of claim 1 further comprising:

The base station controller determines, by the mobile switching center, that the mobile terminal and its calling party belong to the same base station controller, whether it can establish a local exchange, and when determining that a local exchange can be established, sending a local exchange can establish information to the mobile Exchange center;

After receiving the local exchange configurable information, the mobile switching center selects a time to send a local exchange establishment command to the base station controller, and the base station controller is the mobile terminal and the mobile terminal after receiving the local exchange establishment command. The calling party establishes a local exchange; wherein, the step of establishing a local exchange for the mobile terminal and its calling party is: establishing a local switched internal user plane link for the mobile terminal and its calling party.

The method of claim 2, wherein the handover is an internal handover of the base station controller, and the method further includes: the mobile switching center receiving an internal handover request message before performing the handover;

The message carrying the local call identifier includes an internal handover command, where the internal handover command carries a local call identifier;

The local exchange configurable information includes a handover complete message, where the handover complete message carries a local exchange to establish an identifier;

The step of the mobile switching center selecting a timing to send a local exchange setup command to the base station controller after receiving the local exchange configurable information comprises: after the mobile switching center receives the handover complete message with the local exchange identifiable identifier Sending a local exchange setup command to the base station controller.

The method of claim 2, wherein the handover is an external handover of the base station controller, and the message carrying the local call identifier includes a handover request message, where the handover request message carries a local call identifier; The local exchange configurable information includes a handover completion message, where the handover completion message carries a local exchange to establish an identifier;

5. The method of claim 2, 3 or 4, after the step of establishing a local exchange internal user plane link for the mobile terminal and its calling party, further comprising: the base station controller transmitting a local exchange complete message To the mobile switching center, after receiving the local exchange complete message, the mobile switching center tears down the user plane path of the mobile terminal and its calling party from the base station controller to the mobile switching center.

6. The method of claim 2, 3 or 4, wherein

The step of determining whether the local exchange can be established includes: determining, by the base station controller, whether there is a call matching the local call identifier according to the local call identifier, and if yes, determining that a local exchange can be established;

7. The method of claim 3, further comprising: before transmitting a handover complete message to the mobile switching center: the base station controller assigning the mobile terminal the same channel type and voice as the calling party Version; or

8. The method of claim 4, further comprising: prior to transmitting a hand-in completion message to the mobile switching center: the base station controller assigning to the mobile terminal a channel supported by the mobile terminal and its calling party Type and voice version, and initiate an internal switch to the calling party to switch to the channel type and voice version; or

The base station controller assigns the mobile terminal with the same channel type and voice version as the calling party; or

The base station controller converts the channel type of the mobile terminal and its calling party by TC conversion Matches the voice version.

9. A mobile switching center supporting call setup during a hand-in process, the mobile switching center being configured to: determine, when the mobile terminal performs handover during a call, whether the mobile terminal and its calling party belong to the same base station controller after the handover And if yes, sending a message carrying the local call identifier to the base station controller, wherein the local call identifier has been assigned to the mobile terminal and the base station controller where the call partner is located before the handover;

10. A base station controller supporting call setup during a hand-in process, wherein the base station controller is configured to determine whether a local exchange can be established after the mobile exchange center knows that the mobile terminal and its calling party belong to the same base station controller. When it is determined that a local exchange can be established, sending a local exchange can establish information to the mobile switching center;

A local switched internal user plane link is established for the mobile terminal and its calling party upon receipt of a local exchange setup command sent by the mobile switching center.

The base station controller according to claim 10, wherein the base station controller is configured to determine whether a local exchange can be established by: the base station controller searching for presence and presence according to the local call identifier The call matching the call identifier, if yes, determines that a local exchange can be established;

12. A call setup system in a hand-in process, comprising a base station controller and a mobile switching center, wherein

The base station controller is configured to establish a local exchange for the mobile terminal and its calling party when the mobile terminal and its calling party belong to the same base station controller after the switching is known by the mobile switching center.

13. The system of claim 12, wherein

The base station controller is further configured to determine whether the local exchange can be established when the mobile terminal and the call partner belong to the same base station controller after the handover is known by the mobile switching center, and send the local exchange establishable information when determining that the local exchange can be established. To the mobile switching center;

The system according to claim 13, wherein the base station controller is configured to determine whether a local exchange can be established by: the base station controller searching for a presence or absence of the local call identifier according to the local call identifier The matching call, if it exists, determines that a local exchange can be established;