KR20120046382A - System and method for serving a voice call in a mobile communicaiton system - Google Patents

Abstract

PURPOSE: A voice call service system in a mobile communication system and method thereof are provided to register a terminal location in an HSS(Home Subscriber Server)(70) by changing the location of a terminal which receives a paging request message. CONSTITUTION: A GMSC(Gateway Mobile Switching Center)(60) receives a voice call received by a terminal(10) which provides a CS(Circuit Switching) fallback function. An HSS provides routing information for the voice call to the GMSC according to the request of the GMSC. An old MSC(Mobile Switching Center) transmits a paging request message according to a path establishment request message of the GMSC. When location registration information deletion is requested by the HSS before the reception of a paging request message, the MSC requests a call re-establishment to the GMSC. A new MSC(55) requests location registration update to the HSS.

Description

System and method for voice call service in mobile communication system {SYSTEM AND METHOD FOR SERVING A VOICE CALL IN A MOBILE COMMUNICAITON SYSTEM}

The present invention relates to a voice call service system and method in a mobile communication system, and more particularly, to a voice call service system in a mobile communication system that can prevent a voice call that is received by a CS fallback subscriber located at an exchange boundary area from failing. It is about a method.

The 3rd Generation Partnership Project (3GPP), a standardization organization that sets standards for systems and terminals, such as Global System for Mobile Telecomunication (GSM), Wideband Code Division Multiple Access (WCDMA), and Long Term Evolution (LTE) SAE (System Architecture Evolution) standardization, a standardization item for standardization, continues.

The next-generation core network is called Enhanced Packet Core (EPC), which is based on ALL-IP, and consists of pure packet switching network, breaking away from the hybrid network structure in which the existing circuit switching and packet switching networks coexisted.

However, the basic call (Voice Call), a basic service provided by the mobile communication network, has been provided using circuit switching networks in GSM and WCDMA networks, but the new access network called LTE is basically a packet switching network called EPC. Because of the consolidation, the discussion of how to provide the base currency in the network continues within 3GPP, and basically two methods are defined in the standard:

The first method is to provide a voice call through VoIP using IP Multimedia Subsystem (IMS). In this case, IMS should be additionally implemented in addition to the LTE access network and EPC.

The second method is to recycle the circuit switching network possessed by WCDMA, GSM, and CDMA. If the terminal registered to the LTE network attempts a basic call, the basic call service using the existing network (3G circuit switching network) is used. How to provide. In the early stage of LTE network introduction, there will be a circuit switching network that has already invested a lot of money. Therefore, a scheme for fully utilizing the existing circuit switching network can be considered, and the scheme is a circuit switched fallback. It can be said.

1 is a process for explaining a voice call service method in a mobile communication system according to the prior art.

First, when an incoming voice call comes to the terminal 1 providing the CS fallback function to the gateway MSC (GMSC) 9 (S10), the GMSC 9 receives an incoming voice call to the home subscriber server (HSS) 7 Request routing information for and receive a response message (S12).

The HSS 7 stores an MME (Mobility Management Entity) number and an MSC number registered by the terminal 1 when the terminal 1 registers a location.

Thereafter, the GMSC 9 transmits an IAM (Initial Address Message) requesting the establishment of a route to the destination MSC 5 identified by the routing information obtained through the above-described process S12 (S14).

After receiving the IAM from the GMSC 9 through the process S14, the incoming MSC 5 recognizes that the terminal 1 provides the CS callback function, and then paging the terminal 1 through the MME 3. The request message is transmitted (S16).

The terminal 1 receiving the paging request message through the above process S16 transmits a paging response message to the terminating MSC 5 so that a call is established between the terminating MSC 5 and the terminal 1 (S18). .

The receiving MSC 5 receiving the paging response message from the terminal 1 through the process S18 transmits an ACM indicating that it has received all the information necessary for call setup to the GMSC 9 (S20).

If the terminal 1, which has received the paging request message through the above-described process S16, is located in the boundary area of the exchange, before transmitting the paging response message to the destination MSC 5, the location area of the region where the terminal 1 is located. If the (Location Area) is changed, the terminal 1 transmits a paging response message to the destination MSC 5 after re-enrolling the location to the HSS 7.

As described above, when the terminal receiving the paging request message is located in the boundary area of the exchange, when the location area of the region where the terminal is located is changed, the terminal performs the registration again through the new MSC and then the receiving MSC. Since the paging response message is transmitted, there is a problem that the incoming MSC performing the call processing and the MSC registered by the terminal are different from each other so that the voice call received by the CS fallback subscriber fails.

The present invention has been made to solve the above-described problem, and as the location area of the region where the terminal (the terminal providing the CS fallback function) that receives the paging request message is changed, the terminal performs location registration with the HSS. The present invention provides a voice call service system and method in a mobile communication system in which an old MSC requests a call reset to the GMSC so that the GMSC can perform an incoming voice call processing with a terminal through a new MSC. There is this.

Voice call service system in a mobile communication system according to an embodiment of the present invention for achieving the above object, in a mobile communication system providing a CS fallback function, a voice call that is received by a terminal providing a CS fallback function GMSC for receiving; An HSS providing routing information for the voice call to the GMSC in response to a request of the GMSC; When receiving a path setting request message requesting a path setting from the GMSC, the device transmits a paging request message to the terminal and requests deletion of location registration information for the terminal from the HSS before receiving a paging response message from the terminal. A previous MSC requesting a call reset to the GMSC; And a new MSC requesting a location registration update to the HSS according to a location registration update request of the terminal leaving the service area of the previous MSC, wherein the GMSC is connected to the previous MSC according to a call reset request of the previous MSC. After releasing the message, it is preferable to re-request the routing information for the voice call to the HSS, receive a response thereto, and retransmit the routing request message to the new MSC based on the received routing information.

The MSC according to an embodiment of the present invention, upon receiving a voice call received by a terminal providing a CS fallback function, receives a routing request message from the GMSC, which has secured routing information through the HSS, to the terminal through the MME. In the MSC for transmitting a paging request message, before receiving a paging response message from the terminal, location registration information for the terminal from the HSS received a location registration update requested by the terminal as a location area is changed. When requested to delete, it is preferable to delete the location registration information for the terminal, and to request the call reset to the GMSC.

In the GMSC according to an embodiment of the present invention, in the GMSC for transmitting a route request message to the destination MSC based on the routing information obtained through the HSS in response to the voice call received by the terminal providing the CS fallback function, If a call reset request is received from the destination MSC that the location area of the region where the terminal is located is changed through the HSS before the call setup is made through the destination MSC, connection with the destination MSC is established. After releasing, it is preferable to re-secure routing information through the HSS, and re-send a routing request message to a new MSC newly registered by the terminal based on the re-secured routing information.

In the voice call service method in a mobile communication system according to an embodiment of the present invention, a GMSC receiving a voice call to a terminal providing a CS fallback function is routed to a destination MSC based on routing information obtained through the HSS. Transmitting a route establishment request message requesting establishment; After the paging request message is transmitted from the destination MSC to the terminal, if the terminal entering the new location area is requested to delete the location registration information for the terminal from the HSS that is requested to update the location registration through the new MSC. A call reset request process for requesting a call reset to the GMSC; Re-obtaining routing information through the HSS in the GMSC according to the call reset request; Transmitting a route establishment request message to the new MSC newly registered by the terminal based on the re-routed routing information; Transmitting a paging request message from the new MSC to the terminal; Preferably, the terminal transmits a paging response message to the new MSC to establish a call.

According to another aspect of the present invention, there is provided a voice call service method in a mobile communication system, the method comprising: requesting routing information for a voice call from a GMSC that receives an incoming voice call to a terminal providing a CS fallback function to an HSS; ; Receiving routing information for the voice call from the HSS; Transmitting a route establishment request message requesting route establishment to a destination MSC based on the routing information; Before receiving a routing response message from the called MSC, receiving a call reset request from the called MSC through the HSS, recognizing that the terminal has requested a location registration update through the new MSC; Re-requesting routing information for the voice call to the HSS in response to the call resetting request; Receiving routing information for the voice call from the HSS again; It is preferable that the terminal comprises the step of transmitting a route request message to the newly registered MSC based on the routing information.

According to another embodiment of the present invention, a voice call service method in a mobile communication system includes a path setting from a GMSC that receives a voice call to which a destination MSC whose current location is registered by a terminal providing a CS fallback function is received by the terminal. Receiving a path setting request message requesting a request; Transmitting a paging request message to the terminal based on the routing request message; Before receiving a paging response message from the terminal, requesting to delete the location registration information for the terminal from the HSS requested to update the location registration through the new MSC; Deleting the location registration information for the terminal according to the request for deleting the location registration information and requesting a call reset to the GMSC; It is preferable to include the step of releasing the connection with the GMSC in response to the release request of the GMSC.

According to the voice call service system and method in the mobile communication system of the present invention, the terminal registers the location to the HSS as the location area of the region where the terminal (the terminal providing the CS fallback function) that receives the paging request message is located is changed. If the previous MSC (OLD MSC) requests a call reset to the GMSC, the GMSC performs the incoming voice call processing with the terminal through the new MSC, thereby preventing the voice call to the terminal located at the exchange boundary area from failing. It becomes possible.

1 is a process for explaining a voice call service method in a mobile communication system according to the prior art.
2 is a diagram schematically illustrating a configuration of a voice call service system in a mobile communication system according to an embodiment of the present invention.
3 is a process for explaining a voice call service method in a mobile communication system according to an embodiment of the present invention.

Hereinafter, a voice call service system and method in a mobile communication system according to a preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings.

2 is a diagram schematically illustrating a configuration of a voice call service system in a mobile communication system according to an embodiment of the present invention.

In FIG. 2, a user equipment (UE) 10 is connected to a telephone call service through an IP (Internet Protocol) network and provides a CS fallback function.

UMTS Terrestrial Radio Access Network (UTRAN) / GSM / EDGE Radio Access Network (GERAN) is a Universal Mobile Telecommunications System composed of a base station (Node-B or BTS), a radio network controller (RNC), a base station controller (BSC), and the like. / GSM is a wireless access network, located between the terminal 10 and a wireless communication core network (Core Network) to transfer data and control information.

E-UTRAN (Evolved UTRAN) is a wireless access network of LTE, and supports the function of transmitting a paging request for CS fallback purpose to the terminal 10 and a direct connection function to a target cell capable of CS fallback service. do.

The MME 20 is responsible for authentication and registration of the terminal 10 when the terminal 10 accesses the mobile communication network through the E-UTRAN, processes a service request from the terminal 10, and the terminal 10 receives the E-UTRAN. Mobility is guaranteed when moving between base stations in the UTRAN.

The MME 20 described above provides a CS fallback function and is connected to the MSC 50 through the SGs interface.

The Serving Gateway (S-GW) 30 provides a bearer service for delivering a service data packet of a user, such as voice packet information, to the E-UTRAN.

The PDN-GW (Packet Data Network Gateway) 40 allocates an IP address to the terminal 10 connected to the mobile communication network and provides IP connectivity.

The mobile switching center (MSC) 50 actually provides a service to the terminal 10, provides a CS fallback function, and is connected to the MME 20 through an SGs interface.

Accordingly, the MSC 50 requests a terminal call to the MME 20 through the SGs interface and receives a location registration update of the terminal 10.

When the MSC 50 receives the IAM from the GMSC 60, the MSC 50 transmits a paging request message to the terminal 10 through the MME 20, and before receiving the paging response message from the terminal 10. If the request for deleting the location registration information for the terminal 10 from the HSS (70) requesting a location registration update through a new MSC (not shown) from (10), after deleting the location registration information for the terminal 10 Request a call reset to the GMSC 60 that has transmitted the IAM.

The GMSC 60 serves to transfer a call signal to the MSC 50 to which the terminal 10 is connected. When the GMSC 60 receives a voice call to the terminal 10 providing the CS fallback function, the GMSC 60 transmits the call signal to the HSS 70. After requesting and receiving routing information for the voice call, the terminal 10 transmits the IAM to the MSC 50 in which the terminal 10 is located based on the provided routing information.

As described above, the GMSC 60 that has transmitted the IAM to the MSC 50 waits for an address complete message (ACM) to be received in response to the IAM from the MSC 50, before the ACM is received. If the call reset request is received from the MSC 50, the connection with the MSC 50 is released, the routing information for the corresponding voice call is provided to the HSS 70, and received based on the routing information received from the HSS 70 again. The terminal 10 transmits the IAM to the new MSC 55 newly registered.

On the other hand, the HSS 70 is a server for storing and providing information such as the user information and the current location and registration status of the terminal 10 subscribed to the operator operating the mobile communication network.

As described above, the HSS 70 requests and receives routing information from the MSC 50 having the location registered according to the routing information request of the GMSC 60, and then transfers the routing information to the GMSC 60.

In addition, when the location area LA of the region where the terminal 10 is located is changed and the corresponding terminal 10 requests a location registration update through a new MSC (not shown), the HSS 70 transmits to the terminal 10. After updating the location information, request the MSC 50 to delete the location registration information for the terminal 10, and a new location registration response message containing subscriber information for the terminal 10 to the MSC (not shown) send.

Then, when the routing information for the voice call is re-received from the GMSC 60, the terminal 10 receives the routing information from a new MSC (not shown) that is currently registered and is provided with the GMSC 60. To send.

3 is a flowchart illustrating a voice call service method in a mobile communication system according to an embodiment of the present invention.

First, when the GMSC 60 receives a voice call that is received by the terminal 10 providing the CS fallback function (S30), the GMSC 60 requests the routing information for the voice call to the HSS 70. In order to transmit the SRI (Send Routing Information) request message (S32).

After receiving the SRI request message from the GMSC 60 through the process S32, the HSS 70 provides a Roaming Number (PRN) to request routing information from the destination MSC 50 at which the terminal 10 is currently registered. The request message is transmitted (S34), and a PRN response message is received in response (S36).

Thereafter, the routing information obtained through the process S36 is included in the SRI response message and transmitted to the GMSC 60 (S38).

The GMSC 60 receiving the SRI response message from the HSS 70 through the process S38 transmits an IAM requesting the establishment of a route to the destination MSC 50 based on routing information included in the SRI response message ( S40).

The receiving MSC 50 receiving the IAM from the GMSC 60 through the process S40 transmits a paging request message to the terminal 10 through the MME 20 (S42).

The terminal 10 receiving the paging request message through the above process S42 transmits the paging response message to the destination MSC 50 in response to the paging request message, and transmits the paging response message to the destination MSC 50. If the location area LA of the area where the terminal 10 is currently located is changed (S44), the terminal 10 transfers to the HSS 70 through the new MSC 55 that controls the location area where the terminal 10 is moved. In order to request the location registration update, a location registration update request message is transmitted (S46).

After receiving the location registration update request message from the terminal 10 through the process S46, the HSS 70 updates the location information on the terminal 10, and then the terminal MSC (hereinafter referred to as OLD MSC) 50. In operation S48, a deletion request message requesting deletion of location registration information about 10 is transmitted.

The OLD MSC 50, which has been requested to delete the location registration information for the terminal 10 from the HSS 70 through the process S48, deletes the location registration information for the terminal 10 according to the request of the HSS 70. After that (S50), the delete response message is transmitted to the HSS (70) (S52).

On the other hand, the HSS 70 requesting the deletion of the location registration information for the terminal 10 to the OLD MSC 50 through the above-described process S48 registers the location including subscriber information for the terminal 10 to the new MSC 55. The response message is transmitted (S54).

Upon receiving the location registration response message through step S54, the new MSC 55 stores subscriber information for the terminal 10 in the DB (S56).

On the other hand, the OLD MSC (50) that has sent the delete response message to the HSS (70) through the above-described process S52, the call is set up through the new MSC (55) that governs the location area where the terminal 10 is moved The call reset request message for requesting a call reset is transmitted to the GMSC 60 which has transmitted the IAM through S40 (S58).

The GMSC 60 that has transmitted the IAM to the OLD MSC 50, the called MSC, through the process S40 described above, receives the OLD MSC (through the process S58) before receiving the ACM in response to the IAM from the OLD MSC 50. When the call reset request is received from 50), the SRI request message is transmitted again to the HSS 70 in order to secure the routing information for the voice call received through the process S30 (S60).

After receiving the SRI request message from the GMSC 60 through the process S60, the HSS 70 transmits a PRN request message to request routing information to the new MSC 55 at which the terminal 10 is currently registered. In operation S62, a PRN response message is received in response.

Thereafter, the routing information obtained through the process S64 is included in the SRI response message and transmitted to the GMSC 60 (S66).

The GMSC 60 receiving the SRI response message from the HSS 70 through the process S66 transmits an IAM requesting the establishment of a route to the new MSC 55 based on the routing information included in the SRI response message ( S68).

Upon receiving the IAM from the GMSC 60 through the process S68, the new MSC 55 receives the location registration response message in response to the location registration update request message received from the terminal 10 through the process S46. 10) (S70).

The terminal 10 receiving the location registration response message from the new MSC 55 through the process S70 receives a new paging response message, which is a response to the paging request message received from the OLD MSC 50 through the process S42. The call is transmitted to the MSC 55 to establish a call between the new MSC 55 and the terminal 10 (S72).

Upon receiving the paging response message from the terminal 10 through the process S72, the new MSC 55 transmits to the GMSC 60 an ACM indicating that all information necessary for call setup has been received (S74).

The voice call service system and method in the mobile communication system of the present invention are not limited to the above-described embodiments, and various modifications can be made within the scope of the technical idea of the present invention.

Voice call service system and method in a mobile communication system according to the present invention, if the terminal (terminal providing the CS fallback function) receives the paging request message to register the location to the HSS, all MSC (OLD MSC) is GMSC By requesting the call reset, GMSC performs the incoming voice call processing with the terminal through the new MSC, thereby preventing the failure of the voice call coming to the terminal located at the border area of the exchange and increasing the incoming success rate. There is this.

10. Terminal,
20. Mobility Management Entity (MME),
30.Serving Gateway (S-GW),
40.Packet Data Network Gateway (PDN-GW),
50. Mobile Switching Center (MSC),
60.Gateway MSC,
70.Home Subscriber Server

Claims (8)

A mobile communication system providing a CS fallback function,
A GMSC for receiving an incoming voice call to a terminal providing a CS fallback function;
An HSS providing routing information for the voice call to the GMSC in response to a request of the GMSC;
When receiving a path setting request message requesting a path setting from the GMSC, the device transmits a paging request message to the terminal and requests deletion of location registration information for the terminal from the HSS before receiving a paging response message from the terminal. A previous MSC requesting a call reset to the GMSC;
Including the new MSC requesting the location registration update to the HSS in accordance with the location registration update request of the terminal leaving the service area of the previous MSC,
The GMSC releases the connection with the previous MSC according to the call reset request of the previous MSC, requests the routing information for the voice call back to the HSS, receives a response thereto, and based on the received routing information. And resending the routing request message to the new MSC.
The method of claim 1, wherein the HSS,
When receiving a location registration update request from the terminal through the new MSC, after updating the location information for the terminal, requesting the previous MSC to delete the location registration information for the terminal, the new MSC subscriber to the terminal In the mobile communication system transmitting a location registration response message including the information, and if the routing information for the voice call is re-requested from the GMSC, routing information obtained through the new MSC to the GMSC Voice call service system.
In the MSC for transmitting a paging request message to the terminal through the MME when receiving a route setup request message from the GMSC secured routing information through the HSS in response to the voice call received by the terminal providing the CS fallback function,
Before receiving a paging response message from the terminal, if a location area is changed and a request is made to delete location registration information for the terminal from an HSS that receives the requested location registration update, the location for the terminal. MSC, characterized in that to delete the registration information and to request a call reset to the GMSC.
In the GMSC for transmitting a route request message to the destination MSC based on the routing information obtained through the HSS in response to the incoming voice call to the terminal providing the CS fallback function,
If a call reset request is received from the destination MSC that the location area of the region where the terminal is located is changed through the HSS before the call setup is made through the destination MSC, connection with the destination MSC is established. After the release, reestablish routing information through the HSS, and retransmit a routing request message to a new MSC newly registered by the terminal based on the reestablished routing information.
Transmitting, by a GMSC receiving a voice call to a terminal providing a CS fallback function, a routing request message for requesting routing to the destination MSC based on routing information obtained through the HSS;
After the paging request message is transmitted from the destination MSC to the terminal, if the terminal entering the new location area is requested to delete the location registration information for the terminal from the HSS that is requested to update the location registration through the new MSC. A call reset request process for requesting a call reset to the GMSC;
Re-obtaining routing information through the HSS in the GMSC according to the call reset request;
Transmitting a route establishment request message to the new MSC newly registered by the terminal based on the re-routed routing information;
Transmitting a paging request message from the new MSC to the terminal;
And establishing a call by the terminal transmitting a paging response message to the new MSC.
The method of claim 5, wherein the call reset request process,
Transmitting a paging request message from the called MSC to the terminal;
Requesting a location registration update to the HSS through a new MSC if a location area is changed before the terminal transmits a paging response message to the destination MSC;
Requesting deletion of location registration information for the terminal from the called MSC after updating the location information for the terminal in the HSS;
Transmitting a location registration response message including subscriber information for a terminal to the new MSC;
And deleting the location registration information for the terminal according to the request for deleting the location registration information from the destination MSC, and requesting a call reset to the GMSC.
Requesting routing information for the voice call from the GMSC receiving the voice call to the terminal providing the CS fallback function to the HSS;
Receiving routing information for the voice call from the HSS;
Transmitting a route establishment request message requesting route establishment to a destination MSC based on the routing information;
Before receiving a routing response message from the called MSC, receiving a call reset request from the called MSC through the HSS, recognizing that the terminal has requested a location registration update through the new MSC;
Re-requesting routing information for the voice call to the HSS in response to the call resetting request;
Receiving routing information for the voice call from the HSS again;
And transmitting a route setting request message to a new MSC newly registered by the terminal based on the routing information.
Receiving, by a terminal providing a CS fallback function, a destination MSC whose current location is registered, from a GMSC that receives a voice call to the terminal;
Transmitting a paging request message to the terminal based on the routing request message;
Before receiving a paging response message from the terminal, requesting to delete the location registration information for the terminal from the HSS requested to update the location registration through the new MSC;
Deleting the location registration information for the terminal according to the request for deleting the location registration information and requesting a call reset to the GMSC;
And releasing the connection with the GMSC according to the release request of the GMSC.

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