KR20170007016A - Call processing system and method for selecting accessing network in the system - Google Patents

Abstract

The present invention relates to a call processing system and a method for selecting an accessing network in the system. In the method, a first device receives an originating message to transmit the message, which searches for a device registered by a receiver, to a second device. The second device determines a receiving network of the receiver by using registration information of a plurality of receiving networks, and transmits the message including device information of the determined receiving network to the first device. The first device transmits the originating message to a third device corresponding to the device information of the receiving network included in the message received from the second device.

Description

[0001] CALL PROCESSING SYSTEM AND METHOD FOR SELECTING ACCESSING NETWORK IN THE SYSTEM [0002]

The present invention relates to a call processing system and a method of selecting a destination network in the system.

Voice over LTE (VoLTE), which is a service capable of making voice calls using LTE (Long Term Evolution) network which is a 4G (4G) mobile communication, transmits packetized voice data using LTE data network, Can be provided.

The VoLTE terminal registers in the Internet Protocol Multimedia Subsystem (IMS) network in order to receive the VoLTE service. Even if the access network connected to the terminal changes from LTE to 3G, the registration status of the IMS network may not be changed. This is because the terminal has no obligation to report to the IMS network as it moves to 3G.

Since the VoTLE terminal can not be connected to the 3G-connected terminal, the 3GPP standard requires the U-DDR / A (User Data Request / Answer) of the Sh-interface to the HSS (Home Subscriber Server) in the AS (SCC- Operation to determine the 3G subscriber's VoLTE availability and determine the 3G incoming and VoLTE incoming.

At this time, the HSS responds to the VoLTE reception availability in consideration of the 3G / LTE location registration status of the called subscriber and whether VoLTE support of the subscriber's roaming MME (mobility management entity) / eNB (eNodeB) This process is called Terminating Access Domain Selection (T-ADS).

As described above, in the prior art, since the T_ADS process for selecting the destination network must be performed by querying the LTE HSS where the called party is registered through the UDR / A of the Sh interface in the AS of the called party, And there is a separate operation between the AS and the HSS, thereby increasing the load on the incoming call processing for the voice call and delaying the time for the voice call connection.

SUMMARY OF THE INVENTION The present invention provides a call processing system and a method of selecting a destination network in the system by performing a destination network selection function before arriving at a destination network to reduce an unnecessary destination node.

According to an aspect of the present invention,

A method for selecting a destination network for a voice call, the method comprising: receiving, by a first device, an origination message and sending a message to a second device to query a registered device; Determining, by the second device, the destination network of the called party using the registration information of the plurality of destination networks, and transmitting a message including the determined device information of the destination network to the first device; And transmitting the origination message to a third device corresponding to the device information of the destination network included in the message received from the second device by the first device.

Herein, the inquiry message includes a request to the second device to select a destination network, and when the inquiry message is an LIR (Location Information Request), the request to select the destination network is a User Authorization Type And is included in the AVP.

The request for selecting the destination network includes a voice call incoming request and a video call incoming request.

In addition, when the message including the device information of the destination network is an LIA (Location Information Answer) message, the device information of the destination network is included in the Sever name AVP and transmitted.

In addition, when the plurality of destination networks are a VoLTE network and a 3G network, the Sever name AVP includes an S-CSCF name of the VoLTE network or an identification address of an MGCF.

When the callable network is a 3G network, when the MGCF of the 3G network is selected, the called party selects the MGCF corresponding to the information of the location-registered exchange and includes the corresponding identification address in the LIA message.

In addition, the second device includes a table in which exchange information corresponding to a location of the called party is associated with MGCF identification address information.

According to another aspect of the present invention,

A method for selecting a destination network for a voice call service for a terminal capable of roaming between a first network and a second network in a voice call service in which a call processing system provides a voice call using a data network as a first network, Selecting a destination network using location information of a called party when receiving an origination message from an originating terminal located in the first network; And delivering the origination message to a selected destination network destination network.

Here, the step of selecting the destination network may include the steps of: a first device receiving an origination message from the calling terminal; Requesting an inquiry to a second device managing the location information of the called party by the first device; Selecting a destination network among the first network and the second network using the location information of the called party; And transmitting information of a destination apparatus of the called network to the first apparatus in which the second apparatus is selected.

In addition, the first device is an Inter-calling-Call Session Control Function (I-CSCF), and the second device is an HSS (Home Subscriber Server).

According to another aspect of the present invention,

A first apparatus including registration information of a plurality of destination networks and information of destination apparatuses of the plurality of destination networks; And an originating message to request the first device to select a destination network for an incoming call from the plurality of destination networks, receive information of a destination device as a result of selecting a destination network from the first device, And a second device for delivering the origination message.

Herein, the second device generates a request message for selecting the destination network when the originating message is received, and transmits the request message to the first device, and receives information of the destination device as a result of the destination network selection from the first device A message processor for receiving a response message including the response message; And a network selector for selecting the destination network according to the information of the destination apparatus included in the response message received from the message processor and delivering the origination message to the destination apparatus corresponding to the selected destination apparatus information of the destination network do.

The first device includes a table in which exchange information corresponding to the location of the called party is associated with identification address information of the destination device. The first device, when selecting the destination device, And transmits the corresponding identification address to the second device as the information of the destination apparatus.

According to the present invention, it is possible to perform a destination network selection function before reaching a VoLTE destination network, thereby reducing an unnecessary route node, and removing a separate operation for T-ADS by performing a destination network selection through an LIR / LIA message Do.

In addition, it is not a new interface or operation design / development, but the development of a specialization utilizing each database information of IMS / 3G / LTE HSS integrated in the existing interface operation, Implementation is possible.

FIG. 1 is a flowchart illustrating a method of selecting a destination network in a VoLTE service.
2 is a flowchart of a method of selecting a destination network in a call processing system according to an embodiment of the present invention.
3 is a flowchart of a method of selecting a destination network in a call processing system according to another embodiment of the present invention.
4 is a diagram showing a specific configuration of an I-CSCF according to an embodiment of the present invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art can easily carry out the present invention. The present invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. In order to clearly illustrate the present invention, parts not related to the description are omitted, and similar parts are denoted by like reference characters throughout the specification.

Throughout the specification, when an element is referred to as "comprising ", it means that it can include other elements as well, without excluding other elements unless specifically stated otherwise. Also, the terms " part, "" module," and " module ", etc. in the specification mean a unit for processing at least one function or operation and may be implemented by hardware or software or a combination of hardware and software have.

Hereinafter, a general method of selecting a destination network in VoLTE service will be described.

FIG. 1 is a flowchart illustrating a method of selecting a destination network in a VoLTE service.

Referring to FIG. 1, when a caller sends a voice call based on a VoLTE call for a voice call with a called party, the calling party (UE) 10 sends a voice call to the called party (UE) And transmits an INVITE message to the Serving-Call Session Control Function (S-CSCF1) (S1).

The S-CSCF1 30 transmits an INVITE message to the AS1 (Application Server) 40 by triggering Initial Filter Criteria (IFC) (S2). After the AS1 40 performs the voice supplementary service to which the caller subscribes INVITE message to the S-CSCF1 30 (S3).

The S-CSCF1 30 then sends an INVITE message to the I-CSCF 50 and the I-CSCF 50 sends the S-CSCF to which the called party is registered (Location Information Request) to the HSS 60 (S5).

Accordingly, the HSS 60 responds to the I-CSCF 50 via the LIA (Location Information Answer) with the information of the called S-CSCF (S-CSCF2 70 in this case) in which the called party is registered (S6).

The I-CSCF 50 transmits the INVITE message to the S-CSCF2 70 using the information of the S-CSCF2 70 received from the HSS 60 (S7).

Subsequently, the S-CSCF2 70 transmits an INVITE message to the AS2 80 by IFC triggering (S8), and the AS2 80 transmits an INVITE message to the HSS 60 to know whether the called party is VoLTE enabled or not The UDR is inquired (S9).

Accordingly, the HSS 60 notifies the AS2 80 of the VoLTE availability / VoLTE impossibility of the called party in consideration of the LTE / 3G location registration status of the called party, the VoLTE support of the LTE equipment registered to the called party, (S10).

Here, the destination network selection is different according to the result of the VoLTE enable / disable of the called party answered by the HSS 60. [

Assuming that VoLTE is enabled, the AS2 80 transmits the INVITE message to the S-CSCF2 70 (S11) after operating the voice service to which the called party subscribes, and transmits the INVITE message to the S- Transmits an INVITE message to the called terminal 20 via the P-CSCF2 (not shown) connected to the called party so that the VoLTE call is allowed to proceed between the calling terminal 10 and the called terminal 20 (S12) .

In this way, when VoLTE is possible, the LTE network is selected and the VoLTE service is provided.

On the other hand, assuming that VoLTE is impossible, the AS2 80 adds the routing address of the MGCF (Media Gateway Control Function) 90, which is the gateway equipment between the 3G and the IMS network, to the S-CSCF2 70 (S13).

Accordingly, the S-CSCF2 70 transmits an INVITE message to the MGCF 90 in step S14. The MGCF 90 converts the SIP message of the IMS network into a 3G network bearer-independent call control (BICC) So that the voice call with the called terminal 21 through the 3G network proceeds (S14).

In the T-ADS operation in which the steps S9 and S10 are performed to select a destination network, the destination network selection operation is performed by the AS 80 of the called party to the LTE HSS 60 in which the called party is registered, UDR / A.

Therefore, even when the called terminal 21 is connected to the 3G network, the VoLTE destination network must be passed for the T-ADS operation, so that not only the connection delay but also the connection load occurs.

Hereinafter, a call processing system according to an embodiment of the present invention and a method for selecting a destination network in the system for solving the above problems will be described.

First, it is assumed that the called terminal is connected to the LTE network.

2 is a flowchart of a method of selecting a destination network in a call processing system according to an embodiment of the present invention.

Referring to FIG. 2, when a caller sends a voice call based on a VoLTE call for voice communication with a called party, the calling terminal 100 transmits an INVITE message to the S-CSCF1 300 for voice communication with the called terminal 200, Message (S100).

The S-CSCF1 30 transmits an INVITE message to the AS1 400 by IFC triggering in operation S110. The AS1 400 transmits the INVITE message to the S-CSCF1 300 (S120).

The I-CSCF 500 then sends an INVITE message to the I-CSCF 500 (S 130) and the I-CSCF 500 sends an LIR to the HSS 600 to look up the S- (Location Information Request) (S140).

The HSS 600 selects a destination network in consideration of the IMS network registration information, the LTE / 3G location registration status of the called party, and the VoLTE support of the registered LTE equipment with respect to the called party. Here, since the destination terminal 200 is connected to the LTE network, the destination network selection result is VoLTE incoming by the HSS 600, and therefore the HSS 600 transmits the S-CSCF (here, S-CSCF2 700) to the I-CSCF 500 via the LIA (S150).

Accordingly, the I-CSCF 500 transmits the INVITE message to the S-CSCF2 700 (S160) using the information of the S-CSCF2 700 received from the HSS 600, and the S- And transmits an INVITE message to the AS2 800 by triggering (S170).

Thereafter, the AS2 800 transmits the INVITE message to the S-CSCF2 700 again after operating the voice service to which the called party subscribes (S180).

The S-CSCF2 700 transmits an INVITE message to the called terminal 200 via the P-CSCF2 (not shown) connected to the called party so that a VoLTE call is received between the calling terminal 100 and the called terminal 200 (S190).

Here, a T-ADS process for selecting a destination network through the LIR / LIA process of steps S140 and S150 may be performed simultaneously.

Therefore, when the destination terminal 200 is connected to the LTE network and VoLTE reception is enabled, the UDR / UDA process of the conventional Sh interface performing the T-ADS process can be omitted, so that the VoLTE call processing path is reduced by 2 , Which can reduce the transaction load one by one in HSS 600 and AS2 800. [

Next, it is assumed that the called terminal is connected to the 3G network without being connected to the LTE network.

3 is a flowchart of a method of selecting a destination network in a call processing system according to another embodiment of the present invention.

3, when a caller sends a voice call based on a VoLTE call for voice communication with a called party, the calling terminal 100 transmits an INVITE message to the S-CSCF1 300 for voice communication with the called terminal 210, Message (S200).

The S-CSCF1 30 transmits an INVITE message to the AS1 400 by IFC triggering in operation S210. The AS1 400 transmits the INVITE message to the S-CSCF1 300 (S220).

The I-CSCF 500 then sends an INVITE message to the I-CSCF 500 in step S230 and the I-CSCF 500 sends an LIR to the HSS 600 to look up the S- (Location Information Request) (S240).

The HSS 600 selects a destination network in consideration of the IMS network registration information, the LTE / 3G location registration status of the called party, and the VoLTE support of the registered LTE equipment with respect to the called party. Here, since the destination terminal 210 is connected to the 3G network, the destination network selection result is transmitted to the HSS 600 by the HSS 600. Therefore, the HSS 600 inquires the location registration information of the registered 3G, And responds to the I-CSCF 500 via the LIA (S250). At this time, the HSS 600 can process the call to the 3G through the random MGCF address delivery. However, in order to efficiently process the 3G call, the HSS 600 selects the MGCF 900 located nearest to the location where the called party is registered, You can provide an identifying address. This will be described in detail later.

Accordingly, the I-CSCF 500 transmits an INVITE message to the MGCF 900 of the 3G network using the identification address of the MGCF 900 received from the HSS 600 (S260) The SIP message is converted into a 3G network BICC message and transmitted to the 3G network so that voice communication with the called terminal 210 through the 3G network proceeds (S270).

As described above, according to the embodiment of the present invention, when the called terminal 210 is connected to the 3G network, it is possible to transfer the call directly to 3G without going through the incoming IMS network, thereby making it possible to reduce the call processing path by 5 hops, Two transactions in S-CSCF2 700 and AS2 800, respectively, and one transaction load in HSS 600 may be reduced.

In addition, since the called party routes the call directly to the MGCF 900 of the actual location registered area, the inter-area passage can be reduced, thereby simplifying the call and making it possible to receive the call quickly.

Meanwhile, in the call processing system for performing the destination network selection method according to the embodiment of the present invention, the I-CSCF 500 performs T-ADS and the configuration of the I-CSCF 500 will be described.

4 is a diagram showing a specific configuration of I-CSCF 500 according to an embodiment of the present invention.

4, the I-CSCF 500 includes a first interface 510, a second interface 520, a third interface 530, a message processor 540, (550).

The first interface 510 provides an interface to the S-CSCF 300 and 700. The second interface 520 provides an interface to the HSS 600. The third interface 530 provides an interface to the MGCF 900 ). ≪ / RTI >

The message processor 540 receives the INVITE message transmitted from the S-CSCF1 300 through the first interface 510 and generates an LIR message that is a message for inquiring the S-CSCF 700 to which the called party is registered Transmits the LIA message transmitted from the HSS 600 to the HSS 600 through the second interface 520 and analyzes the LIA message through the second interface 520. [

The network selector 550 selects the VoLTE network or the 3G network according to the result of the LIA message analysis performed by the message processor 540 and transmits the INVITE message to the selected network. That is, when the VoLTE network is selected, the network selector 550 transmits the INVITE message to the S-CSCF2 700 through the first interface 510. However, if the 3G network is selected, the network interface 550 transmits the INVITE message through the third interface 530 to the MGCF 900 to send an INVITE message to perform an incoming call.

Hereinafter, specific methods for implementing the T-ADS as described above will be described.

In the method according to an embodiment of the present invention, when the I-CSCF 500 and the HSS 600 process the LIR / LIA message, not only the IMS registration information but also the LTE / 3G location registration information of the HSS 600 .

The HSS 600 acquires the location registration status of the destination access network using the LTE / 3G location registration information when entering the LIR, which is the S-CSCF inquiry message in which the destination VoLTE subscriber is registered, from the I-CSCF 500, And a VoLTE incoming call can be determined.

The reference example for selecting the destination network by the HSS 600 when entering the LIR is shown in Table 1 below.

[Table 1]

In order to perform the destination network selection function using the LIR / LIA message, it is necessary to develop a specialization of the I-CSCF 500 and the HSS 600.

Since the LIR message is a message inquiring the incoming S-CSCF, it does not occur only at the time of VoLTE incoming, and it is also impossible to distinguish between VoLTE incoming and PSVT (Packet Switched Video Telephony) incoming.

In order to recognize that the HSS 600 is the LIR for VoLTE or PSVT reception, the I-CSCF 500 must include separate information that the HSS 600 can recognize in the LIR message.

In the embodiment of the present invention, a User Authorization Type AVP defined as a standard in the LIR message is used. That is, a VoLTE / PSVT call is indicated through a User Authorization Type AVP in a standard LIR message as shown in the following [Table 2] and [Table 3].

[Table 2]

[Table 3]

I-CSCF 500 utilizes SIP method and SDP information for distinguishing VoLTE incoming or PSVT incoming, and distinguishes S-CSCF restoration case as shown in [Table 4].

[Table 4]

Accordingly, the HSS 600 performs the VoLTE call destination network selection function and the PSVT call destination network selection function when the LIR user authorization type is 98 or 99, respectively, and operates according to the existing standard when it is not 98 or 99.

In the case where the destination network selection result in the HSS 600 is a VoLTE incoming call for the LIR message, as shown in [Table 5], the standard VoLTE incoming call including the S-CSCF name in which the called party is registered in the Server name AVP of the LIA message .

However, when the destination network selection result in the HSS 600 for the LIR message is a 3G incoming call, it is necessary to develop a specialization of the HSS 600 for efficient incoming call.

It replies to the Server name AVP of the LIA message with an identification address that identifies the MGCF of the 3G network, not the name. Here, the selection of the MGCF is performed by inquiring the 3G location registration information of the HSS 600. [ To this end, the HSS 600 needs to separately manage the MGCF identification address. The identification address of the MGCF uses the same sip hostname format as the S-CSCF name address to accept it as it is in the Server name AVP.

[Table 5]

Meanwhile, when the destination network selection result is a 3G incoming call, the HSS 600 randomly selects and transmits an MGCF identification address when delivering the MGCF identification address to the I-CSCF 500, so that the HSS 600 can process the incoming call to 3G, The location-based MSC-MGCF table can be managed for initial call processing. That is, information of the MSC (exchange) registered in the called party location is obtained through the 3G location registration information of the HSS 600, and the corresponding address of the MSCF corresponding to the received MSCF is obtained and transmitted. In this manner, the HSS 600 can select the MGCF 900 located nearest to the area where the called party is registered to provide the identification address.

An example of the MSC-MGCF table that the HSS 600 needs to manage is shown in Table 6 below.

[Table 6]

Accordingly, the I-CSCF 500 uses the identification address of the MGCF 900 located closest to the called party received from the HSS 600 through the LIA to directly receive the 3G call through the MGCF 900 without going through the incoming IMS network Can be performed.

As described above, the area-based incoming MGCF selection function using the 3G location registration information and the MSC information in the HSS 600 enables effective call processing in the 3G network.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments, It belongs to the scope of right.

Claims (15)

A method for selecting a destination network for voice communication,
The first device receiving the origination message and sending a message to the second device inquiring the registered device of the called party;
Determining, by the second device, the destination network of the called party using the registration information of the plurality of destination networks, and transmitting a message including the determined device information of the destination network to the first device; And
The first device transmitting the origination message to a third device corresponding to device information of a destination network included in a message received from the second device
Gt; a < / RTI > destination network. The method according to claim 1,
Wherein the inquiring message includes a request to the second device to select a destination network,
If the inquiring message is an LIR (Location Information Request), the request to select the called network is included in the User Authorization Type AVP of the LIR message
Wherein the destination network selection method comprises the steps of: 3. The method of claim 2,
Wherein the request to select the destination network comprises a voice call incoming request and a video call incoming request. 3. The method of claim 2,
Wherein the device information of the destination network is included in the Sever name AVP when the message including the device information of the destination network is an LIA (Location Information Answer) message. 5. The method of claim 4,
Wherein the Sever name AVP includes the S-CSCF name of the VoLTE network or the MGCF identification address when the plurality of the destination networks are the VoLTE network and the 3G network. 5. The method of claim 4,
When the destination network is a 3G network, selecting a MGCF of the 3G network, the called party selects an MGCF corresponding to information of a location-registered exchange and includes the corresponding identification address in the LIA message. The method according to claim 6,
Wherein the second device includes a table in which exchange information corresponding to a location of the called party is associated with MGCF identification address information. A method for selecting a destination network for a voice call service for a terminal capable of roaming between a first network and a second network in a voice call service in which a call processing system provides a voice call using a data network as a first network, ,
Selecting a destination network using location information of a called party when receiving an origination message from an originating terminal located in the first network; And
And transmitting the origination message to a destination apparatus of the called network
Gt; a < / RTI > destination network. 9. The method of claim 8,
The step of selecting the destination network comprises:
The first device receiving an origination message from the calling terminal;
Requesting an inquiry to a second device managing the location information of the called party by the first device;
Selecting a destination network among the first network and the second network using the location information of the called party; And
Transmitting the information of the destination apparatus of the destination network to the first apparatus in which the second apparatus is selected
Gt; a < / RTI > destination network. 10. The method according to any one of claims 1 to 9,
Wherein the first device is an Interrogating-Call Session Control Function (I-CSCF)
The second device is an HSS (Home Subscriber Server)
Wherein the destination network selection method comprises the steps of: A first apparatus including registration information of a plurality of destination networks and information of destination apparatuses of the plurality of destination networks; And
Receiving an origination message and requesting the first device to select a destination network from among the plurality of destination networks for an incoming call; receiving information of a destination device as a result of selecting a destination network from the first device; A second device for delivering an outgoing message
Lt; / RTI > 12. The method of claim 11,
The second device comprises:
When the originating message is received, generating a request message for the destination network selection and transmitting the request message to the first device, and receiving a response message including information of the destination device resulting from the destination network selection from the first device A message processor; And
A network selector for selecting a destination network according to the information of the destination apparatus included in the response message received from the message processor and delivering the origination message to a destination apparatus corresponding to information of the destination apparatus of the selected destination network,
Lt; / RTI > 12. The method of claim 11,
Wherein the first device includes a table in which exchange information corresponding to a location of the called party is associated with identification address information of the destination device,
When the first device selects the destination device, the destination device selects the destination device corresponding to the information of the exchange registered with the destination and transmits the corresponding identification address to the second device as information of the destination device
And the call processing system. 14. The method according to any one of claims 11 to 13,
Wherein the plurality of destination networks are a VoLTE network and a 3G network. 14. The method according to any one of claims 11 to 13,
The first device is an HSS (Home Subscriber Server)
The second device is an Interogating-Call Session Control Function (I-CSCF)
And the call processing system.

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