KR101557846B1 - System and method for service change by called subscriber on call setup - Google Patents

Abstract

A system and method for switching a service by a called party during call setup in a network environment providing ERBT is disclosed. The service switching system and method are characterized in that before setting the call path of the calling terminal, temporary service selection information indicating that service switching is possible in the called terminal is transmitted in advance from the called switching node to the calling switching node, After setting the call destination of the called terminal based on the actual service selection information according to the selection of the called subscriber, the actual service selection information is transmitted to the outgoing exchange node to reset the call path of the calling terminal, The call connection between the called terminal and the called terminal can be normally performed, and the service switching function by the called subscriber can be implemented during call setup.

ERBT, MRBT, Service Transition, Recipient Selection

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a service switching system and method,

The present invention relates to a service switching system and method in a call setup for providing an ERBT environment, and more particularly, to a system and method for switching a service between a caller and a subscriber during call setup, And a service switching system and method for enabling a call connection to be normally performed when a service mode selected by each of a calling subscriber and a called subscriber is different.

In the call connection process for connecting the calling path between the calling terminal and the called terminal, a ring back tone is provided to the calling terminal until the ringing tone of the called terminal actually rings by transmitting a call signal from the communication network to the called terminal, It is general that a ringback tone is provided to the calling terminal from the moment the ringing tone rings at the ringing terminal.

In this way, when the calling terminal tries to establish a call connection to the called terminal, unless the ringing tone is provided from the called terminal to the calling terminal in the communication network until the ringing tone is generated, (ERBT) for providing ringback tone in advance to the calling terminal before the ringing tone is ringing to the ringing terminal when the calling terminal makes a call.

On the other hand, in the conventional communication network, a service switching function is provided during a call setup in which a called party freely selects a service of a voice call and a video call during call connection between the calling terminal and the called terminal.

In the case of a communication network that does not provide ERBT in the call connection process, after transmitting the service switching related information of the called terminal to the calling terminal, based on the transferred service switching related information, a radio access bearer for the calling and called terminal Access Bearer) is allocated to connect the call path between the calling terminal and the called terminal so that voice call and video call services can be performed according to the selection of the called terminal during call set-up.

However, in the communication network providing the ERBT in the call connection process, in order to provide the ERBT, the service switching related information transmitted from the called terminal at the time of call connection processing, that is, It is necessary to allocate the radio access bearer to the originating terminal and provide ERBT to the originating terminal. That is, since the communication network providing the ERBT allocates the radio access bearer to the calling terminal in advance in the state in which the information about the call to the voice call or the video call is not received from the receiving terminal, There is a limitation in providing a function of switching a voice call / video call service according to a selection of a called subscriber even when a call capable of switching service of voice call and video call occurs.

Therefore, in the case of applying the above-described conventional processing technique, in the communication network providing the ERBT, due to the inability to transmit the service switching related information of the called terminal transmitted from the called terminal in the call connection process to the calling terminal, There is a problem in that the function of switching the voice call and video call service can not normally be provided according to the selection of the called party. In addition, when a call is established in a communication network, a radio access bearer of a calling terminal is allocated in a state in which information is not received from the called terminal. Therefore, the called terminal may be a terminal that does not support all the voice call / video call services, And when the service mode selected by each of the called subscribers is different, the call connection can not be normally performed.

SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a service switching system and a method for switching a service of a voice call and a video call freely according to a selection of a called subscriber during a call setup in a communication network environment providing ERBT .

Another aspect of the present invention is to provide a service switching system and method for allowing a call connection to be normally performed when a service mode selected by a calling subscriber and a called subscriber is different in a network environment providing ERBT.

The technical objects to be achieved by the present invention are not limited to the technical matters mentioned above, and other technical subjects which are not mentioned can be clearly understood by those skilled in the art from the following description. There will be.

According to an aspect of the present invention, there is provided a service switching system for routing a call from a calling terminal to a called terminal to a called switching node during call processing capable of switching between a voice call and a video call, An originating exchange node receiving temporary service selection information indicating that the terminal is capable of switching service between a call and a video call and connecting a call path to the originating terminal based on the provisional service selection information; And notifying that the called terminal is capable of performing service switching by transmitting the temporary service selection information to the originating switching node when receiving a call routed from the originating switching node, And a destination switching node for providing a ring back tone to the calling terminal until a call channel is allocated between the terminals and receiving actual service selecting information for notifying whether the service is switched according to the called party selection from the called terminal.

According to another aspect of the present invention, there is provided a service switching method comprising the steps of: an originating switching node receiving a call capable of switching service between a voice call and a video call from a calling terminal; Routing the call received from the calling terminal to the called switching node managing the called terminal; Generating temporary service selection information indicating that the called terminal is a terminal capable of switching service between a voice call and a video call and notifying the called exchange node when the called exchange receives the routed call; Providing a ring back tone to the calling terminal until the called switching node interlocks with the calling switching node and a call path is allocated between the calling terminal and the called terminal; And receiving the actual service selection information indicating whether the destination switching node has switched the service according to the called party selection from the called terminal.

The service switching system and method according to the present invention as described above allows a service of a voice call and a video call to be freely switched according to a selection of a called subscriber during a call setup in a communication network environment providing ERBT.

Also, in the service switching system and method according to the present invention, in a communication network environment providing an ERBT, when a calling mode and a called subscriber have different service modes, call connection can be normally performed during call establishment.

Hereinafter, a service switching system by a called party among call setups according to a preferred embodiment of the present invention will be described in detail with reference to FIGS. 1 and 2 attached hereto.

FIG. 1 is a block diagram illustrating a service switching system according to an embodiment of the present invention. FIG. 1 illustrates a system for performing service switching by selecting a recipient during a call setup process in a communication network providing an ERBT / MRBT.

1, a wired / wireless communication network that implements a service switching system and provides an ERBT / MRBT is a wired / wireless communication network that is capable of providing a wired communication network, a wireless communication network such as WCDMA, Wibro, And the calling terminal 10a and the called terminal 10b are interworked through a wired / wireless communication network.

The service fallback function of the called party is a function that the called subscriber can selectively switch the voice call into the video call and the video call into the voice call during call setup when the calling subscriber makes a voice call or a video call. In a wired / wireless communication network, two services (video and voice) are all supported, but when one of the services is valid or required, only one valid service (preferred or non-preferred service) is selected and the other is discarded.

Referring to FIG. 1, a service switching system according to an embodiment of the present invention includes a calling terminal 10a, a called terminal 10b, an originating switching node 40a, and a terminating switching node 40b.

The originating terminal 10a accesses the wired / wireless communication network through the originating exchange node 40a to request a call origination, and at the time of making the call, transmits the service switching related information meaning that the called terminal supports the service switching function by the called party To the switching node 40a.

When the called terminal 10b receives a call from the wired or wireless communication network via the destination switching node 40b and receives a call capable of switching the service of the voice call and the video call, the call receiving terminal 10b transmits service switching related information And transfers it to the called exchange node 40b.

The originating exchange node 40a processes the call originated from the originating terminal 10a and transmits a call from the originating terminal 10a to the terminating terminal 10b at the time of call processing capable of switching the service of the voice call and video call to the terminating terminal 10a, (40b). Here, the source exchange node 40a first receives the temporary service selection information from the destination switching node 40b before connecting the source terminal 10a to the call terminal, and transmits the temporary service selection information to the destination terminal 10a based on the received temporary service selection information. 10b to the calling terminal 10a after notifying the calling terminal 10a that the service can be switched.

The temporary service selection information is a signal supporting the both video call and voice call service by the destination terminal 10b and is a signal informing the originating terminal of the assumption that the video call / Is provided with temporary service selection information irrespective of the actual service switching capability of the called terminal 10b if a call capable of service switching is routed from the calling terminal to provide Early Ring Back Tone (ERBT) or multimedia ring back tone (MRBT) And transmits it to the originating exchange node 40a.

The destination switching node 40b connects the call between the calling terminal 10a and the receiving terminal 10b in cooperation with the source switching node 40a and allocates a call path between the calling terminal 10a and the called terminal 10b The ring back tone is provided to the calling terminal 10a. For this, the destination switching node 40b notifies the temporary service selection information to the outgoing exchange node 40a before the call selection of the called subscriber at the time of the call processing for the service switch, so that the outgoing exchange node 40a So that the call path of the calling terminal 10a can be set based on the service selection information.

In this manner, before the actual call connection between the calling terminal 10a and the called terminal 10b is established, the terminating switching node 40b can transmit the ERBT or MRBT, regardless of the service switching capability of the terminating terminal 10b , The temporary service selection information indicating that both the video call and the voice call service are available is transmitted to the calling party. In addition, the destination switching node 40b notifies the above-described provisional service selection information to the source switching node 40a and then provides the ERBT or MRBT to the calling terminal 10a in cooperation with the source switching node 40a, The ring back tone is provided in advance to the calling terminal 10a in a state where no incoming signal is transmitted to the terminal 10b.

Thereafter, when the called subscriber selects the voice call or the video call, if the actual service selection information indicating whether the service is switched according to the called party selection is received from the called terminal 10b, the called party switching node 40b determines, based on the actual service selection information And connects the call path to the called terminal 10b. In addition, when the service switching is performed by the called subscriber by confirming the actual service selection information (for example, when the calling party requests the video call but the calling party switches to the voice call) And informs the switching center 40a of the service switching in order to reset the communication path of the calling terminal 10a set in advance based on the calling information. The originating exchange node 40a that has learned the service switching reconfigures the call path to the calling terminal 10a based on the actual service selection information received from the called party so that the call between the calling terminal 10a and the called terminal 10b Enables service switching during a call.

FIG. 2 is a configuration diagram illustrating a service switching system according to another embodiment of the present invention, which illustrates a service switching system in a mobile communication network, typically a WCDMA (Wideband-CDMA) network.

In order to provide the service switching function by the called party, before the originating exchange node 40a establishes the call path of the calling terminal 10a, the call proceeding including the provisional service selection information defined as the calling subscriber selecting BC1 A message (Call Proceeding) is forwarded in advance from the destination switching node 40b to the source switching node 40a. In the state in which the above-described call progress message (Call Proceeding) has been delivered to the source exchange node 40a in advance, the destination switching node 40b receives the actual service selection information from the destination terminal 10b at a later time, A radio access bearer according to a service mode (a video call mode or a voice call mode) is set and a call channel is connected to the call terminal 10a, and the service switching related information of the called subscriber is transmitted To the switching node 40a.

Through this process, the service switching function by the called party can be implemented in the communication network of the ERBT / MRBT environment, and the call is set in the call according to the service mode selected by the called subscriber, . The calling terminal 10a and the terminating terminal 10b can freely change the voice call and video call service according to the user's choice even while the call path is connected and the call is connected between the calling terminal 10a and the called terminal 10b .

2, a service switching system according to another embodiment of the present invention includes a calling terminal 10a, a called terminal 10b, Node Bs 20a and 20b, RNCs 30a and 30b, An originating exchange node 40a, an incoming exchange node 40b, and a home location register 50 (HLR).

The originating terminal 10a performs wireless communication with the node B 20a. When the originating terminal 10a originates a call for call connection, the originating terminal 10a transmits service switching related information indicating that the called terminal 10a supports the service switching function by the called party And transmits it to the originating exchange node 40a via the node B 20a and the RNC 30a in the setup message SETUP.

The service switching related information includes a repeat indicator (RI), a first bearer capability in a message (BC1), and a second bearer capability in a message (BC2) BC2 indicating voice and video are included in a setup message (SETUP) and transmitted to the call switching node 40a in the sense that it is possible to switch the video service.

The destination terminal 10b receives the service switching related information included in the setup message (SETUP) transmitted from the destination switching node 40b in the case of receiving a call, and provides a service Related information to the called exchange node 40b via the node B 20b and the RNC 30b in the Call Confirm message.

The Node Bs 20a and 20b are in charge of wireless communication with the terminals 10a and 10b and deliver messages received from the terminals 10a and 10b to the RNCs 30a and 30b and are transmitted from the RNCs 30a and 30b And wirelessly transmits the message to the terminals 10a and 10b. The RNCs 30a and 30b are responsible for controlling the Node Bs 20a and 20b and deliver messages transmitted from the Node Bs 20a and 20b to the exchange nodes 40a and 40b, And 40b to the nodes B 20a and 20b.

The originating exchange node 40a further includes a routing information transmission message (SRI) for requesting transmission of routing information to the HLR 50 when receiving a setup message (SETUP) from the originating terminal 10a, And transmits the service switching related information included in the SETUP message to the HLR 50 in the routing information transmission message SRI and transmits the routing information transmission message SRI to the HLR 50. [ (SRI ack) and transmits the service switching related information to the destination switching node 40b in an initial address message (IAM) to indicate that the service switching is possible.

When the HLR 50 receives a routing information transmission message (SRI) including the service switching related information from the source switching node 40a, the HLR 50 transmits a roaming number providing message (PRN) to the destination switching node 40b number to the destination switching node 40b and receives a response message (PRN ack) from the destination switching node 40b to route the outgoing call sent from the calling terminal 10a to the destination switching node 40b.

In addition, when the destination switching node 40b receives the address start message (IAM) including the service switching related information from the source switching node 40a after routing the outgoing call from the HLR 50, the calling terminal 10a Including temporary service selection information indicating that the service can be switched regardless of the capability of the called terminal 10b to transmit an Early Ring Back Tone (ERBT) or a Multimedia Ring Back Tone (MRBT) APM (application transport message) to the originating exchange node 40a.

When the above-described exchange switching node 40a receives an application transmission message (APM) including temporary service selection information from the destination switching node 40b after sending an address start message (IAM) to the destination switching node 40b A call progression message is transmitted to the calling terminal 10a via the RNB 30a and the node B 20a and the called terminal 10b transmits an ARBT or MRBT to the calling terminal 10a. And transmits temporary service selection information indicating that the service is switchable, regardless of the capability of the mobile terminal, in the call progress message. Then, after assigning a radio access bearer (RAB) to the calling terminal 10a based on the provisional service selection information, it transmits a continuity message (COT: continuity) to the called exchange node 40b, And receives an address complete message (ACM) from the node 40b.

In addition, when the destination switching node 40b receives the continuation message (COT) from the source switching node 40a after transmitting the application transmission message (APM) to the source switching node 40a, (Or MRBT) to the calling terminal 10a and proceeds to paging the calling terminal 10a while sending the ACM to the calling terminal 10a and proceeding to paging the calling terminal 10b with the ERBT Or MRBT) to provide the ring back tone to the calling terminal 10a in advance in the state that no incoming signal is transmitted to the actual called terminal 10b. Thereafter, a setup message (SETUP) including the service switching related information is transmitted to the receiving terminal 10b while paging the receiving terminal 10b, and a response to the setup message (SETUP) is transmitted from the receiving terminal 10b (Call Confirmed) including the actual service selection information by the called party.

When the call confirmation message (Call Confirmed) is received from the destination terminal 10b, the destination exchange node 40b allocates a radio access bearer (RAB) to the destination terminal 10b, (ALERTING) to the called terminal 10b to generate a ringing tone. Then, it transmits a call progress message (CPG) to the originating exchange node 40a to inform the originating exchange node 40a that the call is progressing to the originating terminal 10a, And transmits a response message (ANM: answer message) to the originating exchange node 40a so that the originating exchange node 40a connects the call channel with the originating terminal 10a.

The HLR 50 sends a roaming number providing message (PRN) to the terminating exchange node 40b when receiving a routing information transmission message (SRI) including the service switching related information BC1, BC2 from the source switching node 40a. (Roaming number 1), roaming number 2 (roaming number 2), and roaming number 2 (roaming number 2) to the response message (SRI ack) for the routing information transmission message (SRI) Lt; RTI ID = 0.0 > 40a. ≪ / RTI >

When the outgoing exchange node 40a receives the response message (SRI ack) including the roaming number 1 and the roaming number 2 from the HLR 50, the service switching related information (IAM) is added to the address start message (IAM) BC1, and BC2 to the destination switching node 40b. Upon receiving the address start message (IAM) including the service switching related information (BC1, BC2) from the source switching node 40a, the destination switching node 40b transmits the ERBT or MRBT to the calling terminal 10a To the outgoing exchange node 40a, an application transfer message (APM) including temporary service selection information BC1, BC2 indicating that service switching is possible regardless of the capability of the destination terminal 10b.

In this manner, when the source exchange node 40a receives the application transfer message APM including the temporary service selection information BC1 and BC2 from the destination switching node 40b, the RNB 30a and the node B 20a BC1 and BC2 to the originating terminal 10a via the base station 10a and transmits a call progress message to the originating terminal 10a via the radio access bearer 10a, (RAB), sends a continuation message (COT) to the terminating switching node 40b and receives an address completion message (ACM) from the terminating switching node 40b.

The terminating exchange node 40b transmits an address completion message (ACM) to the originating exchange node 40a to proceed with the paging process for the terminating terminal 10b and the ERBT (or MRBT And provides the ERBT (or MRBT) to the calling terminal 10a while proceeding with the paging and provides the ring back tone to the calling terminal 10a in advance in the state in which the incoming signal is not transmitted to the actual called terminal 10b. In addition, a setup message (SETUP) including the service switching related information (RI, BC1, BC2) is transmitted to the receiving terminal 10b while paging the receiving terminal 10b, (RI, BC1) from the called terminal 10b when the called terminal 10b supports the service switching, as the response to the message SETUP, , And BC2 (Call Confirmed).

In this manner, when the called exchange node 40b receives the call confirmation message (Call Confirm message) from the receiving terminal 10b, it assigns the radio access bearer (RAB) to the called terminal 10b based on the actual service selection information, An alerting signal is transmitted to the terminating terminal 10b to cause the terminating terminal 10b to generate an incoming call and send a call progress message (CPG) to the originating exchange node 40a, And informs the originating terminal 10a that the call is progressing. If the terminating terminal 10b responds by inputting the call button, it transmits an answer message (ANM) to the originating exchange node 40a and sends it to the originating exchange node 40a Thereby resetting the radio access bearer of the calling terminal 10a and connecting the communication channel between the calling and receiving terminals 10a and 10b.

When the service is switched by the called party, the outgoing exchange node 40a receives an application transfer message (APM) including the actual service selection information from the incoming exchange node 40b, and transmits a modification message MODIFY) to the calling terminal 10a and receives a MODIFY COMPLETE message informing the result of the service change in the response. When the originating terminal 10a receiving the modification message MODIFY resets the radio access bearer according to the switched service mode, the terminating exchange node 40b generates an application transfer message APM informing the successful service switching, Node 40b, thereby enabling switching between the calling and called terminals 10a and 10b and service switching during the call.

Hereinafter, a service switching method by a called party in call setup according to a preferred embodiment of the present invention will be described in detail with reference to FIGS. 3 to 5 attached hereto.

FIG. 3 is a flowchart illustrating a service switching method according to an embodiment of the present invention. FIG. 3 illustrates a method of performing service switching by selecting a recipient during a call setup process in a communication network providing an ERBT / MRBT. This service switching method can be implemented through the service switching system as shown in FIG. 1 and applicable to all wired and wireless communication networks capable of providing the call service and the ERBT / MRBT service. The embodiment of FIG. 3 will be described as follows.

First, the source exchange node 40a receives a call capable of switching service between the voice call and the video call from the calling terminal 10a (S10). When a call capable of switching the service of the voice call and the video call occurs from the calling terminal 10a, the calling switching node 40a requests the routing information to the called switching node 40b to process the call, And routes the call from the terminal 10a to the destination terminal 10b to the destination switching node 40b (S20).

Then, in order to provide the ERBT / MRBT service to the calling subscriber, the terminating switching node 40b generates temporary service selection information indicating that the service switching is possible regardless of the actual capability of the terminating terminal 10b, (S30), the source exchange node 40a allocates the call route to the calling terminal 10a based on the provisional service selection information transmitted from the destination side (S40).

At this time, the terminating exchange node 40b performs a paging operation for the terminating terminal 10b, while interworking with the terminating switching node 40a, and transmits the terminating terminal 10a via the terminating terminal 10a set by the terminating switching node 40a And the ring back tone according to the ERBT / MRBT service is provided to the calling terminal 10a (S50). That is, when a call routed from the calling terminal is received, the called exchange node 40b generates temporary service selection information indicating that the called terminal 10b is a terminal capable of switching service between the voice call and the video call, And provides the ERBT or MRBT to the calling terminal 10a until the call path is allocated between the calling terminal 10a and the called terminal 10b in cooperation with the source switching node 40a, The ring back tone is provided in advance to the calling terminal 10a in a state where no incoming signal is transmitted to the calling terminal 10a.

A call capable of switching between a voice call and a video call is received at the receiving terminal 10b and the called subscriber selects a desired service (video call or voice call) by pressing a button of the receiving terminal 10b, Generates the service selection information and transfers it to the destination exchange node 40b, and the destination exchange node 40b allocates the call route to the destination terminal 10b based on the actual service selection information received from the destination terminal 10b S60). The actual service selection information is a signal indicating whether service switching has been performed according to the recipient selection.

Thereafter, the destination switching node 40b confirms the actual service selection information, and when the service is switched by the called subscriber (for example, the calling party requests the video call but the called party switches to the voice call) In order to reset the communication path to the terminal 10a, the service switching information is transmitted to the source switching node 40a to inform the service switching (S70).

The originating switching node 40a checks whether the voice call / video call service is switched from the called party through the actual service selection information transmitted from the called exchange node 40b (S80), and the service switching according to the called party selection The call connection to the calling terminal 10a is reset based on the actual service selection information in step S81 so that the call between the calling terminal 10a and the called terminal 10b and the service can be switched during the communication in step S90.

FIG. 4 is a flow chart for explaining the 3GPP international standard applicable to the service switching method according to another embodiment of the present invention. In FIG. 4, a basic call for enabling switching of a video / voice service by a called party in a network not provided with an ERBT / FIG.

First, the calling terminal 10a transmits BC1 and BC2 to the originating exchange node 40a in a setup message (SETUP) including all of BC1 and BC2 in the sense that it is possible for the voice / video selection service by the called party during call setup S110). In this case, BC1 and BC2 are audio and video parameters. When BC1 contains audio and BC2 contains video, it indicates that the current call has attempted a voice call and the service can be switched to BC2 to be. If BC1 is video and BC2 is voice, it tries video call as an outgoing call and it means that service can be switched to voice.

Upon receiving the setup message (SETUP), the source exchange node 40a performs a routing information transmission message (SRI) to the HLR 50 to receive information on the destination switching node 40b where the called subscriber is located (step S120) , The HLR 50 routes the call to the terminating exchange node 40b by performing a roaming number providing message (PRN) to the terminating switching node 40b (step S130).

At this time, the source exchange node 40a transmits the address start message (IAM) including the BC1 and BC2 to the destination switching node 40b to notify that the source terminal 10a supports the service switching according to the selection of the destination subscriber (Step S140).

After receiving the address start message (IAM), the destination switching node 40b performs a paging procedure (step S151), then outputs a setup message (SETUP) including BC1 and BC2 information to the called terminal 10b (step S152) , The called terminal 10b sends a Call Confirm message including the service switching related information according to the selection of the called subscriber to the called exchange node 40b (step S153). For example, when the calling subscriber requests the voice mode of BC1 and the called subscriber selects the video mode of BC2 to switch the service, the order of BC in the call confirmation message is changed to BC2 and BC1, Lt; / RTI > node 40b. This means that the called subscriber does not use the BC1 selected in the calling party in the call mode and connects the call to the BC2 selected by the calling subscriber.

The destination switching node 40b transmits the service switching related information received from the destination terminal 10b to the source switching node 40a in the application transmission message APM at step S161, Service switching related information to the calling terminal 10a through a call progress message (step S162).

The calling terminal 10a recognizes that the called terminal 10b has changed the service setting to the BC2 (step S162), and thereafter sets it to the service mode set including the radio access bearer (RAB) setting procedure (steps S170 and S180) The call connection processing between the calling terminal 10a and the called terminal 10b is performed so that the call connection is possible. If BC1 is voice and the BC2 selected by the called party is video, a procedure for changing the call path from voice mode to video mode is performed. Conversely, if BC1 is video and BC2 selected by the called party is voice, A procedure for changing the call path is performed. This procedure can change the radio access bearer (video or voice) during call setup by the called party.

However, if the ERBT is provided in the communication network, before the called subscriber selects the video call / voice call service from the called terminal 10b, the video / voice call service is performed regardless of the capability of the called terminal 10b to provide the ERBT. Information indicating that voice service switching is available is first provided from the destination switching node 40b to the source switching node 40a. That is, the service switching related information actually selected by the called subscriber is not transmitted to the calling terminal but is arbitrarily transmitted to the calling terminal 10a regardless of the called terminal 10b at the called terminal, In the communication network providing the ERBT, there is a problem that the called subscriber can not normally provide the service switching function for selecting the video / voice mode.

By introducing the service switching method as shown in FIG. 5, the service switching function by the called subscriber can be normally provided even in the ERBT environment.

FIG. 5 is a flowchart illustrating a service switching method according to another embodiment of the present invention, which illustrates a service switching method in a mobile communication network, typically a WCDMA (Wideband-CDMA) network. Such a service switching method can be implemented through the service switching system shown in FIG.

First, the calling terminal 10a transmits a setup message (SETUP) to the originating switching node 40a in order to originate a call. In the SETUP message, a RI (repeat indicator), BC1 capability in a message (preferred service)] and BC2 [second bearer capability in a message (less preferred service)]. The fact that BC1 and BC2 are both included in the setup message (SETUP) means that the calling terminal 10a supports the service switching function (voice / video selection service) by the called party during call setup, and the corresponding setup message And is transmitted to the originating exchange node 40a via the originating node B 20a and the RNC 30a (S210).

In the setup message (SETUP) of step S210, BC1 is selected as a preferred service and BC2 is selected as a less preferred service. At this time, BC1 and BC2 are used as parameters for voice and image. When BC1 contains speech and BC2 contains video, it means that the current call originated call attempted a voice call and could switch to a video call BC2 after the call path was connected. If BC1 contains video and BC2 contains audio, it means that the current call originated the video call and can switch to the voice call BC2 after the call path is connected.

When the calling terminal 10a includes the service switching related information such as RI, BC1, and BC2 in the SETUP message and transmits the information to the calling switching node 40a, the calling switching node 40a transmits the service switching related information, 10a transmit the routing information transmission message (SRI) including the corresponding service switching related information BC1 and BC2 to the HLR 50 (S220).

Here, if the calling terminal 10a does not support BC2, the source exchange node 40a transmits a routing information transmission message (SRI) including only BC1, discards BC2 in BC1 and BC2, We continue the call progression only with. If the calling terminal 10a does not support BC1, it does not continue the call progression to BC2 alone but fails the call to BC1. For example, when the calling subscriber advances a video call, BC1 and BC2 are transmitted as images BC1 and BC2 from the calling terminal 10a to the source switching node 40a, In the case of a possible terminal, the originating exchange node 40a abandons BC2, continues call forwarding only to BC1, and can not artificially perform service switching from the called party to BC2.

When the HLR 50 receives a routing information transmission message (SRI) including the service switching related information from the source switching node 40a, the HLR 50 transmits a roaming number providing message (PRN) to the destination switching node 40b number of the call originating node 10a and transmits an outgoing call from the calling terminal 10a to the terminating exchange node 40b by receiving a response message (PRN ack) from the terminating exchange node 40b at step S230.

Through the process up to step S230, the outgoing exchange node 40a routes the call from the calling terminal 10a to the called terminal 10b to the called exchange node 40b at the time of call processing capable of switching the service of the voice call and the video call .

The HLR 50 transmits a roaming number 1 (roaming number 1) to the response message (SRI ack) for the routing information transmission message (SRI) when the called subscriber of the called terminal 10b is a subscriber capable of all of BC1 and BC2, , And roaming number 2 (roaming number 2) to the originating exchange node 40a (S220).

Thus, when the source exchange node 40a receives the response message (SRI ack) including the roaming number 1 and the roaming number 2 from the HLR 50, the calling terminal 10a supports the service switching function by the called party To the destination switching node 40b, the service switching related information (BC1, BC2) to the initial address message (IAM) in step S240.

The destination switching node 40b receives an address start message (IAM) including the service switching related information BC1 and BC2 from the source switching node 40a and transmits an early ring back tone (ERBT) to the calling terminal 10a (BC1, B2) indicating that the service can be switched, regardless of the capability of the called terminal 10b, in order to transmit a multimedia ring back tone (MRBT) message to the originating exchange node 40a (S250).

In step S250, the destination switching node 40b transmits the temporary service selection information BC1 and BC2 to the application transmission message (BC1, BC2) in the sense that BC1 and BC2 are all possible regardless of the capability of the destination terminal 10b for ERBT or MRBT transmission. (APM) to the originating exchange node 40a. The provisional service selection information BC1 and BC2 are transmitted to the called terminal 10a and the called terminal 10b independently of the capability of the called terminal 10b in order to provide an ERBT or MRBT before a call connection is established between the calling terminal 10a and the called terminal 10b And transmits information indicating that both the video call and the voice call service are available at the terminal 10b.

The outgoing exchange node 40a receives the application transfer message APM including the provisional service selection information BC1 and BC2 from the destination exchange node 40b via the RNB 30a and the node B 20a The calling terminal 10a notifies the calling terminal 10b that the service can be switched by transmitting a call proceeding message including the temporary service selection information RI, BC1 and BC2 to the calling terminal 10a (S260 ).

In this way, when the destination switching node 40a notifies the source switching node 40a of the temporary service selection information BC1, BC2 at the time of call processing capable of service switching, (COT: continuity) to the called exchange node 40b (S280), and transmits the continuous message (COT: continuity) to the called exchange node 40b (ACM: address complete message) (S290).

The destination switching node 40b transmits an address completion message (ACM) to the source switching node 40a and then proceeds with the paging process for the destination terminal 10b and in conjunction with the source switching node 40a (Or MRBT) to the calling terminal 10a and provides the ring back tone to the calling terminal 10a in advance (S310) without the receiving signal being transmitted to the actual called terminal 10b.

Then, the destination switching node 40b transmits a SETUP message (SETUP) including the service switching related information (RI, BC1, BC2) to the destination terminal 10b while paging the destination terminal 10b (Call Confirmed) as a response to the setup message (SETUP) from the terminating terminal 10b. When the terminating terminal 10b supports the service switching, the terminating terminal 10b receives the call confirming message (Call Confirmed) including the service switching related information (RI, BC1, BC2) designated by the service switching information (S330).

The Call Confirm message at step S330 illustrates a case where the called subscriber selects BC2 as a preferred service at the called terminal 10b. The called terminal 10b supports the service switching function. However, when the called subscriber selects BC2 other than the BC1 selected in the calling terminal, the called terminal 10b selects BC2 from the call confirmation message (Call Confirm) BC1. If the called terminal 10b can only support BC2, it responds by including BC2 only in a call confirmation message (Call Confirm message).

When the called exchange node 40b receives a call confirmation message from the called terminal 10b, the called exchange terminal 40b transmits the call confirmation message to the called terminal 10b based on the service switching related information (RI, BC1, BC2) And allocates a radio access bearer (RAB) for the mobile station to connect to the link (S340). As described above, the call confirmation message (Call Confirm) coming to the destination switching node 40b includes the service switching related information (RI, BC1, BC2) according to the called party selection. Then, the destination switching node 40b sends an ALERTING signal to the destination terminal 10b to cause the destination terminal 10b to generate a destination ring (S350) (CPG) (S360), and the originating switching node 40a transmits a ringback tone corresponding to the ALERTING signal to the calling terminal 10a to notify that the call is proceeding (S370).

When the called subscriber inputs a call button at the receiving terminal 10b and transmits a connection message (CONNECT) to the called exchange node 40b (S380), the called exchange node 40b transmits a response message ANM The call exchange node 40a transmits a connection message (CONNECT) to the calling terminal 10a so that the calling channel between the called terminal 10b and the calling terminal 10a is transmitted to the calling exchange node 40a (S390) (S410).

The call is completed through the process up to step S410, and the service can be switched by the calling / called subscriber thereafter (S420). However, until this state, the calling subscriber selects BC1 as the preferred service through step S210, and the called subscriber selects BC2 as the preferred service through step S330, so that the radio access bearer on the call / (I.e., the calling party is set to the voice and the called party is set to the video, or conversely, the calling party is set to the video and the called party is set to the voice), normal communication can not be made between the calling party and the called party.

Accordingly, the terminating exchange node 40b transmits the service switching related information indicating whether the service switching has been performed by the called subscriber in the receiving terminal 10b in step S330, that is, the actual service selecting information (modify codec, selected codec BC2 in the application transmission message APM to the originating exchange node 40a at step S430. Here, the terminating switching node 40b checks whether or not the service switching according to the recipient selection is performed through the actual service selection information (modify codec BC2), and when the service switching is performed, It notifies the originating exchange node 40a that the service switchover has been done. That is, in FIG. 5, since the preferred service is switched to BC2 by the called subscriber, the called exchange node 40b transmits an application including the actual service selection information (modify codec, BC2) (S430) to the originating exchange node 40a that the radio access bearer in the call path is changed to BC2 via the transmission message (APM).

The originating exchange node 40a having received the application transfer message (APM) notifies the originating terminal 10a of the service transition of the terminating terminal 10b so that a subsequent procedure for service switching can be performed at the originating terminal (S440 ). The calling exchange terminal 40a sends a modification message MODIFY to the calling terminal 10a to notify the switching of the service to the BC2 in step S440 and the calling terminal 10a having received the modification message transmits the modified service codec (MODIFY COMPLETE) for notifying the result of the change to the outgoing exchange node 40a via the node B 20a and the RNC 30a after changing the preference service from BC1 to BC2 based on the preference service (S450).

The originating exchange node 40a reestablishes the radio access bearer in the call of the originating terminal 10a according to the change result transmitted from the originating terminal 10a in step S460 and then transmits service switching related information successful codec modification to the destination exchange node 40b (S470).

The radio access bearer in the call path between the calling terminal 10a and the called terminal 10b is set to the same type based on the service BC2 selected by the called subscriber through the process up to step S470. The calling subscriber terminal 10a and the called subscriber terminal 10b can freely perform the voice call and video call service according to the user's choice. (S480).

While the present invention has been described in connection with what is presently considered to be practical exemplary embodiments, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, You will understand.

Therefore, it should be understood that the above-described embodiments are provided so that those skilled in the art can fully understand the scope of the present invention. Therefore, it should be understood that the embodiments are to be considered in all respects as illustrative and not restrictive, The invention is only defined by the scope of the claims.

The present invention can be applied to a communication network that provides a function of switching between voice call and video call services. According to the present invention, in a communication network environment providing an ERBT, services of a voice call and a video call can be freely switched according to a selection of a called subscriber during a call setup. In a communication network environment providing an ERBT, When the service mode selected by each subscriber is different, the call connection can be normally performed.

1 is a configuration diagram illustrating a service switching system according to an embodiment of the present invention;

2 is a configuration diagram illustrating a service switching system according to another embodiment of the present invention;

3 is a flowchart illustrating a service switching method according to an embodiment of the present invention;

4 is a flowchart illustrating an international standard applicable to a service switching method according to another embodiment of the present invention.

5 is a flowchart illustrating a service switching method according to another embodiment of the present invention.

DESCRIPTION OF THE REFERENCE SYMBOLS

10a, 10b: terminal 20a, 20b: node B

30a, 30b: RNC 40a, 40b:

50: HLR

Claims (8)

A call connection method for routing a call from a calling terminal to a called terminal during call processing capable of switching between a voice call and a video call, An originating exchange node for receiving provisional service selection information indicating that the called terminal is capable of switching service from the called terminal to the calling terminal and for connecting the calling terminal to the calling terminal; And And notifies the called terminal of the possibility of service switching by transmitting the provisional service selection information to the outgoing exchange node upon receiving the routed call from the outgoing exchange node, A ring back tone is provided to the calling terminal through a call path connected between the calling switching node and the calling terminal until a call is allocated between the calling terminal and the called terminal, And a destination switching node for receiving the destination switching node. The method of claim 1, (RBT) or a multimedia ring back tone (MRBT) to the calling terminal in cooperation with the calling / receiving exchange node to provide a ringback tone in advance to the calling terminal in a state where a call signal is not transmitted to the called terminal Service switching system. The method of claim 1, Wherein the calling terminal is configured to allocate a call channel of the called terminal based on the actual service selection information and to confirm the actual service selection information and to re-establish the call path of the calling terminal when the service switching is performed by the called subscriber, And notifies the service switching by transmitting the actual service selection information to the service switching system. 4. The method of claim 3, And re-establishing a call path to the calling terminal based on the actual service selection information to enable service switching between the calling terminal and the called terminal and during a call. Receiving from the calling terminal a call capable of switching service between a voice call and a video call; Routing the call received from the calling terminal to the called switching node managing the called terminal; Generating temporary service selection information indicating that the called terminal is a terminal capable of switching service between a voice call and a video call and notifying the called exchange node when the called exchange receives the routed call; The originating exchange node notifying the calling terminal that service switching is possible at the called terminal and connecting the call path to the calling terminal; The ring back tone is provided to the calling terminal through a call path connected between the calling switching node and the calling terminal until the called switching node interlocks with the calling switching node and a call path is allocated between the calling terminal and the called terminal ; And And receiving the actual service selection information informing whether the destination switching node has switched the service according to the recipient selection from the destination terminal. 6. The method of claim 5, The destination switching node provides an early ring back tone (ERBT) or a multimedia ring back tone (MRBT) to the calling terminal in cooperation with the calling switching node, And a ring back tone is provided in advance. 6. The method of claim 5, And allocating a call path of the called terminal based on the actual service selection information when the called exchange node receives the actual service selection information. 8. The method of claim 7, If the destination switching node confirms the actual service selection information and the service switching is performed by the called subscriber, notifying the service switching by transmitting the actual service selection information to the source switching node; And And reconfiguring the call connection to the calling terminal based on the actual service selection information to allow the calling and switching node to switch between the calling terminal and the called terminal and to switch the service during the call.

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