KR101581047B1 - Fallback method of intelligent network service and mobile communication system therefor - Google Patents

Abstract

A method for easily providing a fallback function in an intelligent network service and a mobile communication system therefor are disclosed. According to the present invention, it is possible to notify the originating terminal of service conversion availability through a CALL PROCEEDING message based on the result of the codec negotiation of the destination switching center, and, when the codec negotiation result after connection of the originating terminal and the codec information received from the destination terminal are different, And informs the calling terminal that service conversion is not possible.

Early ring back tone (ERBT), fallback, intelligent network service

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fallback method of an intelligent network service and a mobile communication system therefor.

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mobile communication system field, and more particularly, to a method and a mobile communication system for providing a fallback function in an intelligent network service.

SCUDIF (service change and UDI fallback) is a service that performs fallback and service conversion on multimedia (for example, video call) and speech call such as unrestricted digital information (UDI) and restricted digital information (RDI) change) service that is defined in 3GPP.

A service change is a service for switching from a video call to a voice call or a voice call to a video call by a user during a call.

A fallback is a service that allows a caller to set up a call to one possible service without ending the call if the caller requests two possible services (video call and voice call).

Such a SCUDIF function provides a shorter call setup time and a higher call success rate than a voice call attempt through a redial method in the case of a conventional video call failure. In addition, according to the selection of the user during the call, the service can be provided to switch between the voice call and the video call without ending the call.

The mobile communication system provides an early ring back tone (ERBT) service for providing a call waiting tone until a call is connected to a called terminal after a call is made to a calling terminal together with a paging procedure. There is no way to notify the originating terminal of the 3GPP standard when the ERP service supports only voice service. Therefore, the calling terminal can perform speech preferred service change, but it is impossible to fall back to multimedia, which causes a disconnection of a calling-and-receiving state.

The present invention provides a method for easily providing a fallback function in an intelligent network service and a mobile communication system therefor.

The mobile communication system according to the present invention notifies the originating terminal of service conversion availability through a CALL PROCEEDING message based on a codec negotiation result of a destination switching center and notifies the codec negotiation result after the connection of the originating terminal and the codec information And notifies the calling terminal that the service conversion is not possible when the fallback occurs.

Also, the fallback method of the intelligent network service of the present invention comprises the steps of: a) informing the calling terminal through the CALL PROCEEDING message whether the service can be converted based on the codec negotiation result of the destination switching center; b) comparing the codec negotiation result after the connection of the originating terminal with the codec information received from the terminating terminal to recognize occurrence of fallback; And c) when the fallback occurs, notifying the calling terminal that the originating exchange can not convert the service when the fallback occurs.

According to the present invention, a service change and UDI fallback (SCUDIF) method considering an early ring back tone (ERBT) includes a result of codec negotiation (multimedia preferred SCUDIF call or speech preferred SCUDIF call) If the result of the reception from the called terminal is different (fallback to multimedia call or fallback to speech call), unnecessary procedures are not performed for the codec negotiation procedure.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the following description, well-known functions or constructions will not be described in detail if they obscure the subject matter of the present invention.

1 is a block diagram illustrating a procedure for performing a fallback method according to an embodiment of the present invention. Referring to FIG. 1, the calling terminal 10 transmits RI, BCsp, BCmm, and Supported Codec (for example, x, y, z, mm,. To the originating exchange 20 (step S10). FIG. 2 is a diagram showing an example of a standard of an RI (repeat indicator) according to an embodiment of the present invention. BC1 and BC2 have BC values related to speech or multimedia and the order BC1 and BC2 of the bearer capacity BC is the service priority set by the calling terminal.

The originating exchange 20 which has received the SETUP message transmits an initial address message (IAM) for the SCUDIF call to the destination switching center 30 and transmits a supported codec to the destination switching center 30 (S20). The destination exchange 30 receiving the IAM transmits the IAM to negotiate the codec with the ERBT server 40 (S30). The ERBT server 40 does not support the MuMe (mm) codec because it is linked with the ISDN (ISDN user part). Therefore, the terminating exchange 30 removes the mm codec from the IAM to be transmitted to the ERBT server 40 and transmits it. The ERBT server 40 receiving the IAM compares / analyzes the codecs (e.g., x, y, z) supported by the IAM and selects a codec to use for the call, To the destination switching center 30 using an application transport mechanism (APM) (S40). The terminating exchange 30 transmits the codec negotiation result of S30 to S40 with the ERBT server 40 including information on the mm codec to the originating exchange 20 using the APM (S50). The originating exchange 20 constructs an availabe codec list and transmits a CALL PROCEEDING message including RI, BC1 (speech), and BC2 (multimedia) to the calling terminal 10 (S60).

A radio access bearer assignment procedure S70 between the calling terminal 10 and the originating exchange 20, a paging procedure S110 between the called exchange 30 and the called terminal 50, A radio access bearer assignment procedure S110 between the called terminal 30 and the called terminal 50, a CONNECT message S180 between the called terminal 50 and the called exchange 30, A conversation channel between the calling terminal 10 and the called terminal 50 is connected using the CONNECT message between the calling terminal 10 and the called terminal 10 at step S210. Now, the call is established between incoming and outgoing calls.

The call terminal 10 sets a service change not available in the reserved area of the NOTIFY message for the fallback notification procedure when the fallback occurs due to the change of the supportable codec list of the called terminal 50. [ For example, when the calling terminal 50 does not allow a change to a video call during a voice call or does not permit a change to a voice call during a video call, it is inevitable to change the supportable codec list configured in the originating exchange 20. 3 is a diagram illustrating an exemplary configuration of a NOTIFY message according to an exemplary embodiment of the present invention. Referring to FIG. Referring to FIG. 3, in the SPp service in which a voice call is connected to a voice call and a voice call is connected and the voice call is changed according to a subscriber request, only a voice call is possible. SP service, or when a video call is changed to an MM service which can not be changed to a voice call after the call is connected since a video call is possible only in a MMp service in which a video call is connected and a voice call is changed in response to a subscriber request, The control unit 20 sets the notify indicator of the NOTIFY message to be transmitted to the calling terminal 10 to H'40 and notifies the calling terminal 10 that the service conversion is not possible.

Therefore, the caller recognizes that the service conversion is not possible through the NOTIFY message, and does not change the service by pressing the service change key during the call.

In this embodiment, the case where the mobile communication system performs the ERBT service is described as an example. However, when the result of the codec negotiation performed when the external IP is interworked according to the intelligent network service is different from the result received from the called terminal, The same can be applied.

While the above methods have been described through specific embodiments, the methods may also be implemented as computer readable code on a computer readable recording medium. A computer-readable recording medium includes all kinds of recording apparatuses in which data that can be read by a computer system is stored. Examples of the computer-readable recording medium include a ROM, a RAM, a CD-ROM, a magnetic tape, a floppy disk, an optical data storage device, and the like, and may be implemented in the form of a carrier wave (for example, transmission over the Internet) . In addition, the computer-readable recording medium may be distributed over network-connected computer systems so that computer readable codes can be stored and executed in a distributed manner. In addition, functional programs, codes, and code segments for implementing the above embodiments can be easily deduced by programmers of the present invention.

While the invention has been described in connection with certain embodiments thereof, it will be apparent to those skilled in the art that various modifications and variations can be made therein without departing from the spirit and scope of the invention . It is also contemplated that such variations and modifications are within the scope of the claims appended hereto.

1 is a block diagram showing a procedure for performing a fallback method according to an embodiment of the present invention;

FIG. 2 is an exemplary view showing a standard of RI according to an embodiment of the present invention; FIG.

FIG. 3 is an exemplary view showing the configuration of a NOTIFY message according to an embodiment of the present invention; FIG.

Claims (7)

A mobile communication system, And the service provider notifies the calling terminal of service conversion availability based on a result of the codec negotiation of the called exchange. When the codec negotiation result is different from the codec information received from the called terminal after the call connection of the calling and called terminal, And an originating exchange for notifying the terminal of the originating exchange. The method according to claim 1, The destination exchange performs a codec negotiation procedure with an ERBT server to perform an ERBT (early ring back tone) service together with a paging procedure, and notifies the result to the originating exchange. 3. The method of claim 2, Wherein the originating exchange notifies that service conversion is impossible using a reserved area of a Notify message. The method of claim 3, Wherein the ERBT server compares / analyzes a codec supported by the ERBT server and selects a codec to use for the call. As a fallback method of intelligent network service, a) informing the calling terminal of service conversion availability based on a codec negotiation result of the destination exchange; b) comparing the result of the codec negotiation with the codec information received from the destination terminal after the call connection of the originating terminal, and recognizing occurrence of a fallback; And and c) notifying the calling terminal that the originating exchange is unable to convert the service when a fallback occurs. 6. The method of claim 5, Wherein the intelligent network service includes an early ring back tone (ERBT) service. The method according to claim 6, Wherein the originating exchange notifies that service conversion is not possible using a reserved area of a Notify message.

Images