KR101172821B1 - Method for improving the imcomplete call in Video Telephony Service - Google Patents

Abstract

The present invention relates to a video telephony service in a 1xEV-DO system. More particularly, the present invention relates to a video telephony service for improving a drop phenomenon caused by a poor wireless environment during H.323 connection setup in a video telephony service of a 1xEV-DO system. A method of improving incomplete call of service.

According to an embodiment of the present invention, a call signaling is set in an acceptance request message and transmitted to the gatekeeper as the calling mobile terminal attempts a video call, and the gatekeeper accepts the mobile IP address of the called mobile terminal. Transmitting a signaling setup message transmitted from the calling mobile terminal to the called mobile terminal, and in response thereto, transmitting the signal from the called mobile terminal to the called mobile terminal. Transmitting a progress message to the originating mobile terminal, wherein the gatekeeper receives an acknowledgment message several times in succession according to a preset time interval after the accept request message is transmitted from the called mobile terminal to the gate keeper; Transmitting to the called-party mobile terminal.

According to the present invention, even when a user environment is momentarily degraded by increasing the number of transmissions of an acceptance confirmation message that the gatekeeper transmits to the called mobile terminal only once during the existing H.323 connection, the called mobile terminal receives the acceptance confirmation message. The probability of doing so is increased, and as the reception probability increases, the success rate of the video telephone service is increased.

1xEV-DO system, video call service, accept request message, H.323, H.255, drop phenomenon, degradation

Description

{Method for improving the imcomplete call in Video Telephony Service}

1 is a configuration diagram for a video telephony service in a 1xEv-DO system according to an embodiment of the present invention;

2 is a flowchart illustrating a method of improving an incomplete call during video telephony service in a 1xEV-DO system according to an exemplary embodiment of the present invention.

Description of the Related Art

100: calling mobile terminal 101: called mobile terminal

110: calling party radio station 111: called party radio station

120: packet data service node 130: data core network

140: media gateway controller 150: mobility manager

160: Gatekeeper

The present invention relates to a video telephony service in a 1xEV-DO system. More particularly, the present invention relates to a video telephony service for improving a drop phenomenon caused by a poor wireless environment during H.323 connection setup in a video telephony service of a 1xEV-DO system. A method of improving incomplete call of service.

The basic concept of cellular mobile communication was proposed at Bell Laboratories in the 1940s, and practical commercial services started in 1983 in the United States with an analog method called Advanced Mobile Phone Service (AMPS).

Code Divison Multiple Access (CDMA) is a North American-oriented synchronous method in which all base stations and mobile terminals operate in time using a Global Positioning System (GPS) at a base station, and a European-oriented asynchronous method that does not use GPS at a base station. There is this.

Synchronous mobile communication in the wireless section protocol is divided into CDMA One of IS-95 series of 2G (Generation) and CDMA2000 of IMT-2000 series of 3G, and synchronous CDMA defined based on IS-2000 is CDMA2000 1x and There is CDMA2000 3x.

In the above, CDMA2000 1x uses a single 1.25MHz frequency width like the existing IS-95, and CDMA2000 3x uses three existing IS-95 frequency widths.

In addition, 1xEV is based on the High Data Rate (HDR) protocol, which is a high-speed packet data method proposed by Qualcomm. 1xEV-DO transmits only data and 1xEV-DV simultaneously transmits data and voice.

In order to provide video telephony services in the IMT-2000 system, H.323, an international standard defined by the International Telecommunication Union (ITU), must be implemented. The H.323 provides video telephony services in an IP network, which is a packet data network. .

In general, the video telephony service start-up process using the 1xEV-DO system is divided into three stages: EV-DO connection establishment, TCP connection establishment, and H.323 connection establishment.

That is, it performs EV-DO connection setting for resource allocation between the calling mobile terminal and the called mobile terminal and the EV-DO communication network, and when the process is completed, performs TCP connection setting for H.323 processing for the video call. do.

A gate keeper transmits one setup message to a called mobile terminal for H.323 processing for the video call, and thereafter a RAS in H.323 between the called mobile terminal and the gate keeper. (Admission Requset (ARQ) and Admission Confirm (ACF) message exchange are performed through the Registration Admission Status protocol.

That is, in the accept request process, the called mobile terminal requests approval from the gatekeeper, and the gatekeeper transmits a response, that is, an Admission Confirm (ACF) message to the approval request, and then calls. The rest of the setup, the waiting process and the access process, are performed.

However, in the case of the RAS protocol in H.323, there is no response concept because it is based on UDP rather than TCP, unlike other signaling. Therefore, either the destination mobile terminal or the gatekeeper transmits a corresponding message. If the call is not received, the call is terminated after waiting for a time until the response timeout without further progress.

That is, during the H.323 access process, the gator keeper transmits an acknowledgment message to the called-party mobile terminal only once, and at this time, the called-party mobile terminal transmits an accept request message and then receives an acknowledgment message from the gatekeeper. There is a problem that the call is terminated due to a response timeout when the acceptance confirmation message transmitted from the gatekeeper is not received when waiting for a time of about 2 seconds.

The present invention has been made to solve the above problems, and in order to prevent the loss of the acknowledgment message due to instantaneous deterioration of the wireless environment, which is the cause of the poor reception during the H.323 connection process, the gatekeeper to the called mobile terminal. An object of the present invention is to provide a method for resolving an incomplete call of a video telephone service that transmits an acknowledgment message several times in succession.

In order to achieve the above object, an incomplete call improvement method of a video telephony service according to an embodiment of the present invention comprises: a) setting a call signaling in an accept request message as a video call is attempted by the calling mobile terminal; Transmitting to a keeper, b) sending, from the gate keeper, an acknowledgment message containing the mobile IP address of the called mobile terminal to the calling mobile terminal, and c) the gate keeper at the calling mobile terminal. Transmitting the signaling setup message transmitted to the called mobile terminal, and in response, transmitting the progress message transmitted from the called mobile terminal to the calling mobile terminal, d) the called mobile terminal; After the acceptance request message is sent to the gatekeeper at a predetermined time interval, the gatekeeper And transmitting an acknowledgment message to the called-party mobile terminal a plurality of times in succession.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1 is a configuration diagram for a video telephone service in a 1xEV-DO system according to an embodiment of the present invention.

As shown, the system for video telephony service includes mobile terminal 100 (101), wireless station (110) (111), packet data service node (120), data core network (130), media gateway controller (140). , Mobility manager 150, gatekeeper 160.

The mobile terminal 100 or 101 is a mobile IP input / output device for providing a video telephone service. The mobile terminal 100 or 101 is a mobile IP input / output device that encodes / decodes video and audio signals into frames to form an IP packet and sends the voice / video encoder to another H.323 entity. And H.323 protocol stacks (H.225, H245) for connection and management of calls.

The mobile terminal 100 (101) is preferably QCIF (174 × 144) or more pixels, support at least 10 frames per second, it is preferable that the video and camera functions are supported.

Radio station 110, 111 is a base station performing wireless communication with the mobile terminal 100, 101, RP interface processing, packet subscriber state management, packet service connection with a wireless network and data core network 130 with It includes a controller that performs the interworking.

The packet data service node 120 is configured to perform a PPP connection and visit subscriber management with the mobile terminal 100, 101, and forward / receive packet data of the mobile terminal 100, 101.

The data core network 130 is configured to be connected to the packet data service node 120, the media gateway controller 140, the mobility manager 150, and the gatekeeper 160.

The mobility manager 150 is configured to perform an outgoing / incoming packet data transfer function in association with the packet data service node 120 at the current location of the mobile terminal 100, 101.

The gatekeeper 160 is connected to the data core network 130 to process an image call, manage subscriber information and status of the mobile terminal 100 and 101, and perform authentication and charging according to the subscriber information. It is composed.

2 is a flowchart illustrating an incomplete call improvement method occurring during a video call service in a 1xEV-DO system according to an embodiment of the present invention.

First, in the state in which the EV-DO connection setting and the TCP connection setting are completed between the calling mobile terminal 100 and the called mobile terminal 101, an admission request message is generated as the calling mobile terminal attempts a video call. Call signaling is set to ARQ and transmitted to the gatekeeper 160 (S200).

The gatekeeper 160 is an ITU standard protocol for call control in an H.225 (H.323 voice / video environment) through an Admission Confirmation (ACF) and a mobile terminal for establishing a call in a RAS channel. A protocol transmitted between the gatekeepers) and the mobile IP address of the called mobile terminal 101 are found and transmitted to the calling mobile terminal 100 (S210).

Thereafter, the originating mobile terminal 100 transmits an H.225 call signaling setup message (setup) to the called mobile terminal 101 via the gatekeeper 160 (S220).

On the other hand, the called-party mobile terminal 101 responds by transmitting an H.225 call progress message (Call Processing) to the calling-party mobile terminal 100 via the gatekeeper 160 (S230).

On the other hand, the called-party mobile terminal 101 is registered with the gatekeeper 160, but is not yet accepted (Admission) state, so the acceptance request message (Admission Request; ARQ) to the gatekeeper 160 Transmit (S240).

Thereafter, the gatekeeper 160 transmits an acceptance confirmation message (ACF) to the called-party mobile terminal 101 in response to the acceptance request message ARQ and accepts it (S250).

At this time, in order to improve the existing method, which is likely to be lost due to instantaneous deterioration of a wireless environment as the number of transmission of the acknowledgment message is one time, in one embodiment of the present invention, the number of transmission of the acknowledgment confirmation message is at least three times. Set to run continuously.

That is, with the video-related timer of the video telephony service set to 30 seconds, for example, EV-DO connection setup, TCP connection setup and H.323 connection setup must be successfully performed within the set time. A confirmation message must be sent at least three times in succession. To do this, the gatekeeper 160 sends a setup message (setup) with the time allotted to the H.323 connection setup, for example, within 15 seconds. Set the interval for sending confirmation messages.

More specifically, the gatekeeper 160 sets a time margin of 200 ms for processing an acceptance request message (ACF) transmitted by the called-party mobile terminal 101, and an acceptance confirmation message (ACF) sets the gate keeper (ACF). When a time margin of 200 ms is set in the mobile terminal 101 at the called party 160, the time available for transmitting the acknowledgment message (ACF) at least three times in succession by the gatekeeper 160 is about 1.5. Seconds.

Accordingly, the acknowledgment message may be continuously transmitted from the gatekeeper 160 to the called-party mobile terminal 101 at least three times at a time interval of 500 ms.

Thereafter, the called mobile terminal 101 sends an H.225 waiting message (Alerting) to the calling mobile terminal 100 (S260), and then connects the H.225 connected message (Connect) to the calling mobile terminal 100. Send a call to notify the call setup (270).

Through this, the calling mobile terminal 100 and the called mobile terminal 101 are H.245 (ITU control signal protocol for H.323 multimedia communication) provided by the gatekeeper 160, and are qualified as a mobile terminal. To exchange and open and close logical channels) to perform a video telephony service through control channel signaling.

Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art to which the present invention pertains can implement the present invention in other specific forms without changing the technical spirit or essential features, The examples are to be understood in all respects as illustrative and not restrictive.

In addition, the scope of the present invention is specified by the appended claims rather than the detailed description, and all changes or modifications derived from the meaning and scope of the claims and their equivalent concepts are included in the scope of the present invention. Should be interpreted as

As described above, in the method of improving an incomplete call of a video telephone service of the present invention, the present invention increases the number of transmissions for an acknowledgment message that a gatekeeper transmits only once to a called mobile terminal during a conventional H.323 connection. Even if the environment is momentarily degraded, the probability that the called-party mobile terminal receives the acceptance confirmation message increases, and the increase in the reception probability increases the success rate of the video telephone service.

Claims (4)

In the video telephone service method between the calling mobile terminal and the called mobile terminal, a) establishing call signaling in an accept request message and transmitting the same to a gatekeeper as the calling mobile terminal attempts a video call; b) transmitting, at the gatekeeper, an acceptance confirmation message including the mobile IP address of the called mobile terminal to the calling mobile terminal; c) the gatekeeper transmits a signaling setup message transmitted from the calling mobile terminal to the called mobile terminal, and in response, the gatekeeper transmits a progress message sent from the called mobile terminal to the calling mobile terminal. Transmitting to; d) transmitting, by the gatekeeper, an acknowledgment message to the called-party mobile terminal a plurality of times in succession after a acceptance request message is transmitted to the gatekeeper by the called-party mobile terminal; A method for improving an incomplete call of a video telephone service. The method of claim 1, and in step d), the gatekeeper transmits the acceptance confirmation message at least three times in succession at a time interval set to the called-party mobile terminal. The method according to claim 1 or 2, And the acceptance confirmation message is transmitted at a time interval of 500 ms. The method of claim 1, after step d), e) transmitting, by the gatekeeper, to the calling mobile terminal a waiting message sent from the called mobile terminal; and f) establishing a call by the gatekeeper transmitting the access message transmitted from the called mobile terminal to the calling mobile terminal.

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