KR20000025676A - Broadband video telephone apparatus and method for processing events - Google Patents

Abstract

PURPOSE: A broadband video telephone apparatus is provided to cope with video telephone service changes flexibly and to facilitate a maintenance of a telephone apparatus by converting an event source into an event having a certain structure form. CONSTITUTION: A video telephone application module(10) provides video telephone application services for executing various commands and performing event conversions, processes, and record procedures. a user-to-user signal module(20) performs capability exchanges, logic channel establishment and release, mode change requests, reciprocal transfer delays under a control of the video telephone application module(10). A video telephone apparatus module(30) is composed of a hardware for the video telephone and application program interfaces and displays images from a camera and an MPEG-2 decoder.

Description

Broadband videophone device and event processing method

The present invention relates to a broadband video telephony device for providing video telephony services in a broadband integrated information network (hereinafter referred to as B-ISDN). In particular, a call state and an event suitable for a new B-ISDN international standard can be defined by itself. Broadband that enables efficient and flexible event handling by allowing the user to reuse the system with minimal changes without changing the application software of the video telephony device even when the defined call state or event is changed or added. A video telephone apparatus and an event processing method thereof.

When viewed at any point in time, the broadband videophone device analyzes call status and events occurring at that time and provides proper operation.

In order to implement a videophone device for a certain purpose (ISDN, LAN, B-ISDN, etc.), call conditions and events that are appropriate for the purpose must be defined first, and an appropriate processing method must be implemented for each event.

Currently, ISDN video phone or Internet video phone S / W, which is generally used, cannot be used in B-ISDN network due to differences in user-user signaling and communication networks.

B-ISDN communication network can accommodate a variety of multimedia services because it provides a wideband (Broadband) transfer bandwidth (bandwidth) that can not be provided in the existing communication network.

In order to accommodate such various multimedia services, more various signaling messages are required than conventional signaling methods.

For this purpose, the B-ISDN communication network recommends new network-to-user and user-to-user signaling that is different from existing signaling.

These new signaling procedures are much more complex and diverse than existing ones, resulting in more events within the video telephony device.

In addition, future video phone service is expected to add or change significant service for various reasons.

In this case, you need to change existing events or add new ones.

Therefore, in order to develop a broadband video telephony device for a B-ISDN network, there has been a problem of processing an event more systematically and efficiently than a conventional method.

Accordingly, the present invention was devised to solve the above-mentioned problems, and when a call state or event defined by itself defining a call state and event conforming to the new B-ISDN international standard is changed or added. To provide a wideband videophone device and an event processing method that can efficiently and flexibly handle events by making it possible to reuse them with minimal changes without changing the application software of the videophone device as a whole. There is this.

1 is an overall block diagram of a broadband video telephone apparatus according to the present invention.

<Description of Symbols for Major Parts of Drawings>

10: video call application module 20: user-user signal module

30: video telephone device module 11: user command processing section

12: Phonebook section 13: Timer processing section

14: event conversion section 15: event processing section

16: Event Logging Section 17: Overlay Application Section

18: MPEG-2 Application Section 19: ATM Application Section

21: H.245 API Section 22: H.245 Protocol Management Section

23: H.245 protocol section 24: message processing section

31-34: API 35: Overlay Device

36: MPEG-2 decoder 37: MPEG-2 encoder

38: ATM matcher

In order to achieve the above object, the present invention executes various commands generated from a video telephone user, manages a phone book and a timer, and performs an event conversion, processing, and recording process for various event sources generated in the video telephone apparatus. A video telephony application module for providing a video telephony application service to perform a task;

Under the control of the video telephone application module, among the H.245 protocol procedures of the international standard, the host / slave terminal determination, capability exchange, logical channel establishment and release, mode change request, round trip transmission delay, etc. are performed. An end-to-end signaling module for carrying out end-to-end control messages and processing protocols for each control message, such as performing ASN.1 encoding and vice versa; And

It is composed of hardware part of broadband video telephone device and application program interface (API) for each device, and it is an international standard for moving picture compression of camera input or media (Moving Picture Experts Group, hereinafter referred to as MPEG). -2 shows video output from decoder and encodes MPEG-1 quality voice and MPEG-2 quality video, which is essential for broadband video telephony service for Broadband ISDN (hereinafter referred to as B-ISDN). In addition, it is characterized in that it comprises a video telephone device module for interfacing to an asynchronous transfer mode (hereinafter referred to as ATM) network.

In addition, in order to achieve the above object, the present invention provides a local telephone user command generated from a user of a broadband video telephone apparatus, a timeout generated in a timer processing section, and an H.245 generated in an H.245 protocol management section. An event conversion process of converting an event source into an event as a result of execution of an API function, such as information about a socket state occurring in an ATM API section;

An event processing step of processing an event for each input event converted through the event conversion process using telephone state information which is a newly defined integrated state variable by using a correlation between a current call step and a VC state; And

And an event recording process for systematically recording the event processing process in the order in which they occurred.

The operation principle according to the present invention will be described in detail as follows.

The present invention defines itself call conditions and events that conform to the new B-ISDN international standard.

Even if the call state or event defined in this way is changed or added, it is possible to handle the event efficiently and flexibly so that it can be reused with minimal change without changing the application software of the video telephone apparatus as a whole.

Since the present invention corresponds to a part of the overall components of the video telephone apparatus, it is necessary to understand other parts in order to properly understand the present invention.

Considering this point, a general description of the video telephone apparatus will be given first.

In particular, the components related to the present invention will be described in detail, and the remaining parts are simply mentioned.

Event processing, which is a subject matter of the present invention, is described in detail after this description.

Broadband video telephony device is located at the network end of B-ISDN network and provides RAST-1 (Receive-and-Send Terminal with an AAL1 interface) standard of ITU-T H.310 terminal type to provide video telephony service to general users. To accept.

The logical channel procedure of the ITU-T H.245 protocol can be used to make voice calls only with a remote terminal (hereinafter, referred to as a voice-only communication mode). It may also be used in the voice + video communication mode from now on.

ITU-T H.310 recommendation is a recommendation for a system and a terminal for a voice video communication service, and RAST-1 means a bidirectional terminal that can be connected to a public network.

The H.310 recommendation calls for a call phase to accommodate various multimedia services of B-ISDN networks.

That is, the call stage is divided into A, B, and C stages, and the call stage A is separated into four sub-steps such as A1, A2, A3, and A4.

Call stage C is subdivided into C1 and C2.

The wideband video telephone apparatus accommodates the call steps of H.310 while using MPEG-1 audio and MPEG-2 video among the H.310 RAST-1 type terminal specifications.

The tasks performed at each call stage are as follows.

1) Call step "A1" (initial VC setup)

Q.2931 SETUP message is used to set up the first virtual channel.

In the broadband video telephone apparatus, the first virtual channel is defined as a control virtual channel (VC).

Control VC is used for H.245 message exchange and operates at 64 Kbits / s bit rate in AAL-1 SAP.

2) call phase "A2" (capability exchange and primary / slave terminal determination)

Broadband video telephony devices exchange capability information on the control VC in this call phase using the capability exchange signaling procedure of the H.245 protocol.

In addition, the master or slave terminal is determined using the master / slave terminal decision procedure.

3) call step "A3" (additional VC setting)

In this step, a second virtual channel is set. In the broadband video device, this additional virtual channel is defined as an audio video VC (Audio and Video Virtual Channel).

Audio video VC is set up to transfer audio and video data between local and remote terminals.

4) Call Step "A4" (Logical Channel Setup)

In this step, the logical mode of the H.245 protocol is used to determine the communication mode between the local and remote terminals.

If the communication mode is the voice-only communication mode, only the voice logical channel should be set. In the voice + video communication mode, both the voice and video logical channels should be set.

Broadband video phones use only two types of logical channels, voice and video.

5) Call step "B" (voice video communication)

The broadband videophone device transmits audio and video data during this phase.

In addition, a logical channel establishment procedure may be performed to change any communication mode currently in use, and a corresponding procedure of the H.245 protocol may be performed to measure round trip transmission delay time.

6) Call Step "C1" (Logical Channel Release)

This step closes all logical channels in use.

7) Call Step "C2" (Virtual Channel Release)

In this step, the control VC and the audio video VC are released.

This call phase classification is intended to efficiently perform three kinds of functions.

The first uses the ITU-T Q.2931 signaling procedure to connect and disconnect virtual channels.

Second, it performs the various procedures provided by the H.245 protocol.

Finally, voice and video data are exchanged on the set virtual channel.

First, an "event source" is defined before describing the apparatus.

The event source represents a case in which the processing of the corresponding event differs depending on the call state among important events that can occur in the broadband video telephone apparatus.

This may be generated by a telephone user command or may be generated from a communication network.

Each event source is converted into an event of a certain structure through an event conversion process.

Broadband video telephony device is divided into three modules (10, 20, 30) and many sections (11, 12) as shown in FIG. 1 to implement a video telephony service conforming to the aforementioned ITU-T H.310 standard. , 13, 14, 15, and 34).

The video telephony application module 10 again includes a user command processing section 11, a phone book section 12, a timer processing section 13, an event conversion section 14, an event processing section 15, an event recording section 16 ).

The user command processing section 11 corresponds to a part of processing a command input by a video telephone user, and the types and functions of commands corresponding to an event source among various commands are shown in Table 1.

<Table 1> Types of user commands corresponding to event sources

Command Explanation Make a Call (Voice Only Communication Mode) Attempt to make a phone call to talk to the remote terminal in voice-only communication mode. Make a Call (Voice + Video Communication Mode) Attempt to connect to remote terminal in voice + video communication mode. Hang up Disconnect from the phone you are using. Changed to voice only communication mode While talking to the other party through video communication, try to change the call to voice-only communication mode for privacy protection. Change to voice + video communication mode While talking to the other party in voice only communication mode, try to change the call to voice + video communication mode. Image On Resend the previously turned off video during a call. Video off Turn off the play video during a call Voice on Turn on the previously turned off voice again during a call. Voice off Turn off the call voice during the call. Round trip delay measurement Measure signal round trip delay time between local and remote terminals. Terminal information Shows general information such as the current connection status of the terminal. Connection acceptance (voice only communication mode) Allows incoming calls from remote terminals to be accessed in voice-only communication mode, i.e. only voice calls. Connection acceptance (voice + video communication mode) Allow calls from remote terminals to be connected in voice + video mode, i.e. make video calls. Access denied Rejects an incoming call from a remote terminal.

Phone book section 12 manages the other party's phone number.

Phone numbers are supported by ITU-T E.164 and ISO 8348 / ITU-T X.213 NSAP (Network Service Access Point) schemes. Phone number management includes three methods: adding phone numbers, deleting phone numbers, and modifying phone numbers. Managed by a branch function.

The video phone user can add the phone number of the other party that he / she wants to record to the phone book using the add phone number function, while the phone number that is no longer needed can be deleted using the phone number delete function.

In addition, to modify the existing phone number can be easily modified using the phone number modification function.

The timer processing section 13 manages the timers required by the video phone application module 10. In the video telephone application module 10, six timers are required in total, but there are three timers that actually generate an event source as follows.

1) Timer for control VC setting

The broadband video telephony device waits for 30 seconds for a setup response when setting up the control VC in call step A1.

If there is no response during this time from the remote terminal, the timeout event source is forwarded to the event translation section 14.

The event conversion section 14 converts this to an event and forwards it to the event processing section 15.

This section finally abandons the control VC configuration to the remote terminal.

2) Timer for answering phone

When the local terminal receives a telephone connection request from the remote terminal, the local user is informed of the fact by the information notification display.

If the user wants to connect the phone, answer using the Accept button.

If the user does not want to connect the phone, answer using the reject button.

If the user is not present, the user cannot express his or her consent or rejection.

In this situation, the videophone device waits for 30 seconds for a user response.

In other words, when this timer times out, it passes the timeout event source towards the event conversion section 14.

The section converts this to an event.

The event processing section 15 forwards the rejection response to the remote terminal on behalf of the user.

3) Timer for setting voice video VC

When setting the audio video VC in the call step A3, it waits for the setting response for 30 seconds.

If there is no response during this time from the remote terminal, the timeout event source is forwarded to the event translation section 14.

The section converts this to an event.

The event processing section 15 abandons the audio image VC setup to the remote terminal.

The event conversion section 14 and the event processing section 15 refer only to the general content and to the details separately and independently.

First, the event conversion section 14 analyzes various situations occurring in the video telephone apparatus, converts them into events, and delivers them to the event processing section 15.

The event handling section 15 determines the appropriate output according to one input and two state variables, such as events, call steps and virtual channels.

The event record section 16 records or stores this information for use in testing or maintenance.

At the same time this information may be viewed in detail by the selection option.

The user-user signal module 20 is a module that provides the ITU-T H.245 protocol.

ITU-T H.245 is a recommendation for a protocol for transporting end-to-end control messages that control the operation of the terminal.

Several protocols are built into the entire H.245 protocol.

Each of these protocol procedures define their own messages using the ITU-T X.680 Recommendation, ASN.1 (Abstract Syntax Notation One) notation, and exchange these messages with the same protocol procedure of the remote terminal Perform the function.

The H.245 message, which is a message of each of these protocol procedures, is actually encoded and forwarded to the remote terminal according to the ASN.1 Encoding Rules of the ITU-T X.691 Recommendation.

That is, the user-user signal module 20 transmits the H.245 message encoded data via the ASN.1 encoding law to the remote terminal, and the remote terminal transmits the received data to the reverse process of the ASN.1 encoding law. By converting back to an H.245 message.

The length of the H.245 message is greatly reduced through this ASN.1 coding law.

The user-user signaling module 20 is again referred to as the H.245 Application Program Interface (API) section 21, the H.245 protocol management section 22, the H.245 protocol section 23, And message processing section 24.

Here is a brief description of each section:

The H.245 API section 21 provides the videophone application module 10 with various API functions for performing H.245 protocol procedures, a user-user signaling function.

That is, the video phone application module 10 uses these API functions to perform a user-user signaling function.

Here each API function is performed in an asynchronous way.

Here, the asynchronous method means that the video phone application module 10 immediately performs its original task after calling the H.245 API function without waiting for the result to be completely processed.

The user-user signaling module 20 completes the corresponding protocol procedure using the H.245 protocol section 23 for the function called by the videophone application module 10, and the H.245 protocol management section 22 Passes the result to the event translation section 14 as an event source.

As such, the H.245 protocol management section 22 functions to deliver the event source resulting from the H.245 protocol section 23 to the event conversion section 14 in the video telephony application module 10.

The event source generated from the H.245 protocol section 23 is finally transformed into an event through the event conversion section 14 in the video telephony application module 10. The event source is summarized as follows.

1) UU_MSDSE

Results of the host / slave terminal determination procedure in H.245 protocol procedures.

This event source has either the main or dependent terminal output.

2) UU_CESE

Results of a capability exchange procedure in H.245 protocol procedures.

3) UU_STARTUP

Result of protocol initialization function among H.245 API functions.

This function is performed only at the calling terminal.

4) UU_LISTEN

Result of protocol initialization function among H.245 API functions.

This function is performed only at the called terminal.

5) UU_RESPONSE

An event source that asks a local telephone user whether to accept or reject a video communication requested by a remote telephone user.

6) UU_B_LCSE

The result of logical channel establishment / release procedure in H.245 protocol procedure.

This event source has a result of voice logical channel setting, voice logical channel release, video logical channel setting, and video logical channel release.

7) UU_RESET

Results of a H.245 API function that releases all logical channels in use.

8) UU_RTDSE

Results of a round trip delay measurement procedure in H.245 protocol procedures.

This event source reports the measured round trip delay time.

9) UU_ENDSESSION

It is an event source that notifies the videophone application module 10 of the local terminal that all remote logical channels have been released.

10) UU_AUDIOON

Event source for notifying the local telephone user that the other party's telephone user has reactivated the voice function previously turned off.

11) UU_AUDIOOFF

Event source for notifying the local telephone user that the other party's telephone user has deactivated the voice function.

12) UU_VIDEOON

Event source for notifying the local telephone user that the other party's telephone user has reactivated the video function that was previously turned off.

13) UU_VIDEOOFF

Event source to notify local telephone user that the other party's telephone user has disabled video function.

The H.245 protocol section 23 is a key part of the user-user signaling module 20, which is the part that actually performs the H.245 protocol procedure.

These include Master Slave Determination, Capabilities Exchange, Logical Channel Signaling, Mode Request, Round Trip Delay, and Hold Loop. There is a protocol procedure for performing a maintenance loop, specific commands, and indications.

The message processing section 24 encodes the H.245 message used in each protocol procedure through the ASN.1 encoding law and performs the reverse process.

The video telephone device module 30 is composed of a hardware part and an API function part for each device.

Such a module will be described briefly in relation to the system of the video telephone apparatus as it is not directly related to the present invention.

The hardware part includes an overlay device 35, MPEG-2, an international standard for media integrated video compression (hereinafter referred to as MPEG) -2 decoder 36, MPEG-2 encoder 37, asynchronous transfer mode (Asynchronous Transfer). Mode (hereinafter, referred to as ATM).

The overlay device 35 shows the camera input (video of the local telephone user) or the video (video of the other telephone user) output from the MPEG-2 decoder 36 on the Windows NT screen.

The MPEG-2 encoder 37 provides a function of encoding MPEG-1 quality voice and MPEG-2 quality video, which are essential for a broadband video telephony service for B-ISDN.

The MPEG-2 decoder 36 provides the reverse process.

The API functions 31, 32, 33, and 34 for each device provide API functions for the video telephony application module 10 to control each device, and the ATM API 34 generates a network-related event source.

The broadband video telephony device allows the video telephony application module 10 to access the Q.2931 protocol, which is a user-to-network signaling function, with the API functions of Windows Sockets version 2.

That is, the control VC and the video audio VC are sockets, and the virtual channel is set / released using the WSAConnect () / closesocket () function of the Windows Sockets API.

The Windows Sockets API has a built-in feature that tells an application asynchronously about the different states for a socket: the socket setup complete, the socket release complete, the state that can send data to the socket, and the data that is entered on the socket. .

This device uses some of the various states for these sockets as network-related event sources. Each description is as follows, and the detailed description can be referred to from the Windows Sockets 2 API specification.

1) FD_ACCEPT: Occurs when the remote terminal informs the local terminal that it has requested a socket connection.

2) FD_CONNECT: Occurs when the socket connection is complete.

3) FD_CLOSE: Occurs when the set socket is released.

4) FD_READ: Occurs when data can be read from the socket.

5) FD_WRITE: Occurs when data can be sent to the socket.

The overall description of the broadband video telephony device has been described so far, and the content will be focused on the parts directly related to the event processing process.

The event processing process consists of three stages.

The first is the event conversion process.

Second is event processing.

Finally, the event recording process is performed.

The event conversion function converts an event source into an event. An event source occurs in four cases as follows.

1) Local phone user commands (dial, hang up, etc.) that occur in user command processing section (11)

2) Time out occurring in timer processing section 13

3) Execution result for H.245 API function occurring in H.245 protocol management section (22)

4) Information about the socket state occurring in ATM API section 34

These event sources are converted into events by the event conversion section 14 as shown in Table 2, Table 3, Table 4, and Table 5. Each event is represented by the following structure: .

struct {

WORD Event;

UINT Socket;

WORD Length;

PVOID * Info;

};

Here, Event represents the type of event, and Socket is the socket handle that generated the event.

Length is the length of the Info [] array.

The Info [] array is used to display additional information about the event.

Table 2. Event Sources from User Command Processing Section 11

Event source Event structure Event Socket Length Info Make a Call (Voice Only Communication Mode) HOOK_OFF_AUDIO NULL 0 NULL Make a Call (Voice + Video Communication Mode) HOOK_OFF_VIDEO NULL 0 NULL Hang up RELEASE_ REQUEST NULL 0 NULL Voice only mode change COMMMODE_CHANGE NULL One AUDIO_ONLY Change voice + video mode COMMMODE_CHANGE NULL One AUDIO_VIDEO Image On VIDEO_ON NULL 0 NULL Video off VIDEO_OFF NULL 0 NULL Voice on AUDIO_ON NULL 0 NULL Voice off AUDIO_OFF NULL 0 NULL Round trip delay measurement ROUNDTRIP NULL 0 NULL Connection acceptance (voice only communication mode) USER_RESPONSE_ACCEPT_AUDIO NULL 0 NULL Connection acceptance (voice + video communication mode) USER_RESPONSE_ACCEPT_VIDEO Access denied USER_RESPONSE_REJECT NULL 0 NULL

Table 3 Event Sources in Timer Processing Section

Event source Event structure Event Socket Length Info Timeout for Control VC Setting TIME_OUT_VCConnect Control VC 0 NULL Timeout for User Response TIME_OUT_UserResponse Control VC 0 NULL Timeout for VC setting TIME_OUT_VCConnect Audio Video VC 0 NULL

Table 4 Event Sources Occurring in H.245 Protocol Management Section (22)

Event source Event structure Kinds variable Event Socket Length Info UU_MSDSE FAILMASTERSLAVE MSDSE_FAIL Control VC 0 NULL MSDSE_SUCCESS One MASTERSLAVE UU_CESE FAILSUCCESS CESE_FAIL Control VC 0 NULL CESE_ SUCCESS UU_STARTUP FAILSUCCESS STARTUP_FAIL Control VC 0 NULL STARTUP_SUCCESS UU_LISTEN FAILSUCCESS LISTEN_FAIL Control VC 0 NULL LISTEN_SUCCESS UU_RESPONSE Audio Logic Channel Settings Video Logic Channel Settings RESPONSE_OPEN_AUDIO_LC Control VC 0 NULL RESPONSE_OPEN_VIDEO_LC UU_B_LCSE Voice Logic Channel Settings Voice Logic Channel Release Video Logic Channel Settings Video Logical Channel Release B_LCSE_OPEN_AUDIO_LC Control VC 0 NULL B_LCSE_CLOSE_AUDIO_LC B_LCSE_OPEN_VIDEO_LC B_LCSE_CLOSE_VIDEO _LC UU_RESET FAILSUCCESS RESET_FAIL Control VC 0 NULL RESET_SUCCESS UU_RTDSE FAILDelayTime (msec) RTDSE_FAIL Control VC 0 NULL RTDSE_SUCCESS One DelayTime UU_ENDSESSION FAILSUCCESS ENDSESSION_FAIL Control VC 0 NULL ENDSESSION_SUCCESS UU_AUDIOON none REMOTE_AUDIO_ON Control VC 0 NULL UU_AUDIOOFF none REMOTE_AUDIO_OFF Control VC 0 NULL UU_VIDEOON none REMOTE_VIDEO_ON Control VC 0 NULL UU_VIDEOOFF none REMOTE_VIDEO_OFF Control VC 0 NULL

<Table 5> Information about socket status in ATM API function

Event source Event structure Kinds variable Event Socket Length Info FD_ACCEPT FAIL SUCCESS RELEASE_INDICATION Control VC 0 NULL Audio Video VC CONNECT_INDICATION Control VC Audio Video VC FD_CONNECT FAILSUCCESS CONNECT_FAIL Control VC 0 NULL Audio Video VC CONNECT_SUCCESS Control VC Audio Video VC FD_CLOSE none RELEASE_INDICATION Control VC 0 NULL Audio Video VC FD_WRITE none H245API_START Control VC 0 NULL Audio Video VC

If the first stage of the event processing process is separated and operated independently, it is easy to add a new event or change an existing event.

The event processing process is the most essential part of the video telephony application module 10 that performs a necessary operation of the video telephony device for an input event.

The event handling section is designed to perform specific actions when an event is entered, depending on two state variables, the current call phase and the VC state.

The event and call steps are described in detail above, and the following describes the VC state.

In the video telephone apparatus, the control VC and the audio video VC are used, and the state of each VC is shown in Table 6.

Here, the control VC has more channel states than the audio video VC.

This occurs largely for two reasons.

First, since the control VC is set in the call step A1, it is necessary to perform tasks necessary for dial-up at this stage.

These essential tasks include answering user calls and checking for simultaneous call requests.

Answering a user call is as follows.

When the video telephone apparatus receives a dial-up request from a remote terminal, the video telephone apparatus notifies the user as a call reception indication and a ring tone, and waits for a user's acceptance or rejection response.

If the user is not present, the user waits for a limited time.

During this time, the control VC does not send a response to the control VC configuration to the remote terminal while maintaining the WaitingUserResponse state.

Simultaneous call setup refers to a case where two terminals (local terminal and remote terminal) request a telephone connection to each other at the same time.

In this case, since two bidirectional VCs are set, one of them must be released.

The crossing state is recorded the moment the simultaneous call setup is detected, and changes to another channel state when the simultaneous call condition disappears.

<Table 6> Channel status of control VC and audio video VC

Channel status Explanation Control VC Idle Both the local terminal and the remote terminal do not make a control VC setting request. WaitingSetupAck The response to the control VC setting requested by the local terminal does not arrive. WaitingUserResponse When a control VC setting request of a remote terminal is received. The answering call is displayed to the local user, and the call is continuously ringing. However, the local user has not received a response to the telephone connection (voice only communication mode, voice + video communication mode, or connection rejection). Crossing This is the case where the remote terminal makes a control VC setting request without receiving a response to the control VC setting requested by the local terminal. That is, two UEs simultaneously make a control VC setting request. Donone This is the case where control VC setting is completed between two terminals. However, the master / slave terminal procedure or capability exchange procedure does not start at all on the established control VC. Incoming The control VC setting between the two terminals is completed, and the incoming main / slave terminal procedure or the incoming capability exchange procedure is being performed. That is, it indicates that the H.245 protocol procedure has not yet completed after initiating the call. Outgoing The control VC setting between the two terminals is completed, and a calling main / slave terminal procedure or a calling capability exchange procedure is being performed. That is, it indicates that the H.245 protocol procedure has not yet completed after initiating for origination. Active The control VC configuration between the two terminals is completed and the H.245 protocol procedures (main / slave terminal determination procedure, capability exchange procedure), which are essential for dial-up, are completed. Audio Video VC Idle Both the local terminal and the remote terminal do not make a voice image VC setting request. WaitingSetupAck There is no response to the voice video VC set requested by the local terminal. Active This is the case where the audio image VC setup requested by the local terminal or remote terminal is completed. This state means a state in which audio and video data can be transmitted in both directions on the audio video VC.

Second, since the video phone application module 10 operates asynchronously with the user-user signaling module 20, the video phone application module 10 stores information on the execution state of the H.245 protocol procedure as the control VC channel state.

The videophone application module 10 processes the events originating from the H.245 protocol management section 22 based on this channel state information.

That is, the video telephony device performs the host / slave terminal determination and capability exchange in the H.245 protocol procedure before dialing according to international standards.

The two terminals can know the terminal type (Terminal Type) and the terminal (Terminal Capability) from this procedure, this information is used as a very useful information to determine the dial-up.

The outgoing and incoming channel status indicates that the H.245 protocol procedure is initiated on the control VC by the local terminal under call step A2, but the result of the procedure has not yet been delivered to the video telephony application module 10.

Here, the outgoing state and the incoming channel state exist for the same channel state for the following reasons.

Some of the H.245 API functions separate and use outgoing and incoming functions to satisfy the H.245 protocol procedure.

Therefore, the outgoing channel state occurs when the local terminal is the originating terminal, and the outgoing channel state occurs when the local terminal is the called terminal.

At this point, we have completed the description of the events, call phases, and VC states.

Next, an event processing method performed in the event processing section 15 will be described.

The event processing method collectively refers to a series of actions that a video telephony device should take under the condition of one input (event) and two state variables (call step, VC state).

Here, by using the correlation between the current call step and the VC state, two state variables can be rearranged into one state variable.

One integrated status variable is defined as Phone Status.

Table 7 summarizes the relationship between the current call level, VC state, and phone state.

Here, some of the correlation between the call phase and the VC state is considered meaningless and omitted.

<Table 7> Correlation between call phase, control VC, voice image VC and phone state

Arc steps Control VC Audio Video VC Phone A A1 Idle Idle Idle WaitingSetupAck Idle H245VCSetup WaitingUserResponse Idle WaitingUserResponse Crossing Idle Callcrossing A2 Donone Idle H245VCDone Outgoing Idle H245ProtocolOutgoing Incoming Idle H245ProtocolIncoming A3 Active Idle AVVCSetup Active Outgoing WaitAVVCAck A4 Active Active LCSetup B Active Active AVMode C C1 Active Active LCRelease C2 Active Active VCRelease

In this way, the video phone device may be redefined as an event processor operating with an input event and a phone state variable, and the video phone device for B-ISDN uses the phone state information for each input event. Process as follows.

The following description focuses on the events that may occur in each phone state, and among them, a method for handling an event that does not require processing is omitted.

<Table 8> Event processing method using event and phone state

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The final stage of event processing is the event recording process.

The event recording section systematically records these event processing in the order in which they occurred.

The recorded event may be usefully used for error correction or video telephone service maintenance during the development of the video telephone apparatus.

The event-related record items recorded by the video telephone apparatus are as follows.

1) call step information, control VC status information, voice video VC status information

2) The structure of the input event (event code, socket handle, variable length, variable contents)

3) Socket handle information currently set

4) H.245 protocol related information (terminal type, logical channel type, communication mode, etc.)

These record items are saved in file form, and simultaneously viewed on the Windows NT screen if desired by the user.

As described in detail above, the present invention defines a suitable event for a telephone service for B-ISDN and integrates it into a telephone state by using a correlation between a current call step and a VC state corresponding to a state variable. In order to improve the reliability of the service and cope with various changes in the function of the video telephony service in the future, we can propose an event processing method that went through three steps.

Therefore, by converting the event source into an event having a certain structure through the event conversion process, it is possible to flexibly cope with the video telephone service change, and separate the event recording process to record time and systematically to maintain the telephone apparatus. In order to facilitate the operation, an event processing method that can be used in the B-ISDN communication network can be presented for each input event.

In addition, preferred embodiments of the present invention are disclosed for the purpose of illustration, those skilled in the art will be able to various modifications, changes, additions, etc. within the spirit and scope of the present invention, such modifications and modifications belong to the following claims You will have to look.

Claims (5)

Video telephony application module that provides video telephony application service that executes various commands generated from video telephony user and manages phonebook and timer to perform event conversion, processing and recording process for various event sources generated from video telephony. And; Under the control of the video telephony application module, among the H.245 protocol procedures of the international standard, the master / slave terminal determination, capability exchange, logical channel establishment and release, mode change request, round trip transmission delay are performed, and A user-to-user signal module for carrying out the end-to-end control message and processing protocol for each control message, such as performing ASN.1 encoding and vice versa; And It is composed of hardware part of video phone and application program interface (API) for each device, and it is an international standard for moving video compression of camera input or media (Moving Picture Experts Group (MPEG) -2). It displays the video output from the decoder and encodes MPEG-1 quality voice and MPEG-2 quality video, which are essential for broadband video telephony service for broadband ISDN (hereinafter referred to as B-ISDN). A broadband video telephony device comprising a video telephony device module for interfacing to an asynchronous transfer mode (hereinafter referred to as ATM) network. The method of claim 1, The video phone application module, A user command processing section for processing a command input by a video telephone user; A phone book section that manages the other party's phone numbers by three functions: add phone number, delete phone number, and modify phone number; A timer processing section for managing necessary timers in the videophone; An event conversion section for converting various event sources occurring in the videophone into events; An event processing section which receives the converted event, call step and virtual channel in the event conversion section and determines an appropriate output according to a state variable; An event recording section for recording or storing information output from the event processing section; And An overlay application section for driving an overlay device, an MPEG-2 application section for driving an MPEG-2 decoder / encoder, and an ATM application section for driving an ATM interface. The method of claim 2, The user-user signal module, An H.245 API section for providing the video telephony application module with various API functions for performing H.245 protocol procedures, a user-user signaling function; An H.245 protocol management section for transmitting a result of the corresponding protocol procedure to a function called by the video telephone application module to an event conversion section in the video telephone application module as an event source; Master Slave Determination, Capabilities Exchange, Logical Channel Signaling, Mode Change Request, Round Trip Transmission H.245 protocol section to complete the corresponding protocol procedures for Round Trip Delay, Maintenance Loop, Specific Commands and Indications; And A H.245 message used in each protocol procedure left in the H.245 protocol section includes a message processing section for performing encoding and vice versa through the ASN.1 encoding law. Telephone device. The method of claim 1, The video telephone device module, An API function for each device for generating a network-related event source by providing an API function for the video telephone application module to control an overlay device, an MPEG-2 decoder, an MPEG-2 encoder, and an ATM matcher; An overlay device for showing an image of a local telephone user, which is a video of a local telephone user, or an image of an opposite telephone user output from an MPEG-2 decoder; An MPEG-2 decoder that decodes MPEG-1 quality audio and MPEG-2 quality video essential for B-ISDN wideband video telephony services; MPEG-2 encoder that encodes MPEG-1 quality voice and MPEG-2 quality video essential for broadband video telephony service for B-ISDN; And Broadband videophone device comprising an ATM matcher. Local telephone user commands from the user of the videophone, timeouts in the timer handling section, H.245 API functions in the H.245 protocol management section, and socket status in the ATM API section. An event conversion process of converting an event source of information into an event; An event processing step of processing an event for each input event converted through the event conversion process using telephone state information, which is a newly defined integrated state variable, using a correlation between a current call step and a virtual channel state; And And an event recording process for systematically recording the event processing process in the order of occurrence.