JPH07177198A - Multimedia communication system - Google Patents

Abstract

(57) [Summary] [Object] An object of the present invention is to provide a multimedia communication function capable of independently and asynchronously changing a communication medium in which each communication terminal is communicating. [Composition] A multimedia communication integrated control unit 1700 is provided in a communication terminal station 1000 composed of a camera 1200, a monitor 1300, a microphone 1400, a speaker 1500, and an operation console 1600, and each communication terminal station (1000a to 1000a).
Exclusively control the change request of the communication media issued independently and asynchronously from the user of c). [Effect] The media can be changed during communication without switching to the communication media that the user does not expect.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a multimedia communication system, and more particularly, to an arbitrary selection of communication media during communication in a multimedia communication terminal having a communication function of a plurality of media such as voice, video and data. Regarding change method.

[0002]

2. Description of the Related Art As a conventional technique for changing a communication medium in a multimedia communication terminal, for example, Japanese Patent Laid-Open No.
A "multimedia terminal" described in Japanese Patent No. 223755 is known. In the above conventional technology, when the partner terminal stops transmitting video data during communication or switches to another communication medium, the terminal does not continuously display a screen without video data or a distorted video. I have to. More specifically, an image switching unit that selects and outputs either the received image signal received from the partner terminal or the control image signal from the control unit that controls the own terminal is provided, and the image data received from the partner terminal is displayed. The screen to be displayed can be selected depending on the presence or absence.

[0003]

In the above-mentioned prior art, the self-terminal does not output a meaningless screen in response to an arbitrary change of the communication medium of the partner terminal. However, the communication between the communication terminals of each other is performed. No consideration is given to the fact that the own terminal and the other terminal change the media independently and asynchronously without falling into an unexpected state. Therefore, there is a problem in that, when both of the communicators simultaneously choose to use different media during communication between the multimedia communication terminals, it is not possible to communicate with the media that meets expectations.

For example, of two terminals that have communicated with each other via audio and video media, one terminal attempts to shift to communication with audio-only media and the other terminal uses video-only media. Trying to move to communication,
When the desired communication media are changed at the same time, the voice line is disconnected at one terminal and the video line is disconnected at the other terminal. As a result, there is a problem in that both the voice line and the video line between the terminals are disconnected at the same time, and both the voice and the video are cut off.

A communication terminal supporting a multimedia communication function needs to consider the following requirements. For example, communication media such as audio information and video information used in videophones are valuable because they are real-time media. Being in real time means
This means that even if the own terminal and the other terminal are physically separated from each other via the communication network, both terminals share the same at the same time. For operations such as changing shared resources (communication media here), control based on some rule, that is, access right control of shared communication media, is required so that the operations do not conflict with each other.

An object of the present invention is to provide a multimedia communication function capable of independently and asynchronously changing the communication medium in which each communication terminal is communicating.

[0007]

In order to achieve the above object, the present invention exclusively controls a change request of a communication medium that occurs independently and asynchronously from a user or user of each communication terminal. In this case, it is necessary for each communication terminal to change the communication medium in communication after exchanging a change request with each other and confirming it.However, the load of the terminal is changed between the terminals operating independently and asynchronously via the communication network. Alternatively, delays due to congestion of lines and transmission / reception buffers inevitably cause collision of communication media change requests.

Therefore, in the present invention, so that each terminal exclusively selects a change request of the communication medium to be exchanged, the request is withdrawn due to the conflict of change requests, or is assigned in advance in accordance with the content of each change request. Based on priority
Introduce contention control such as selecting only higher priority change requests. That is, by limiting only one communication media change request accepted at the same time point, the conventional problem due to competition of communication media change requests can be solved.

[0009]

According to the multimedia communication system of the present invention, each terminal issues a communication media change request to the other terminal and starts a competition monitoring timer for monitoring the competition of the communication media change request. During the monitoring time by the above timer, when collision or conflict of the change request of the communication medium is detected, each terminal rejects (does not accept) the change request of the communication medium, or the communication medium with a higher priority is sent. Conflict control, such as accepting only requests to change The change request that is rejected can be reissued as a new request.

According to the present invention, since each terminal changes the communication medium only in response to the change request selected by the contention control, it is possible to avoid inconsistent switching of the communication medium.

[0011]

1 shows an example of the configuration of a communication system according to the present invention. In FIG. 1, A, B and C are users and 10
00 (1000a to 1000c) is a communication terminal station of each user, and 2000 is a communication network connecting the communication terminal stations.

In the communication terminal station 1000a, 1100 is a multimedia communication integrated control unit, 1200 is a camera for displaying the user A, 1300 is a monitor for displaying a video signal as an image, 1400 is a user A's voice. A microphone for sound, 1500 is a speaker for reproducing an audio signal, 1600 is a console such as a keyboard, 1700 is a terminal adapter (TA) for connecting / disconnecting lines such as video and audio. is there.

Multimedia communication integrated control unit 1100
Captures audio / video signals from the camera 1200 or the microphone 1400 and transmits them to the other communication terminal station 1000b or 1000c via the communication network 2000. In addition, the monitor 13 receives audio / video signals from other communication terminal stations.
00 or a speaker 1500. In this configuration example, each communication terminal station 1000 uses TA17 for connection with the communication network 2000.
However, the function of the TA 1700 may be incorporated in the multimedia communication integrated control unit as a board that controls the line control, for example.

FIG. 2 shows a multimedia communication integrated control unit 1.
The structural example of 100 is shown. In FIG. 2, 1110 is a centralized control processor unit, 1120 is a communication line interface (I / F) unit, 1130 is a line demultiplexing unit, and 1140 is a video CODE that controls coding and decoding of a video signal.
C section, 1150 is an audio CODEC section that controls encoding and decoding of an audio signal, 1160 is a video input / output section, 11
Reference numeral 70 is a voice input / output unit.

The central control processor unit 1110 includes elements such as a processor, a memory and a bus.
The various programs stored in the memory are read and processed. The communication line I / F unit 1120 follows the instruction from the centralized control processor unit 1110 to send the multiplexed signal from the line demultiplexing unit 1130 via the TA 1700 to the communication network 2000.
The multiplexed signal received from the communication network 2000 via the TA 1700 while being transmitted to the line demultiplexing unit 113.
Output to 0.

The line demultiplexing unit 1130 uses a video CODE.
Various signals such as data signals from the C unit 1140, the voice CODEC unit 1150, and the centralized control processor unit 1110 are multiplexed and output to the communication line I / F unit 1120, and also multiplexed from the communication line I / F unit 1120. The signal is separated, and the video CODEC unit 1140 and the audio CODE are separated.
The data is output to the C unit 1150 and the centralized control processor unit 1110.

The video input / output unit 1160 inputs the video signal of the camera 1200 and outputs it to the video CODEC unit 1140 according to the instruction of the centralized control processor unit 1110, and inputs the video signal from the video CODEC unit 1140 to the monitor 1300. Output.

The voice input / output unit 1170 is the microphone 1
The audio signal of 400 is input and output to the audio CODEC unit 1150, and the audio signal from the audio CODEC unit 1150 is output to the speaker 1500.

FIG. 3 shows a configuration example of the video input / output unit 1160. In FIG. 3, 1161 is a signal switcher and 1
162 is a scan converter mechanism (or image signal conversion mechanism). The signal switcher 1161 includes a central control processor unit 1110, a camera 1200, a scan converter mechanism 1162, and a video CODEC unit 11.
The input / output combination of the screen (video) signal between 40 is switched. The central control processor unit 1110 includes a monitor 1300.
A synchronization signal for displaying an image is superimposed on the data signal and sent.

FIG. 4 is a diagram showing an example of a procedure for changing the communication medium according to the conventional method. Here, the change request of the communication medium is changed to the communication medium of voice only by the MS.
EL (A), change to video-only communication media is MSE
L (V), change to both voice and video communication media is M
It will be referred to as SEL (AV). Audio and video shall be communicated on separate lines. Reference numeral 1300 indicates a monitor, 1310 indicates a video output state, 1500 indicates a speaker, and 1510 indicates a voice output state.

In FIG. 4, steps (1) to (2)
Indicates a case where one terminal sends a communication media change request to the other terminal to switch the communication media. Steps (3) to (4) indicate that both terminals simultaneously send a communication media change request. The case of sending is shown.

In (1), the user A and the user B are in communication with each other between the terminal stations 1000a and 1000b via the audio media and the video media. Here, the user A selects the shift to the communication medium of only voice, and the terminal 1
000a transmits MSEL (A) -1 to the terminal 1000b, the terminal 1000 receiving MSEL (A) -1
b instructs the TA1700 to disconnect the video line,
TA1700 disconnects the video line. As a result, (2)
As shown in, the communication is voice only.

In (3), the user A selects the shift to the communication medium of only voice, and the terminal station 1000a to the terminal station 1
User M when sending MSEL (A) -3 to 000b
Choose to switch to video-only communication media,
The state in which MSEL (V) -5 is transmitted from 00b to the terminal station 1000a is shown. Terminal station 1 that received MSEL (A) -3
000b instructs the TA 1700 to disconnect the video line, so that the TA 1700 disconnects the video line. On the other hand, the terminal station 1000a receiving MSEL (V) -5
The voice line is disconnected to instruct the TA 1700 to disconnect the voice line. As a result, as shown in (4), both audio and video cannot be output.

FIG. 5 shows the format of the communication frame of the communication media change request MSEL (X) in the present invention. In the communication frame 7, INFO indicates transmission information 8 and includes a command identifier, a communication media identifier 9, a communication terminal station identifier 10, and a priority 11. The command identifier is for identifying the type of the frame to be transmitted, but in the present embodiment, the frame is intended only for the communication medium change request, and the consideration of the type of the command identifier is omitted. Communication media identifier 9
Is for identifying the type of communication medium desired by the user. For example, when the user selects communication using only voice media, the identifier is set to "20". The communication terminal station identifier 10 and the priority setting table 11 will be described later in the description of the application example.

FIG. 6 shows a communication media selection according to the present invention.
The change procedure is shown below. A visual timer CMT (Collision Monitoring Time) is used to control contention of communication media change requests.
r) is provided. Also, a flag CMF (Collision Monito) indicating that competition for communication media change requests is being monitored.
ring flag).

First, the CMF is initialized (step 10
0), occurrence of any event of input of communication media change request from own station (terminal), reception of communication media change request transmitted from partner station, termination of monitoring timer for monitoring request conflict, Wait until (110). When any of these events occurs, the event type is determined (200).

If the input event is an event from the own station, it is judged whether CMF is "0" or "1" (300), and C
If the MF is "0", since the own station is before the transmission of the communication media change request or after the end of the monitoring timer, the communication media change request is transmitted to the partner station (310) and CMT is started (320). CMF is set to "1" to indicate that request conflicts are being monitored (330). If the CMF is "1", the input event is already transmitted from the own terminal, and then the duplication input again from the own station while monitoring the presence or absence of the communication media change request from the other party by the monitoring timer. Display that it is input on the monitor (3
40), refuses to accept input from its own station. The above display is erased after a certain period of time.

If the input event is from the partner station, it is determined whether the CMF is "0" or "1" (400), and C
If the MF is “0”, it means that the communication media change request has not been transmitted from the own station to the other station. Therefore, it is determined that there is no competition for the communication media change request, and the line switching operation is performed, A communication medium according to the requested communication medium identifier is output (410). If the CMF is "1", it means that the local station has received the request from the partner immediately after transmitting the communication media change request to the partner station. Therefore, it is judged that a conflict has occurred between the transmitted request and the received request, the line switching operation is suspended, and the fact that the conflict has occurred is displayed on the monitor (420). The above display is also erased after a certain time. When the monitoring timer expires, the CMF is returned to "0" (500) and the communication media change request from the own station and the partner station is awaited (110).

FIG. 7 shows an example of a procedure for selecting / changing a communication medium according to the present invention. In FIG. 7, steps (1) and (2) show a state in which both terminals simultaneously send communication media change requests, so that the requests conflict with each other, and (3) and (4) show communication media change requests to be performed thereafter. Indicates switching.

In (1), the user A selects the shift to the communication medium containing only voice, and the terminal station 1000a to the terminal station 10a.
When MSEL (A) 12 is transmitted to 00b, user B selects transition to a communication medium of only video, and terminal station 100
The state (corresponding to 310 in FIG. 5) in which the MSEL (V) 13 is transmitted from 0b to the terminal station 1000a is shown. Both stations are MS
At the same time as transmitting EL, the monitoring timer 14 that monitors the request of the other party is started (320 in FIG. 5). The user's re-input is not accepted during the time from starting and ending the monitoring timer (340 in FIG. 5).

In (2), the terminal station 1000b that has received the MSEL (A) 12 before the monitoring timer 14 expires.
However, it is determined that the competition between the received MSEL (A) 12 and the MSEL (V) 13 transmitted by the terminal station 1000b has occurred, and the change of the communication medium is prohibited. After that, the fact that the conflict has occurred is displayed on the monitor 1300 while the communication medium currently being communicated is output (420 in FIG. 5). Similarly, by the time the monitoring timer expires, MSEL (V) 13
The terminal station 1000a that has received the message also determines that a conflict has occurred, and displays that conflict has occurred on the monitor 1300 (420 in FIG. 5). Therefore, the requests sent by both terminals are invalid.

In the present invention, in (3), when the monitoring timer 14 times out (500 in FIG. 5), the user A re-inputs the MSEL (A) 15. If there is no conflict between the communication media change requests sent to each other, that is,
If the request transmitted from the other party is not received before the monitoring timer 16 expires, the communication can be changed to voice-only communication as shown in (4) (410 in FIG. 5).

By the above control procedure, each terminal can select / change an independent asynchronous communication medium by retransmitting a new request without interruption of the output of the communication medium when the communication medium change request conflict occurs.

In the above embodiment, after the self-terminal issues a communication media change request to the partner terminal, the receiving terminal communicates regardless of whether the request content received within a certain time is the same as the request content already transmitted. The media has not been changed (prohibition of changing communication media). However, if the request content received from the other party is the same as the request content sent from the own station,
That is, when the communication media identifiers desired by the own station and the partner station are the same, the communication media may be changed.

FIG. 8 shows a control procedure when one terminal issues change requests to the same medium at substantially the same time. However, the routine shown in FIG. 8 corresponds to the changed part in FIG. 6, and is the procedure part after the time point when the event is received from the partner station. Before the start of this routine, the communication media identifier and the communication terminal identifier are set in the table at each terminal (8, 9 in FIG. 5).

The communication media identifier of the transmission request is S-me.
d (Send-media), the communication media identifier of the reception request is R
-Med (Recieve-media), the communication terminal station identifier of the local station is L-term (Local-terminal), and the communication terminal station identifier of the partner station is R-term (Remote-terminal). It is assumed that an event has occurred from the partner station until the monitoring timer expires after the own station sends a communication media change request to the partner station. If the CMF is "1" (step 40)
0), that is, when there is a conflict of communication media change requests, S-med and R-med are compared (420),
If both communication media identifiers are the same, L-ter
m is compared with R-term (421). Since only one of the communication terminal stations needs to change the communication medium, the terminal station having a large L-term changes the communication medium to the communication medium corresponding to the communication medium identifier of the received MSEL (422). If the two communication media identifiers are different, it is displayed on the monitor that a conflict has occurred without changing the communication media (423).

FIG. 9 is a diagram showing a control example in the case where requests having the same communication media identifier compete with each other. In FIG. 9, in step (1), when the user A selects a communication medium having only voice and transmits the MSEL (A) 17 to the partner station, the user B also transmits the MSEL (A) 18 to the partner station. Shows the state. MSE before the watch timer 20 expires
Upon receiving the L (A) 17, the terminal station 1000b receives the S-med
And R-med are compared (420 in FIG. 8). In this example, since the two communication media identifiers are the same, the communication terminal station identifiers are compared (421 in FIG. 8). In this case, L
The terminal station 1000b having a small −term does not change the communication medium. Terminal station 1 that received MSEL (A) 18
000a performs the same process as 1000b, and L-ter
1000a with a larger m changes to voice communication (422 in FIG. 8). Therefore, in step (2), only voice media is communicated.

FIG. 10 shows another embodiment of the control procedure of the present invention which employs priority control. In the present invention, the priority is set in advance for each communication media change request,
When both communication terminals issue a communication media change request at the same time, priority control may be performed so as to follow the change request with the higher priority. The routine shown in FIG. 10 corresponds to the changed portion of FIG. 6, and shows the portion that starts when an event is received from the partner station. Before starting this routine, it is assumed that the communication terminal station identifier and the priority of each MSEL are set in the table in each terminal (1 in 10 of FIG. 5).
1).

The priority of the transmission request is S-pri (Send-prior
ority) and the priority of the reception request as R-pri (Recieve-pri
ority). It is assumed that after the communication media change request is transmitted to the partner station, a conflict occurs and the CMF becomes "1" (400). After each terminal receives the request from the other party, S
Comparing -pri and R-pri (420). Since it is sufficient for any communication terminal to change the communication medium, the terminal having a high S-pri changes to the communication medium corresponding to S-med (421). If the priorities are the same, the L-term and the R-term are compared (42 as in the case where a request having the same content as the transmission request is received from the partner station).
2), the terminal station having a large L-term changes the communication medium according to the requested communication medium identifier (42).
2).

FIG. 11 shows a procedure for selecting / changing a communication medium during communication by introducing priority control. In FIG. 11, in step (1), when user A selects a communication medium containing only voice and transmits MSEL (A) 21 to the partner station, user B selects a communication medium containing only video, The state which transmitted MSEL (V) 22 to a station is shown. The terminal station 1000b that has received the MSEL (A) 21 before the monitoring timer expires compares the S-pri with the R-pri (420 in FIG. 10). The terminal station 1000b that determines that S-pri is smaller than R-pri does not change the communication medium. On the other hand, the terminal station 10 that has received the MSEL (V) 22
00a performs the priority comparison similarly to the terminal station 1000b,
Since S-pri is larger than R-pri, the communication is changed to voice communication (421 in FIG. 10). By this switching, in step (2), a communication state of only the audio medium is established between both terminals. According to the priority control, when contention of communication requests occurs, it is possible to switch media according to the request of one of the users.

[0041]

According to the present invention, a multimedia communication terminal during communication can arbitrarily change the communication medium to a specific one or a plurality of communication media without causing an unexpected change to the communication medium. . Even if a request from the other multimedia communication terminal conflicts with the request to change the communication medium and the request from the terminal is not accepted, the message to that effect is displayed to change to the expected communication medium. Request can be reissued.

[Brief description of drawings]

FIG. 1 is a diagram showing an example of a configuration of a communication system according to the present invention.

FIG. 2 is a diagram showing a configuration example of a multimedia communication integrated control unit.

FIG. 3 is a diagram showing a configuration example of a video input / output unit.

FIG. 4 is a diagram for explaining a conventional method for changing communication media.

FIG. 5 is a diagram showing a frame format.

FIG. 6 is a flowchart showing an embodiment of a control procedure according to the present invention.

FIG. 7 is a diagram for explaining control according to the present invention.

FIG. 8 is a flowchart showing a control procedure when the same requests compete with each other.

FIG. 9 is a diagram for explaining control according to the present invention when the same requests conflict.

FIG. 10 is a flowchart showing one embodiment of a control procedure according to the present invention having a priority control function.

FIG. 11 is a diagram for explaining control according to the present invention when priority control is adopted.

[Explanation of symbols]

1000 ... communication terminal station, 2000 ... communication network, A ... user,
1100 ... Multimedia integrated control unit, 1200 ... Camera, 1300 ... Monitor, 1400 ... Microphone, 15
00 ... speaker, 1600 ... console, 1700 ... terminal adapter.

Claims (5)

[Claims] 1. A multimedia communication terminal having a communication function for a plurality of types of media, a means for issuing a change request command of a communication medium being communicated to a communication partner, a change request command from the own terminal and a partner terminal. And a means for controlling the execution of the communication media change request according to the relationship with the change request command, and dynamically changing the communication media in communication to a specific one or a plurality of communication media. And multimedia communication method. 2. The multimedia communication terminal comprises means for prohibiting the change of the communication medium for a certain period after issuing the change request command, and the change of the communication medium independently and asynchronously issued from each multimedia communication terminal. 2. The multimedia communication system according to claim 1, wherein one of the requests is exclusively selected to dynamically change the communication medium in communication. 3. The multimedia communication system according to claim 1, wherein the multimedia communication terminal changes the communication medium in response to a change request command received when the change of the communication medium is not prohibited. . 4. In a multimedia communication terminal having a communication function of a plurality of media, means for issuing a change request command of a communication medium in communication to a communication partner, and communication for a certain period after the change request command is issued. A means for monitoring the reception of the change request command of the media, and when the change request content of the received change request command and the change request content of the change request command issued by the local terminal are the same, the communication media is changed according to one of the change request contents. And a means for performing communication, the communication medium being communicated can be dynamically changed to one or more specific communication media. 5. In a multimedia communication terminal having a communication function for a plurality of media, a means for allocating a priority in advance according to the contents of a change request of the communication medium in communication, and a communication medium in communication with a communication partner. A means for issuing the change request command and a means for monitoring the reception of the change request command of the communication medium within a certain period after the change request command is issued are provided. A multimedia communication system characterized by being able to dynamically change the communication medium.