JPH07193799A - Picture communication terminal equipment - Google Patents

Abstract

PURPOSE:To efficiently utilize an HSD channel by resetting the collision of still picture transmission when still picture transmission is requested from two different channels simultaneously or almost simultaneously. CONSTITUTION:At the time of transmitting a still picture, a still picture transmission/reception managing means 14 manages the state of a still picture transmission/reception controlling means 10 as 'in still picture transmitting' and sends a code meaning 'HSD ON: transmitting' to a BAS transmission/ reception controlling means 5 by using a free area in an escape table for BAS codes in the case of a still picture transmitting request, and in the case of acknowledge (ACK) to the still picture transmitting request, sends a code meaning 'HSD ON : receiving'. When transmission processing requests are issued from two different channels simultaneously or almost simultaneously, the means 5 collates a received code with the state of the means 10 at the time of receiving the code and manages a call control means 3 so that a calling side at the time of connecting a communication channel is a still picture transmitting side and a called side is a still picture receiving side.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image communication terminal device for transmitting and receiving image signals, audio signals, data and conference control signals to and from other stations via a communication line.

[0002]

2. Description of the Related Art FIG. 3 shows a functional block diagram of a conventional image communication terminal device. In FIG. 3, 1 is a communication line, 2 is a communication line interface, 3 is call control means for managing calls such as calling, receiving, and disconnecting, and 4 is multiplexing of image signals, voice signals, data, and conference control signals. Multiplexing / separating means 5 for performing demultiplexing and demultiplexing is a bit rate allocation signal (Bit) for transmitting and receiving a terminal capability for structuring various communication channels.
rate allocation signal (hereinafter referred to as “BAS”) transmission / reception control means, 6 audio transmission / reception control means for encoding and decoding audio signals, 7 audio input / output equipment, and 8 encoding / decoding moving image signals. A moving image transmission / reception control means for performing, 9 is an image input / output device, 10 is a still image transmission / reception control means for performing encoding, decoding and transmission / reception of a still image signal, 11 is low speed data (Low Speed Data) for transmitting / receiving low speed data. "LS
D ") transmission / reception control means, 12 is an LSD communication terminal device, and 13 is a system control means for managing the entire image communication terminal device.

The operation of this conventional image communication terminal device will be described. First, the call control means 3 transmits and receives a call setting signal such as an incoming and outgoing call through the communication line interface 2,
A communication channel connection with the other party is established. After the communication channel connection is completed, the mode initializing procedure is performed by the multiplexing / separating means 4 through the communication channel, and after the synchronization is established, B
The AS transmission / reception control means 5 exchanges capabilities to determine the capabilities of the communication terminal. As a result, the BAS transmission / reception control means 5
Activates each of the voice transmission / reception control unit 6, the moving image transmission / reception control unit 8, the still image transmission / reception control unit 10, and the LSD transmission / reception control unit 11, which are capable of communicating voice, image, data, and conference control signals. Each is possible.

A case will be considered below in which a still image is transmitted and received when a remote communication conference is held by the conventional image signal terminal device having the above-mentioned configuration. At this time, for example, when the still image transmission / reception control means 10 for transmitting / receiving a still image cannot transmit / receive at the same time, if two different stations start transmitting at the same time or substantially at the same time, a collision of still image transmission occurs. FIG. 4 shows the sequence of the collision. FIG. 4 shows a case where the station (A) and the station (B) simultaneously issue a still image transmission request after the communication channel is established as described above.

First, in the stations (A) and (B),
The system control means 13 which has received the still image transmission request is BAS
The BAS transmission / reception control means 5 that has issued a request for transmitting a still image to the transmission / reception control means 5 uses the high-speed data (High S) for the multiplexing / separation means 4 to transmit a still image.
A BAS code of "HSD on" is set in the multiplexing / demultiplexing means 4 so as to secure a channel of "peded Data" (hereinafter referred to as "HSD"). The multiplexing / separating means 4 receiving the BAS code opens (secures) the HSD channel.
At the same time, a still image transmission request is placed on the BAS on the communication channel and sent to the communication partner via the communication line interface 2 and the communication line 1.

Thereafter, a request for transmitting a still image from the other party is received by the multiplexing / separating means 4 and notified to the BAS transmission / reception control means 5. The BAS transmission / reception control means 5 starts the process for transmitting the still image, by determining that the request for transmitting the still image from the other party is an approval response to the request for transmitting the still image. In Figure 4,
The still image transmission procedure is divided into processes such as initialization process, compression (encoding), transmission, and termination process. First, B
The AS transmission / reception control means 5 issues an initialization processing (transmission) request to the still image transmission / reception control means 10. System control means 1
3, after receiving the normal end response to the initialization processing (transmission) request, similarly performs the encoding processing (omitted in FIG. 4),
A transmission process is issued to the still image transmission / reception control means 10. The still picture transmission / reception control means 10 starts the transmission processing of the still picture by the secured HSD channels, but since the transmission / reception processing cannot be performed at the same time, an error occurs in the stations (A) and (B).

The still picture transmission / reception means 10 notifies the system control means 13 of this abnormality, and the system control means 13 having received the notification issues a still picture transmission stop request to the BAS transmission / reception control means 5. BA that received a request to stop transmitting still images
The S transmission / reception control means 5 multiplexes the "HSD off" BAS code so as to close (release) the HSD channel.
The separation means 4 is set. Upon receiving the BAS code, the multiplexing / separating means 5 releases the HSD channel and sends a still image transmission stop request to the BAS on the communication channel and sends it to the communication partner via the communication line interface 2 and the communication line 1. At this time, the system control means 13 issues a termination processing request to the still picture transmission / reception control means 10 to terminate the still picture communication processing.

[0008]

In the above-mentioned conventional image communication terminal device, since the still image transmission / reception control means 10 for transmitting / receiving a still image cannot transmit / receive simultaneously, different two stations are required to transmit the still image at the same time or almost at the same time. When a still image transmission collides, the still image communication is not actually performed, but there is a time (useless processing time) in which the HSD channel is secured, which accounts for the entire transfer rate. If the percentage of HSD channels cannot be ignored, voice,
This has a great adverse effect on communication of other media such as moving images. That is, although the still image is not actually transmitted / received, there is a time when the voice becomes unclear or the image is disturbed. HSD channel is CCIT
According to the T (International Telegraph and Telephone Advisory Committee) recommendation, the maximum number of time slots (64 Kbit / s) will be used.
The transfer rate that is usually used is 2B (64Kbit /
This is a very important problem when communicating s × 2).

An object of the present invention is to provide an image communication terminal device capable of canceling a collision of still image transmission and efficiently using an HSD channel when still image transmission is requested by two different stations at the same time or almost at the same time. It is to be.

[0010]

An image communication terminal device of the present invention comprises a call control means for managing calls such as incoming and outgoing calls, and a still image transmission / reception control means for transmitting / receiving a still image transmitted as high speed data. And a bit rate allocation signal indicating the terminal capability of structuring various communication channels, and a bit rate allocation signal including a code meaning "high-speed data transmission" when a still image transmission request is made. It has a bit rate allocation signal transmission / reception control means, and has a function of transmitting / receiving an image signal, an audio signal, data and a conference control signal via a communication line. Further, when a still image transmission / reception request is received from another station by providing a still image transmission / reception management unit that manages the state of the still image transmission / reception control unit as “still image transmission in progress” at the time of the still image transmission request in the own station. When the status of the still image transmission / reception control unit managed by the still image transmission / reception management unit is "still image transmission", the call information stored in the call control unit when the communication channel is connected is set to the calling side. If so, a still image is transmitted, and if the call information is the called side, a still image is received from another station.

[0011]

According to the structure of the present invention, the still picture transmission / reception management means for managing the state of the still picture transmission / reception control means is provided, and when the still picture transmission request from another station is received, the still picture transmission / reception management means manages it. When the status of the still image transmission / reception control means that is being set is "still image transmission", the still image is sent if the call information stored in the call control means when the communication channel is connected is the calling side. If the call information is the called side, the still image is received from the other station, so that when the still image transmission request is issued at the same time or almost at the same time at the own station and the other station, the transmission is stopped. Cancel the collision of image transmission,
The HSD channel can be used efficiently.

[0012]

Embodiments of the present invention will be described in detail below with reference to the drawings. FIG. 1 is a functional block diagram of an image communication terminal device according to an embodiment of the present invention. In FIG. 1, 1 is a communication line, 2 is a communication line interface, 3 is call control means for managing calls such as calling, receiving, and disconnecting, 4 is multiplexing of image signals, voice signals, data, and conference control signals. Multiplexing / demultiplexing means for performing demultiplexing and demultiplexing, 5 is a BA for transmitting / receiving terminal capability for structuring various communication channels.
S transmission / reception control means, 6 is audio transmission / reception control means for encoding and decoding an audio signal, 7 is an audio input / output device, 8 is a moving image transmission / reception control means for encoding and decoding a moving image signal, and 9 is an image. Input / output equipment, 10 is still image transmission / reception control means for encoding / decoding and transmitting / receiving still image signals, 11 is LSD transmission / reception control means for transmitting / receiving low-speed data, 12 is LSD communication terminal device, 13 image communication terminal It is a system control means for managing the entire apparatus. These 1
The configurations and functions of the devices and means of 13 are basically the same as those in the conventional image communication terminal device.

In this embodiment, a still image transmission / reception management means 14 is provided in addition to the configuration of the conventional image communication terminal device. The still image transmission / reception management unit 14 manages the state of the still image transmission / reception control unit 10 and the state of the call control unit 3, and receives a transmission request from the still image transmission / reception control unit 10 of the communication partner station or a response to the transmission request. And each "HS
D ON: Transmission ”(normal time other than still image transmission collision) or“ H
A code signifying "SD on: reception" (at the time of still image transmission collision) is set in the BAS transmission / reception control means 5 to cancel the still image transmission collision at the normal time and the still image transmission collision other than the still image transmission collision. The entire still image transmission / reception control means 10 is efficiently managed.

The operation of the image communication terminal device of this embodiment configured as described above will be described. First, the call control means 3 transmits / receives a call setting signal such as an incoming / outgoing call through the communication line interface 2 to establish a communication channel connection with the other party. At this time, the call control means 3 stores information on whether the call is made or received. After the connection of the communication channel is completed, the mode initializing procedure is performed by the multiplexing / separating means 4 via the communication channel, and the BAS transmission / reception control means 5 is established after the synchronization is established.
The capability exchange is performed and the capability of the communication terminal is determined. As a result, those having communication capability are respectively the voice transmission / reception control unit 6, the moving image transmission / reception control unit 8, and the still image transmission / reception control unit 1.
0, LSD transmission / reception control means 11 is activated, and voice, image,
Communication of data and conference control signals is possible respectively.

At this time, when the still image transmission / reception control means 10 for transmitting / receiving a still image cannot simultaneously transmit / receive, different two stations (A) -calling side and (B) -calling side simultaneously start transmission. The sequence at that time is shown in FIG. First,
In the stations (A) and (B), the system control unit 13 that has received the still image transmission request is the still image transmission / reception management unit 1.
4, the still image transmission / reception control means 10 is set as "still image transmission in progress".
While setting the state of No. 2, the BAS transmission / reception control means 5 is sent a code indicating "HSD on: transmission" using the empty area of the escape table of the BAS code shown in the CCITT recommendation.

Thereafter, the "HSD on: transmission" code transmitted from the other party is received via the multiplexing / demultiplexing means 4, the communication line interface 2, and the communication line 1, and is passed through the multiplexing / demultiplexing means 4 of the own station. , BAS transmission / reception control means 5 notifies still image transmission / reception management means 14 that a still image transmission request has come from the communication partner station. In response to the notification, the still image transmission / reception management unit 14 compares the notification content (still image transmission request) with the state of the still image transmission / reception control unit 10 (still image transmission), and determines that the still image transmission has collided. Call control means 3
Based on the call information (calling / calling) stored in the caller, the initialization request is sent to the still image transmission / reception control means 10 as the sender of the still image if the calling side and as the receiver of the still image if the called side. Issue and start still image transmission / reception processing.

In FIG. 2, the still image transmission / reception procedure is divided into processes such as initialization process, compression (encoding), transmission, reception, decompression (decoding), and ending process (encoding. , Decryption processing is omitted in FIG. 2). According to the above
The station (A) performs encoding, transmission processing, and termination processing as a still image transmission side, and the station (B) performs negotiation with the station (A) as a still image reception side, reception, decoding, and termination. Perform processing.

In the station (B), the state of the still image transmission / reception control means 10 is set by the still image transmission / reception management means 14 and the still image reception waiting state is set to "receiving still image".
Also, processing after receiving a still image (decoding or displaying, saving, etc.)
The execution state is shown as "processing after receiving still image".
In addition, "empty" in FIG. 2 indicates a state in which the still image transmission / reception control means 10 is not under any execution control.

As described above, according to this embodiment, even when two different stations request to transmit still images at the same time or almost at the same time, the transmission collision is automatically released, and the transmission / reception sequence is the same as the normal transmission / reception sequence. It is possible to efficiently use the HSD channel.

[0020]

The image communication terminal device of the present invention is provided with still image transmission / reception management means for managing the state of the still image transmission / reception control means, and when a still image transmission request from another station is received,
When the state of the still image transmission / reception control unit managed by the still image transmission / reception management unit is "still image transmission", the call information stored in the call control unit when the communication channel is connected is For example, a still image is transmitted, and if the call information is the called side, a still image is received from another station. For this reason, when a still image transmission request is issued at the same station or at another station at the same time or almost at the same time, it is possible to cancel the collision of the transmission of the still image and efficiently use the HSD channel.

[Brief description of drawings]

FIG. 1 is a functional block diagram of an image communication terminal device according to an embodiment of the present invention.

FIG. 2 is a sequence diagram when two different stations simultaneously perform transmission in one embodiment of the present invention.

FIG. 3 is a functional block diagram of a conventional image communication terminal device.

FIG. 4 is a sequence diagram showing a still image transmission collision by a conventional image communication terminal device.

[Explanation of symbols]

 1 Communication line 2 Communication line interface 3 Call control means 4 Multiplexing / separation means 5 BAS transmission / reception control means 6 Audio transmission / reception control means 7 Audio input / output equipment 8 Video transmission / reception control means 9 Image input / output equipment 10 Still image transmission / reception control means 11 LSD Transmission / reception control means 12 LSD communication terminal device 13 System control means 14 Still image transmission / reception management means

Claims (1)

[Claims] 1. A call control unit for managing calls such as incoming and outgoing calls, a still image transmission / reception control unit for transmitting / receiving a still image transmitted as high-speed data, and a terminal capability for structuring various communication channels. A bit rate allocation signal transmission / reception control means for transmitting and receiving the bit rate allocation signal shown, and transmitting the bit rate allocation signal including a code signifying "high-speed data transmission" when a still image transmission request is made. An image communication terminal device having a function of transmitting and receiving a signal, a voice signal, data, and a conference control signal through a communication line, wherein the status of the still image transmission / reception control means is set to "stationary" when a still image transmission request is made in its own station. Still image transmission / reception management means for managing as "image transmission in progress" is provided, and when a still image transmission request from another station is received, the still image transmission / reception management means manages it. When the status of the still image transmission / reception control means is "still image transmission", if the call information stored in the call control means at the time of connection of the communication channel is the calling side, the still image transmission is performed. The image communication terminal device is characterized in that if the call information is a called side, a still image is received from another station.