JPH01200887A - Bidirectional video communication system - Google Patents

Abstract

PURPOSE:To attain a video or a sound bidirectional communication by adding the terminal equipment of a bidirectional video communication in a television common audible network. CONSTITUTION:As a CATV, plural commercial televisions are received in a TV common audible device 12 through a television antenna 11, they are power amplified and transmitted to the television commonly audible network through ahead end 19. An independent program or a video signal from a TV studio is transmitted to the television commonly audible network through an independent TV program device 14 or the head end 19. According to the request of a user, the busy information of a television channel and the called is retrieved to command an used channel to a caller side and the called by a MCA system, set to the television channel of the caller side and the called side, transmit the video of a television camera and display mutually the video signal on receivers and attain a speech.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to video conferences, video telephones, video service systems, etc. using coaxial CATV and difficult-to-see public viewing networks.

(Prior Art) Conventionally, this type of two-way video communication system has mainly been one in which communication is carried out between fixed facilities using dedicated lines.

(Problem to be Solved by the Invention) However, in the conventional two-way video communication system described above, video TV telephones and video TV conferences are mainly one-to-one communications using dedicated lines, and communication is performed between arbitrary points. has a video channel, e.g. 6 MIIz or 32 Mbit/s (B
There was a problem in that a large-scale system using a wideband communication path such as PS) and a video switch capable of exchanging wideband signals was required.

The present invention utilizes empty channels of a common television viewing system such as CATV, and provides multi-channel access (hereinafter referred to as M
The purpose of the present invention is to provide a two-way video communication system that performs two-way video and audio communication by applying a method (referred to as CA).

(Means for Solving the Problems) In order to achieve the above object, the present invention includes the following means.

(1) An empty channel in a television public viewing network such as CATV is used as a communication channel for video communication.

(2) Securing empty TV channels within the TV common listening network;
This is shared as the MCA method.

(Function) Therefore, according to the present invention, by adding the terminal device of the above-mentioned two-way video communication system to a television common viewing network, video communication between subscribers and between a center and subscribers is made possible. It has this effect.

(Embodiment) FIGS. 1 and 2 show the configuration of an embodiment of the present invention. FIG. 1 is a functional configuration diagram of the center equipment of the two-way video communication system, and FIG. 2 is a functional configuration diagram of the subscriber equipment of the system.

In FIG. 1, 1 is a center device, 11 is a TV antenna, 12 is a TV shared listening device, 13 is a TV studio, and 14 is a TV antenna.
15 is independent television program equipment, 15 is MCA communication center equipment,
16 is a keyboard having dials, function buttons, and a handset for making calls. 17 is a controller for a two-way video communication system (hereinafter referred to as a TV phone controller); 18 is a memory for storing the channel number 9 of the TV phone controller 17, call number, usage time, etc.; 19 is an optical fiber, coaxial line, etc. a head-end device for coupling with the transmission line 20 of
2 is a TV telephone device installed at the center station, 22 to 26 are the main bodies of the TV telephone device, 27 is a receiver, A is a speaker attached to the receiver, 28 is a TV camera, and B is attached to the TV camera. A microphone, 29 a TVffi speech controller, 30 a channel checker, and the center device and TV phone device (center equipment) of the MCA communication system.
is formed.

FIG. 2 shows a subscriber device of a TV telephone device. In FIG. 2, reference numeral 20 denotes a transmission path, which connects the center device 1 to each subscriber device in series. 21 is a signal coupler, 3
3 is a TV phone device of the subscriber equipment, 31 is a filter for separating the image sending and receiving channels, 32 is a switch connected to either side of the filter 31, 33 is a TV signal receiver, and 34
is a frequency synthesizer for channel switching, 35
is a TV signal transmitter, 36 is a TV receiver, A is a speaker attached to the TV receiver 36, 37 is a TV camera, B is a microphone attached to the TV camera 37,
38 is a TV telephone controller, which forms the majority of the TV telephone device. 39 is for CATV reception and MCA
A filter that shares the communication device of the system, 40 is an MCA
Communication device, 41 is a keyboard including dials and function buttons for accessing the MCA communication system and the Tvt1 talk system, C is a display such as a dial, D is a dial and function buttons, and E is a telephone handset. . 42 is a TV receiver for CATV.

FIG. 3 shows an example of channel arrangement in this embodiment.

In FIG. 3, G is a TV channel in the 50M11Z band, G2 is a TV channel in the 150MIZ band, and G is a UHF TV channel in the 400MHz band.

Further, TV indicates a television broadcast, unmarked indicates an empty channel, MCA indicates a channel for the MCA communication system, and TVT indicates a channel for video telephones. MCA above, TVT
Each channel is not specially allocated, but is an empty commercial television channel used only within the common television network.

The MCA communication system uses TV channel 6M1 (z) as a narrowband communication path, and the 50kHz bandwidth is 120ch, but it is divided into n groups, one group is divided into mch, and the MCA system is used for telephone communication. , FAX communication, and security communication.

TVT has a 6M11Z interval similar to commercial television broadcasting, and is designed to be economical so that general commercial color television receivers and television cameras can be used.

FIG. 4 shows the flow of connection of call video in the above embodiment.

Next, the operation of the above embodiment will be explained. In FIG. 1, the CATV is a TV set via a TV antenna 11
A communal listening device 12 receives a plurality of commercial televisions, amplifies the power of the received signals, and transmits the received signals to a television public listening network through a head end 19. In addition, independent programs and video signals from the TV studio 13 are sent to a television public viewing network through an independent TV program device 14 and a head end 19.

Next, the case of making a videophone call will be explained.

(1) When making a video call from the center to a subscriber in dwelling unit 1, the operator of center equipment 1 dials (D) on the keyboard 16.
Dial the residential unit 1 subscriber number. This dial indicates a videophone call. For example, if book 3 is the number 0136 of the subscriber of dwelling unit 1, the MCA center device 15 accesses the videophone controller 17 and sends the called party number 0136 (
Figure 4 S). The TV phone controller 17 accesses the memory 18 and checks whether the TVT channel memory and 0136 are busy, and if not, selects a pair of empty TVT channels and sends the caller center the message shown in FIG. Group G, T
VTch2 of group G2 to 0136 on the called side
Assign ch2. During this period, MCA center installation [11
15 calls 0136 of dwelling unit 1 and uses the communication channel (S
(S, S3 in Figure 4)
MCA center device 15 connects G2 TVTch to 0136
Give instructions to use 2. This data is MCA
The system sends the above TVT channel number, G, (7) TVT from the coupler 21 and filter 39 of 0136 of dwelling unit 1 to the TV telephone controller 38 via the MCA communication device 40.
ch2 is transmitted (Fig. 4, 84).

The TV telephone controller 38 supplies channel data to be used by the frequency synthesizer 34 that generates the reception station and transmission frequencies of the TV signal receiver 33 and the TV signal transmitter 35 to operate them, and also rings a call bell. This paging may be performed at the paging stage before issuing the TVT channel command. Here, if the called party answers, videophone communication between the center and 0136 of dwelling unit 1 is started (Ss in FIG. 4). The above method uses an MCA system phone and a TVT video imager, but calls can be made using the TV receiver's speaker, hands-free communication using the TV camera's microphone, or between the TV receiver's speaker and the MCA system's handset. It can take various forms, such as using a microphone or a separately provided hand microphone (not shown). Closing can be done by either side.

(2) When making a video call between dwelling unit 1 and dwelling unit 2, dwelling unit 1
The calling party uses the keyboard 41 to dial the TVT number of the called party. For example, assume that the dial number is Umbrella 3-1298. The above-mentioned dial number is sent from 0136 of dwelling unit 1 to MCA center device 15 of center device 1 (Fig. 4 S,
), the above data is sent to the TV telephone controller 17 of the center device 1, and the TV telephone controller 17 checks whether the above 1298 is busy and whether the TVT channel is vacant (S, in Fig. 4).
. If there is an empty channel, enter the channel number.
If it is Ch 4, there is a TV T ch of G3 in dwelling unit 1.
4 to 1298 of dwelling unit 2 instructing TV channel 4 of G2 (Fig. 4 S a ) - During this period, the MCA center device 15 transmits a communication channel (Sc
HP) to the call channel (Schp) to 1298 of dwelling unit 2.
') and have them switch (S, , S work in Figure 4), and then switch G, T V Tch to 1298 of dwelling unit 2.
4 (S in Figure 4). Dwelling unit 2-1
298 responds, 1298 receives 02TvTC.
Send the video of TV camera 37 using h4, and use G3TVTc
h4 image is received by the TV receiver 36, and on the other hand, on the residential unit 1 side, the image is transmitted by G3TV Tch4 LZ and G, TV
Tch4 Performs image reception by 2. Regarding audio, see above (1)
) are used.

(3) Ending the videophone call The end of the call is done by either on-hook or end button of the handset E on the keyboard 41 from either the dwelling unit 1 side or the dwelling unit 2 side, and this information is transmitted to the center equipment. The TV telephone controller 17 of @1 is notified (502 in Fig. 4).
, the center device 1 sends out a call termination signal again (
Figure 4 S, , S, ).

Additionally, a function button is provided on the keyboard to switch between hands-free calls using the TV camera's microphone and TV receiver speaker, handset calls that share the MCA system, hands-free calls that use the hand microphone and TV receiver speaker, etc. and allow the user to freely choose.

Further, although the transmission signal of the video telephone has been described using the FDM system, the same function can be achieved in the case of the TDM system.

In addition, the transmission line should be a coaxial line or an optical fiber line, the downlink should be CATV and the uplink should be a separate line, a separate line could be used to arrange channels freely ignoring commercial TV, and the line should be two-way. It is also possible to perform physical band division and the above-mentioned tube splitting.

(Effects of the Invention) As is clear from the above embodiments, the present invention enables two-way communication of video and audio using vacant channels of a public listening system, and makes two-way communication requiring a wide band economical. This has the effect that it can be realized.

[Brief explanation of the drawing]

FIG. 1 is a functional block diagram of a video telephone (TVT) using a CATV public listening network in an embodiment of the present invention, FIG. 2 is a functional block diagram of a TVT subscriber in an embodiment of the present invention, and FIG. 3 4 is a channel layout diagram showing an example of channel usage, and FIG. 4 is a flowchart showing a call video connection procedure. 1... Center device, 2, 3... TV telephone device, 11
...TV antenna, 12...TV shared listening device, 13
...TV studio, 14...Independent TV program equipment, 1
5... MCA center device, 16.41... Keyboard, 17.29° 38... TV telephone controller, 18.
...Memory, 19...Head end, 20...Transmission line (coaxial line or optical fiber line), 21...Coupler, 22-26...TV telephone device body, 27, 36
-TV receiver, 28.37-TV camera, 30...channel checker, 31°39...filter, 32...
・Switcher, 33...TV signal receiver, 34...Frequency synthesizer, 35...TV signal transmitter, 40...
- MCA communication device, 42...TV receiver. Patent applicant Matsushita Electric Industrial Co., Ltd. 1'l 1 ■-,, TV electric δ♂R) 4J Figure 2 [-,--1

Claims (1)

[Claims] Multi-channel access (
voice, fax, and data lines using the MCA) system,
It is equipped with a videophone transmission line that uses a plurality of available TV channels, and searches for information such as the available TV channels and the called party's conversation in accordance with the user's request, and provides the calling party and the called party with the available channels. A two-way video communication system in which the MCA system commands the calling side and the called side to set television channels and transmit the video from the television camera, and the video signals are displayed on the receivers of both parties so that they can talk. .