JP2000341308A - Information transmission system and information transmitter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an information transmission system with a simple configuration at a low cost and to provide an information transmitter for the system. SOLUTION: Image transmitters 2-1-2-3 are connected sequentially in series through a communication line L. The image transmitters 2-1-2-3 generate an ATM cell including a video signal, an audio signal and a control signal and transmit it to the communication line L. Furthermore, each of the image transmitters 2-2, 2-3 is provided with a cell reception section and a cell buffer and transmits the ATM cell sent from an upper-steam image transmitter to a downstream image transmitter with the ATM cell generated by its own transmitter. In this case, the uppermost image transmitter 2-1 is used for a master clock supply source, which sequentially distributes the clock signal to the image transmitters 2-2, 2-3 and an image receiver 3. The lowermost image receiver 3 selectively receives the ATM cells sent from the image transmitters 2-2, 2-3, decodes them and displays them on a monitor 4.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an information transmission system used for a road monitoring system, for example, and an information transmission device used in the information transmission system.

[0002]

2. Description of the Related Art There is an information transmission system in which an image pickup device is installed at a different place, and a photographed moving image or sound is transmitted to another place in real time and used for road monitoring or the like. In such a system, since it is necessary to transmit moving image data, audio data, and control data to each imaging device without delay, the ATM (Asynchro) suitable for multimedia transmission is used.
nous Transfer Mode) The transmission method is exclusively used.

FIG. 11 shows a conventional configuration of this type of information transmission system. Images photographed by the television cameras 11 to 13 are respectively connected to image transmission devices 804 to 80 connected thereto.
6. For example, in MPEG (Moving Picture Experts Grou
p) Encoding is performed based on an encoding method such as 2. The coded data is assembled into ATM cells in units of 53 bytes, and then sent from each of the image transmission devices 804 to 806 to the cell switches 809 to 811.

On the other hand, the center CT has an image receiving device 80.
7, cell switch 812, monitor 4 are installed,
Cell switches 809 to 811 and cell switch 81
The ATM cell is exchanged via the second ATM cell. Thereby, the image transmitting devices 804 to 806 and the image receiving device 8
In this way, the mutual communication by the ATM between 07 is achieved, real-time display of an image on the monitor 4, audio reception, control of the television cameras 11 to 13, and the like become possible.

By the way, in order to provide control signals to each of the television cameras 11 to 13, each of the image transmission devices 804 to 8 is provided.
In order to distribute the synchronization clock to the transmission line 06, a down line to each of the image transmission devices 804 to 806 is required. Traditionally,
Cell switches 809 to 811 are connected to the image transmission devices 804 to 806, respectively.
This has been dealt with by setting a communication path from No. 1 to each of the image transmission devices 804 to 806.

However, providing a cell switch for each image transmitting apparatus as described above directly leads to a complicated system configuration. Further, in combination with the fact that the cell switch is expensive, the above configuration has a problem that the cost burden for constructing the system is large.

[0007]

As described above, in the conventional information transmission system, a cell switch is provided for each image transmitting apparatus, so that the configuration is complicated.
There was a problem that the cost burden when constructing the system was large.

[0008] The present invention has been made in view of the above circumstances,
An object of the present invention is to provide a low-cost information transmission system and an information transmission apparatus with a simple configuration.

[0009]

In order to achieve the above object, the present invention provides three or more information transmission devices having at least one of a transmission device having information input means and a reception device having information output means. An information transmission system, which is sequentially connected in series via a communication line having a chain or ring shape and performs packet transmission via the communication line, wherein the information transmission device includes a transmission device among the information transmission devices To
A packet transmitting unit that packetizes the acquired information obtained by the information input unit and transmits the packet to the downstream side of the communication line is provided, and the information transmission device disposed in the middle of the communication line among the information transmission devices The packet transmission means for directly transferring the packet transmitted from the upstream side of the communication line to the downstream side of the communication line, the information transmission device including a receiving device among the information transmission devices,
A packet receiving means for selectively receiving a desired packet from packets transmitted from the upstream side of the communication line and giving the obtained information included in the packet to the information output means for output. is there.

[0010] Here, packet transmission refers to so-called AT.
In addition to M transmission, it includes general connectionless communication such as frame relay communication.

By taking such means, the acquired information including, for example, video information acquired by the information input means is packetized and transmitted to an adjacent downstream information transmission apparatus. This packet is blindly transferred from the information transmission apparatus to the downstream side as it is. As described above, the packet including the acquired information is sequentially transferred to the downstream side via each information transmission device, and is received by the information transmission device including the reception device. The receiving device selectively receives a desired packet, and the information contained in the packet is provided to the information output means and used for displaying a video, for example.

In this manner, the receiving device can receive all of the information obtained by the information input device without providing a cell switch or the like. It is possible to eliminate a switching device such as a cell switch or a router while keeping the specifications related to information transmission. This can contribute to simplification of the configuration and can reduce costs.

Further, according to the present invention, the information transmitting apparatus having the receiving apparatus further includes means for generating a control packet for remotely controlling information input means of a desired transmitting apparatus, and transmitting the control packet to a communication line. An information transmission device including a transmission device selectively receives a control packet addressed to the own device transmitted via a communication line, and controls an operation of an information input unit included in the own device according to the control content of the control packet. This is further provided with a means for performing.

By doing so, it is possible to bidirectionally exchange, for example, image signals and control signals between the information transmission apparatuses without providing a cell switch or the like. This can contribute to the simplification of the configuration and reduce the cost.

[0015]

Embodiments of the present invention will be described below in detail with reference to the drawings. (First Embodiment) FIG. 1 is a block diagram showing a first embodiment of an information transmission system according to the present invention. In FIG. 1, the same parts as those in FIG. 11 are denoted by the same reference numerals, and only different parts will be described here.

In FIG. 1, television cameras 1-1 to 1--1
3 are connected to the image transmission devices 2-1 to 2-3, respectively. Further, the center CT is provided with an image receiving device 3 and a monitor 4 for displaying a received image. Here, the image transmitting devices 2-1 to 2-3 and the image receiving device 3 are sequentially connected in series via a communication line L such as an optical fiber.

FIG. 2 shows the configuration of the image transmission devices 2-1 to 2-3. Taking the image transmission device 2-2 as an example, a video input signal and an audio input signal from the television camera 1-2 are supplied to a video encoding unit 21 and an audio encoding unit 22, respectively, and are encoded by the MPEG2 system. Is done. The coded data obtained by the multiplexing unit 23 together with a control signal indicating the directional angle and the operation state of the television camera 1-2 are obtained.
After being multiplexed, it is supplied to the cell transmitting section 24 as a 53-byte ATM cell.

The image transmitting device 2-2 includes a cell receiving section 25 for receiving ATM cells transmitted from the image transmitting device 2-1 to the communication line L, and a cell buffer for temporarily storing the received ATM cells. 26. Then, the ATM cell from the multiplexing unit 23 and the temporarily stored ATM cell from the image transmitting device 2-1 are transmitted to the cell transmitting unit 24.
Is transmitted to the image transmission device 2-3 via the communication line L.

The image transmitting device 2-3 also has a similar configuration.
The ATM cells from the image transmitting devices 2-1 and 2-2 are transmitted to the image receiving device 3 together with the ATM cells generated by the image transmitting device 2-3 itself. Note that the image transmitting device 2-1 has almost the same configuration, but since it is located at the end of the communication line L, it is not always necessary to provide the cell receiving unit 25 and the cell buffer 26.

FIG. 3 shows the configuration of the image receiving device 3. That is, the ATM cell provided from the image transmitting device 2-3 via the communication line L is provided to the selecting unit 32 after being received by the cell receiving unit 31. In the selecting unit 32, A of the channel corresponding to any of the image transmitting devices 2-1 to 2-3 is selected.
The TM cell is selected by the user, and
Given to.

In the separating section 33, the given ATM cell is separated into video data, audio data, and a control signal. The video data is decoded by the video decoding unit 34, output to a monitor (not shown), and displayed as an image. The audio data is decoded by the audio decoding unit 35 and then output to a monitor speaker (not shown) or the like. The control signal is sent to a central control unit (CPU) (not shown) and the like.
It is used for grasping the state of the corresponding television camera.

Next, the operation of the above configuration will be described.
The images captured by the television cameras 1-1 to 1-3 are provided as image signals to the image transmitting devices 2-1 to 2-3, respectively, and are converted into cells. Here, a channel number A is assigned to the ATM cell generated by the image transmitting device 2-1 (referred to as a cell A), and the cell A is further transferred to the image transmitting device 2-2.
Sent to

Next, the A generated by the image transmitting device 2-2.
A channel number B is assigned to the TM cell (referred to as a cell B). Then, together with the previously received cell A, the cell B
Is sent to the image transmission device 2-3. Similarly, from the image transmission device 2-3, the cell C with the channel number C is transmitted to the image reception device 3 together with the cells A and B.

At this time, the image transmitting device 2-2 extracts a clock from the cell A given from the image transmitting device 2-1 and operates in synchronization with the image transmitting device 2-1 based on the extracted clock. Similarly, the image transmitting device 2-3 extracts a clock from the cells A and B, and synchronizes with the image transmitting device 2-2.

As described above, each of the image transmission devices 2-1 to 2-3 is
Is a device which assigns a channel identifier to an ATM cell generated by itself, sends the ATM cell to the communication line L, and transfers the ATM cell received from the preceding image transmitting apparatus to the downstream side via the communication line L. It is.

As a result of such an operation, the image receiving device 3 is provided with all of the ATM cells generated by the image transmitting devices 2-1 to 2-3. In response, the image receiving device 3 selects one of the images captured by the TV cameras 1-1 to 1-3 by the user's channel designation and displays the image on the monitor. To switch the image, the image receiving device 3 may switch the channel. Similarly to the above, the image receiving device 3 extracts a clock from the ATM cells A, B, and C from the image transmitting device 2-3, and operates in synchronization with the image transmitting device 2-3 based on the clock.

Thus, in this embodiment, the TV camera 1
Image transmitting apparatus 2-1 connected to -1 to 1-3, respectively
To 2-3 are sequentially connected in series by a communication line L. The image transmission devices 2-1 to 2-3 generate ATM cells including a video signal, an audio signal, and a control signal, and transmit the ATM cells to the communication line L. Further, the cell receiving unit 25 and the cell buffer 2 are provided to the image transmitting apparatuses 2-2 and 2-3 where the image transmitting apparatuses exist on the upstream side.
And the ATM transmitted from the upstream image transmitting apparatus.
The cell is sent to the downstream image transmitting device together with the ATM cell generated by the own device. At that time, the most upstream image transmission device 2-
1 is a master clock supply source, and clocks are sequentially distributed from this to the image transmitting devices 2-2, 2-3 and the image receiving device 3. The image receiving device 3 located at the most downstream position selectively receives the ATM cells sent from the image transmitting devices 2-1 to 2-3, decodes the ATM cells, and displays the decoded cells on the monitor 4.

That is, the image transmitting devices 2-2 to 2-3
Has a function of transferring the ATM cells received from the upstream side to the downstream side, and the image receiving apparatus 3 has a function of selecting the ATM cells.
-1 to 2-3 and the image receiving device 3 are sequentially connected in series by the communication line L, so that necessary and sufficient information can be transmitted. For this reason, it is not necessary to connect a cell switch to each of the image transmitting devices 2-1 to 2-3, which can contribute to simplification of the system configuration and promote cost reduction.

Further, in order to newly install a television camera, a new image transmitting apparatus may be provided and sequentially added to the configuration of FIG. 1 in series. This makes it possible to provide an information transmission system that is highly expandable.

(Second Embodiment) Next, a second embodiment of the present invention will be described. FIG. 4 is a diagram showing the system configuration. The same parts as those in FIG. 1 are denoted by the same reference numerals,
Here, only different portions will be described. In FIG. 4, a plurality of image receiving apparatuses 5-1 to 5-3 are provided at the center CT.
And a monitor 4 connected thereto. The image transmitting apparatuses 2-1 to 2-3 and the image receiving apparatuses 5-1 to 5-3 are connected in series by a communication line L. here,
The image receiving device 5-3 is located at the end of the communication line L and has the same configuration as the image receiving device 3 in FIG.

FIG. 5 shows the configuration of the image receiving apparatuses 5-1 to 5-2. The image receiving devices 5-1 to 5-2 newly include a cell buffer 51 and a cell transmitting unit 52 in addition to the configuration of the image receiving device 3 in FIG. That is, the image receiving device 5-1
.About.5-2, select the ATM cell of the desired channel from the ATM cells received via the communication line L, decode and display it on the monitor, temporarily store the received ATM cell in the cell buffer 51, and then transmit the cell 52 to communication line L
To be re-transmitted.

According to the above configuration, the receiving devices 5-1 to 5-
After the receiving process is performed in step 2, the ATM cell is transferred to a receiving device further downstream. By selectively receiving this, images captured at different points can be monitored simultaneously at one place. That is, it is possible to simultaneously monitor images taken at a plurality of points while taking advantage of the advantages obtained in the first embodiment.

(Third Embodiment) Next, a third embodiment of the present invention will be described. FIG. 6 is a system configuration diagram. Note that parts common to those in FIG. 1 are denoted by the same reference numerals.
In FIG. 6, a plurality of image transmission devices 9-1 to 9-3 are provided.
And the image receiving device 8 are connected in a ring by a communication line L. Each of the image transmission devices 9-1 to 9-3 has a camera control device 6- in addition to the television cameras 1-1 to 1-3.
1 to 6-3 are connected respectively.

The camera control devices 6-1 to 6-3 control the connected television cameras 1-1 to 1-3, such as zooming and turning, based on a control signal provided through the communication line L. .

FIG. 7 shows the configuration of the image transmission devices 9-1 to 9-3. For example, in addition to the configuration shown in FIG. 2, the image transmitting device 9-1 includes a control signal separating unit 91 that separates a cell including a control signal to the television camera 1-1 from an ATM cell received by the cell receiving unit 25. Have. Image transmission device 9
Similarly, 2-2 to 9-3 also include a control signal separating unit 91 for separating and extracting a control signal to a television camera connected to the own device.

FIG. 8 shows the configuration of the image receiving device 8. The image receiving device 8 includes a cell multiplexing unit 81 between the cell buffer 51 and the cell transmitting unit 52 in FIG. The cell multiplexing unit 81 is provided with the television camera 1 provided from the control console 7.
The control signals to -1 to 1-3 are converted into ATM cells, which are multiplexed with the received cells transmitted from the cell buffer 51 and supplied to the cell transmitting section 52.

In the above configuration, the television camera 1-1
~ 1-3 and the image receiving device 8 are realized interactively. That is, when an operation such as zooming or turning is designated and input to any of the television cameras from the control console 7, a control signal to that effect is converted into an ATM cell, and the image transmitting device 8 first transmits the control signal to the image transmitting device 8. 9-1. The image transmitting device 9-1 determines whether or not the received ATM cell is addressed to itself, that is, whether or not the received ATM cell is directed to the own channel. If not, the ATM cell is transmitted to the next image together with the image information cell. Transmit to the transmission device 9-2.

As described above, the ATM cells including the control information are sequentially transferred to the image transmitting devices 9-2 and 9-3, and if one of the image transmitting devices determines that the ATM cell is addressed to itself, the A
The TM cell is taken in and is discarded after message decoding. For example, when a control signal addressed to the image transmitting device 9-2 is transmitted, a message included in the control signal is supplied to the camera control device 6-2 to be used for controlling the television camera 1-2.

On the other hand, each of the television cameras 1-1 to 1-3 is
Immediately after the above control or periodically, it gives its own state (turning angle, zoom ratio, etc.) to the image transmitting devices to which it belongs. The control signal is converted into an ATM cell in each of the image transmitting devices 9-1 to 9-3, and is transmitted to the image receiving device 8 via the image transmitting device located on the downstream side.
Each of the television cameras 1-1 to 1-3 is obtained from these ATM cells.
The control information indicating the state of the monitor 4 is decoded, and the monitor 4 and the control console 7 are decoded.
Is displayed, for example, visually.

As described above, the image transmitting devices 9-1 to 9-3
By connecting the image receiving device 8 to the image receiving device 8 via the communication line L in a ring shape, two-way communication can be performed between the television cameras 1-1 to 1-3 and the image receiving device 8. External control of 1-1 to 1-3 can be performed.

Further, since the image receiving device 8 controls the television cameras 1-1 to 1-3, there is no need to install a so-called workstation for controlling the system itself. This can contribute to simplification of the system configuration.

(Fourth Embodiment) Next, a fourth embodiment of the present invention will be described with reference to FIG. Parts common to those in FIG. 6 are denoted by the same reference numerals. In FIG. 9, FIG.
The image transmission / reception device 10 is provided in the ring of the communication line L in FIG. The installation position of the image transmitting / receiving device 10 does not matter.

FIG. 10 shows the configuration of the image transmitting / receiving apparatus 10. The image transmitting / receiving apparatus 10 distributes the ATM cell received by the cell receiving unit 31 into two parts, retransmits one of the ATM cells to the communication line L via the cell buffer 51, and transmits the other to the separating unit
Give to 3. The separating unit 33 separates the video data, the audio data, and the control signal, and outputs each of them in the same manner as in FIG. The decoded video output and audio output are supplied to the monitor 4 for display and monitoring, but the control signal is supplied to the camera control device 6-2.

On the other hand, the encoded video signal, audio signal, and control signal from the television camera 1-2 are multiplexed by the multiplexing unit 23 and then supplied to the cell transmitting unit 52, The data is transmitted to the communication line L together with the temporarily stored received ATM cells.

According to the above configuration, the image transmitting / receiving apparatus 10 located at a different place from the image receiving apparatus 8 can acquire images and sounds at a plurality of points in the same manner as the image receiving apparatus 8. For this reason, it is possible to flexibly respond to the needs at the time of system design, and to obtain merits such as distributing the load related to monitoring. Further, if the above configuration is further developed, it is possible to obtain an image of another point at all of the image capturing locations.

The present invention is not limited to the above embodiment. For example, it goes without saying that the number of television cameras is not limited to three. In the above embodiment, ATM transmission has been described as an example. However, the present invention can be applied to other transmission systems such as frame relay and Ethernet.

In addition, various modifications can be made without departing from the gist of the present invention.

[0048]

As described in detail above, according to the present invention, the information transmission device is caused to transfer the packet received from the upstream side to the downstream side. Sufficient data transmission can be performed, thereby making it possible to provide a low-cost information transmission system and its information transmission device with a simplified configuration.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a first embodiment of an information transmission system according to the present invention.

FIG. 2 is a block diagram showing a configuration of the image transmission devices 2-1 to 2-3 in FIG.

FIG. 3 is a block diagram showing a configuration of the image receiving device 3 of FIG.

FIG. 4 is a block diagram showing a second embodiment of the information transmission system according to the present invention.

FIG. 5 is a block diagram showing a configuration of the image receiving apparatuses 5-1 and 5-2 of FIG. 4;

FIG. 6 is a block diagram showing a third embodiment of the information transmission system according to the present invention.

FIG. 7 is a block diagram showing a configuration of the image transmission devices 9-1 to 9-3 in FIG. 6;

FIG. 8 is a block diagram showing a configuration of the image receiving device 8 of FIG. 6;

FIG. 9 is a block diagram showing a fourth embodiment of the information transmission system according to the present invention.

FIG. 10 is a block diagram showing a configuration of the image transmitting / receiving device 10 of FIG.

FIG. 11 is a block diagram showing a conventional configuration of an information transmission system.

[Explanation of symbols]

 1-1 to 1-3: TV camera 2-1 to 2-3: Image transmitting device 3: Image receiving device 4: Monitor CT: Center L: Communication line 21: Video encoding unit 22: Audio encoding unit 23 ... Multiplexing unit 24 ... Cell transmitting unit 25 ... Cell receiving unit 26 ... Cell buffer 31 ... Cell receiving unit 32 ... Selecting unit 33 ... Demultiplexing unit 34 ... Video decoding unit 35 ... Sound decoding unit 5-1 and 5-2 ... Image receiving device 51 Cell buffer 52 Cell transmitting unit 9-1 to 9-3 Image transmitting device 91 Control signal separating unit 8 Image receiving device 6-1 to 6-3 Camera control device 7 Control console 8 ... Image receiving device 10 ... Image transmitting and receiving device

Claims (11)

[Claims] 1. A device comprising at least one of a transmitting device having information input means and a receiving device having information output means.
An information transmission system in which at least one information transmission device is sequentially connected in series via a communication line in a chain or ring shape, and performs packet transmission via the communication line. The information transmission device including the transmission device includes a packet transmission unit that packetizes the acquired information acquired by the information input unit and transmits the packet to the downstream side of the communication line, and is provided in the middle of the communication line among the information transmission devices. The information transmission device to be arranged includes a packet transfer unit that transfers a packet transmitted from the upstream side of the communication line to the downstream side of the communication line as it is, and among the information transmission devices, the information transmission device including the reception device includes: A desired packet among the packets transmitted from the upstream side of the communication line is selectively received, and the obtained information included in the packet is given to the information output means. Information transmission system comprising the packet reception means allowed to output Te. 2. An information transmission device comprising the receiving device,
The information transmission apparatus further includes means for generating a control packet for remotely controlling the information input means of a desired transmission device and transmitting the control packet to a communication line. 2. The information transmission apparatus according to claim 1, further comprising a unit configured to selectively receive a control packet addressed to the device and control an operation of an information input unit included in the device according to the control content of the control packet. system. 3. An information transmission device including the transmission device,
A multiplexing unit that encodes at least a plurality of information materials including at least the obtained information and multiplexes the coded plurality of information materials together with control information; and a case where a packet is transmitted from an upstream side of a communication line. Transmission buffer means for receiving and storing the packet, and means for transmitting the multiplexed packet generated by the multiplexing means and the received packet stored in the transmission buffer means to the downstream side of the communication line, respectively. The information transmission system according to claim 1, wherein: 4. An information transmission device comprising said receiving device, wherein when a packet is transmitted from an upstream side of a communication line, a receiving buffer means for receiving and storing the packet, and a receiving buffer stored in the receiving buffer means. Means for transmitting a packet to the downstream side of the communication line, means for selectively reading a desired packet from the received packets stored in the reception buffer means and separating the multiplexed data into a plurality of information materials, 2. The information transmission system according to claim 1, further comprising means for decoding the plurality of separated information materials and playing them back in association with each other. 5. A device comprising at least one of a transmitting device having information input means and a receiving device having information output means.
The information transmission apparatus used in an information transmission system in which one or more information transmission apparatuses are sequentially connected in series through a series of chain-like or ring-like communication lines, and perform packet transmission through the communication lines. An information transmission apparatus comprising: a packet transfer unit that transfers a packet transmitted from an upstream side of a line to a downstream side of the communication line as it is. 6. An information transmission device comprising the transmission device, further comprising a packet transmission unit for packetizing the acquired information acquired by the information input unit and transmitting the packet to a downstream side of the communication line. The information transmission device according to claim 5, wherein And means for selectively receiving a control packet addressed to the own device transmitted via the communication line and controlling the operation of the information input means provided in the own device according to the control content of the control packet. 7. The device according to claim 6, wherein
An information transmission device according to claim 1. 8. A multiplexing means for encoding each of a plurality of information materials including at least the acquired information, and multiplexing the coded plurality of information materials together with control information, wherein a packet is transmitted from an upstream side of a communication line. Transmission buffer means for receiving and storing the packet when transmitted; transmitting the multiplexed packet generated by the multiplexing means and the received packet stored in the transmission buffer means to the downstream side of the communication line, respectively. 7. The information transmission apparatus according to claim 6, further comprising: means. 9. An information transmission device comprising the receiving device, wherein the information transmission device selectively receives a desired packet among packets transmitted from an upstream side of a communication line, and transmits the acquired information included in the packet to the information. 6. The information transmitting apparatus according to claim 5, further comprising a packet receiving means for giving an output means to output the packet. 10. The information transmission apparatus according to claim 9, further comprising: means for creating a control packet for remotely controlling information input means of a desired transmission apparatus and transmitting the control packet to a communication line. 11. A receiving buffer means for receiving and storing a packet when the packet is transmitted from an upstream side of the communication line, and transmitting the received packet stored in the receiving buffer means to a downstream side of the communication line. Means, means for selectively reading a desired packet from the received packets stored in the reception buffer means and separating the multiplexed data into a plurality of information materials, and decoding the plurality of separated information materials, respectively. 10. The information transmission apparatus according to claim 9, further comprising: means for reproducing in association with each other.