JPH06326727A - Multi-cast connection control system in atm network - Google Patents

Abstract

PURPOSE:To revise the connection form instantaneously even when a speaker is changed in a lecture service without deterioration in the utilizing efficiency of the ATM network. CONSTITUTION:Plural subscriber terminal equipments 1 are connected with an ATM exchange 10 having an in-exchange copy function via a subscriber line 5. The system is provided with a service agent section 20 which executes multi-cast connection control while being connected to the ATM exchange 10 through M-sets of information input channels 12, an SA control channel 11, an information output channel 13 and a signal control channel 14 for controlling the signal for the ATM exchange 10.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a multicast connection control system in an ATM network. At present, it is expected that a broadband communication network using ATM technology will be realized at an early stage as a network capable of supporting multimedia and high-speed communication of terminals. Here, it is important to realize not only a high-speed switching network but also a network capable of providing various communication services in response to user needs.

Presently, typical broadband communication services that are expected to be used include multimedia conferences and multicast of lectures. The major features of these communications are:
This is not conventional 1: 1 communication but 1: N communication or N: N communication.

[0003]

2. Description of the Related Art There is no example in which a lecture service has been realized by using a conventional switching network / transmission network, but the following methods are currently available as a method for simply realizing multicast in an ATM network. (1) Method of performing cell copy at terminal (2) Method of performing cell copy inside switch FIG. 3 is an explanatory diagram of a conventional multicast method,
A method of performing cell copy at the terminal (1) is shown.
In the figure, 1 is a plurality of subscriber terminals, which are connected via a network 2. In this method, assuming that the number of connected terminals is N, each terminal 1 establishes a path 3 to N-1 terminals excluding its own terminal. The features of this method are as follows. The network side only needs to support 1: 1 communication. During 1: N communication, it is easy to perform control between two specified parties, such as performing a confidential talk function, by using only a specific path by a speaker.

FIG. 4 is another explanatory view of the multicast system, which shows a system (2) for performing cell copy inside the switch. In this method, the cells are copied in the exchange 4, and therefore have the following features. The terminal side can perform a large number of communications without being aware of the communication destination, which reduces the load. A minimum path is required from the calling terminal to the exchange 4.

[0005]

In the multicast system shown in FIG. 3, N-1 communication channels are set up on the subscriber terminal of the speaker, and the maximum obtainable band per channel is narrow. Become. Further, since the subscriber terminal side bears communication guarantees such as cell copy processing, media synchronization for the N-1 communication destination, and delay countermeasures, there is a problem that the processing amount on the terminal side becomes large.

Further, when providing a lecture service using this technique, there is a problem that a path from a new speaker must be instantly established when the speaker moves, such as during a question and answer session. As a method for solving this problem, FIG.
There is a method of fixing the path with a full mesh in advance as shown in. However, this method has a problem that the utilization efficiency of the network is poor.

Further, in the multicast system shown in FIG. 4, even when a lecture is given in this system, a path from a new speaker must be instantly established when the speaker moves, such as during a question and answer session. The points remain. Also, as with the cell copy at the subscriber terminal, the method of fixing the path is
There is a problem in that the efficiency of using the network is poor.

The present invention has been made in view of the above problems, and the connection form is instantly changed without lowering the utilization efficiency of the ATM network and even when the speaker is changed in the lecture service. It is an object of the present invention to provide a multicast connection control system in an ATM network that can be used.

[0009]

FIG. 1 is a block diagram showing the principle of the present invention. The same parts as those in FIG. 3 are designated by the same reference numerals. The system shown in the figure is an ATM in which a plurality of subscriber terminals 1 have an intra-exchange copy function via a subscriber line 5.
It constitutes a system connected to the exchange 10. In the figure, reference numeral 12 denotes M information input channels for inputting information from a subscriber terminal, and 11 denotes S from a specific subscriber terminal 1.
One SA control channel for inputting a control signal for A control, 13 one information output channel for outputting information processed in the SA, and 14 one signal control signal for the ATM switch 10. It is a channel for signal control. A service agent unit (SA) 20 is connected to the ATM exchange 10 via these channels and controls multicast connection.

[0010]

The service agent section 20 receives the information from the calling subscriber terminal 1 through the information input channel 12,
Information processing is performed, and the result is transferred to the ATM exchange 10 via the information output channel 13, and the ATM exchange 10
The input information is copied and broadcast to any subscriber terminal 1. With such a configuration, according to the present invention, the AT
It is possible to change the connection mode instantly even when the speaker is changed in the lecture service without lowering the utilization efficiency of the M network.

[0011]

The operation sequence of the principle diagram of FIG. 1 will be described in more detail. The ATM switch 10 sets a channel for multicasting the input channel from the service agent unit 20 toward the subscriber terminal designated by the arbitrary subscriber terminal a from the SA control channel 11. ATM switch 10 of FIG.
It can be seen that the information output channel 13 is multicast to all the subscriber terminals 1. The calling subscriber terminal 1 uses the information input channel 12 on the subscriber line 5 to set an upstream channel toward the input channel of the service agent unit 20 and transfers the information. In the subscriber terminal a, this terminal is a terminal for controlling the form of the multicast connection, and the M information input channels 12 are multiplexed to the service agent unit 20 using the SA control channel 11, or Can be selected. The information processed (processed) by the service agent unit 20 is output from one information output channel 13 to the ATM exchange 10, is multicast by the ATM exchange 10, and arrives at each subscriber terminal 1.

As described above, according to the present invention, the change from one calling subscriber terminal 1 to another calling subscriber terminal 1 is only required to change the uplink channel setting from the subscriber terminal 1 to the information input channel 12, Since it is not necessary to change all channels for multicasting, switching of the calling subscriber terminal 1 can be realized at high speed and easily. Further, as a result, it is not necessary to fixedly connect the downlink channels in advance in all patterns between the subscriber terminals, and one downlink channel (information output channel 13) can be used from beginning to end, so that the utilization efficiency of the network is improved. Good.

FIG. 2 is a block diagram showing the configuration of an embodiment of the present invention. The same parts as those in FIG. 1 are designated by the same reference numerals. In the figure, 30 is a service agent unit 20.
Is a communication path set up between the ATM switch 10 and the ATM switch 10. Logical channel (1) is connected to service agent unit 20 and A
The signal control channel 14 and the logical channel (2) used to control the TM switch 10 are used to control the service agent unit 20 from the chairman terminal (the terminal a capable of controlling the service agent unit 20 described above). The SA control channel 11 and the logical channel (3) are the information output channel 13 for carrying the voice / image information synthesized by the service agent unit 20 to the ATM switch 10, and the logical channels (4) to (6) are the voices from the speaker. An information input channel 12 for transmitting an image from the ATM exchange 10 to the service agent unit 20. The cell information input to the ATM exchange 10 via the logical channel (3) is broadcast by the ATM exchange 10 to each subscriber terminal.

The service agent section 20 is provided inside the ATM transmission / reception section 21, a plurality of image / sound separation sections 22, a plurality of frame buffer memories (FBM) 23, an image synthesis section 24, a speech synthesis section 24A, and an image synthesis section 24. The frame buffer memory 25, the image / audio synthesizer 26, the controller 27, the signal processor 28, and the multicast destination management table 29. The control unit 27 receives the signal sent via the SA control channel 11, and controls the image synthesis unit 24, the voice synthesis unit 24A, the signal processing unit 28, and the multicast management table 29.

The ATM transmission / reception unit 21 is a so-called network terminating device. The image / sound separation unit 22 separates image information and sound information from the information in which the image and sound from the ATM transmission / reception unit 21 are multiplexed, and digitizes and outputs them. The frame buffer memory 23 has R, G, B information corresponding to one pixel of the terminal monitor for the number of pixels of the terminal monitor.

The image synthesizing unit 24 synthesizes the information from the plurality of frame buffer memories 23 in accordance with the layout instructed by the control unit 27, and writes this in the frame buffer memory 25 in the image synthesizing unit. The frame buffer memory 25 in the image synthesizing section 24 is an image obtained by synthesizing the image of the speaker that can be seen from each subscriber terminal 1. Although only the image synthesizing unit 24 has been described above, the sound separated by the image and sound separating unit 22 is also
The voice synthesis unit 24A performs voice synthesis in the same manner.

The image / sound synthesizing section 26 is a section for multiplexing the synthesized image synthesized by the image synthesizing section 24 and the synthesized speech synthesized by the speech synthesizing section 24A, and the multiplexed signal is an ATM transmitting / receiving section. 21 is sent to the ATM exchange 10. The control unit 27 determines the layout of the composite image based on the control signal sent from the chairperson terminal via the logical channel (2) (SA control channel 11) and disconnects the channel to the ATM switch 10. , It has a function to instruct connection and broadcast request.

The multicast management table 29 is a table for managing the multicast destination terminals, and the control unit 27 requests the ATM switch 10 for channel setting via the signal processing unit 28 based on this multicast management table 29. The signal processing unit 28 gives an instruction to connect or disconnect the ATM exchange 10 based on a request from the control unit 27. The operation of the system configured as described above will be described below.

Before the start of the lecture, the chairperson obtains the image / audio information input channel (4) from the SA control channel 11 and the chairperson terminal 1. Here, the image / sound information input channel refers to the information input channel 12 through which information in which the image and the sound input to the service agent unit 20 are multiplexed flows. The chairperson terminal 1 notifies the control unit 27 of the multicast destination using the SA control channel 11. Upon receiving this notification, the control unit 27 writes the multicast destination in the multicast destination management table 29.

Next, the control unit 27 refers to the multicast destination management table 29 to control the signal processing unit 28, and uses the signal control channel (1) to operate the ATM switch 1
Request 0 to set the channel for multicast. Further, the chairperson can control the control unit 27 in the service agent unit 20 via the SA control channel (2) to determine the layout of images to be multicast. That is, the layout can be changed during the lecture by this control.

At the start of the lecture, the lecturer opens an image / audio information input channel (5). Even when the user wants to also multicast the image and sound from the subscriber terminals 1 other than the speaker at the start of the lecture or during the lecture, the image / sound information input channel (6) is similarly set up. From the image / audio information input channels (5) and (6) (indicated by the information input channel 12 in FIG. 1) thus extended, through the ATM transmission / reception unit 21,
The image / sound information that has entered the image / sound separation unit 22 is separated by the image / sound separation unit 22 into image information and sound information. The image information will be described below, but the same applies to the audio information.

First, the R, G, B image information extracted by the image / audio separating section 22 is written in the frame buffer memory 23. The image synthesizing unit 24 writes the synthetic image in the frame buffer memory 25 in the image synthesizing unit 24 based on the pixel information of the frame buffer memory 23 and the layout instruction from the chair terminal 1.

Information is read from the frame buffer memory 25 in the image synthesizing unit 24, and the image and voice synthesizing unit 26 multiplexes the image and the audio signal synthesized by the audio synthesizing unit 24A in the same manner as the image. The image / sound output information of the image / sound synthesis unit 26 is passed from the ATM transmission / reception unit 21 to the ATM exchange 10 via the image / sound information output channel (3) (the information output channel 13 in FIG. 1) and is multicast.

At the time of question and answer, the chairman calls to that effect. The person who asks a question establishes an image / sound information input channel (6) to the service agent unit 20. When more than one questioner appears, the chair selects one of them.

Subscriber terminal b who wishes to attend the lecture during the lecture
(Not shown) uses point-to-point communication to establish a channel on the chairperson terminal 1 and informs the chairperson of the desire to attend. The chair instructs the control unit 27 in the service agent unit 20 to add a new subscriber terminal using the SA control channel (2). This new subscription is possible even after the channel setting for the called subscriber terminal is completed.

In accordance with this instruction, the control unit 27 in the service agent unit 20 additionally writes b in the multicast destination management table 29. Further, it uses the signal control channel (1) to instruct the ATM switch 10 to add b to the multicast destination. On the way, also for the subscriber terminal 1 desiring to leave, the channel is disconnected in the same procedure.

At the end of the conference, the control unit 27 in the service agent unit 20 is notified via the SA control channel (2) that the chairman terminal disconnects all channels.
The control unit 27 in the service agent unit 20 instructs the ATM exchange 10 to disconnect all the lines 5 (see FIG. 1) used in this service via the signal processing unit 28, and further the information of the multicast destination management table 29. Erase.

[0028]

As described above in detail, according to the present invention, in the lecture service using the ATM network, when the speaker is changed, the channel from the calling subscriber terminal 1 to the service agent unit 20 is changed. This can be realized without changing the connection form of the channel from the service agent unit 20 to the ATM exchange 10 and from the ATM exchange 10 to the called subscriber terminal 1. Therefore, it is possible to switch the calling subscriber terminal quickly and easily.

The downlink channel is the information output channel 1.
Since only one of 3 is required, the network efficiency is better than that when fixedly connecting in all patterns between terminals before the lecture.
As described above, according to the present invention, there is provided a multicast connection control system in an ATM network capable of instantly changing the connection form even when the speaker is changed in the lecture service without lowering the utilization efficiency of the ATM network. Can be provided.

[Brief description of drawings]

FIG. 1 is a principle block diagram of the present invention.

FIG. 2 is a configuration block diagram showing an embodiment of the present invention.

FIG. 3 is an explanatory diagram of a conventional multicast method.

FIG. 4 is an explanatory diagram of a conventional multicast method.

FIG. 5 is an explanatory diagram of a conventional multicast method.

[Explanation of symbols]

 1 Subscriber Terminal 5 Subscriber Line 10 ATM Switch 11 SA Control Channel 12 Information Input Channel 13 Information Output Channel 14 Signal Control Channel 20 Service Agent Section

Claims (5)

[Claims] 1. A system in which a plurality of subscriber terminals (1) are connected to an ATM exchange (10) having an intra-exchange copy function through a subscriber line (5), and M information input channels (12) are provided. , An SA control channel (11), an information output channel (13), and a signal control channel (14) for signal control with one ATM exchange (10) and an ATM exchange (10). A service agent unit (20) that is connected and performs multicast connection control is provided, and the service agent unit (20) receives information from the calling subscriber terminal (1) via an information input channel (12) and The processing is performed, and the result is transferred to the ATM exchange (10) through the information output channel (13). The ATM exchange (10) copies the input information and sets it to any subscriber terminal. A multicast connection control system in an ATM network, characterized in that the broadcast communication is performed in (1). 2. An image synthesizing unit (24) for synthesizing an image sent from a subscriber terminal (1) in the service agent unit (20) and a voice sent from the subscriber terminal (1). A voice synthesizing unit (24A) for synthesizing a voice is provided, and the image synthesizing unit (24) and the voice synthesizing unit (24A) are controlled from a subscriber terminal (1) via an SA control channel (11). The multicast connection control system in an ATM network according to claim 1, wherein 3. The service agent unit (20)
Can request the ATM switch (10) to disconnect the input path from the specific subscriber terminal (1) by an instruction sent from a subscriber terminal (1) via the SA control channel (11). The multicast connection control system in an ATM network according to claim 1, wherein 4. The service agent unit (20)
Receives an instruction from the subscriber terminal (1) via the SA control channel (11) to send the specified subscriber terminal (1) to the called subscriber even after the channel setting for the called subscriber terminal is completed. The ATM switch (10) can be requested to be added to the terminal.
A multicast connection control system in the described ATM network. 5. A control unit (17) for controlling the overall operation of the service agent unit (20) and a multicast destination management table (29) for managing multicast destination subscriber terminals are provided, and the control unit (17) is provided. ), When a new subscriber terminal is added based on the control information sent via the SA control channel (11), writes the subscriber terminal in the multicast destination management table (29) and joins the member who is leaving midway. 2. The multicast connection control system in an ATM network according to claim 1, wherein when there is a subscriber terminal, the control unit (17) deletes the subscriber terminal from the multicast destination management table (29).