JPH0832957A - Image information distribution system - Google Patents

Abstract

PURPOSE:To save data in a network by setting a virtual path to be distributed to plural subscriber housing nodes between an image information supply node and an image information distribution node in one virtual path. CONSTITUTION:Image information sending requests for the image information supply nodes 1a, 1b are terminated at image information supply devices 1a, 1b via subscriber nodes 4a, 4b, the image information distribution node 3 and a junction node 2. When the nodes 1a, 1b recognize the image information sending requests from subscribers 5a-5h, the subscribers 5a-5h are selected, respectively. Thence, ATM cells are distributed to the nodes 4a, 4b by the image information distribution node 3. Image information bracketed to the nodes 4a-4b are distributed to lines in accordance with the subscribers 5a-5h housed in the nodes 4a, 4b, and the ATM cells are sent out to the subscribers 5a-5h. In a subscriber terminal, received image information and control signal are converted into original image information and control signal. By employing such distribution system, connection in accordance with the subscriber is not required to set.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structure of a communication system for distributing image information to a single or plural destinations, and more specifically, a communication network using an asynchronous transfer mode (hereinafter referred to as ATM) communication system. And to an image information distribution system for providing image information to subscribers.

[0002]

2. Description of the Related Art With the advent of the ATM communication system, it has become possible to transmit information, such as images, which requires a broadband transmission path, through a public switched network. On such a system, it becomes more common to broadcast image information such as video dial tone in addition to conventional one-to-one communication. A system that provides video dial tones on a public network efficiently broadcasts wideband image information and pay-per-view to collect a fee for each program viewed by a subscriber who is served by a cable television system (CATV). (Pay Per View: PPV) and a method of providing a video on demand (VOD) for providing a desired program at a desired time by a subscriber have become problems. In the conventional technology, CA is used through a public network
When providing image information from a TV or the like, JP-A-1-238
As disclosed in Japanese Patent No. 392, a synchronous transfer mode (Sync
hronousTransfer Mode (STM) communication system provides image information. That is, the image information of a plurality of channels is assigned to each time slot from the center that provides the image information, transmitted to the downstream remote node, and the image information is assigned from the remote node to the time slot assigned to each subscriber. It was configured to transmit. In this configuration, it is necessary to always allocate a fixed band as a transmission channel for CATV. Further, in the case of providing image information corresponding to individual subscribers such as video-on-demand, there arises a problem that there is not enough time slots between the center and remote nodes. As described above, it is possible to adopt the ATM method as a method of avoiding the problem of lack of time slots and the deterioration of the use efficiency of the transmission path by always securing the transmission band for CATV. However, when the information is distributed by the ATM system, the distribution switch for ATM is provided, which causes the hardware to be large and the control to be complicated. For example, it was necessary to employ a control system as shown in Japanese Patent Laid-Open No. 2-186791, which distributes each information to each output route by using a distribution switch.

[0003]

SUMMARY OF THE INVENTION An object of the present invention is to provide a system for distributing and providing image information suitable for solving the above problems with a simple structure and control method. More specifically, CA is sent to the subscriber's home via the public network.
A system for providing TV image information, capable of efficiently using a transmission line, providing necessary information at a high speed when a subscriber needs such as a PPV service and a VOD service, and being convenient for the subscriber. It is to realize an excellent image information distribution system economically with a simple configuration using the ATM communication system.

[0004]

As means for solving the above problems, an image information distribution system of the present invention comprises an image information providing node, an image information distribution node, a subscriber accommodation node and a subscriber terminal, and each node The ATM communication system is used for transmitting and receiving the image information to and from the subscriber terminal. Here, the image information providing node is a node that sends out image information such as video and audio received from another node or stored in the own node and compressed by a method such as MPEG2. An optical splitter that passively distributes an optical signal is installed in an optical fiber network between a device in a node or an image information distribution node and a subscriber accommodation node,
The image information received from the image information providing node is distributed to a plurality of subscriber accommodation nodes. Then, the subscriber accommodation node receives the image information from the image information distribution node and distributes it to the subscribers, and the subscriber terminal converts the image information received from the subscriber accommodation node into a normal television signal form. This is a configuration for sending to the monitor. In this configuration, when a plurality of subscribers request the same image information, one ATM is provided from the image information providing node to the image information distribution node.
The connection is set, the image information requested by a plurality of subscribers is transmitted to the image information distribution node, and the image information distribution node is configured to distribute the image information to all subscriber accommodation nodes. Between the provider node and the image information distribution node, the image information that requires a wide band should be economically transmitted by a single connection. Moreover, the image information is classified into a plurality of types, and a virtual path (hereinafter referred to as VP) is set for each type, that is, an ATM connection is set.
The line quality is ensured in units of P so that the image information is provided in a substantially constant quality, and the image quality does not vary among subscribers.

Further, in the above-mentioned configuration, all the subscriber accommodation nodes receive all the image information transmitted by the image information distribution node, so that the subscriber is accommodated in the subscriber accommodation node. A containing the requested image information
A cell filter for extracting TM cells is installed, and only ATM cells containing necessary image information are extracted from the line and sent to each subscriber. In this way, the image information distribution node is configured to distribute the image information without controlling the image information in units of specific outgoing routes, and to distribute the image information with simple control. When each subscriber requests the necessary image information from the subscriber terminal to the subscriber accommodation node, the subscriber-adapted cell filter provided in the subscriber accommodation node stores the ATM cells carrying the image information. The value of the virtual path VP (hereinafter referred to as VPI) and the value of the virtual channel (hereinafter referred to as VC) (hereinafter referred to as VCI) are set, and the V
Only the ATM cells having the PI / VCI are allowed to pass, and the ATM cells having the other VPI / VCI are discarded, so that only the necessary image information is received.

[0006]

When the same image information is distributed from the image information providing node to a plurality of subscribers, an ATM connection is set up for each subscriber up to the node accommodating the subscriber and the image signal is sent to each subscriber. , A band for transmitting image information is required for the number of subscribers, but according to the configuration of the present invention, a virtual path VP is set for each image service, and one line is provided from the image information providing node to the image information distribution node. AT
By transmitting the image information through the M connection, it is possible to efficiently use the line resource between these nodes, and the image information distribution node can distribute the image information without using a multicast switch. Further, by setting the virtual path VP for each service, it becomes easier to manage each image service as compared with the case where the VP is set for each subscriber, and provide a service of equal quality to all subscribers. You can

Further, when the subscriber accommodation node has already received the image information required by a certain subscriber, a short procedure and response are made by the procedure of transmitting the image information only by the negotiation between the node and the subscriber. Image information can be sent to subscribers in time.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of an image information distribution system according to the present invention will be described in detail below with reference to the drawings. Example 1 (1) System Configuration FIG. 1 is an overall configuration diagram of a system showing a configuration and logical connection of an image information distribution system of the present invention. The image information distribution system stores image information and provides an image information providing node 1 that provides image information corresponding to a request from a subscriber (in this embodiment, two node A corresponding to an image providing service described later). (Constituted by (1a) and node B (1b)), and a subscriber 5 (constituted by subscribers A to H (5a to 5h) in this embodiment) that receives the image providing service,
A subscriber accommodation node 4 that accommodates the subscriber 5 and sends out the image information requested by the subscriber 5 (in this embodiment, two nodes A (4a) and B (4b) corresponding to the number of subscribers).
And the image information distribution node 3 that distributes the image information from the image information providing node 1 to the subscriber accommodation node 4 in the asynchronous transfer mode between the three types of nodes and each subscriber. The image information corresponding to the request from the subscriber is connected by a transmission line (hereinafter referred to as an ATM line), and the image information providing node 1 distributes the image information to the subscriber 5 by ATM cells. In the figure, the image information distribution network 6 is an ATM for distributing the image information from the image information distribution node 3 to all the subscriber accommodation nodes 4.
It is a line network. The relay node 2 relays information according to the distribution distance of image information and the like. In the present embodiment,
Although it is provided between the image information providing node 1 and the image information distribution node 3, it may be provided between other nodes or not provided depending on the scale of the image information distribution system.

FIG. 2 is a block configuration diagram showing an example of the configuration of the image information providing node 1. The image information storage device 11 stores in advance a large number of image information to be provided to subscribers.
a to 11b and selectors 12a to 12b for selecting image information from the storage devices 11a to 11b according to the request of the subscriber.
And image information memories 13a to 13b that temporarily hold the selected image information in association with the service to be provided, and CLADs 14a to 14 that convert the image information into ATM cells.
b, a multiplexer 15 for multiplexing a plurality of ATM cells,
Line terminating device 1 which is an interface with an ATM line
6 and a controller 17 for controlling the entire image information providing node 1. In this embodiment, the image information storage devices 11a and 11b are provided with MPEG2 (Moving Pic).
The image information is stored in a compressed form by a method such as the tures Expert Group 2), so that a large number of image information can be stored. Further, as will be described later, the memories 13a and 13b may be provided not in the image information providing node 1 but in other nodes.

FIG. 3 and FIG. 4 are block configuration diagrams showing an example of the configuration of the image information distribution device 3, and each device is an ATM demultiplexing / multiplexing device 3 for distributing ATM cells.
2 and the line terminators 31 and 33a which are interfaces with the ATM line, and the control device 34 which controls the entire image information distribution device 3. here,
In the image information distribution device 3 of FIG. 3, when the ATM cells are distributed to all the subscriber accommodating nodes 4a to 4b, the ATM demultiplexing / multiplexing device 32 distributes the ATM cells and corresponds to the subscriber accommodating nodes. The line terminating device is required, and the line terminating device 33b is added. Further, in the image information distribution device 3 of FIG. 4, when the ATM cells are distributed to all the subscriber accommodation nodes 4a to 4b, the image information distribution network 6 distributes the ATM cells.
An optical splitter 35, which is a passive element, is attached to the line terminating device 33a.
Any of the image information distribution devices 3 may be used in the image information distribution system of the present invention.

FIG. 5 and FIG. 6 are block configuration diagrams showing an example of the configuration of the subscriber accommodation node 4.
An ATM demultiplexer 42 for distributing ATM cells;
A line terminating device 41 which is an interface with the TM line,
44a, 44b, cell filters 43a-43b for extracting only ATM cells containing image information requested by the subscriber, and a controller 45 for controlling the subscriber accommodation node 4 as a whole. did. Here, as described above, the subscriber accommodating node 4 of FIG. 6 does not have the image information memories 13a and 13b in the image information providing node 1, but instead has a function of providing the image information providing service in this node. 1 shows an example of a configuration having an image information memory 48 that is temporarily held by the ATM demultiplexing / multiplexing device 4.
2 and the cell filter 43 between the distributors 46a to 46b.
And the image information memory 48 via the selectors 47a and 47b. In the image information distribution system of the present invention, an image information memory that is temporarily held in correspondence with a service that provides image information is installed in the system according to system specifications (for example, hardware scale such as memory amount and response speed limitation). The position of the subscriber accommodation node 4 can be determined and the configuration of the subscriber accommodation node 4 can be selected.

FIG. 7 is a block diagram showing a configuration example of a subscriber terminal of the subscriber 5, which includes a line terminating device 51 which is an interface with an ATM line, and a CLAD 52 which converts an ATM cell into a form of image information. , Monitor image information 57
Tuner 53 that converts to a format that can be displayed on
(In this embodiment, information compressed by a method such as MPEG2 is expanded and converted into an input signal of a monitor such as an NTSC signal), and a cable driver 54 which is an interface with the monitor 57 and a interface via an interface 55. Control pad 5 for inputting requests from the operator to the system
8. A control device 56 for controlling the subscriber terminal as a whole. Each of the subscribers A to H (5a to 5h) performs an operation such as retrieval of image information from the control pad 58 connected to each subscriber terminal, converts the control signal into a subscriber terminal, and then controls the system. By sending a signal and displaying the image information received from the image information providing node 1 in response to the request on the monitor 57, the image providing service by the image information distribution system of the present invention is realized.

FIG. 8 is a block diagram showing a configuration example of the cell filter 43 provided in the subscriber accommodating node 4.
A highway 68 that receives an ATM cell from the TM multiplexer / demultiplexer 42 and a virtual path identifier (Virtua) in the ATM cell.
l Path Identifier (VPI) and virtual channel identifier (V
VP for detecting irtual Channel Identifier (VCI)
I / VCI detector 63, VPI of ATM cell including image information requested by the subscriber, and VPI for registering VCI value
/ VCI table 64, detector 63 and table 6
A comparator 65 for comparing the values of VPI and VCI of 4;
A delay device 61 for delaying the M cells by a time corresponding to the operation time of the comparator 65, an empty cell generator 62 for sending empty ATM cells to the subscriber, and a highway corresponding to the comparison result of the comparator 65. 69, a selector 66 for selectively transmitting an ATM cell containing image information requested by the subscriber or an empty ATM cell, and is controlled by a control device 45 provided in the subscriber accommodation node 4 via a control line 67. It was configured. In this cell filter, the control device 45 sets the VPI and VCI values of the ATM cell including the image information requested by the subscriber in the table 64, and the VPI / VCI values other than the set values are set.
By discarding the ATM cell having the VCI, only the image information requested by the subscriber is distributed to the subscriber. The value of VPI / VCI set in the table 64 may be single or plural. When a plurality of ATM cells are set, a plurality of types of ATM cells are sent to the subscriber. In this case, the subscriber side may be provided with a device for recognizing these and appropriately distributing them, for example, an ATM switch.

(2) System Operation The operation of the image information distribution system according to the present invention will be outlined below with reference to FIG. (A) Request from subscriber Image information providing node 1a generated by operating any of the control pads 58 of subscribers A to H (5a to 5h)
The image information transmission request to 1b is sent to the control device 45 of the subscriber accommodation node (4a to 4b), the image information distribution node 3
After passing through the control device 34 and the relay node 2, the control device 17 of the image information providing devices 1a to 1b terminates. Since the control signal indicating the request from the subscriber has a smaller amount of information than the image information, the ATM cell of the upstream line of the ATM line (line for transmitting information from the subscriber to the image information providing node) shown in FIG. In addition to the method of multiplexing and transmitting to
These control signals are sent to CCITT recommended N (not shown).
o. 7 common line signal system may be used for common line or individual line transmission / reception.

(B) Provision and distribution of image information (i) Controller 17 for image information providing nodes 1a-1b
From the input control signal, the subscribers A to H (5a to 5)
When the image information transmission request from h) is recognized, each subscriber A
To H (5a to 5h) request the image information from the image information storage devices 11a to 11b by the selectors 12a to 12b. If the image information is image information corresponding to each subscriber such as video-on-demand or image information that allows the subscriber to operate the image information, a hippie interface (Hi
gh Performance Parallel Interface (HIPPI) via subscribers A to H (5
a to 5h) corresponding to the ATM connection (corresponding to the type of image information providing service and the type of image information provided (for example, program channel)) image information memory 13a
To image data other than that, the image information memories 13a to 13b are passed. Further, a VPI corresponding to the type of image information providing service and a VCI corresponding to the type of image information to be provided (for example, a program channel) are defined, and the image information is converted into an ATM cell form by the CLADs 14a to 14b. , Are multiplexed together with ATM cells carrying other image information in a multiplexer 15. Here, when the control device 17 needs to send a control signal to another node or a subscriber, the control signal is transmitted to the multiplexing device 15.
The ATM shown in FIG.
It is sent to the downlink of the line (the line for transmitting information from the image information providing node to the subscriber). The transmitted image information and control signals are sent to the image information distribution node 3 via the relay node 2, if any. The control signal may be transmitted by using a different line as in the case of the uplink.

(Ii) As a method of distributing the ATM cell from the image information distribution node 3 to the subscriber accommodation node 4a or 4b connected thereto, either one of the following two types of image information distribution node 3 is selected, and either of the following is selected. Method. The image information distribution node 3 shown in FIG. 3 distributes ATM cells to all the subscriber accommodation nodes 4a-4b (in this case, A
The TM demultiplexing / multiplexing device 33 distributes ATM cells). All subscriber accommodation nodes 4 in the image information distribution network 6
ATM cells are distributed to a to 4b (in this case, in the image information distribution network 6, the image information distribution node 3 of FIG.
The optical splitter 35 shown in (1) passively distributes ATM cells).

(Iii) The image information distributed to the subscriber accommodating nodes 4a-4b passes through the line terminal 41 and is transmitted to the AT.
In the M demultiplexing device 42, the subscriber accommodation nodes 4a ...
It is distributed to the lines corresponding to the subscribers 5a to 5h accommodated in 4b. Here, the ATM multiplexer / demultiplexer 42 is basically
All the received ATM cells are distributed to the ATM lines corresponding to all subscribers. Then, the next-stage cell filters 43a to 43
b, VPI and VCI in the ATM cell are detected by the detector 6
V set in the VPI / VCI table 64 by referring to
If the ATM cell has a VPI / VCI other than the PI / VCI value, it is discarded (empty cell is sent), and the same VPI /
If the ATM cell has VCI, the reception ATM cell delayed by the delay unit 61 is selected, and the subscriber is allowed to pass only the ATM cell having VPI / VCI including the requested image information. Terminations 44a to 44
The ATM cells are sent to the subscribers 5a to 5h via b.
Incidentally, the image information memory 13a in the image information providing node 1-
As an alternative to 13b, when installing the image information memory 48 corresponding to the ATM connection in the subscriber accommodation node shown in FIG. 6, video on demand (Video On Demand:
VOD) services, etc., the image information memory 4
The image information transmitted from the image information providing node 1 is stored in 8. Depending on the type of image providing service, the image information memory 48 is passed and the data is sent from the line terminals 44a and 44b to the subscribers 5a to 5h via the cell filters 43a and 43b.

(Iv) At the subscriber terminal 50, the image information and control signals received in the form of ATM cells are converted by the CLAD 52 into the original image information and control signals. The image information transmitted in the compressed form up to this point is expanded in the tuner 53, converted into a television signal form by the cable driver 54, and then sent to the monitor 57. The subscriber views the image information on this monitor. To select other image information, control is performed by the control pad 58 shown in FIG.

As described above, according to the image information distribution system of the present invention, the virtual path VP is determined corresponding to the type of image information providing service, and the type of image information provided in the VP (for example, The ATM connection is set by the method of defining the virtual channel VC corresponding to the program channel), that is, the connection is not set for each subscriber, so that the VP and the VC providing the image information can be commonly used, and the network resource can be used. Can be saved. (For example,
Between the image information providing node and the image distribution node, it is sufficient to set as many VPs as services. Furthermore, VP
And VC are commonly used, the sequence of these settings can be simplified. In addition, a node near the subscriber is provided with a cell filter for each subscriber, and only the image information requested by the subscriber is selected and provided to the subscriber, and the image information is commonly provided in the network. Depending on the VP and VC used, broadcasting is performed up to the node where the cell filter is installed. Therefore, the control device sets the cell filter in response to the request from the subscriber, and the ATM connection setting in the network. It is possible to configure a system that saves network resources with simple control.

<Embodiment 2> According to the image information distribution system of the present invention, a pay per view (PPV) in which a subscriber pays a viewing fee for a general television broadcast or program.
Various image information providing / distributing services such as a service and a video-on-demand (VOD) service in which a subscriber can view arbitrary image information stored in the image information providing node at an arbitrary time can be realized. An example of an image information providing / distributing service using this system will be described below. (1) General broadcasting service 1 The image information providing node A (1a) is connected to the subscribers C to F (5c).
5f), an embodiment (signal flow) for providing a general broadcast service will be described with reference to FIG. Specifically, the programs of the television channels α1 to α2 selected by the subscribers C to F (5c to 5f) by operating the control pad 58 are sent from the image information providing node A (1a) to the subscriber by the following procedure. It is what is sent. (A) The image information providing node A (1a) is connected to the control device 17
After identifying the general broadcast service and the television channel to be provided from the control signal received from the subscriber side, the virtual path VP (8b) for the general broadcast service
From the image information providing node A (1a) to the relay node 2
The image information distribution node 3 is set via the image information distribution node 3 and the subscriber accommodation node A (4a) and the subscriber accommodation node B (4b) are set from the image information distribution node 3 via the image information distribution network 6. Furthermore, the virtual path VP (8
In b), virtual channels VC (7b-7
c) is set, and for each virtual channel VC (7b to 7c),
The television channels α1 and α2 for general broadcasting are assigned. Here, the virtual channel VC (7b to 7c) in the virtual path VP (8b) is the image information providing node A (1a).
From the image information distribution node 3 to the subscriber accommodation node A (4a) and the subscriber accommodation node B (4b), points are set by point-to-point (Point-to-Point). Two-multipoint (Point-
to-Multipoint). That is, the image information is transmitted from the image information distribution node 3 to the subscriber accommodation nodes 4a ...
4b, subscriber accommodation nodes 4a-
In 4b, all the image information received by the image information distribution node 3 will be received. (B) In the subscriber accommodation nodes 4a to 4b, only the virtual channel VC requested by the subscriber accommodated in each subscriber accommodation node is selected. This is realized by discarding the virtual channel VC which is not viewed by the subscriber by the cell filter 43 in each subscriber accommodation node.
In this embodiment, the subscribers C, D and E are assigned to the television channel α1.
And the subscriber F requests the television channel α2, the cell filters corresponding to each of the subscribers C, D, and E select only VC (7b) and the television assigned to VC (7b). The cell filter that receives the channel α1 and corresponds to the subscriber F selects only VC (7c),
The television channel α2 assigned to (7c) can be received.

(2) General Broadcasting Service 2 FIG. 9 is an operation sequence diagram showing an embodiment of the general broadcasting service provided by the image information distribution system of the present invention.
It shows a transmission / reception relationship between image information and control information when the subscriber views the general broadcast α + 1 after viewing the general broadcast α. The operation will be described below with reference to FIG. (A) Subscriber A (5a) is a subscriber terminal (FIG. 7, 50)
After the power switch (not shown) of 100 is turned on (100), the control pad (Fig. 7, 58) is operated to select the television channel α for general broadcasting (101), and the subscriber terminal (Fig. 7, 50) is selected. Requests the subscriber accommodation node A (4a) to set up an ATM connection for the television channel α (102). Then, the subscriber accommodation node A (4a)
Cell filter for subscriber A (see FIG. 5 or FIG.
VP of the ATM cell carrying the television channel α in a)
The I / VCI value is set (103). Subscriber A is now
An ATM connection for the television channel α is established between the terminal of 1) and the subscriber accommodation node A (104).

(B) The subscriber accommodation node A (4a) requests the image information distribution node 3 to set up an ATM connection (105). Following that, the image information distribution node 3
Requests the image information providing node A (1a) to set up an ATM connection (106). In the image information providing node A (1a), VPI and VCI are set, and A is set between the image information providing node A (1a) and the image information distribution node 3.
A TM connection is established (107). Then, the image information distribution node 3 sets VPI and VCI, and establishes an ATM connection between the image information distribution node 3 and the subscriber accommodation node A (4a) (108). In this way, the image information providing node A (1a) to the subscriber A (5
An ATM connection is established between the subscriber terminal (a) in FIG. 7A and the subscriber terminal (FIG. 7, 50) in the image information providing node A (1a). ) Is sent (109), the subscriber A
In (5a), the program on the television channel α can be viewed on the monitor (57, 57).

(C) In the image information distribution system of the present invention, the subscriber accommodating node A (4a), after setting the ATM connection for transmitting the above-mentioned television channel α, further executes the television channel α requested by the subscriber. The image information distribution node 3 is requested to set the ATM connection for receiving the television channels α-1 and α + 1, which are the television channels before and after (110).
Requests the image information providing node A (1a) to set up an ATM connection for transmitting the television channels α-1 and α + 1 (111). In response to this, the image information providing node A (1a) sets the VPI and VCI, and the image information providing node 1a sends the AT to the image information distribution node 3.
M connection is established (112), and then VPI and VCI are set in the image information distribution node 3, and A is set from the image information distribution node 3 to the subscriber accommodation node A (4a).
A TM connection is established (113). As a result, the programs of the television channels α-1 and α + 1 are transmitted from the image information providing node A (1a) to the subscriber accommodation node A (4a) through the respective ATM connections (11
4, 115). However, at this point, the VPI / VCI table (FIG. 7, 64) in the cell filter of the subscriber accommodating node A (4a) contains the television channel α-1 or α.
Since the VPI / VCI value indicating +1 is not registered,
The programs of the television channels α-1 and α + 1 are not transmitted to the terminal of the subscriber A.

(D) In this state, when the subscriber A (5a) selects the television channel α + 1 (116), the subscriber A (5a)
From the subscriber terminal of (5a), an ATM connection setting request for α + 1 is sent to the subscriber accommodation node A (4a) (117). In the subscriber accommodation node A (4a), the VPI / VCI table (FIG. 7, 64) for the television channel α of the cell filter for the subscriber A (5a) is released (11
8) Set the VPI / VCI value of the ATM cell carrying the television channel α + 1 (119). This allows
An ATM connection for the television channel α + 1 is established from the subscriber accommodation node A (4a) to the subscriber terminal of the subscriber A (5a) (121). According to the image information distribution system of the present invention, in the subscriber accommodation node A (4a), in the above sequence (115), the television channel α + has already been transmitted.
Since image 1 is received, image information providing node A
Even if the control signal is not transmitted to (1a), the ATM connection for the television channel α + 1 is established only by the negotiation to the subscriber accommodation node A (4a), and the program of the television channel α + 1 can be received in a short time.

(E) The subscriber accommodating node A (4a) sends a request for disconnecting the ATM connection for α-1 to the image information distribution node 3 after setting the cell filter for receiving the television channel α + 1. (122), the image information distribution node 3 sends an ATM to the image information providing node A (1a).
A disconnection request is sent (123). Then, the subscriber accommodation node A (4a) is an ATM for α + 2.
A connection setting request is sent to the image information distribution node 3 (125), and the image information distribution node 3 sends an α + 2 ATM connection setting request to the image information providing node A (1a) (126). Then, the image information providing node A (1a) establishes an α + 2 ATM connection to the image information distribution node 3 (127), and the image information distribution node 3 establishes an ATM connection to the subscriber accommodation node A (4a). (128). The television channel α + 2 is transmitted through this ATM connection (129), but the VPI / VCI value of the ATM cell carrying the television channel α + 2 is within the cell filter for the subscriber A (5a) of the subscriber accommodation node A (4a). Since it is not registered in the VPI / VCI table 64 of No. 1, it is not transmitted to the terminal of the subscriber A, as in the case of (c) above. As described above, the subscriber A views the general broadcast α, and then the general broadcast α
Although the sequence for viewing +1 has been described, the control signal for executing the above sequence can be transmitted / received by the common line system or by the individual line.

(3) General Broadcasting Service 3 FIG. 10 is an operation sequence diagram showing another embodiment of the general broadcasting service provided by the image information distribution system of the present invention, which belongs to the subscriber accommodation node A (4a). Subscriber A
While (5a) is watching the program on the television channel α-1 of the general broadcast, another subscriber B (5b) belonging to the same subscriber accommodation node A (4a) selects and views the program on the television channel α. The operation sequence in this case is shown. The operation will be described below with reference to FIG. (A) The subscriber A (5a) turns on the power switch of the subscriber terminal (200), and then the television channel α-1 of the general broadcast.
(201), the subscriber terminal requests the subscriber accommodation node A (4a) to set up an ATM connection for the television channel α-1 (202). Then, the control device of the subscriber accommodation node A (4a) (FIG. 5 or FIG.
5) is VPI / of the cell filter for subscriber A (5a)
A carrying the television channel α-1 to the VCI table 64
The VPI / VCI number of the TM cell is set (203).
Now, an ATM connection is established between the subscriber accommodation node A and the terminal of the subscriber A (204). This operation is similar to (a) of (2) described above.

(B) The subscriber accommodation node A (4a) requests the image information distribution node 3 to set up an ATM connection for α-1 (205). Subsequently, the image information distribution node 3 requests the image information providing node A (1a) to set up an ATM connection carrying the television channel α-1 (206). In the image information providing node A (1a), V
Image information providing node A (1a) by setting PI and VCI
An ATM connection for α-1 is established between this and the image information distribution node 3 (207). Then, in the image information distribution node 3, VPI and VCI are set, and α-1 is set between the image information distribution node 3 and the subscriber accommodation node A (4a).
An ATM connection for the connection is established (208). Through the ATM connection thus established, the television channel α-1 is sent from the image information providing node A (1a) to the subscriber accommodation node A (4a) (209).

(C) As in the previous example, the subscriber accommodating node A (4a) is a television channel before and after α-1 after transmitting the television channel α-1 to the image information distribution node 3. The sequence for requesting the television channels α-2 and α to the image information providing node A (1a) is executed. That is, the subscriber accommodating node A (4a) has an A for television channel α and a television channel α-2 in the image information distribution node 3.
The image information distribution node 3 requests the setting of the TM connection (210), and the image information distribution node A (1a) requests the setting of the ATM connection carrying the television channels α and α-2 (211). In response to this, in the image information providing node A (1a), VPI and VCI are set, and the image information providing node A (1a) sets α in the image information distribution node 3.
And establish an ATM connection for α-2 (212),
Then, in the image information distribution node 3, VPI and VCI
Is set to establish an ATM connection for α and α-2 from the image information distribution node 3 to the subscriber accommodation node A (4a) (213). In this way, the information of the television channel α and the television channel α-2 is transmitted from the image information providing node A (1a) to the subscriber accommodation node A (4a) through the established ATM connection (214, 2).
15). However, at this point, the subscriber accommodation node A (4
In the cell filter 43 of a), the television channels α and α-2
Subscriber A does not set VPI / VCI for
(5a) cannot receive programs on the television channels α and α-2.

(D) In this state, if the subscriber B (5b) belonging to the same subscriber accommodation node A (4a) turns on the power switch of the subscriber terminal (216) and selects the television channel α for general broadcasting, (217), the subscriber terminal of the subscriber B (5b) requests the subscriber accommodation node A (4a) to set up an ATM connection for the television channel α (21).
8). The control device 45 of the subscriber accommodation node B (4b),
In the VPI / VCI table 64 of the cell filter for the subscriber C (5c), the V of the ATM cell carrying the television channel α is written.
The PI / VCI number is set (219). This allows
An ATM connection is established between the subscriber accommodation node A (4a) and the terminal of the subscriber B (5b) (220).
According to the image information distribution system of the present invention, in the subscriber accommodation node A (4a), the program of the television channel α is already received by the sequence (214) set by the subscriber B (5b). AT at (220)
Subscriber B (5b) only by establishing M connection
Can receive programs on TV channel α in a short time (2
21).

(E) The subscriber accommodating node A (4a) has the television channels α-1 and α + before and after it, as in the previous example.
The sequence for receiving 1 is executed, but since α-1 has already been received in the sequence (209), the sequence for receiving α + 1 (222 to 226) is executed. Since the VPI / VCI table of the cell filter for the subscriber B (5b) of the subscriber accommodating node A (4a) is set so as to pass only the cell including the image information of the television channel α, the subscriber B ( 5b) will watch only the television channel α.

(4) General Broadcast Service 4 FIG. 11 is an operation sequence diagram showing another embodiment of the general broadcast service provided by the image information distribution system of the present invention, which belongs to the subscriber accommodation node A (4a). Subscriber C
When (5c) is watching a program on the television channel α-1 of general broadcasting, a subscriber E (5e) belonging to another subscriber accommodation node B (4b) selects and views the program on the television channel α. 3 shows an operation sequence of. Less than,
The operation will be described with reference to FIG. (A) When the subscriber C (5c) turns on the power switch of the subscriber terminal (600) and selects the television channel α-1 of the general broadcast (601), the subscriber terminal becomes the subscriber accommodation node A ( 4a) to request the ATM connection setting for the television channel α-1 (602). Then, the control device 45 of the subscriber accommodation node A (4a), the subscriber C (5c)
VPI / VCI table 64 of the cell filter for the VPI / VCI of the ATM cell carrying the television channel α-1
The number is set (603). Now, between the subscriber accommodation node A (4a) and the subscriber terminal of the subscriber C (5c),
An ATM connection is established (604).

(B) The subscriber accommodation node A (4a) requests the image information distribution node 3 to set up an ATM connection for α-1 (605). Subsequently, the image information distribution node 3 requests the image information providing node A (1a) to set up an ATM connection carrying the television channel α-1 (606). In the image information providing node A (1a), V
Image information providing node A (1a) by setting PI and VCI
An ATM connection for α-1 is established between this and the image information distribution node 3 (607). Then, in the image information distribution node 3, VPI and VCI are set, and α-1 is set between the image information distribution node 3 and the subscriber accommodation node A (4a).
ATM connection is established (608). Through the ATM connection established in this way, the program of the television channel α-1 is transmitted to the image information providing node A (1a).
From the subscriber accommodating node A (4a) (60
9). Further, as described above, in the image information distribution network 6, since the line is set up by point-to-multipoint, the image information distribution node 3 also sends a television to the subscriber accommodation node B (4b) belonging to this node. ATM cells carrying image information on channel α-1 are simultaneously distributed (609).

(C) As in the previous example, the subscriber accommodation node A
(4a) transmits the television channel α-1, and then transmits the television channels α-2 and α, which are television channels before and after α-1, to the image information distribution node 3 to the image information providing node A.
In order to make a request to (1a), the image information distribution node 3 is requested to set the ATM connection for the television channel α and the television channel α-2 (610), and the image information distribution node 3 makes the image information distribution node A (1a). ) Request to set up an ATM connection carrying the television channels α and α-2 (611). In response to this, the image information providing node A (1
In a), VPI and VCI are set, and ATM connections for the television channels α and α-2 are established from the image information providing node A (1a) to the image information distribution node 3 (6
12), and subsequently, in the image information distribution node 3, VPI and V
CI is set, and from the image information distribution node 3 to the subscriber accommodation node A (4a), A for the television channels α and α-2 is set.
A TM connection is established (613). Through the ATM connection thus established, the programs of the television channels α and α-2 are sent from the image information providing node A (1a) to the subscriber accommodation node A (4a) (614, 6).
15). As in the above-described embodiment, at this point, the cell filter 43 in the subscriber C (5c) of the subscriber accommodation node A (4a) has a VP for the television channels α and α-2.
Subscriber C (5c) because I / VCI is not set
Cannot receive the television channels α and α-2.

(D) In this state, the subscriber accommodation node B (4
When the subscriber E (5e) belonging to b) turns on the power switch of the subscriber terminal (616) and selects the television channel α of the general broadcast (617), the subscriber terminal of the subscriber E (5e) becomes the subscriber. The accommodation node B (4b) is requested to set up an ATM connection for the television channel α (618). The control device 45 of the subscriber accommodating node B (4b) determines that the subscriber E
VPI / VCI table 6 of cell filter for (5e)
4. VPI / V of ATM cell carrying TV channel α
The CI number is set (619). As a result, an ATM connection is established between the subscriber accommodation node B (4b) and the subscriber terminal of the subscriber E (5e) (620). According to the image information distribution system of the present invention, in the subscriber accommodation node B (4b), since the television channel α is already received by the sequence (614) set by the subscriber C (5c), the sequence ( The subscriber E (5e) can receive the program of the television channel α (621) only by establishing the ATM connection in 620).

(E) The subscriber accommodation node B (4b) receives the television channel α-1 before and after the television channel α to be received.
And the sequence for receiving α + 1 is executed, but since the television channel α-1 has already been received in the sequence (609), the sequence (622 to 626) for receiving the television channel α + 1 is executed. Since the VPI / VCI table of the cell filter for the subscriber E (5e) of the subscriber accommodation node B (4b) is set to pass only the ATM cell containing the image information of the television channel α, Person E (5e) is on television channel α
You will only watch.

The embodiment of the general broadcasting service provided by the image information distribution system of the present invention has been described above. In the image information distribution system of the present invention, a virtual path corresponding to the type of the image information providing service is used in the ATM line. The VP is set, and further, in this VP, the virtual channel VC corresponding to the type of the image information to be provided is set, and the image information is transmitted by the ATM cell, that is, the image information to be provided is supported. When the subscribers belonging to the image information distribution node 3 are requesting the same television channel from the image information providing nodes 1a and 1b to the image information distribution node 3, 1
It becomes possible to transmit by using the ATM connection of the book, and the transmission capacity can be saved as compared with the case where the individual ATM connection is set for each subscriber and the image information of the same content is transmitted by each ATM connection. Further, in the general broadcasting service, when the subscriber switches the television channel, the control pad 58 is operated and the control device 56 converts the control signal into a television channel switching request. After the control signal from such a subscriber is received by the control device of each node, it is switched to the television channel desired by the subscriber and a new program is transmitted. However, when the control signal is relayed by a plurality of nodes, a lot of delay occurs, and it takes time from the subscriber sending the television channel switching request until the television channel is actually switched. To reduce this time, in the present invention, the television channel numbers are, for example, 1, 2, 3 ,. ． ． 12, 1,
2, 3 ,. ． ． In many cases, the configuration is such that it is easy to cyclically switch, that is, when the subscriber switches the TV channel, the TV channel before and after the current viewing, for example, the current TV channel α is being watched. In many cases, the image distribution node 3 switches to the television channel α-1 or the television channel α + 1. Therefore, when the subscriber requests to view the television channel α, the image distribution node 3 adds to the television channel α and before and after it. The television channel α-1 and the television channel α + 1, which are television channels, are also requested from the image information providing node.
Therefore, when the subscriber who is watching the television channel α switches to the television channel α-1 or the television channel α + 1, the television channel α-1 and the television channel α + 1 have already been received by the subscriber accommodation nodes 4a to 4b. ing. Therefore, control signals can be exchanged only between the subscriber and the subscriber accommodation nodes 4a-4b. Further, when the subscriber who is watching the television channel α switches to the television channel α + 1, the image distribution node 3 determines that the television channels before and after the television channel α + 1,
That is, in addition to the switched α + 1, α + 2 and α are received, and if no subscriber belonging to the image information distribution node 3 is watching the television channel α-1, the disconnection request of this television channel is sent to the image information providing node 1a, 1b is transmitted. With such a configuration, the television channel can be switched at a higher speed than in the case where the control signal for the television channel switching request is relayed to the image information providing nodes 1a and 1b. Of course, in the case where the programs are not assigned to all the TV channels, the TV channel close to the TV channel being watched may be selected and received.
Although one TV channel is selected and received, a plurality of front and rear TV channels may be selected and received.
Further, as another method for realizing high-speed switching of TV channels by previously receiving at the subscriber accommodation node a program of a TV channel other than the TV channel requested by the subscriber, the content type of each program is Group by each (eg, news, sports, music, etc.)
Then, when the subscriber selects a program belonging to a certain group, the system selects some other programs belonging to this group to be received by the subscriber accommodation node, or vice versa. It is also possible to select some programs and receive them at the subscriber accommodation node. It is also possible to select and receive a program with a high audience rating. Such control is performed by, for example, storing the number of the TV channel provided by the program in advance in the management operation device of the system shown in the figure, or designating the number of TV channels to be received in advance. By registering the content (type, etc.) of the program to be provided, and having a function of managing the audience rating, the usage status, etc., it is possible to change the number of the television channel in the same procedure as the above-mentioned embodiment. It can be easily realized by increasing the number of steps. Alternatively, the subscriber may notify the system of such information at the start of use of the terminal and control based on the content of the notification. In any case, in the system of the present invention, the ATM connection corresponding to the image information to be provided is established instead of establishing the ATM connection for each subscriber. Therefore, some other programs are selected in advance, Even when the subscriber accommodating node receives the image information, the transmission capacity can be saved as compared with the case where the image information having the same content is transmitted through each ATM connection, and the image information is transmitted to the node close to the subscriber. Since the subscriber can simplify the number and procedure of control information transmitted / received to / from the system in order to receive the image information, the subscriber can easily respond to the channel switching request and can provide the program, which is easy to use. Services can be realized economically. Further, since the ATM connection corresponding to the image information to be provided is established, the quality control of the image information may be carried out in this unit, which is more economical than the quality control for each subscriber. It is possible to perform quality control and provide each subscriber with image information of uniform quality without image quality variations among the subscribers.

<Embodiment 3> An embodiment of the pay-per-view (PPV) service provided by the image information distribution system of the present invention will be described. Here, the PPV service is
This is a program that is broadcast from the image information providing node at a certain fixed time and pays a fee each time the subscriber views the program once. More specifically, the subscriber requests the image information providing node to watch a television channel of the PPV service before the program starts, waits for the program to start, and watches the PPV program when the program starts. The PPV program may be of a type that is charged when the PPV program is viewed for a certain period of time or longer, or of a type that is charged based on the viewing time.

(1) PPV service 1 FIG. 1 shows an embodiment (signal flow) in which the image information providing node A (1a) provides the PPV service to the subscriber A (5a) and the subscriber B (5b). Will be explained. This is because the subscriber A (5a) and the subscriber B (5b) use the control pad 58 shown in FIG.
a to request the PPV service, and the image information providing node 1a
Is to send a program corresponding to the request to the subscriber. (A) When the control device 17 identifies from the control signal received from the subscriber side that the request is for the PPV service, the image information providing node 1a causes the virtual path VP for the PPV.
(8a) is set from the image information providing node A (1a) to the image information distribution node 3 as point-to-point, and from the image information distribution node 3 to the subscriber accommodation node A (4a) as a virtual path by point-to-multipoint. The VP (8a) is set, and the virtual channel VC (7a) corresponding to the PPV television channel is set in the VP (8a). That is, like the general broadcasting service shown in the previous embodiment,
An ATM connection defining a VP corresponding to the image information providing service and a VC corresponding to the image information is set. (B) In the subscriber accommodation node A (4a), the subscriber A (5a) and the subscriber B (5) accommodated in the subscriber accommodation node
When b) requests the PPV service, the virtual channel VC (7a) is set to the subscriber A (5a) and the subscriber B (5).
Set up to b) and provide PPV programs. Other P
The PPV program is not transmitted to the subscriber C (5c) and the subscriber D (5d) who have not requested the PV service.
This control is performed by the subscriber-adapted cell filter of the subscriber accommodation node A (4a) in response to the request from the subscriber,
It is determined by whether or not to set the VPI / VCI value that provides the V program, and is the same as the general broadcasting service shown in the previous embodiment. Also in this method, even when a plurality of subscribers belonging to the image information distribution node 3 request the same PPV program, one ATM connection is provided from the image information providing node A (1a) to the image information distribution node 3. Since the ATM cells are distributed from the image information distribution node 3 to all subscriber accommodation nodes belonging to the image information distribution node 3, the ATM cells are transmitted between the image information providing node A (1a) and the image information distribution node 3. The transmission line can be saved.

(2) PPV Service 2 FIG. 12 shows P provided by the image information distribution system of the present invention.
It is an operation sequence diagram which shows the Example of PV service,
It shows the operation when the subscriber A (5a) selects the PPV television channel γ, waits for the start of the program, and then watches the television channel γ until the end of the program. (A) Subscriber A (5a) turns on the subscriber terminal (300), and uses the control pad 58 shown in FIG.
When the V service is selected (301), the subscriber terminal requests the subscriber accommodation node A (4a) to set up an ATM connection for PPV (302). Then, the subscriber accommodation node A (4a) requests the image information distribution node 3 to set up an ATM connection for PPV (303), and the image information distribution node 3 requests the image information distribution node A (1a) for PPV. Request the ATM connection setting of (30
4). As a result, the image information providing node A (1a)
Start ATM connection setting for PV (305)
Then, an ATM connection for PPV is established in the image information distribution node 3 (306). After that, the image information distribution node 3 sends the PPV AT to the subscriber accommodation node A (4a).
The M connection is established (307). Further, the control device 45 of the subscriber accommodation node A (4a) uses the cell filter 4
PP in the VPI / VCI table 64 in 3a-43b.
The VPI / VCI value of the ATM cell carrying the V image information is set (308). With this sequence, an ATM connection for PPV is established between the subscriber accommodation node A (4a) and the subscriber terminal of the subscriber A (5a) (3
09).

(B) The subscriber accommodation node A (4a) requests the image information distribution node 3 to display the PPV menu (310). In this embodiment, the image information distribution node 3 is
Since the PPV service has not been received yet, the image information providing node A (1a) is requested to display the menu (31
1). In the image information providing node A (1a), the PPV menu display is activated (312), and the PPV previously established.
The PPV menu is sent to the subscriber terminal of the subscriber A (5a) through the ATM connection (313). Subscriber A
The subscriber terminal of (5a) displays the received PPV menu on the monitor 57 (314). Subscriber A (5a) is
From the displayed PPV menu, the TV channel γ is selected using the control pad 58 (31
5). The subscriber terminal converts this request into a control signal and sends it to the subscriber accommodation node A (4a) (316). In this embodiment, since the subscriber accommodation node A (4a) has not yet received the television channel γ, it sends a selection request for the television channel γ to the image information distribution node 3 (317), and the image information distribution node 3 , And sends a selection request for the television channel γ to the image information providing node A (1a) (318).

(C) The image information providing node A (1a)
CLAD 14a for converting the image information into ATM cells in the image information memory 13a which stores the image information of the television channel γ
Alternatively, 14b is connected (319). As described in the first embodiment, the image can be directly sent from the image information storage device to the CLAD without passing through the image information memory 13a. Then, the control device 17 transmits the screen until the program starts (for example, the time until the program transmission starts) while counting down the transmission start time of the television channel γ,
Display on the monitor 57 of the subscriber terminal (320 to 32)
5).

(D) At the start time of the television channel γ, the image information providing node A (1a) starts transmitting the program of the television channel γ (326). This image information is transmitted through the previously established ATM connection for PPV (327), and the subscriber views the program of the television channel γ (328). When the transmission of the television channel γ is finished, the image information providing node A (1a) displays the end of the television channel γ (329). This is PPV
It is transmitted through the ATM connection for use (330), and in addition to the termination display, the charge of the PPV service is displayed to the subscriber (331). Finally, the image information providing node A (1
a), the image information distribution node 3 and the subscriber accommodation node A (4a) disconnect the ATM connection for PPV and release the VPI / VCI table of the cell filter (332 to 336).

(3) PPV Service 3 FIG. 13 shows P provided by the image information distribution system of the present invention.
FIG. 11 is an operation sequence diagram showing another embodiment of the PV service, in which when the subscriber B (5b) requests the PPV service, another subscriber A (5a) has already requested the PPV service and the subscriber accommodation PPV is connected to node A (4a).
FIG. 7 shows an operation when an ATM cell carrying a television channel γ for the TV is received. In the figure, the sequence 400 shows that when another subscriber has already requested the television channel γ for the PPV service and the ATM cell for the PPV is received at the subscriber accommodation node, for example, in the above-mentioned embodiment, The steps up to (c) are completed,
The terminal of the subscriber A (5a) shows a state of waiting for the start of the program (states of 321 to 324 in FIG. 12).

(A) In this state, the subscriber B (5b)
Turn on the power switch of the subscriber terminal (401) and select the PPV service on the control pad 58 (402).
Then, the subscriber terminal sends the PP to the subscriber accommodation node A (4a).
A V ATM connection setting is requested (403).
At the subscriber accommodation node A (4a), the PPV is already present between the image information providing node 1 and the subscriber accommodation node A (4a).
Subscriber B has an ATM connection established for
Only the VPI / VCI for PPV is set in the VPI / VCI table of the cell filter for (5b) (40
4) Set an ATM connection for PPV so that the ATM cell for PPV can be sent to the subscriber terminal of the subscriber B (5b) (405).

(B) The subscriber accommodation node A (4a) requests the image information distribution node 3 to display the PPV menu (406). Further, the image information distribution node 3 requests the image information providing node A (1a) to display the PPV menu (407). The image information providing node A (1a) is P
The PV menu display is activated (408), and the PPV ATM connection between the image information providing node A (1a) and the subscriber accommodating node A (4a) already established and the sequence (405) are established. Then, the PPV menu is transmitted through the ATM connection between the subscriber accommodation node A (4a) and the subscriber terminal of the subscriber B (5b) (409). The subscriber terminal then receives the received PP
The V menu is displayed on the monitor 57 (410). The subscriber B (5b) selects the program of the PPV television channel γ (411), and this γ selection request is sent to the subscriber accommodation node A (4a) (412).

(C) Since the subscriber accommodating node A (4a) has already received the program of the television channel γ in the sequence 400, the subscriber accommodating node A (4a) which has received the selection request from the subscriber B (5b). (4a) is subscriber A (5a)
A screen similar to that of the television channel γ until the start of the program (for example, the time until the start of the program transmission) is displayed by the subscriber B (5b).
The transmission is also started to the subscriber terminal of (413). This is displayed on the monitor 57 at the subscriber's house (414).

(D) At the start time of the television channel γ, the image information providing node A (1a) starts transmitting the program of the television channel γ (415). The image information is also sent to the subscriber B (5b) through the PPV ATM connection established in the above sequence (41).
6). The subscriber B (5b) views this on the monitor 57 (417). When the program of the television channel γ is finished, the image information providing node A (1a) starts sending a γ delivery end display (418). This information is A for PPV.
Subscriber B sent over TM connection (419)
In step (5b), the monitor 57 receives the end of the program on the TV channel γ of PPV and the charge display (420). After that, the image information providing node A (1
A) activates the disconnection of the ATM connection for PPV (421). This is transmitted to the subscriber terminal and PPV
The service ends (422-425).

(4) PPV Service 4 FIG. 14 shows P provided by the image information distribution system of the present invention.
FIG. 10 is an operation sequence diagram showing another example of the PV service, in the case where the subscriber A (5a) selects the PPV television channel γ, watches the television channel γ after waiting for the start of the program, and is waiting for the program. Shows the operation when receiving another image information distribution service. (A) When the subscriber A (5a) turns on the power switch of the subscriber terminal (300) and selects the PPV service on the control pad 58 (301), the subscriber terminal becomes the subscriber accommodation node A (4a). To request setting of ATM connection for PPV (302). Then, the subscriber accommodating node A (4a) sends the PPV A to the image information distribution node 3.
Request TM connection setting (303). In this embodiment, since no subscriber has requested the PPV service at this point, the image information distribution node 3 requests the image information providing node A (1a) to set up an ATM connection for PPV (304). ). Image information providing node A
(1a) sets the VPI and VCI of the ATM connection for PPV (305), and the image information providing node A (1
An ATM connection for PPV is established from a) to the image information distribution node 3 (306). Subsequently, the image information distribution node 3 sets the VPI and VCI, and the image information distribution node 3 transfers the PPV A to the subscriber accommodation node A (4a).
A TM connection is established (307). The subscriber accommodation node A (4a) sets the VPI / VCI value in the VPI / VCI table 64 of the cell filter for the subscriber A (5a) so that the ATM cell for PPV is passed (30).
8). As a result, an ATM connection for PPV is established between the subscriber accommodation node A (4a) and the subscriber terminal of the subscriber A (5a) (309).

(B) The subscriber accommodation node A (4a) requests the image information distribution node 3 to display the PPV menu (310). In this embodiment, the image information distribution node 3 is
Since the PPV service has not been received, the image information providing node A (1a) is requested to display the PPV menu (311). The image information providing node A (1a) is a PPV.
Is started (312), and the PPV menu is transmitted through the ATM connection established in the above sequence (313). The monitor 57 at the subscriber's house receives this and displays the PPV menu (31
4). In this embodiment, when the subscriber looks at the displayed menu and selects the program of the television channel γ with the control pad 58 (315), the subscriber terminal receives the request and sends a request for the transmission of the television channel γ of the PPV. Is sent to the subscriber accommodation node A (4a) (316). Subsequently, the subscriber accommodation node A (4a) sends the PPV to the image information distribution node 3.
Requesting the transmission of the television channel γ of (317). Further, the image information distribution node 3 has the image information providing node A.
It requests (1a) to send out the PPV television channel γ (318).

(C) The image information providing node A (1a)
The CLAD 14a for converting the image information into ATM cells in the image information memory 13a which stores the TV channel γ program.
Alternatively, 14b is connected (319). As described in the previous embodiment (2), the image information is stored in the image information storage device 11a or 11 without using the image information memory 13a.
It can also be sent directly to CLAD from b. The control device 17 sends information indicating the sending start time of the program of the television channel γ through the PPV ATM connection (320), and sends it to the subscriber A (5a) through the already established ATM connection (321). Receiving this, the subscriber A (5a) knows the start time of the program of the PPV television channel γ on the monitor (322).

(D) In this state, the subscriber A (5a)
When the television channel α is selected (701) in order to watch the program of the television channel α of the general broadcast until the start time of the television channel γ of PPV, the subscriber accommodation node A (4) is selected.
In a), after temporarily canceling the VPI / VCI value for the TV channel γ of PPV set in the cell filter (temporarily canceling the cell filter), a timer (not shown) in the control device 45 is started (703). ), The VPI / VCI value of the ATM cell carrying the television channel α of general broadcasting is set in the VPI / VCI table of the cell filter (704). In the present embodiment, the subscriber accommodation node A (4a) has already received the television channel α of the general broadcast, so the connection for the television channel α is immediately established (70
5). The television channel α is sent 706 through this ATM connection. If the subscriber accommodation node A (4
In a), if the general broadcast television channel α is not received, the general broadcast television channel α is received by the procedure described in the second embodiment.

(E) At the start time of the PPV television channel γ, an interrupt is generated from the timer, which triggers the VP of the ATM cell carrying the PPV television channel γ.
The I / VCI value is set in the cell filter (707).
Then, the interruption signal indicating the start of transmission of the television channel γ is transmitted from the subscriber accommodation node A (4a) to the subscriber terminal (708), and displayed on the monitor 57 of the subscriber terminal of the subscriber A (709). Then, the transmission of the PPV television channel γ is started (326). Subsequent operations (end operation and the like) are the same as those of the other PPV services described above. As described above, according to the image information distribution system of the present invention, it is possible to select a high-speed program with a short waiting time, which is similar to a general broadcasting service, and there is no variation in image quality among subscribers. It is possible to realize a quality and economical image providing service. Further, during the waiting time of the PPV service, the other image providing service can be easily received, so that the image providing service which is convenient for the subscriber can be realized.

<Embodiment 4> An embodiment of the video on demand (VOD) service provided by the image information distribution system of the present invention will be described. Here, the VOD service is an image information providing service of a type in which a subscriber can select arbitrary image information at any time and view the image information. Furthermore, the subscriber can send and receive control signals such as screen control in an interactive manner with the image information distribution system via the network to “pause”, “play” or “rewind” the image information. Or "fast forward"
You can also have a function to control the screen provided.

(1) VOD Service 1 FIG. 1 shows an embodiment (signal flow) in which the image information providing node B (1b) provides the VOD service to the subscriber G (5g) and the subscriber H (5h). Will be explained. This is because the subscriber G (5g) and the subscriber H (5h) receive the image information providing node B from the control pad 58 shown in FIG.
The VOD service is requested to (1b), and the image information providing node B (1b) provides the image information corresponding to the request to the subscriber. (A) The image information providing node B (1b) is connected to the control device 17
Identifies a VOD service request from the control signal received from the subscriber side, it establishes a virtual path VP (8c) for VOD, and the subscriber G is placed in this virtual path.
A virtual channel VC (7d) and a virtual channel VC (7e) are established for (5g) and the subscriber H (5h), respectively. That is, similarly to the other image information providing services shown in the above-mentioned embodiment, the ATM connection from the image information providing node to the subscriber is established. However, in the VOD service, since various requests for screen control as described above are made to the image information provided by the subscriber, some virtual channels VC are established for the subscriber.
Next, the image information providing node B (1b) searches the image information requested by each subscriber, and the image information storage devices 11a to 11a.
1b to image information memory 13a corresponding to virtual channel VC
To each of subscribers 13b to 13b, subscriber G (5g) and subscriber H
The image information requested by (5h) is copied at high speed using a HIPPI interface or the like, and the image information storage devices 11a to 11
Open b. In this way, when the VOD service is provided, the image information is stored in the image information memory 1 corresponding to the virtual channel.
By copying to 3a to 13b, when a subscriber is viewing certain image information with the VOD service, even if another subscriber requests the image information, the subscriber who is currently viewing the image information. There is no need to wait for the person to finish the VOD service. Of course, the image information storage devices 11a-11
If another subscriber requests the image information while the image information is being copied from b to the image information memories 13a to 13b, the other subscriber has to wait during the copying, but this waiting time is the same image. The size can be reduced by installing a plurality of image information storage devices that store information.

(B) In the subscriber accommodation node B (4b),
Similar to the image providing service shown in the above embodiment, the cell filter for the subscriber is set. That is, the requested image information is provided only to the subscriber G (5g) and the subscriber H (5h), and the image information is not sent to other subscribers accommodated in the subscriber accommodation node. Although this image information is broadcast from the image information distribution node 3 to the other subscriber accommodation node A (4a) via the image information distribution network 6, the other subscriber accommodation node A (4a).
Also in a), since the cell filter operates, the image information of the VOD service is not transmitted to the accommodated subscribers.

(C) In the VOD service provided by the image information distribution system of the present invention, the image information providing node B (1
In b), as shown in FIG. 2, the image information storage device 1
The image information of 1a to 11b is stored in the image information memories 13a to 13
Since it is copied to b once and the information of this memory is provided,
An image provided interactively with the system via the network by the subscriber G (5g) or the subscriber H (5h) operating the control pad 58 shown in FIG. 7 to control the reading of the memory or the like. To "pause" the information,
It is possible to perform screen control such as "restart", "rewind", and "fast forward". This is to provide the same function for the screen provided by the VOD service so that the subscriber can operate the image information device such as the video tape recorder installed in the home to repeat the desired screen or quickly see it. To do. When ending the VOD service, the subscriber operates the control pad 58 again to notify the image information providing node B (1b) of the end of the VOD service. Image information providing node B
(1b), when receiving the control signal indicating the end, disconnects the ATM connection to the subscriber, similarly to other image providing services, and further, the image information memories 13a to 13
Open b. In this embodiment, the image information providing node is provided with a memory. However, as described in the first embodiment, the image information memory 48 is provided in the subscriber accommodation node 4b shown in FIG. By copying to
A screen control function can also be realized. Further, the relay node 2 or the image information distribution node 3 in the network may be provided with an image information memory, and the image information may be stored in the image information memory corresponding to the ATM connection to realize the above control.

Like the image information distribution system of the present invention,
With the configuration that temporarily stores the image information in the memory and provides it,
Not only will subscribers be able to control their screens as desired,
Even when a plurality of subscribers request the same program, the occupying time of the image storage device can be shortened, so that a high-speed system with a small waiting time for subscribers can be realized. Of course, the waiting time is further shortened by providing a plurality of image storage devices. Further, similarly to the case where the program provided in the previous embodiment is transmitted to the node close to the subscriber, if the memory for accumulating the image is arranged at the node close to the subscriber, the transmission / reception of the screen control signal can be performed. It is possible to realize a system that is simplified and that is capable of high-speed response with less delay.

(2) VOD Service 2 FIG. 13 shows V provided by the image information distribution system of the present invention.
FIG. 9 is an operation sequence diagram showing an example of an OD service, in which the subscriber G (5g) selects the VOD television channel β and then transfers and copies the image information β to the image information memory in the image information providing node B (1b). By operating the image information memory in the middle of watching, the transmission of the image information β was “stopped”, then the transmission of the image information β was “restarted”, and the operation when the service was finally ended was shown. It is a thing.
In addition, in this embodiment, in addition to the subscriber G (5 g), no one is VO.
The D service is not selected. (A) The subscriber G (5g) turns on the power switch of the subscriber terminal (500), and the control pad 58 shown in FIG.
When the VOD service is selected using (501), the subscriber terminal causes the subscriber accommodation node B (1b) to send the A for VOD.
It requests the setting of the TM connection (502). Then, the subscriber accommodation node B (1b) requests the image information distribution node 3 to set up an ATM connection for VOD (503), and the image information distribution node 3 receives the request, and the image information distribution node B (1b). ) To the ATM connection setting for VOD (504). As a result, the image information providing node B (1b) activates the setting of the virtual path VP for VOD (505), and the image information providing node B (1b)
VP for VOD is established between the image information distribution node 3 from b) (506). After that, a VP for VOD is established between the image information distribution node 3 and the subscriber accommodation node B (4b) (507). Next, in this VP, VOD
A virtual channel VC for VOD that provides image information of the service is established. First, the image information providing node B
(1b) activates the VC setting for VOD (508),
After establishing a VC for VOD between the image information providing node B (1b) and the image information distribution node 3 (509), a VC for VOD between the image information distribution node 3 and the subscriber accommodation node B (4b). By establishing (510). Further, the control device 45 of the subscriber accommodation node B (4b) uses the cell filters 43a to 4a for the subscriber G (5g).
The VPI / VCI value of the ATM cell carrying the image information for VOD is set in the VPI / VCI table 64 in 3b (511). Through the above procedure, the ATM connection for VOD is established.

(B) The image information providing node B (1b)
The VOD menu transmission is activated (512) and the established A
Subscriber G (5g) menu through TM connection
To the monitor 57 of the subscriber's house,
A menu is displayed (514). Subscriber G (5g)
Shows the VOD TV channel β from this menu.
The selection is made using the control pad 58 shown in (515).
The subscriber terminal converts this request into a control signal and sends it to the image information providing node B (1b) (516). (C) The image information providing node B (1b) retrieves the image information β of the program selected by the subscriber from the image information storage devices 11a to 11b (517) and sends it to the image information memory 13a (518). In addition, the image information storage devices 11a to 11
When the transmission of the image information β from the image information memory 13a to the image information memory 13a is completed, a display indicating that the VOD image information β is ready to be transmitted is activated (519), and the transmission ready display of the VOD image information β is displayed through the VOD ATM connection. Subscriber G (5
By sending (520) to the subscriber terminal of g), the preparation for sending the image information β is displayed on the monitor 57 of the subscriber's house (521). At this point, when the subscriber G (5g) inputs a reproduction command of the image information β from the control pad 58 (522), this command is converted into a control signal, and the image information providing node B (1b) from the subscriber terminal. (523 to 524). With this as a trigger, the reproduction of the image information β is started (525), and the image information β is sent from the image information providing node B (1b) to the subscriber G (5g) (526). That is, subscriber G
The image information β of the VOD service can be viewed on the monitor 57 of (5g) (527).

(D) The subscriber G (5g) requests the stop of the image information β being provided by inputting an image stop command from the control pad 58 while viewing the image information β (528). )be able to. This request signal includes the frame number of the image information being received by the subscriber G (5g), and this is sent to the image information providing node B (1b) (529). The image information providing node B (1b) analyzes the frame number of the image information included in the image stop request signal (530), and the subscriber G (5g).
, The image information of that frame number is continuously transmitted (53
1 to 532), the monitor 57 of the subscriber G (5g) 57
Then, the image having the frame number requested by the subscriber is displayed as a still screen (533), and the image information β being provided is stopped. Next, when the subscriber G (5 g) inputs an image reproduction command from the control pad 58 (53
4) This is sent as a control signal to the image information providing node B (1b) (535). This control signal also includes the frame number of the image information currently being received, as in the case of stopping the image. The control device 17 of the image information providing node B (1b) that has received this control signal restarts the reproduction of the image information β (536). This image information β is sent to the terminal of the subscriber G (5g) through the ATM connection (537) and reproduced on the monitor 57 of the subscriber G (5g) (538). That is, the program selected by the subscriber is provided again as a moving image.

(E) When the subscriber G (5g) requests the termination of the VOD service (539), the subscriber terminal of the subscriber G (5g) sends a VOD service termination request (540), which is subscribed. It is sent from the person accommodation node B (4b) to the image information distribution node 3 and the image information providing node B (1b) (541, 542). Receiving this, the control device 17 of the image information providing node B (1b) releases the image information memory 13a (543), activates the VOD charge display (544), and sends the subscriber G through the ATM connection.
It is sent to (5g) (545). The monitor 57 of the subscriber G (5g) displays the charge of this VOD service (5
46). After that, the ATM connection (VP / VC) for VOD is disconnected in order from the image information providing node B (1b) (547 to 550). When the ATM connection is disconnected, the VO is displayed on the monitor 57 of the subscriber G (5g).
The D service end is displayed (551). With this VOD
The service ends.

In the embodiments described above, the frame number is used as the control parameter of the image information, but other than this, as an alternative to the frame number for specifying the image information frame, the address of the image information memory or the image Even if the time stamp information in the ATM cell containing the information is used, the same control can be performed. Even if the control signal of the image from the subscriber arrives at the control device after a delay due to the delay in the network, the subscriber can use the parameter. The user can search for and provide the desired screen (for example, since the image transmitted from the memory is advanced when the control signal arrives, the control device performs control such as returning a little to the requested screen). It is possible to realize a VOD service that is easy to use and easy to watch when you want to see the screen you want to see. Further, in the present embodiment, the VOD service capable of screen control has been described by taking stop and play as an example, but the control such as “fast forward” and “rewind” as described above is also performed by the subscriber. By controlling the image memory with the control parameter of the image information in response to a command request, the same sequence can be realized, and a user-friendly VOD with an excellent human interface capable of screen control corresponding to the subscriber's request Service, ie
Dedicated device (VTR, etc.) that the subscriber has at home
An image providing service having a function similar to that of obtaining image information by operating can also be realized in a system via a network. As in the case of the first to third embodiments, transmission / reception of control information between the subscriber and the system is carried out by using an individual line or a common line.
Alternatively, the function of the present invention can be achieved regardless of which ATM connection carrying image information is used for transmission and reception.

<Embodiment 5> The image information distribution system of the present invention can provide various image providing services to which additional functions are added in addition to the various image providing services shown in the above-described embodiments. For example, the program reservation function can be provided to the subscriber by controlling the cell filter in the subscriber accommodation node with time. The operation will be described below. The subscriber can access the subscriber accommodation node A from the subscriber terminal.
(4a) or the subscriber accommodating node B (4b), from the control pad 58 before the start of the program (a program such as the above-mentioned general broadcasting service, PPV service, VOD service, etc.) viewing request of the program to be viewed (requested ( Reserve. The control device 45 in the subscriber accommodating nodes 4a-4b,
The program reserved by the subscriber and its start time are stored, a timer up to the program start time is started, and when the timer recognizes that the program start time is reached, the VPI / VPI of the ATM cell carrying the TV channel of the program is recognized. The ATM connection is set, such as setting the VCI value in the VPI / VCI table 64 in the cell filter. At this time, the control device 45 in the subscriber accommodation node also sends a control signal for turning on the power of the device in the subscriber's house, and turns on the power of the subscriber terminal and the monitor in the subscriber's house. By this procedure, the device in the subscriber's premises is automatically turned on at the time when the subscriber reserves, and the program reserved by the subscriber is sent.
Then, at the time when the program ends, a control signal for turning off the power supply of the subscriber terminal and the monitor in the subscriber's house is transmitted, and thereafter the setting of the cell filter is canceled. The TV channel setting sequence is the same as in the above-described embodiment. By providing this power-on / off procedure, even if the subscriber does not reserve the program, the system side can forcibly turn on the power of the device at the subscriber's house and broadcast the emergency broadcast, for example, when a disaster occurs.

[0064]

As described above, according to the image information distribution system of the present invention, it is possible to realize a system having a simple structure, a high-speed response with a short waiting time and a good usability. More specifically, (1) between the image information providing node and the image information distribution node, the VP to be distributed to the plurality of subscriber accommodation nodes is set by one VP, so that the resources in the network can be saved. (2) Since the VP is assigned to each image service type, the sequence of VP and VC setting for each image service can be simplified. (3) When the image information is always sent to the node close to the subscriber, the image can be sent to the subscriber in a short procedure and response time by the procedure of sending the image information by the negotiation between the node and the subscriber. .
(4) There is an effect that it is possible to provide a substantially constant image information quality for each same image service, and to simplify image quality management for each service.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing an overall configuration of an image information distribution system of the present invention.

FIG. 2 is a block configuration diagram similarly showing the configuration of an image information providing node.

FIG. 3 is a block configuration diagram similarly showing the configuration of an image information distribution node.

FIG. 4 is a block configuration diagram showing another configuration of the image information distribution node.

FIG. 5 is a block configuration diagram similarly showing a configuration of a subscriber accommodation node.

FIG. 6 is a block configuration diagram showing another configuration of the subscriber accommodation node.

FIG. 7 is a block diagram showing the structure of a subscriber terminal.

FIG. 8 is a block diagram showing the structure of a cell filter.

FIG. 9 is a sequence diagram showing an operation of an image providing service by the image information distribution system of the present invention.

FIG. 10 is a sequence diagram showing another operation of the image providing service.

FIG. 11 is a sequence diagram showing another operation of the image providing service.

FIG. 12 is a sequence diagram showing the operation of another image providing service.

FIG. 13 is a sequence diagram showing another operation of the image providing service.

FIG. 14 is a sequence diagram showing another operation of the image providing service.

FIG. 15 is a sequence diagram showing the operation of another image providing service.

[Explanation of symbols]

1a, 1b ... Image information providing nodes, 11a, 11b
... Image information storage device, 12a, 12b ... Selector,
13a, 13b ... Image information memory, 14a,
14b ... CLAD, 15 ... Multiplexing device,
16 ... Line termination device, 17 ... Control device, 2 ... Relay node, 3 ...
Image information distribution node, 31, 33a, 33b ... Line terminating device, 32 ... ATM demultiplexing / multiplexing device, 34 ... Control device, 35 ... Optical splitter, 4
a, 4b ... subscriber accommodation node, 41, 44a,
44b ... Line termination, 42 ... ATM demultiplexer / multiplexer,
43a, 43b ... Cell filter, 45 ... Control device, 46a, 46b ... Distributor, 47a, 47b ... Selector, 48 ...
Image information memory, 5a to 5h ... Subscribers A to H,
50 ... Subscriber terminal, 51 ... Line termination,
52 ... CLAD, 53 ... tuner,
54 ... Cable driver, 55
... Interface, 56 ... Control device, 57 ... Monitor, 58 ...
Control pad 6 ... Image information distribution network, 61 ... Delay device, 62 ... Empty cell generator, 63 ...
VPI / VCI detector, 64 ... VPI / VCI setting table, 65 ... Comparator, 66 ... Selector,
67 ... Bus connected to control device 45, 6
8,69 ... Signal highway, 8a ... PPV
Virtual path for broadcast, 8b ... virtual path for general broadcast,
8c ... VOD virtual path, 7a, 7b, 7c, 7d,
7e ... Virtual channel established in each virtual path.

Claims (3)

[Claims] 1. An image information distribution system for distributing and providing image information to subscribers of the communication network in a communication network composed of a transmission line for transferring information in an asynchronous transfer mode and a plurality of nodes for performing communication processing of the information. In, the plurality of nodes,
An image information providing node having an information source of image information to be provided to a subscriber, a plurality of subscriber accommodating nodes accommodating terminals of a subscriber receiving image information, the image information providing node and the subscriber accommodating node And an image information distribution node that distributes the image information received from the image information providing node to the subscriber accommodation node by installing the image information providing node between the image information providing node and the image information distributing node. A first virtual path and a virtual channel in an asynchronous transfer mode corresponding to the type of image information providing service provided to the subscriber and the image information provided by the service are set in the transmission line by point-to-point connection. Image information provided by the subscriber between the image information distribution node and the plurality of subscriber accommodation nodes by transferring the image information requested by the subscriber. A second virtual path and a virtual channel in an asynchronous transfer mode corresponding respectively to the service type and the image information provided by the service, are set in the transmission path by point-multipoint connection, and transferred to the image information distribution node. The distributed image information is distributed and transferred to all the subscriber accommodation nodes, and each of the plurality of subscriber accommodation nodes has a virtual path and a virtual path including image information requested by the subscriber corresponding to the accommodated subscriber. An image information distribution system comprising a filter device for extracting only cells in an asynchronous transfer mode of a channel and transferring only image information requested by a subscriber to a subscriber terminal. 2. When the subscribers accommodated in the plurality of subscriber accommodation nodes connected to the image information distribution node request the same image information, the image information providing node and the image information distribution node And a virtual channel and a virtual channel corresponding to the requested image information are set to transfer the image information requested by the subscriber, and the image information distribution node is connected to the image information distribution node. Image information is distributed and transferred to all of the plurality of subscriber accommodating nodes, and at each of the plurality of subscriber accommodating nodes, only the terminal of the subscriber who has requested to receive the image information transferred by the filter device. The image information distribution system according to claim 1, wherein the image information is transferred to. 3. The image information distribution system sets a virtual path in an asynchronous transfer mode on the transmission line corresponding to the type of image providing service provided by the image information providing node, and further provides by the service. A virtual channel is set in the virtual path corresponding to the program or image information to be stored, and the program or image information requested by the subscriber to the image information providing node is transferred to the subscriber accommodation node. The image information distribution system according to claim 1.