JP3146865B2 - Image information distribution system - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a communication system for distributing image information to one or more destinations, and more particularly to a communication network using an asynchronous transfer mode (ATM) communication system. The present invention relates to an image information distribution system for providing image information to a subscriber.

[0002]

2. Description of the Related Art With the advent of the ATM communication system, information that requires a wide-band transmission line, such as an image, can be transmitted 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 the conventional one-to-one communication. A system that provides video dial tones over a public network efficiently broadcasts wideband image information and pay-per-view that charges a fee for each program viewed by a subscriber who is being served by a cable television system (CATV). (Pay Per View: PPV) and a method of providing a video on demand (Video On Demand: VOD) for providing a desired program at a desired time by a subscriber have become issues. In the prior art, CA
When providing image information such as a TV, Japanese Patent Application Laid-Open
No. 392, the synchronous transfer mode (Sync.
The provision of image information is realized by the hronousTransfer Mode (STM) communication method. That is, image information of a plurality of channels is allocated to each time slot from a center providing image information, transmitted to a downstream remote node, and the remote node allocates image information to a time slot allocated to each subscriber. It was a configuration to transmit. In this configuration, it is necessary to always allocate a certain band as a transmission channel for CATV. In the case of providing image information corresponding to individual subscribers such as video-on-demand, there arises a problem that time slots are insufficient between the center and the remote node. As described above, adoption of the ATM system can be considered as a system for avoiding the problem of insufficient time slots and the deterioration of the use efficiency of the transmission line by always securing the transmission band for CATV. However, when distributing information by the ATM method, a distribution switch for the ATM is provided, which causes an increase in hardware size and complexity of control. For example, it is necessary to adopt a control method such as that disclosed in Japanese Patent Application Laid-Open No. Hei 2-186791, in which each information is distributed to each outgoing route 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-mentioned problems, with a simple configuration and control method. More specifically, a CA is connected to a subscriber's house via a public network.
A system for providing image information of a TV, which can efficiently use a transmission line, provide high-speed information such as a PPV service or a VOD service when a subscriber needs it, and use the subscriber's convenience. And an economical image information distribution system with a simple configuration using an ATM communication system.

[0004]

As means for solving the above problems, an image information distribution system according to the present invention comprises an image information providing node, an image information distribution node, a subscriber accommodating node, and a subscriber terminal. The transmission and reception of image information between stations and with the subscriber terminal use the ATM communication system. Here, the image information providing node is a node that sends out image information such as video and audio compressed by a method such as MPEG2 received from another node or stored in its own node, and the image information distribution node is An optical splitter for passively distributing 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 subscriber, 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 sent from the image information providing node to the image information distribution node.
Setting a connection, transmitting image information requested by a plurality of subscribers to the image information distribution node, and distributing the image information to all subscriber accommodation nodes from the image information distribution node; Between the providing node and the image information distribution node, an economical configuration can be used in which image information requiring a wide band can be transmitted by only one connection. In addition, the image information is classified into a plurality of types, and a virtual path (hereinafter referred to as a VP) is set for each type, that is, an ATM connection is set.
The configuration is such that the line quality is ensured in units of P, and the quality of the image information is substantially constant in the unit of providing the image information, so that there is no variation in the image quality among the subscribers.

Further, in the above-mentioned configuration, all the subscriber accommodation nodes receive all the image information transmitted by the image information distribution node. A containing the requested image information
A cell filter for extracting TM cells is provided, and only ATM cells containing necessary image information are extracted from the line and transmitted to each subscriber. As described above, the image information distribution node distributes the image information without controlling the image information for each specific departure route, and distributes the image information with simple control. When each subscriber requests necessary image information from the subscriber terminal to the subscriber accommodating node, each subscriber transmits the ATM cell carrying the image information to a cell filter corresponding to the subscriber provided in the subscriber accommodating node. A value of a virtual path VP (hereinafter, referred to as VPI) and a value of a virtual channel (hereinafter, referred to as VC) (hereinafter, referred to as VCI) are set.
The configuration is such that only the ATM cells having the PI / VCI are passed, 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 the subscriber to the node accommodating the subscriber and the image signal is transmitted to each subscriber. However, according to the configuration of the present invention, a virtual path VP is set for each image service, and one band is provided from the image information providing node to the image information distribution node. AT
By transmitting the image information through the M connection, the line resources can be efficiently used between these nodes, and the image information can be distributed from the image information distribution node without using the multicast switch. Also, by setting a virtual path VP for each service, it becomes easier to manage each image service as compared with a case where a VP is set for each subscriber, and to provide services of the same quality to all subscribers. Can be.

[0007] When a subscriber has already received image information required by a certain subscriber at a subscriber accommodating node, a short procedure and a short response can be achieved by a procedure for transmitting image information only by negotiation between the node and the subscriber. Image information can be sent to the subscriber in a timely manner.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of an image information distribution system according to the present invention will be described below in detail with reference to the drawings. First Embodiment (1) System Configuration FIG. 1 is an overall configuration diagram of a system showing a configuration and a 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 nodes A corresponding to an image providing service described later). (1a) and a node B (1b)), and a subscriber 5 (configured by the subscribers A to H (5a to 5h) in this embodiment) to receive the image providing service.
A subscriber accommodating node 4 for accommodating the subscriber 5 and transmitting the image information requested by the subscriber 5 (in this embodiment, two nodes A (4a) and node B (4b) corresponding to the number of subscribers)
And an image information distribution node 3 for distributing the image information from the image information providing node 1 to the subscriber accommodating node 4. The three types of nodes and each of the subscribers are connected in the asynchronous transfer mode. It is connected by a transmission line (hereinafter referred to as an ATM line) and distributes and provides image information corresponding to a request from a subscriber from an image information providing node 1 to a subscriber 5 by an ATM cell. In the figure, an image information distribution network 6 is an ATM for distributing image information from the image information distribution node 3 to all the subscriber accommodation nodes 4.
It is a network. Further, the relay node 2 relays information according to the distribution distance of image information and the like.
Although provided between the image information providing node 1 and the image information distribution node 3, depending on the scale of the image information distribution system, it may be provided between other nodes or without.

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

FIGS. 3 and 4 are block diagrams each showing an example of the configuration of the image information distribution device 3. In each of the devices, an ATM demultiplexer 3 for distributing ATM cells is used.
2 and line terminating devices 31 and 33a, which are interfaces with the ATM line, and a control device 34 for controlling the entire image information distribution device 3. here,
In the image information distribution device 3 of FIG. 3, when distributing ATM cells to all the subscriber accommodation nodes 4a to 4b, the ATM separation / multiplexing device 32 distributes the ATM cells. A line termination device is required, and a line termination device 33b is added. In the image information distribution device 3 of FIG. 4, when distributing ATM cells to all the subscriber accommodation nodes 4a to 4b, the image information distribution network 6 distributes the ATM cells.
The optical splitter 35 as a passive element is connected to the line terminating device 33a.
In the image information distribution system of the present invention, any image information distribution device 3 may be used.

FIG. 5 and FIG. 6 are block diagrams showing examples of the structure of the subscriber accommodating node 4.
An ATM demultiplexer 42 for distributing ATM cells;
A line terminating device 41 which is an interface with a TM line,
44a, 44b, a cell filter 43a-43b for extracting only ATM cells containing image information requested by the subscriber, and a control unit 45 for controlling the entire subscriber accommodating node 4. did. Here, as described above, the subscriber accommodation node 4 in FIG. 6 does not provide the image information providing nodes 1 with the image information memories 13a to 13b, but allows the node to correspond to a service for providing image information. 1 shows an example of a configuration in which an image information memory 48 temporarily holds the data.
2 and the cell filter 43, the distributors 46a to 46b
And an image information memory 48 via selectors 47a and 47b. In the image information distribution system of the present invention, an image information memory that is temporarily stored in correspondence with a service that provides image information is installed in the system according to system specifications (for example, a hardware scale such as a memory amount and a response speed limit). And the configuration of the subscriber accommodation node 4 can be selected.

FIG. 7 is a block diagram showing an example of the configuration of the subscriber terminal of the subscriber 5. The line termination device 51 is an interface with an ATM line, and the CLAD 52 converts an ATM cell into image information. Monitor image information 57
Tuner 53 for converting to a format that can be displayed
(In the present embodiment, information compressed by a method such as MPEG2 is decompressed and converted into an input signal of a monitor such as an NTSC signal). Control pad 5 for inputting requests from the user to the system
And a control device 56 for controlling the entire subscriber terminal. 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 control signal at the subscriber terminal, and then controls the system. By transmitting a signal and displaying the image information received from the image information providing node 1 in response to the request on the monitor 57, an 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 accommodation node 4.
A highway 68 for receiving ATM cells from the TM demultiplexer 42 and a virtual path identifier (Virtua) in the ATM cells.
l Path Identifier: VPI and virtual channel identifier (V
VP that detects irtual Channel Identifier (VCI)
An I / VCI detector 63 and a VPI for registering VPI and VCI values of ATM cells including image information requested by the subscriber.
/ VCI table 64, detector 63 and table 6
4, a comparator 65 for comparing the values of VPI and VCI,
A delay unit 61 for delaying the M cell by a time corresponding to the operation time of the comparator 65, an empty cell generator 62 for transmitting an idle ATM cell to the subscriber, and a highway corresponding to the comparison result of the comparator 65 69, a selector 66 for selecting and transmitting an ATM cell containing image information requested by the subscriber or an empty ATM cell, and is controlled by the control device 45 provided in the subscriber accommodation node 4 via the control line 67. The configuration was adopted. The cell filter sets the VPI and VCI values of the ATM cell including the image information requested by the subscriber in the table 64 by the control unit 45, and outputs the VPI / VCI other than the set value.
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 singular or plural. When a plurality of ATM cells are set, a plurality of types of ATM cells are transmitted to the subscriber. In this case, the subscriber may be provided with a device for recognizing and appropriately distributing the ATM cells, for example, an ATM switch.

(2) System Operation An outline of the operation of the image information distribution system according to the present invention will be described below with reference to FIG. (A) Request from subscriber Image information providing node 1a generated by operating control pad 58 of any of subscribers A to H (5a to 5h)
1b is transmitted to the control device 45 of the subscriber accommodation node (4a-4b), the image information distribution node 3
Of the image information providing apparatuses 1a and 1b via the relay device 2 and the relay node 2. The control signal indicating the request from the subscriber has a smaller amount of information as compared with the image information. In addition to the method of multiplexing and transmitting,
These control signals are transmitted to a CCITT recommendation N (not shown).
o. The transmission and reception may be performed by a common line or an individual line of the 7 common line signal system.

(B) Provision and distribution of image information (i) Controller 17 of image information providing nodes 1a to 1b
Are input to the subscribers A to H (5a to 5a) from the input control signal.
h), each subscriber A
To H (5a to 5h) are selected by the selectors 12a to 12b from the image information storage devices 11a to 11b. If the image information is image information corresponding to each subscriber, such as video-on-demand, or image information capable of operating the image information from the subscriber, a hippie interface (Hi
gh Performance Parallel Interface (HIPPI) via a high-speed interface such as subscribers A to H (5
a to 5h) corresponding to the ATM connection (corresponding to the type of the image information providing service and the type of the provided image information (for example, the channel of the program)).
13b to 13b. In the case of other image information, the image information is passed through the image information memories 13a to 13b. Further, a VPI corresponding to the type of the image information providing service and a VCI corresponding to the type of the provided image information (for example, a program channel) are determined, and the CLADs 14a to 14b convert the image information into an ATM cell form. Multiplexed together with the ATM cell carrying other image information by the 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.
And the ATM shown in FIG.
It is transmitted to the down line of the line (the line for transmitting information from the image information providing node to the subscriber). The transmitted image information and control signal are sent to the image information distribution node 3 via the relay node 2 if there is one. As for the transmission of the control signal, a method using another line as in the uplink direction may be used.

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

(Iii) The image information distributed to the subscriber accommodation nodes 4a to 4b passes through the line termination 41,
In the M separating / multiplexing device 42, the subscriber accommodation nodes 4a to 4
4b is distributed to lines corresponding to the subscribers 5a to 5h. Here, the ATM demultiplexer 42 is basically
All the received ATM cells are distributed to ATM lines corresponding to all subscribers. Then, the next-stage cell filters 43a to 43a
b, VPI and VCI in the ATM cell are detected by the detector 6
3 and the V set in the VPI / VCI table 64
If the ATM cell has a VPI / VCI other than the PI / VCI value, the ATM cell is discarded (an empty cell is sent out) and the same VPI / VCI
If the ATM cell has the VCI, the receiving ATM cell delayed by the delay unit 61 is selected and the subscriber is filtered to pass only the ATM cell having the VPI / VCI including the requested image information, and then the line is switched. Terminals 44a-44
b to send ATM cells to the subscribers 5a to 5h.
Note that the image information memories 13a to 13a in the image information providing node 1
As an alternative to 13b, when the image information memory 48 corresponding to the ATM connection is installed in the subscriber accommodation node shown in FIG. 6, the video on demand (Video On Demand:
When providing a VOD service or the like, the image information memory 4
8 stores the image information transmitted from the image information providing node 1. Depending on the type of the image providing service, the image information is passed through the image information memory 48 and transmitted from the line terminals 44a to 44b to the subscribers 5a to 5h via the cell filters 43a to 43b.

(Iv) The subscriber terminal 50 converts the image information and control signal received in the form of the ATM cell into the original image information and control signal by the CLAD 52. The image information transmitted so far in a compressed form is expanded in the tuner 53, converted into a television signal form by the cable driver 54, and sent to the monitor 57. The subscriber views image information on the 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, a virtual path VP is determined according to the type of image information providing service, and the type of image information provided in the VP (for example, An ATM connection is set by a method of defining a virtual channel VC corresponding to a channel of a program, that is, a connection is not set for a subscriber, so that VP and VC for providing image information can be used in common, and network resources can be used. Can save money. (For example,
VPs may be set between the image information providing node and the image distribution node by the number corresponding to the service.) Furthermore, VP
And VC are commonly used, so that the sequence of these settings can be simplified. Also, at a node close to the subscriber, a cell filter is provided for the subscriber, where only the image information requested by the subscriber is selected and provided to the subscriber, and the provision of the image information in the network is common. According to the VP and VC used, the configuration is such that broadcasting is performed up to the node where the cell filter is installed, so that the control unit sets the cell filter in response to the request of the subscriber, and also sets the ATM connection in the network. And the like can be simplified, and a system that saves network resources by simple control can be configured.

<Embodiment 2> According to the image information distribution system of the present invention, pay per view (PPV) in which a subscriber pays a viewing fee for each general television broadcast or program.
Various image information provision and distribution services such as a service and a video-on-demand (VOD) service that allows a subscriber to view arbitrary image information stored in the image information providing node at an arbitrary time can be realized. Hereinafter, an embodiment of an image information providing / distributing service using the present system will be described. (1) General broadcasting service 1 Image information providing node A (1a) is connected to subscribers C to F (5c).
1 to 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 transmitted from the image information providing node A (1a) to the subscribers in the following procedure. Is to be sent. (A) The image information providing node A (1a)
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 information is set in the image information distribution node 3 via the image information distribution node 3, and is set in the subscriber accommodation node A (4 a) and the subscriber accommodation node B (4 b) via the image information distribution network 6. Further, the virtual path VP (8
b) includes virtual channels VC (7b to 7b) corresponding to programs.
c), and for each virtual channel VC (7b to 7c),
The television channels α1 and α2 of the general broadcast are respectively allocated. Here, the virtual channels VC (7b to 7c) in the virtual path VP (8b) correspond to the image information providing node A (1a).
From the image information distribution node 3 to the subscriber accommodating node A (4a) and the subscriber accommodating node B (4b) are set in a point-to-point manner. 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 to 4c.
4b, and is accommodated in the subscriber accommodation nodes 4a to 4b.
In 4b, all the image information received by the image information distribution node 3 is received. (B) The subscriber accommodation nodes 4a and 4b select only the virtual channel VC requested by the subscriber accommodated in each subscriber accommodation node. This is realized by discarding the virtual channel VC which is not viewed by the subscriber at the cell accommodation node in each of the subscriber accommodation nodes.
In this embodiment, the subscribers C, D, and E have the television channel α1.
, And the subscriber F requests the television channel α2. Therefore, the cell filters corresponding to the subscribers C, D, and E select only the VC (7b) and select the TV assigned to the VC (7b). The cell filter receiving the channel α1 and corresponding 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 a general broadcasting service provided by the image information distribution system of the present invention.
This figure shows the transmission and reception relationship between image information and control information when a subscriber views general broadcast α + 1 after viewing general broadcast α. Hereinafter, the operation will be described with reference to FIG. (A) Subscriber A (5a) is a subscriber terminal (FIG. 7, 50)
After turning on a power switch (not shown) (100), the control pad (58, FIG. 7) is operated to select a general broadcast television channel α (101), and the subscriber terminal (FIG. 7, 50) is selected. Requests the subscriber accommodating 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 (FIG. 5 or FIG. 6, 43)
a) VP of ATM cell carrying TV channel α
An I / VCI value is set (103). Now subscriber A
An ATM connection for the television channel α is established between the terminal and the subscriber accommodation node A (104).

(B) The subscriber accommodating node A (4a) requests the image information distribution node 3 to set up an ATM connection (105). Subsequently, the image information distribution node 3
Requests the image information providing node A (1a) to set up an ATM connection (106). The image information providing node A (1a) sets VPI and VCI, and sets A between the image information providing node A (1a) and the image information distribution node 3.
A TM connection is established (107). Subsequently, 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). As described above, the image information providing node A (1a) sends the subscriber A (5
An ATM connection is established with the subscriber terminal (a) of FIG. 7 (a), and the program (image information) of the television channel α is transmitted from the image information providing node A (1a) to the subscriber terminal (FIG. 7, 50). ) Is sent (109), so that the subscriber A
(5a) allows the user to view the program on the television channel α on the monitor (57 in FIG. 7).

(C) In the image information distribution system of the present invention, the subscriber accommodating node A (4a) sets up the ATM connection for transmitting the above-described television channel α, and further sets the television channel α requested by the subscriber. Requesting the image information distribution node 3 to set up an 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 sends an AT from the image information providing node 1a to the image information distribution node 3.
The M connection is established (112), and then the VPI and VCI are set in the image information distribution node 3, and A is transmitted 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 time, the VPI / VCI table (64 in FIG. 7) in the cell filter of the subscriber accommodating node A (4a) includes the television channel α-1 or α.
Since the VPI / VCI value indicating +1 is not registered,
The programs on 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)
An ATM connection setting request for α + 1 is sent from the subscriber terminal (5a) to the subscriber accommodation node A (4a) (117). The subscriber accommodating node A (4a) releases the VPI / VCI table (64 in FIG. 7) for the television channel α of the cell filter for the subscriber A (5a) (11).
8) The VPI / VCI value of the ATM cell carrying the television channel α + 1 is set (119). This allows
An ATM connection for the television channel α + 1 is established from the subscriber accommodating 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), the television channel α +
Since the first program has been received, the 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 on the television channel α + 1 can be received in a short time.

(E) The subscriber accommodating node A (4a) sets a cell filter to receive the television channel α + 1, and then sends a disconnection request for the ATM connection for α-1 to the image information distribution node 3. (122), the image information distribution node 3 sends the ATM to the image information providing node A (1a).
A connection disconnection request is sent (123). Then, the subscriber accommodating node A (4a) has 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, an ATM connection for α + 2 is established from the image information providing node A (1a) to the image information distribution node 3 (127), and an ATM connection is established from the image information distribution node 3 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 stored in the cell filter for the subscriber A (5a) of the subscriber accommodation node A (4a). Is not registered in the VPI / VCI table 64, and is not transmitted to the terminal of the subscriber A as in (c) described above. As described above, the subscriber A views the general broadcast α, and thereafter, 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 a common line method or transmitted / received by an 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, and belongs to the subscriber accommodating node A (4a). Subscriber A
While (5a) is viewing the program on the general broadcast television channel α-1, another subscriber B (5b) belonging to the same subscriber accommodation node A (4a) selects and views the program on the television channel α. It shows an operation sequence in the case. Hereinafter, the operation will be described with reference to FIG. (A) After the subscriber A (5a) turns on the power switch of the subscriber terminal (200), the television channel α-1 of general broadcasting
(201), the subscriber terminal requests the subscriber accommodating 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) is a VPI / cell filter of the subscriber A (5a).
A that carries television channel α-1 to VCI table 64
The VPI / VCI number of the TM cell is set (203).
Thus, an ATM connection is established between the subscriber accommodation node A and the terminal of the subscriber A (204). This operation is the same as (a) of (2) described above.

(B) The subscriber accommodating 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 that carries the television channel α-1 (206). In the image information providing node A (1a), V
PI and VCI are set, and the image information providing node A (1a)
And an image information distribution node 3 to establish an ATM connection for α-1 (207). Subsequently, the image information distribution node 3 sets VPI and VCI, and sets α-1 between the image information distribution node 3 and the subscriber accommodation node A (4a).
An ATM connection is established (208). The television channel α-1 is transmitted from the image information providing node A (1a) to the subscriber accommodating node A (4a) through the ATM connection thus established (209).

(C) As in the previous example, the subscriber accommodating node A (4a) transmits the television channel α-1, and then sends the television channel to the image information distribution node 3 before and after α-1. A sequence for requesting the image information providing node A (1a) for the television channels α-2 and α is executed. That is, the subscriber accommodating node A (4a) provides the image information distribution node 3 with the television channel α and the A for the television channel α-2.
Requesting the setting of the TM connection (210), the image information distribution node 3 requests the image information providing node A (1a) to set the ATM connection for carrying the television channels α and α-2 (211). In response to this, the image information providing node A (1a) sets VPI and VCI, and sends the image information providing node A (1a) to the image information distribution node 3 with α.
And establish an ATM connection for α-2 (212),
Subsequently, in the image information distribution node 3, VPI and VCI
Is set, and an ATM connection for α and α-2 is established from the image information distribution node 3 to the subscriber accommodation node A (4a) (213). As described above, 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 time, the subscriber accommodation node A (4
In the cell filter 43 of FIG.
Subscriber A because no VPI / VCI has been set for
(5a) cannot receive the programs of the television channels α and α-2.

(D) In this state, when the subscriber B (5b) belonging to the same subscriber accommodating node A (4a) turns on the power 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 accommodating 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)
The VPI / VCI table 64 of the cell filter for the subscriber C (5c) contains the V of the ATM cell carrying the television channel α.
A 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, the subscriber accommodating node A (4a) has already received the program on the television channel α by the sequence (214) set by the subscriber B (5b). AT at (220)
Subscriber B (5b) only by establishing M connection
Can receive the program of the television channel α in a short time (2
21).

(E) The subscriber accommodating node A (4a), as in the previous example, transmits the television channels α-1 and α +
1 is executed, but since α-1 has already been received in the sequence (209), the sequence (222 to 226) for receiving α + 1 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 to pass only the cell including the image information of the television channel α, the subscriber B ( In 5b), only the television channel α is viewed.

(4) General Broadcasting Service 4 FIG. 11 is an operation sequence diagram showing another embodiment of the general broadcasting service provided by the image information distribution system of the present invention, belonging to the subscriber accommodating node A (4a). Subscriber C
(5c) is a subscriber E (5e) belonging to another subscriber accommodation node B (4b) selecting and viewing a program on the television channel α while viewing a program on the general broadcast television channel α-1. FIG. 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 general broadcasting (601), the subscriber terminal becomes the subscriber accommodation node A ( 4a), an ATM connection setting for the television channel α-1 is requested (602). Then, the control device 45 of the subscriber accommodating node A (4a) sets the subscriber C (5c).
VPI / VCI of the ATM cell carrying the television channel α-1 in the VPI / VCI table 64 of the cell filter for
A number is set (603). Thus, 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 accommodating node A (4a) requests the image information distribution node 3 to set 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 that carries the television channel α-1 (606). In the image information providing node A (1a), V
PI and VCI are set, and the image information providing node A (1a)
And an image information distribution node 3 to establish an α-1 ATM connection (607). Subsequently, the image information distribution node 3 sets VPI and VCI, and sets α-1 between the image information distribution node 3 and the subscriber accommodation node A (4a).
608 is established (608). Through the ATM connection established in this way, the program on the television channel α-1 is transmitted to the image information providing node A (1a).
Is sent to the subscriber accommodation node A (4a) (60
9). In addition, as described above, in the image information distribution network 6, since a line is set up in a point-to-multipoint manner, the image information distribution node 3 transmits the television to the subscriber accommodation node B (4b) belonging to this node. ATM cells carrying image information of channel α-1 are simultaneously distributed (609).

(C) As in the previous example, the subscriber accommodating node A
(4a), after transmitting the television channel α-1, the image information distribution node 3 transmits the television channels α-2 and α which are the television channels before and after α-1 to the image information providing node A.
(1a), the image information distribution node 3 requests the image information distribution node 3 to set up an ATM connection for the television channel α and the television channel α-2 (610), and the image information distribution node 3 requests the image information distribution node A (1a). ) Is requested to set up an ATM connection that carries 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 an ATM connection for the television channels α and α-2 is established from the image information providing node A (1a) to the image information distribution node 3 (6).
12) Then, in the image information distribution node 3, VPI and V
By setting the CI, the image information distribution node 3 sends the A for the television channels α and α-2 to the subscriber accommodation node A (4a).
A TM connection is established (613). Through the ATM connection established in this way, the programs on the television channels α and α-2 are transmitted from the image information providing node A (1a) to the subscriber accommodation node A (4a) (614, 6).
15). At this time, as in the above-described embodiment, the cell filters 43 in the subscriber C (5c) of the subscriber accommodation node A (4a) have the VPs for the television channels α and α-2.
Since the I / VCI has not been set, the subscriber C (5c)
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 of the subscriber terminal (616) and selects the television channel α for general broadcasting (617), the subscriber terminal of the subscriber E (5e) It requests the accommodation node B (4b) to set up an ATM connection for the television channel α (618). The control device 45 of the subscriber accommodation node B (4b)
VPI / VCI table 6 of cell filter for (5e)
4 shows the VPI / V of the ATM cell carrying the television channel α.
The CI number is set (619). Thus, 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, the subscriber accommodation node B (4b) has already received the television channel α by the sequence (614) previously set by the subscriber C (5c). The subscriber E (5e) can receive the program of the television channel α only by establishing the ATM connection in 620) (621).

(E) The subscriber accommodating node B (4b) sets the television channels α-1 before and after the received television channel α.
And a sequence for receiving α + 1. However, since the television channel α−1 has already been received in the sequence (609), a 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 accommodating node B (4b) is set so as to pass only the ATM cells including the image information of the television channel α, the subscription is performed. Person E (5e) has the 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, the virtual path corresponding to the type of the image information providing service is provided on the ATM line. A VP is set, and a virtual channel VC corresponding to the type of image information to be provided is set in the VP, and the image information is transmitted in an ATM cell. Since the ATM connection is established, the image information providing nodes 1a and 1b to the image information distributing node 3 are connected to the image information distributing node 3 if the subscribers request the same television channel.
Transmission is possible through this ATM connection, and individual ATM connections are set for each subscriber, and transmission capacity can be reduced as compared with the case where image information of the same content is transmitted through each ATM connection. In addition, 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 television signal into a control signal and transmits 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 a 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 when the subscriber sends out the television channel switching request to when the television channel is actually switched. In order to shorten this time, in the present invention, the number of the television channel is, for example, 1, 2, 3,. . . 12,1,
2, 3,. . . In many cases, the configuration is such that it is easy to switch cyclically, that is, when the subscriber switches the television channel, the user is watching the previous and next television channels currently being viewed, for example, the current television channel α. In this case, since the switching to the television channel α-1 or the television channel α + 1 is often performed, when the subscriber requests viewing of the television channel α, the image distribution node 3 adds to the television channel α, The television channels α-1 and α + 1, which are television channels, are also requested to the image information providing node.
Therefore, when a subscriber who is watching television channel α switches to television channel α-1 or television channel α + 1, television channels α-1 and α + 1 are already received by subscriber accommodation nodes 4a-4b. ing. Therefore, transmission and reception of the control signal can be performed only between the subscriber and the subscriber accommodation nodes 4a to 4b. When the subscriber who is watching the television channel α switches to the television channel α + 1, the image distribution node 3 sets the television channels before and after the television channel α + 1 as:
That is, in addition to the switched α + 1, α + 2 and α are received. If no subscriber belonging to the image information distribution node 3 is watching the television channel α-1, a request to disconnect the television channel is sent to the image information providing nodes 1a, 1a, 1b. With such a configuration, it is possible to switch a television channel at a higher speed than when relaying a control signal for a television channel switching request to the image information providing nodes 1a and 1b. Of course, if no programs are assigned to all TV channels, a configuration may be adopted in which a TV channel close to the currently viewed TV channel is selected and received.
Although one TV channel is selected and received, a configuration may be adopted in which a plurality of TV channels before and after are selected and received.
Further, another method for previously receiving a program on a television channel other than the television channel for which the subscriber has requested viewing at the subscriber accommodating node and realizing high-speed switching of the television channel is as follows. Group by group (eg, news, sports, music, etc.)
If the subscriber selects a program belonging to a certain group, the system selects some other programs belonging to this group and receives them at the subscriber accommodation node, or conversely, selects another program belonging to another group. It is also possible to select some programs and receive them at the subscriber accommodation node. Also, a program with a high audience rating can be selected and received. Such control is performed, for example, by storing the number of a television channel provided by a program in advance in a management operation device or the like of an illustrated system, specifying the number of television channels to be received in advance, By providing the function of managing the rating, usage status, and the like of registering the content (type, etc.) of the program to be provided, it is possible to change the number of the TV channel in the same procedure as the above-described embodiment. It can be easily realized simply by increasing the number of procedures. Alternatively, a method may be used in which the subscriber notifies the system of the information at the start of use of the terminal, and performs control based on the content of the notification. In any case, the system of the present invention does not establish an ATM connection for each subscriber, but establishes an ATM connection corresponding to image information to be provided. Even in a configuration in which the subscriber accommodating node receives the image information, the transmission capacity can be reduced as compared with the case where the same content of image information is transmitted through each ATM connection, and the image information is transmitted to a node close to the subscriber. , Which simplifies the number and procedure of control information transmitted and received by the subscriber to the system to receive the provision of image information. 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 performed in this unit. It is possible to perform quality control and to provide each subscriber with image information of equal quality without variation in image quality for each subscriber.

<Embodiment 3> An embodiment of a 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 type of broadcast that is broadcast from the image information providing node at a certain time and pays a fee each time a subscriber views the program once. More specifically, the subscriber makes a request to the image information providing node to watch the TV channel of the PPV service before starting the program, waits for the program to start, and watches the program when the PPV program starts. , PPV program may be of a type in which the user is charged for watching the PPV program for a predetermined time or more, or a type in which the user is charged based on the viewing time.

(1) PPV Service 1 An embodiment (signal flow) in which the image information providing node A (1a) provides the PPV service to the subscribers A (5a) and B (5b) is shown in FIG. This will be described with reference to FIG. This is because the subscriber A (5a) and the subscriber B (5b) can use the control pad 58 shown in FIG.
requesting the PPV service to the image information providing node 1a
Sends a program corresponding to the request to the subscriber. (A) The image information providing node 1a, when the control device 17 identifies from the control signal received from the subscriber side that the request is a PPV service request, the PPV virtual path VP
(8a) is set point-to-point from the image information providing node A (1a) to the image information distribution node 3, and a virtual path from the image information distribution node 3 to the subscriber accommodation node A (4a) in a point-to-multipoint manner. VP (8a) is set, and a virtual channel VC (7a) corresponding to the PPV television channel is set in VP (8a). That is, similar to 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 subscribers A (5a) and B (5
b) requests a virtual channel VC (7a) and a subscriber A (5a) and a subscriber B (5) when the PPV service is requested.
b) is set, and a PPV program is provided. Other P
The PPV program is not transmitted to the subscriber C (5c) or the subscriber D (5d) who has not requested the PV service.
This control is performed in accordance with a request from the subscriber in the cell filter corresponding to the subscriber of the subscriber accommodation node A (4a).
It is determined by whether to set a VPI / VCI value for providing a V program, and is the same as the general broadcast service shown in the previous embodiment. 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 cell is distributed from the image information distribution node 3 to all the subscriber accommodation nodes belonging to the image information distribution node 3, the ATM cell is transmitted from the image information providing node A (1a) to the image information distribution node 3. The transmission path can be saved.

(2) PPV Service 2 FIG. 12 shows the PPV service provided by the image information distribution system of the present invention.
It is an operation | movement sequence diagram which shows the Example of a PV service,
This shows an operation in a case where the subscriber A (5a) selects the PPV television channel γ, waits for the start of the program, and watches the television channel γ until the end of the program. (A) The subscriber A (5a) turns on the power of the subscriber terminal (300), and uses the control pad 58 shown in FIG.
Upon selecting the V service (301), the subscriber terminal requests the subscriber accommodating node A (4a) to set up an ATM connection for PPV (302). Then, the subscriber accommodating 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 sends an image information providing node A (1a) to PPV. Request the setting of the ATM connection (30)
4). As a result, the image information providing node A (1a)
Start setting of ATM connection for PV (305)
Then, an ATM connection for PPV is established in the image information distribution node 3 (306). Thereafter, the image information distribution node 3 sends the PPV AT to the subscriber accommodation node A (4a).
An M connection is established (307). The control device 45 of the subscriber accommodation node A (4a)
In the VPI / VCI table 64 in 3a to 43b, the PP
The VPI / VCI value of the ATM cell carrying the image information for V is set (308). By 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 accommodating node A (4a) requests the image information distribution node 3 to display a PPV menu (310). In this embodiment, the image information distribution node 3
Since the PPV service has not yet been received, a menu display is requested to the image information providing node A (1a) (31).
1). In the image information providing node A (1a), the PPV menu display is activated (312), and the PPV menu 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)
From the displayed PPV menu, a television 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, the subscriber accommodation node A (4a) sends a selection request for the television channel γ to the image information distribution node 3 (317). Sends a request to select the television channel γ to the image information providing node A (1a) (318).

(C) The image information providing node A (1a)
A CLAD 14a for converting image information into ATM cells in an image information memory 13a storing image information of a television channel γ.
Alternatively, 14b is connected (319). As described in the first embodiment, the image can be sent directly from the image information storage device to the CLAD without going through the image information memory 13a. Then, the control device 17 transmits a screen (for example, a time until the start of program transmission) until the start of the program 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 on 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 on the television channel γ (328). When the transmission of the television channel γ ends, the image information providing node A (1a) displays the end of the television channel γ (329). This is PPV
(330), and the subscriber is notified of the PPV service charge and the like in addition to the end display (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 a PPV service provided by the image information distribution system of the present invention.
FIG. 13 is an operation sequence diagram showing another embodiment of the PV service, in which when a subscriber B (5b) requests a PPV service, another subscriber A (5a) has already requested the PPV service and the subscriber is accommodated. The node A (4a) has a PPV
Operation when an ATM cell carrying a television channel γ is received. In the figure, a sequence 400 is performed when another subscriber has already requested the television channel γ in the PPV service and an ATM cell for PPV is received at the subscriber accommodation node, for example, in the above-described embodiment, The steps up to (c) are completed,
The terminal of the subscriber A (5a) is in a state of waiting for the start of the program (the state of 321 to 324 in FIG. 12).

(A) In this state, the subscriber B (5b)
The power switch of the subscriber terminal is turned on (401), and the PPV service is selected by the control pad 58 (402).
And the subscriber terminal sends the PP to the subscriber accommodation node A (4a).
A request is made for an ATM connection setting for V (403).
In the subscriber accommodating node A (4a), the PPV is already provided between the image information providing node 1 and the subscriber accommodating node A (4a).
Subscriber B because the ATM connection for
Only the VPI / VCI for PPV is set in the VPI / VCI table of the cell filter for (5b) (40).
4) An ATM connection for PPV is set so that the ATM cell for PPV can be transmitted to the subscriber terminal of the subscriber B (5b) (405).

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

(C) Since the subscriber accommodation node A (4a) has already received the program of the television channel γ in the sequence 400, the subscriber accommodation node A (4a) that has received the selection request from the subscriber B (5b) (4a) is the subscriber A (5a)
A screen (for example, the time until the start of program transmission) until the start of the program on the television channel γ is set to the subscriber B (5b)
(413). At the subscriber's house, this is displayed on the monitor 57 (414).

(D) At the start time of the television channel γ, the image information providing node A (1a) starts transmitting a program on the television channel γ (415). The image information is also transmitted to the subscriber B (5b) through the PPV ATM connection established in the above sequence (41).
6). The subscriber B (5b) watches this on the monitor 57 (417). When the program of the television channel γ ends, the image information providing node A (1a) starts sending a γ transmission end display (418). This information is stored in the A
Sent over the TM connection (419), subscriber B
(5b) The monitor 57 receives the end of the program on the television channel γ of the PPV and the display of the fee on the monitor 57 (420). Then, as in the previous embodiment, 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 the PPV
The service ends (422 to 425).

(4) PPV Service 4 FIG. 14 shows a PPV service provided by the image information distribution system of the present invention.
FIG. 13 is an operation sequence diagram showing another embodiment of the PV service, in which a subscriber A (5a) selects a PPV television channel γ, waits for the start of the program, and watches the television channel γ, and is waiting for a program. 9 shows an operation when another image information distribution service is received. (A) When the subscriber A (5a) turns on the power switch of the subscriber terminal (300) and selects the PPV service with the control pad 58 (301), the subscriber terminal becomes the subscriber accommodation node A (4a). Request for setting up an ATM connection for PPV (302). Then, the subscriber accommodating node A (4a) sends the PPV A to the image information distribution node 3.
A request for setting a TM connection is made (303). In this embodiment, at this point, since no subscriber has requested the PPV service, 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 sets the image information providing node A (1).
From a), an ATM connection for PPV is established to the image information distribution node 3 (306). Subsequently, the image information distribution node 3 sets the VPI and the VCI, and sends the PPV A to the subscriber accommodation node A (4a) from the image information distribution node 3.
A TM connection is established (307). The subscriber accommodating node A (4a) sets the VPI / VCI value in the VPI / VCI table 64 of the cell filter for the subscriber A (5a) so as to pass the ATM cell for PPV (30).
8). Thus, 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 accommodating 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
Since the PPV service has not been received, the image information providing node A (1a) requests the menu display of the PPV (311). The image information providing node A (1a)
Is started (312), and the menu of the PPV is transmitted through the ATM connection established in the above sequence (313). The monitor 57 at the subscriber's house receives the message and displays the PPV menu (31).
4). In this embodiment, when the subscriber sees the displayed menu and selects the program of the television channel γ by using the control pad 58 (315), the subscriber terminal receives the request and sends a request to transmit 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.
Of the television channel γ is requested (317). Further, the image information distribution node 3 includes an image information providing node A
A request is made to (1a) for transmission of the PPV television channel γ (318).

(C) The image information providing node A (1a)
A CLAD 14a for converting image information into ATM cells in an image information memory 13a storing a program of a television channel γ.
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 11a without using the image information memory 13a.
b can also be sent directly to the CLAD. The control device 17 transmits information indicating the transmission start time of the program on the television channel γ through the PPV ATM connection (320), and transmits the information to the subscriber A (5a) through the already established ATM connection (321). The subscriber A (5a) having received the information knows the start time of the program on the television channel γ of the PPV on the monitor (322).

(D) In this state, the subscriber A (5a)
When the user selects the television channel α (701) in order to view the program of the general broadcast television channel α until the start time of the PPV television channel γ, the subscriber accommodation node A (4)
In a), the VPI / VCI value for the television channel γ of the PPV set in the cell filter is temporarily released (cell filter is temporarily released), and 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 the general broadcast is set in the VPI / VCI table of the cell filter (704). In this embodiment, since the subscriber accommodation node A (4a) has already received the general broadcast television channel α, a connection for the television channel α is immediately established (70).
5). The television channel α is transmitted 706 through the ATM connection. If the subscriber accommodating node A (4
If a) does not receive the general broadcast television channel α, the general broadcast television channel α is received in the procedure described in the second embodiment.

(E) At the start time of the TV channel γ of the PPV, an interruption from the timer occurs, which triggers the VP of the ATM cell carrying the TV channel γ of the PPV.
The I / VCI value is set in the cell filter (707).
Then, an interruption display for starting the transmission of the television channel γ is transmitted from the subscriber accommodating node A (4a) to the subscriber terminal (708), and displayed on the monitor 57 of the subscriber terminal of the subscriber A (709). Thereafter, transmission of the PPV television channel γ is started (326). The subsequent operation (end operation and the like) is the same as 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 low waiting time, as in general broadcast services, and furthermore, there is no variation in image quality among subscribers, A quality and economical image providing service can be realized. In addition, since another image providing service can be easily received during the waiting time of the PPV service, a user-friendly image providing service can be realized.

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

(1) VOD Service 1 FIG. 1 shows an embodiment (signal flow) in which the image information providing node B (1b) provides a VOD service to the subscribers G (5g) and H (5h). This will be described with reference to FIG. This is because the subscriber G (5g) and the subscriber H (5h) can use the control pad 58 shown in FIG.
(1b) requests the VOD service, 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)
Identifies a request for a VOD service from the control signal received from the subscriber side, establishes a virtual path VP (8c) for VOD, and establishes a subscriber G 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, the ATM connection from the image information providing node to the subscriber is established in the same manner as the other image information providing services shown in the above embodiment. However, in the VOD service, the above-described various screen control requests are made for the image information provided by the subscriber, so that some virtual channels VC are established for the subscriber.
Next, the image information providing node B (1b) searches for image information requested by each subscriber, and stores the image information storage devices 11a to 11a-1.
1b to image information memory 13a corresponding to virtual channel VC
-13b, subscriber G (5g) and subscriber H
The image information requested by (5h) is copied at high speed by a HIPPI interface or the like, and the
Release b. As described above, when providing the VOD service, the image information is stored in the image information memory 1 corresponding to the virtual channel.
3a to 13b, when a certain subscriber is viewing certain image information with the VOD service and another subscriber requests the image information, the subscriber who is currently viewing the image information is requested. There is no need to wait until the user ends the VOD service. Of course, the image information storage devices 11a to 11
If another subscriber requests the image information while copying the image information from b to the image information memories 13a to 13b, the other subscribers have to wait during the copying. 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-described embodiment, the setting of the cell filter corresponding to the subscriber is performed. 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 transmitted to other subscribers accommodated in the subscriber accommodation node. This image information is broadcast from the image information distribution node 3 to another subscriber accommodation node A (4a) via the image information distribution network 6, but is transmitted to the other subscriber accommodation node A (4a).
Even in a), since the cell filter operates, the image information of the VOD service is not sent to the accommodated subscriber.

(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-11b is stored in image information memories 13a-13.
b, and provide the information of this memory.
When the subscriber G (5g) or the subscriber H (5h) operates the control pad 58 shown in FIG. 7 to control the reading of the memory and the like, the image is provided interactively with the system via the network. "Pause" the information,
Screen control such as "restart", "rewind", and "fast forward" can be performed. This provides the same function for the screen provided by the VOD service so that if the subscriber operates an image information device such as a video tape recorder installed in the house, the desired screen can be repeated or viewed quickly. Is what you 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), upon receiving the control signal indicating the end, disconnects the ATM connection to the subscriber similarly to other image providing services, and furthermore, the image information memories 13a to 13b.
Release b. In the present embodiment, the configuration in which the memory is provided in the image information providing node is shown. 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 and 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-described control.

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

(2) VOD Service 2 FIG. 13 shows the VOD service provided by the image information distribution system of the present invention.
FIG. 11 is an operation sequence diagram showing an embodiment of an OD service, in which a subscriber G (5g) selects a VOD television channel β and then transfers and copies the image information β to an image information memory in an image information providing node B (1b). By operating the image information memory while watching, the transmission of the image information β is “stopped”, then the transmission of the image information β is “resumed”, and finally the service is terminated. Things.
In this embodiment, no one except the subscriber G (5 g) receives a VO.
It is assumed that 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 subscriber terminal selects the VOD service by using (501), the subscriber accommodation node B (1b) sends the AOD for VOD to the subscriber accommodation node B (1b).
A request for setting a TM connection is made (502). Then, the subscriber accommodating 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 (503). ) Is requested to set an ATM connection 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) starts.
A VP for VOD is established between the image information distribution node 3 and b) (506). Thereafter, 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) starts VC setting for VOD (508),
After establishing (509) a VC for VOD between the image information providing node B (1b) and the image information distribution node 3, a VC for VOD is established between the image information distribution node 3 and the subscriber accommodation node B (4b). (510). The control device 45 of the subscriber accommodating node B (4b) includes the cell filters 43a to 43g for the subscriber G (5g).
The VPI / VCI value of the ATM cell carrying the VOD image information is set in the VPI / VCI table 64 in 3b (511). Through the above procedure, an ATM connection for VOD is established.

(B) The image information providing node B (1b)
The VOD menu transmission is started (512), and the established A
Menu G for subscriber G (5g) through TM connection
(513), the monitor 57 at the subscriber's house
A menu is displayed (514). Subscriber G (5g)
Uses this menu to set the VOD TV channel β
Is selected with the control pad 58 shown in FIG.
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) searches the image information storage devices 11a to 11b for image information β of the program selected by the subscriber (517) and sends out the image information β to the image information memory 13a (518). The image information storage devices 11a to 11a
When the transmission of the image information β is completed from b to the image information memory 13a, the display of the completion of transmission preparation of the VOD image information β is activated (519), and the transmission preparation completion display of the VOD image information β is transmitted through the ATM connection for VOD. Subscriber G (5
By transmitting to the subscriber terminal of g) (520), completion of preparation for transmitting 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 subscriber terminal transmits the image information providing node B (1b). (523 to 524). In response to this, reproduction of the image information β is started (525), and the image information providing node B (1b) sends the image information β to the subscriber G (5g) (526). That is, the subscriber G
The image information β of the VOD service can be viewed on the monitor 57 of (5g) (527).

(D) While viewing the image information β, the subscriber G (5g) issues an image stop command from the control pad 58 to request the stop of the image information β being provided (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 transmitted 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 the frame number is continuously transmitted (53).
1 to 532), the monitor 57 of the subscriber G (5 g)
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 (5g) 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 contains 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) receiving the control signal starts reproducing the image information β again (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 termination of the VOD service (539), a VOD service termination request is sent from the subscriber terminal of the subscriber G (5g) (540), and this is subscribed. Is transmitted from the person accommodation node B (4b) to the image information distribution node 3 and the image information providing node B (1b) (541, 542). Upon 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 activates the subscriber G through the ATM connection.
(5g) (545). The monitor 57 of the subscriber G (5g) displays the fee of this VOD service (5
46). Thereafter, the VOD ATM connection (VP / VC) 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 (5 g).
D service end is displayed (551). This is VOD
The service ends.

In the above-described embodiment, the frame number is used as the control parameter of the image information. However, as an alternative to the frame number for specifying the image information frame, the address of the image information memory, the image The same control is possible by using the time stamp information in the ATM cell including the information. Even if the control signal of the image from the subscriber arrives at the control device with a delay due to the delay in the network, the control is performed by this parameter. The user can search for the desired screen and provide it (for example, since the image transmitted from the memory when the control signal arrives is advanced, the control device performs control such as slightly returning to the requested screen). It is possible to realize an easy-to-use VOD service in which an operation that can be viewed when a desired screen is viewed is simple. Further, in the present embodiment, the VOD service capable of controlling the screen has been described by taking stop and playback as an example. However, the control such as “fast forward” and “rewind” as described above may also be performed by the subscriber. By controlling the image memory with the control parameters of the image information in response to the command request, the same sequence can be realized, and the user-friendly VOD with excellent human interface capable of controlling the screen corresponding to the subscriber's request. Service, ie
Dedicated equipment (VTR, etc.) as if the subscriber were at home
, An image providing service having the same function as that of obtaining image information by operating is also realized by a system via a network. As in the first to third embodiments, transmission and reception of control information between the subscriber and the system are performed by an individual line or a common line,
Alternatively, the function of the present invention can be achieved by using any one of the ATM connections for carrying image information.

<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 described in the above embodiments. For example, a program reservation function can be provided to a subscriber by controlling a cell filter in the subscriber accommodation node with time, and the operation thereof will be described below. The subscriber enters the subscriber accommodation node A from the subscriber terminal.
(4a) or the subscriber accommodating node B (4b) requests a viewing request of a program to be viewed (programs such as the aforementioned general broadcast service, PPV service, VOD service, etc.) from the control pad 58 before the start of the program ( make a reservation. The control device 45 in the subscriber accommodation nodes 4a to 4b
The subscriber stores the reserved program and its start time, activates a timer until the program start time, and recognizes the program start time by the timer. The ATM connection is set, for example, the VCI value is set in the VPI / VCI table 64 in the cell filter. At this time, the control device 45 in the subscriber accommodating node also sends out a control signal for turning on the power of the device in the subscriber's home, and turns on the subscriber terminal and the monitor in the subscriber's home. By this procedure, at the time reserved by the subscriber, the device in the subscriber's home is automatically turned on, and the program reserved by the subscriber is transmitted.
Then, at the time when the program ends, a control signal for turning off the power of the subscriber terminal and the monitor in the subscriber's house is transmitted, and then the setting of the cell filter is released. The sequence of the television channel setting is the same as in the above-described embodiment. By providing the power-on / off procedure, the system can forcibly turn on the power supply of the device at the subscriber's home and broadcast an emergency broadcast even in the event of a disaster, for example, even if the subscriber does not reserve a program.

[0064]

As described above, according to the image information distribution system of the present invention, it is possible to realize an easy-to-use system with a simple configuration, high-speed response with little waiting time. More specifically, (1) between the image information providing node and the image information distribution node, a VP to be distributed to a plurality of subscriber accommodation nodes is set by one VP, so that resources in the network can be saved. (2) Since a VP is assigned for each image service type, the sequence of VP and VC setting for each image service can be simplified. (3) When image information is always transmitted to a node close to the subscriber, an image can be transmitted to the subscriber in a short procedure and response time by a procedure for transmitting image information by negotiation between the node and the subscriber. .
(4) An almost constant image information quality can be provided for each image service, and image quality management can be simplified for each service.

[Brief description of the drawings]

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

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

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

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

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

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

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

FIG. 8 is a block diagram showing the configuration 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 node, 11a, 11b
... Image information storage device, 12a, 12b ... Selector,
13a, 13b ... image information memory, 14a,
14b: CLAD, 15: Multiplexer,
16 ... line termination device 17 ... control device 2 ... relay node 3 ...
Image information distribution nodes, 31, 33a, 33b: line termination device, 32: ATM demultiplexer, 34: controller, 35: optical splitter, 4
a, 4b ... subscriber accommodation nodes, 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, 5
7 monitor, 58 control pad 6 image information distribution network 61 delay unit 62 empty cell generator 63
VPI / VCI detector, 64: VPI / VCI setting table, 65: comparator, 66: selector,
67 ... bus connected to the control device 45, 6
8, 69 ... signal highway, 8a ... PPV
Virtual path, 8b... General broadcast virtual path,
8c... VOD virtual path, 7a, 7b, 7c, 7d,
7e: Virtual channel established in each virtual path.

Claims (3)

(57) [Claims] An image information distribution system for distributing and providing image information to subscribers of the communication network in a communication network including a transmission path 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 accommodation nodes accommodating a terminal of the subscriber receiving the image information, the image information providing node and the subscriber accommodation node And an image information distribution node for distributing image information received from the image information providing node to the subscriber accommodation node, and between the image information providing node and the image information distributing node. Setting a first virtual path and a virtual channel in the asynchronous transfer mode corresponding to the type of image information providing service provided to the subscriber and the image information provided by the service in the transmission path by point-to-point connection; Transferring image information requested by a subscriber, and providing image information to the subscriber between the image information distribution node and the plurality of subscriber accommodation nodes. A second virtual path and a virtual channel in the asynchronous transfer mode corresponding to the type of service and the image information provided by the service, respectively, are set in the transmission path by a point-multipoint connection and transferred to the image information distribution node. The distributed image information is distributed to all the subscriber accommodation nodes, and further, each of the plurality of subscriber accommodation nodes has a virtual path and a virtual path including the 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. The image information providing node and the image information distribution node when respective subscribers accommodated in the plurality of subscriber accommodation nodes connected to the image information distribution node request the same image information. And setting one virtual path and virtual channel corresponding to the requested image information to transfer the image information requested by the subscriber, wherein the image information distribution node is connected to the image information distribution node. has been image information distributed forwarded to all of the plurality of subscriber accommodation nodes, their respective in <br/> of the plurality of subscriber accommodation node, requests the reception of the image information transferred by said filter device 2. The image information distribution system according to claim 1, wherein the image information is transferred only to the terminal of the subscriber who has made the request. 3. The image information distribution system sets a virtual path in an asynchronous transfer mode on the transmission path in accordance with a type of image providing service provided by the image information providing node, and further provides with the service. A virtual channel is set in the virtual path corresponding to the program or image information to be transmitted, 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.