JP2002232476A - Communication system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a communication system that can realize an IP multicast communication that extends an application range of itself and applies a broadband communication channel to distribution of outgoing data. SOLUTION: When a broadband communication channel is need for outgoing data, a 2-way data communication channel (incoming direction) of a conventional access network is used for an incoming signal, the broadband outgoing data distribution channel newly added is used for the outgoing signal, a reception request or a reception stop request from a subscriber terminal sent to the 2-way data communication channel is identified and the reception request or the reception stop request is routed to a data distribution means that distributes data to the outgoing data distribution channel so as to conduct 2-way IP multi-cast communication.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention is used for point-to-multipoint communication in IP communication (called IP multicast communication). In particular, it relates to a technology for extending a transmission band.

[0002]

2. Description of the Related Art In the field of IP communication, an IP multicast communication technique has been developed as a system for performing multicast distribution of data in response to a request from a subscriber terminal device.

FIG. 3 shows the operation of the IP multicast communication. When the subscriber terminal device receives the data, the subscriber terminal device 1-11 that desires to receive the data receives an IGMP (Internet Group Management Protocol) of the subscriber terminal device 1-11.
A reception request 1-42 is sent to the routing device 1-12 of the IP layer which is the terminal point of the (rotocol). The routing device 1-12 responds to the request and outputs the data 1-4.
3 transmission is started.

[0004] IGMP is a protocol for defining one group composed of a plurality of subscriber terminal devices and controlling information transfer on the Internet in units of this group.

[0005] Similarly, the operation for stopping data reception is similarly performed by the subscriber terminal device 1-21 which desires the stop operation.
Is a reception stop request 1 to the routing device 1-22.
-44, and the routing device 1-22 performs data 1-
45 transmission is stopped.

In FIG. 3, for the sake of simplicity, the subscriber terminal 1-11 transmits a reception request 1-42 to perform data reception, and the subscriber terminal 1-21 receives a reception stop request 1-42. The situation in which data reception is stopped by transmitting 44 will be described. However, any of the subscriber terminal devices 1-11 and 1-21 can transmit a reception request and a reception stop request, respectively.

On the other hand, in a PON (Passive Optical Network) system for economically realizing an optical access network, a subscriber direction for broadcast-type video distribution or the like (hereinafter, referred to as a downward direction, and the opposite direction is referred to as an upward direction). In the case of providing a broadband application that requires a broadband transmission band, multiplexing a downlink data distribution line by wavelength multiplexing is excellent in terms of service expandability. Further, even when the bandwidth used by the bidirectional data communication line is insufficient, broadband applications can be provided by wavelength multiplexing.

FIG. 4 shows a configuration for providing a broadband application in the PON system. In FIG. 4, λ1 is the PON system upstream signal wavelength, and λ2 is P
The ON system downstream signal wavelength, and λ3 is an extension wavelength (downstream data distribution line) of the PON system. A dashed two-way arrow is a two-way data communication between the subscriber terminal device 2-11 and the other communication network 10, and a dashed-dot two-way arrow is a two-way arrow between the subscriber terminal device 2-12 and the other communication network 10. , And the dashed left arrow indicates downlink data distribution.

The PON communication system includes ONU (O
ptical Network Unit) 2-41 and 2-42, optical wavelength demultiplexers 2-51 and 2-52, optical splitter, bidirectional data communication line 2-31, downlink data distribution line 2-32, OLT (OpticalLine) Terminal) 2-43,
An optical wavelength conversion device 2-53 and a data distribution device 2-21 are included.

[0010] Subscriber terminals 2-11 and 2-12
Performs two-way communication with another communication network 10 such as the Internet via the two-way data communication line 2-31. Further, the subscriber terminal devices 2-11 and 2-12 receive the data distribution from the data distribution device 2-21 via the downlink data distribution line 2-32.

Similarly, even when n subscriber terminal devices are provided, any of the subscriber terminal devices can have the same function.

[0012]

Conventional IP multicast communication is performed using a bidirectional data communication line as shown in FIG. Therefore, even if an attempt is made to realize IP multicast communication using an independent broadband downlink data distribution line as shown in FIG. 4, a reception request or a reception stop request from the subscriber terminal device is transmitted to the data distribution source. It is difficult to realize because it is not possible.

Therefore, as in the example of the PON system shown in FIG. 4, an efficient communication system capable of providing a broadband application by wavelength division multiplexing is described above.
P multicast communication cannot be applied and IP
The application range of multicast communication has been narrowed.

SUMMARY OF THE INVENTION The present invention has been made in view of such a background, and an object of the present invention is to expand a range to which IP multicast communication can be applied, to broaden a downlink data distribution line, and to realize IP multicast communication. It is an object of the present invention to provide a communication system that can perform the communication.

[0015]

According to the present invention, a downlink data distribution line independent of a bidirectional data communication line is provided to secure a downlink broadband communication line. IP multicast procedure
This implements multicast communication.

That is, in the conventional IP multicast communication, data transmission / reception is performed using a bidirectional data communication line of an access network. Therefore, IP multicast communication could not be performed by an independent downlink data distribution line.

In the present invention, when a broadband communication line is required in the downstream direction, a bidirectional data communication line (upstream direction) of the conventional access network is used for the upstream signal, and a new signal is newly added to the downstream signal. Data for identifying a reception request or a reception stop request from the subscriber terminal transmitted to the two-way data communication line and transmitting the data to the down-link data distribution line using the wideband downlink data distribution line. By routing these reception requests or reception stop requests to the distribution means, bidirectional IP multicast communication is performed.

[0018] Thus, the use band limitation caused by the access network according to the prior art is released, and it is possible to cope with a broadband application, and the transmission band can be effectively used by applying the IP multicast technology. .

That is, the present invention provides a bidirectional data communication line installed between a subscriber terminal device and another communication network, a downlink data distribution line, and the data distribution line. And a data distribution unit that distributes data to a user terminal device.

Here, it is a feature of the present invention that the data distribution means performs data distribution or data distribution to the subscriber terminal device according to a data distribution request or a data distribution stop request coming from the subscriber terminal device. Means for performing a stop, a means for identifying a data distribution request and a data distribution stop request to the data distribution means from data arriving from the subscriber terminal device via the data communication line, and the identification means Means for routing the data to the data distribution means when the data distribution request or the data distribution stop request arrives according to the identification result of the above.

[0021]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described with reference to FIG. FIG. 1 is a diagram showing the principle of a multicast communication system according to the present invention. The one-dot chain line bidirectional arrow is bidirectional data, the dashed rightward arrow is a data reception request signal,
The dashed left arrow is downlink broadband data.

The present invention provides a bidirectional data communication line 3-51 installed between the subscriber terminal device 3-11 and the other communication network 10, a downlink data distribution line 3-52,
The subscriber terminal device 3 is connected by the data distribution line 3-52.
This is a communication system provided with a data distribution device 3-21 that distributes data to -11.

Here, the feature of the present invention is that the data distribution device 3-21 responds to the data distribution request or the data distribution stop request coming from the subscriber terminal device 3-11. 11 to the data distribution device 3-21 from among data arriving from the subscriber terminal device 3-11 via the two-way data communication line 3-51 and data distribution. Routing function blocks 3-31 and 3-41 for identifying a stop request are provided. The routing function blocks 3-31 and 3-41 receive the data distribution request or the data distribution stop request according to the identification result. Is to route this data to the data distribution device 3-21.

Hereinafter, embodiments of the present invention will be described in more detail.

(First Embodiment) A first embodiment of the present invention will be described with reference to FIG. The communication system of the first embodiment is an IGM
Subscriber terminal device 3-11, data distribution device 3-21, bidirectional data communication line 3-51, downlink data distribution line 3-52 corresponding to P, routing function block 3 located on the subscriber side -31, a routing function block 3-41 on the data distribution device side.

The operation in which the subscriber terminal device 3-11 receives data will be described. The subscriber terminal device 3-11 transmits an IGMP data reception request to the data distribution device 3-21. This data reception request is sent to the bidirectional data communication line 3-5 via the routing function block 3-31.
1 is transferred in the upstream direction, and the routing function block 3
Arrive at -41. At this time, the routing function block 3-31 recognizes that the subscriber terminal device 3-11 has transmitted the IGMP data reception request. The routing function block 3-41 includes a bidirectional data communication line 3
A data reception request is identified from other signals transmitted through -51, and is transmitted to the data distribution device 3-21. The data distribution device 3-21 distributes data according to the data reception request.

The data is sent to the downstream data distribution line 3-
52 and arrives at the subscriber's routing function block 3-31. The routing function block 3-31 transfers the data to the subscriber terminal device 3-11 that has made the IGMP data reception request. Thereby, the subscriber terminal device 3-11 receives the data. Here, IP multicast communication using two communication lines is realized.

When the subscriber terminal device 3-11 transmits a data reception request to the routing function block 3-31, and when the data distribution device 3-21 is already distributing data, the routing function block 3-31. Is
Without transferring the data reception request to the data distribution device 3-21, the data already being distributed can be transferred to the subscriber terminal device 3-
To 11

Next, the operation in which the subscriber terminal device 3-11 stops receiving data will be described. Subscriber terminal device 3-11
The IGMP data transmission stop request is transmitted to the data distribution device 3-21. This data reception stop request arrives at the routing function block 3-31. The routing function block 3-31 stops the transfer of the data to the subscriber terminal device 3-11 according to the data reception stop request. That is, the data reception stop request transmitted by the subscriber terminal device 3-11 does not actually arrive at the data distribution device 3-21, and the routing function block 3-31 transmits the data from the data distribution device 3-21. Unsubscribe from. The data distribution device 3-21 naturally stops the data distribution unless the data distribution is completed and a new data reception request does not arrive.

In this example, the subscriber terminal device 3-11 and the routing function block 3-31 on the subscriber side are shown independently, but the subscriber terminal device 3-11 '(dotted line in the figure) and the access network It operates even if it is deployed in the device that constitutes the.

Although the routing function block 3-41 on the data distribution device side is shown independently, this access from a device constituting an access network including the bidirectional data communication line 3-51 and the data distribution device 3-21. It operates even if it is installed in a device constituting a transmission section to the network.

[0032] For convenience of explanation, one data distribution apparatus is described, but the apparatus operates even when a plurality of data distribution apparatuses are installed. Further, the present invention can be operated by a data distribution device connected to the present system via another network.

(Second Embodiment) A second embodiment of the present invention will be described with reference to FIG. FIG. 2 shows the communication system of the present invention
It is a figure for explaining the example applied to the N system. In FIG. 2, λ1 is a PON system upstream signal wavelength (upstream access network), λ2 is a PON system downstream signal wavelength (downstream access network), and λ3 is a PON system extended wavelength (downstream data distribution line). The right arrow of the dashed line is a data reception request signal of the subscriber terminal device 4-11, the two-way arrow of the dashed line is two-way data of the subscriber terminal device 4-11, and the right arrow of the dashed line is the subscription. Is a data reception stop request signal of the user terminal device 4-12, and the left arrow of the broken line is downlink broadband data.

As shown in FIG. 2, the communication system according to the second embodiment comprises ONUs 4-61, 4 comprising a PON system.
-62, OLT 4-63, optical splitter, IGMP-compatible subscriber terminal devices 4-11, 4-12, data distribution device 4-21, routing function blocks 4-31, 4-32 located on the subscriber side , A routing function block 4-41 on the data distribution device side, a bidirectional data communication line 4-51, and a downlink data distribution line 4-52.

The operation in which the subscriber terminal device 4-11 receives data will be described. The subscriber terminal device 4-11 transmits an IGMP data reception request to the data distribution device 4-21. The data reception request is transferred via the routing function block 4-31 to the upstream signal wavelength of the PON system which is the uplink access network of the bidirectional data communication line 4-51, and arrives at the routing function block 4-41. At this time, the routing function block 4-31
Recognizes that the subscriber terminal device 4-11 has made a data reception request by IGMP. The routing function block 4-41 identifies a data reception request from other signals transferred on the uplink access network of the bidirectional data communication line 4-51, and transfers this to the data distribution device 4-21. The data distribution device 4-21 distributes data according to the data reception request. The data is converted into an extended wavelength band of light that is not used in the PON system, which is a downstream data distribution line, and the downstream data distribution line 4-
WDM (Wa)
and distributed by one optical fiber.

The distributed optical signal is separated for each wavelength of light and arrives at the subscriber's routing function block 4-31. The routing function block 4-31 is an IGM
This data is transferred to the subscriber terminal device 4-11 which has issued the data reception request of P. Thereby, the subscriber terminal device 4
-11 receives data. Here, IP multicast communication using two communication lines is realized.

When the subscriber terminal device 4-11 transmits a data reception request to the routing function block 4-31, and when the data distribution device 4-21 is already distributing data, the routing function block 4-31. Is
Without transferring the data reception request to the data distribution device 4-21, the data already distributed is transmitted to the subscriber terminal device 4-21.
To 11

Next, the operation in which the subscriber terminal device 4-12 stops receiving data will be described. Subscriber terminal device 4-12
The IGMP data transmission stop request is transmitted to the data distribution device 4-21. This data reception stop request arrives at the routing function block 4-32. The routing function block 4-32 stops the transfer of the data to the subscriber terminal 4-12 according to the data reception stop request. That is, the data reception stop request transmitted by the subscriber terminal device 4-12 does not actually arrive at the data distribution device 4-21, and the routing function block 4-32 transmits the data from the data distribution device 4-21. Unsubscribe from. The data distribution device 4-21 naturally stops the data distribution unless the data distribution is completed and a new data reception request does not arrive.

In this embodiment, the subscriber terminal device 4-11 and the subscriber-side routing function block 4-31, and the subscriber terminal device 4-12 and the subscriber-side routing function block 4-32 are independently represented. Operates even if it is installed in an apparatus constituting an access network such as subscriber terminal devices 4-11 'and 4-12' (dotted lines in the figure) and ONUs.

Although the routing function block 4-41 on the side of the data distribution device is shown independently, the devices constituting the access network and the data distribution device 4-21 are separately shown.
It operates even if it is installed in a device that constitutes a transmission section from the network to the access network.

In FIG. 2, in order to make the explanation easy to understand, the subscriber terminal device 4-11 transmits a data reception request to perform data reception, and the subscriber terminal device 4-12 transmits a data reception stop request. The situation in which data reception is stopped will be described.
12, a data reception request and a data reception stop request can be transmitted. Similarly, even when n subscriber terminal devices are installed, n subscriber terminal devices can transmit a data reception request and a data reception stop request, respectively.

Note that, for convenience of explanation, the case where one data distribution device is used has been described, but the device operates even when a plurality of data distribution devices are installed. Further, the present invention can be operated by a data distribution device connected to the present system via another network.

[0043]

As described above, according to the present invention,
It is possible to provide a communication system capable of expanding the range to which the IP multicast communication can be applied, broadening the bandwidth of the downlink data distribution line, and realizing the IP multicast communication.

[Brief description of the drawings]

FIG. 1 is a principle diagram of a communication system according to the present invention.

FIG. 2 is a diagram for explaining an embodiment in which the communication system of the present invention is applied to a PON system.

FIG. 3 is a diagram showing an operation of IP multicast.

FIG. 4 is a diagram for explaining a PON method.

[Explanation of symbols]

1-11, 1-21, 2-11, 2-12, 3-11,
4-11, 4-12, 3-11 ', 4-11', 4-1
2 'subscriber terminal device 1-12, 1-22, 1-32 routing device 1-31, 2-21, 3-21, 4-21 data distribution device 1-42 reception request 1-43, 1-45 data 1-44 Reception stop request 1-41 Multicast data 2-51, 2-52, 4-71, 4-72 Optical wavelength demultiplexer 2-41, 2-42, 4-61, 4-62 ONU 2-43, 4-63 OLT 2-53, 4-73 Optical wavelength converter 3-31, 3-41, 4-31, 4-32, 4-41
Routing function block 2-31, 3-51, 4-51 Two-way data communication line 2-32, 3-52, 4-52 Downlink data distribution line 10 Other communication network

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 5K030 GA01 HA08 HC01 JL08 JT02 LB06 LD02 LD13 5K033 AA09 BA13 CB13 CC01 DA16 DB01 DB21

Claims (1)

[Claims] 1. A two-way data communication line installed between a subscriber terminal device and another communication network, a subscriber direction data distribution line, and the data distribution line. A data distribution unit that distributes data to the subscriber terminal device according to a data distribution request or a data distribution stop request coming from the subscriber terminal device. Means for stopping distribution, means for identifying a data distribution request and a data distribution stop request to the data distribution means from data arriving from the subscriber terminal device via the data communication line; When the data distribution request or the data distribution stop request arrives according to the identification result of the means, this data is Communication system, comprising the means for routing the data distribution means.