JPH10285176A - Data broadcast system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To execute broadcast of one direction and two directions by converting a frame from a terminal into a cell, transmitting it to a one-to-N communication path, converting the cell from the one-to-N communication path into the frame and sending the converted frame to the terminal. SOLUTION: In the case of executing broadcast to the other terminals 4b and 4c from the terminal 4a, the frame from the terminal 4a is resolved into fixed length in a frame/cell conversion part 10 and they are converted into plural cells. For transmitting the plural generated cells to the other terminals 4b and 4c, a cell multiplex communication equipment 1a previously sets the one-to-N communication path 2a. The respective cells of the path 2a are sent to a cell/frame conversion part 11 with respect to a cell multiplex communication equipment 1b through a repeating line 3a. Then, the copied cells are repeated in the direction of the cell multiplex communication equipment 1c of a post stage and the respective cells are inputted to a conversion part 11 from the communication path 2a in the communication equipment 1c of the post stage. Then, the cell is assembled and converted into the original frame and it is supplied to a frame transmission part 12.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a data broadcasting system for performing broadcasting between data terminals on the premise of a branch service of an existing dedicated digital line in a communication network having a logical multiplex relay system.

A conventional dedicated digital line service provided by a telecommunications carrier includes a service called a branch service, which provides a one-to-N one-way branch service and a two-way branch service. Since these dedicated digital line branching services can transmit a large amount of data communication to multiple sites at once, the newspapers that transmit a large amount of image data to a printing plant can be used for paper transmission, and the publishers can use this service. It is used for plate making information transmission. Users who use such a dedicated digital line branching service install and use a time-division multiplexing device. However, as a recent communication network relay system, the bandwidth between media can be effectively used, and high-speed, large-capacity devices can be used. Is being switched to a logical multiplexing relay system such as a cell relay / frame relay that can communicate with a wireless communication system. In this case, it is difficult to use a branch service of a dedicated digital line, and improvement thereof is desired.

[0003]

2. Description of the Related Art Conventionally, in a dedicated digital line service provided by a telecommunications carrier, there are a one-way branch service and a two-way branch service as services called a branch service, which will be described below with reference to the drawings.

FIG. 26 is an explanatory diagram of a one-way branch service of a dedicated digital line. In the figure, 80 is the network of the communication carrier, 81a to 81d are the communication facilities of the communication carrier,
810 is a branching unit for transmitting signals from the main station provided in the communication facilities 81b and 81c to each terminal, and 811 is a communication facility 8
1b and 81c, a logical product unit for calculating the logical product of the transmission signal from the terminal to the main station and the signal on the trunk line, 82 is a trunk line connecting the communication equipments 81a to 81d, and 820 is a downlink trunk line. , 821 are uplink trunk lines, 83a to 83d are dedicated digital lines for connecting the communication equipments 81a to 81d of the communication carrier and the terminals of the user, and 84a to 84d are the terminals of the user. In this example, 84a functions as a master station, and 84b to 84d function as slave stations.
84c is also called a branch station.

The protocol of each terminal uses the HDLC procedure (High-level Data Link Control) because the line speed is relatively high and transmission errors can be checked on the receiving side.
It is common to use the frame format of (procedure). Although the frame size is basically variable,
In many cases, the frame length, the header information in the frame (the configuration of addresses and control fields to be described later), and the like are uniquely defined between the terminals of the user using the dedicated line. H
The frame format of the DLC is a flag (0111) indicating the head.
1110 pattern), followed by an address,
Control field, information field (arbitrary bit length),
A configuration is provided in which FCS (Frame Check Sequence) and a flag indicating the end are arranged in this order. When the slave station does not transmit from its own station, each slave station continuously transmits all "1" signals (indicating an idle state).

In the one-way branch service, one master station 84
a, a plurality of slave stations 84b to 84d are connected to
Transmission signals from the master station 84a are transmitted to the communication facilities 81b and 81c.
At the branch point, the terminals 84b and 84c of the slave station and the trunk line are branched, so that signals from the master station to a plurality of slave stations can be broadcast. The transmission signal from the slave station is multiplexed by performing a logical operation in a logical product unit 811 that performs a logical product in a bit unit for each branch and is multiplexed and transmitted to the master station 84a. That is, the transmission signal of all “1” is output from the slave station that does not perform transmission, and the logical product section 811 calculates the logical product of the transmission signal from the lower slave station and the signal of all “1” from the own station. Therefore, the lower transmission signal (including “1” and “0”) is sent to the master station as it is. Also, when transmitting from the own station to the master station, if the transmission signal of the own station is all “1” in the AND section 811 and the transmission signal of the lower station is all “1”, the transmission signal of the own station is used as it is. Sent to the side.

For this reason, in the case of transmission from a slave station, a data error occurs if transmission is performed from a plurality of slave stations at the same time.
It is necessary to take measures such as shifting the transmission timing between the slave stations.

FIG. 27 is an explanatory diagram of a bidirectional branch service of a dedicated digital line. In the figure, 90 is the network of the communication carrier, 91a to 91d are the communication facilities of the communication carrier,
910, 913, 914 are branch units provided in the communication facilities 91b, 91c, 911, 912, 915 are logical product units provided in the communication facilities 91b, 91c, and 92 is a relay connecting the communication facilities 91a to 91d. 920, a downlink trunk line, 921, an uplink trunk line, 93a to 93d, dedicated digital lines for connecting the communication facilities 91a to 91d of the telecommunications carrier to the user terminals, and 94a to 94d provided by the user. In the bidirectional branch service, all connected terminals are equally positioned as master stations. In this example, terminals 94a and 94d at both ends are called terminal stations, and terminals 94b and 94c including branches are called branch stations. .

A transmission signal from one terminal station (for example, a terminal 94a) is subjected to the following three operations in a communication facility 91b accommodating the first branch station 94b. First, the branch 9
The transmission signal to the next stage branched at 10 is ANDed with the transmission signal from the own station 94b in the AND section 911 and relayed to the next branch station 94c. The reception signal input to the branch station 94b is the transmission signal from the terminal station 94a.
The AND operation of the signal branched at 10 and the signal obtained by branching the received signal relayed from the branch station 94b at the next stage by the branching unit 914 is performed at the AND unit 915, and the output is output to the branching station 9
4b. Further, the branch station 94b is connected to the terminal station 94a.
The transmission signal transmitted to the branch station 94c is divided into a signal obtained by branching the reception signal relayed from the branch station 94c at the next stage by the branching unit 914,
The logical product with the transmission signal from 4b is taken by the logical product unit 912 and transmitted to the terminal station 94a.

By performing such processing for each branch station, a transmission signal from one master station can be broadcast to all other master stations. The transmission signal of each station is shown in FIG.
As in the case of the one-way branch service, the stations are controlled so as to shift the timing from each other, and the station which does not transmit outputs an all "1" signal indicating an idle state. Input for product operation.

The dedicated digital circuit 83a shown in FIG.
To 83c and the dedicated digital circuits 93a to 93 in FIG.
In d, time-division multiplexing communication is performed. In an actual dedicated digital line branching service, a time-division multiplexing device (not shown) is installed and used at each terminal installed by a user.
The time division multiplexing device has a mechanism for synchronizing between the terminal line and the dedicated digital line.

The dedicated digital line branching service enables a large amount of data communication to be transmitted to a plurality of bases at once, so that it is used for transmitting a paper image of a newspaper company or transmitting platemaking information at a publisher. ing. Communication applications using these broadcasts are designed on the premise of the following communication method and operation in accordance with the functions of the branch service.

When using the one-way branch service,
The sender is always fixed at one terminal, and the response time of each terminal is set beforehand so that multiple terminals do not respond at the same time, and responds at the time specified by the information from the sender. Is provided. During reception, a signal of a bit string of all "1" is transmitted from the terminal to the line so as not to cause an error on the line. The signal of the bit string of all "1" s has the effect of always transmitting the same signal to the next stage by combining it with the operation of taking the logical product in bit units in the communication equipment of the communication carrier.

In the bidirectional branch service, it is possible to use a plurality of transmission sources. However, if the transmission is performed simultaneously, an error occurs in the data on the transmission line, and the reception side also receives a plurality of pieces of information separately. Therefore, it is operated so that the number of terminals transmitting simultaneously is always one. However, there is no need to control the switching of the transmission source on the branch service side at all, and it is sufficient if the transmission control is performed so that the number of transmission sources is always one between terminals on the communication application side.
For the response, the same mechanism as in the case of the one-way branch service is required. In the operation during reception, a signal of a bit string of all "1" is transmitted from the terminal to the line as in the case of the one-way branch service.

The terminal protocol uses the HDLC procedure (High-level Data Link Control protocol) because the line speed is relatively high and transmission errors can be checked on the receiving side.
(ocedure) frame format is used, but the frame size and header information in the frame are uniquely defined. Also, the original retransmission function of the HDLC procedure and RR
(Receive Ready: delivery confirmation) Whether or not to use the response confirmation method using a frame is also uniquely defined, and is not necessarily required.

In recent years, a relay system of a communication network, which has been a time-division multiplex system, has been replaced with a logical multiplex system such as a cell relay / frame relay which can more effectively utilize a band between media and can perform high-speed and large-capacity communication. Has been switched to. However, when the relay method by logical multiplexing is changed,
Unlike time-division multiplex communication equipment, signals from lines are received and transferred asynchronously, and there is no mechanism to synchronize the signals from each line. It is not possible to realize a branch broadcast using a logical product of bits.

Therefore, if there is a terminal having such a communication application, it has not been possible to completely shift the communication network to a completely logically multiplexed relay system.

What is necessary for such a communication application at the time of network migration is not to use the branch service of the dedicated digital line, but to keep the connection between the terminal and the communication network as one line and to change the protocol. This is a function that broadcasts to multiple terminals, and broadcasts in one direction (the transmission source is fixed to one terminal).
Not only that, but also to realize two-way broadcasting (a plurality of terminals can be a transmission source) using functions in the communication network.

In the ATM (Asynchronous Transfer Mode) system, which is one of the cell relays among the logical multiplexing systems,
V of UNI (User Network Interface) interface
Since one-to-N communication paths are defined as a standard specification after 3.1, the one-way branch service can use the one-to-N communication path mechanism, but the interface with the terminal is an ATM UNI. Therefore, the data terminal of the slave station cannot be connected as it is, and there is no standard specification of the communication path corresponding to the bidirectional branch service. In addition, cell relays other than ATM have their own cells determined for each communication device and cannot be standardized, and the standard specification does not define a 1: N communication path for the frame relay system. further,
Since the connection interface with the terminal is not an ATM or a frame relay but a proprietary protocol for frame synchronization, there is no standard specification for its accommodation itself.

[0020]

As described above, since there is no standard specification of a branch service in the standard specifications of each communication system of the logical multiplexing cell relay and the frame relay, a communication application based on the existing branch service is used as it is. However, it cannot be accommodated in a communication network having a logical multiplexing relay system.

An object of the present invention is to provide a broadcast system capable of accommodating a terminal having a communication application on the premise of an existing branch service in a communication network having a logical multiplexing relay system without changing the conventional protocol operation mode. Aim.

[0022]

According to the present invention, there is provided means for converting a unique protocol for frame synchronization into a relay protocol for logical multiplexing, and means for broadcasting for transmitting data transmitted from one terminal to a plurality of terminals. In particular, a mechanism is provided for bidirectional broadcasting when there are a plurality of terminals instead of just one transmission source. Further, there is provided means for converting from a logical multiplexing protocol to a unique protocol for frame synchronization, organizing data from a plurality of partners, and transmitting the data to a terminal.

FIG. 1 shows a first principle configuration of the present invention, in which a terminal provided with an existing application is connected to a network using logical multiplexing of fixed-length cells to realize bidirectional broadcasting.

In FIG. 1, reference numerals 1a to 1c denote cell multiplex communication devices having a communication function of relaying fixed-length cells by cell multiplexing and a cell switching function, and reference numerals 10 to 12 denote configurations provided in each multiplex communication device. , 10 is a frame / cell conversion unit that receives a frame (a frame such as an existing HDLC) from a terminal and converts it into a fixed-length cell, and 11 is a cell / frame conversion that converts a relayed cell into an original frame. A frame transmitting unit 12 for controlling transmission of frames from a plurality of terminals to the terminals, and 2a, 2b and 2c relaying data from the terminals within the cell multiplex communication device or between cell multiplex communication devices. One or more one-to-N communication paths for transferring to a plurality of other parties. One cell is transferred on a trunk line. Relaying to the next stage of the cell multiplex communication system sends out the contents terminal. Reference numerals 3a and 3b denote trunk lines for connecting cell multiplex communication devices, and reference numerals 4a to 4c denote terminals provided with an application corresponding to a dedicated digital line for performing communication using existing frames.

In the first principle configuration, when a broadcast is transmitted from the terminal 4a to the other terminals 4b and 4c, a frame (a frame such as an HDLC procedure) from the terminal 4a is sent to the frame / cell converter 10 by the frame / cell converter 10. It is decomposed into a fixed length and converted into a plurality of cells. In order to transmit a plurality of cells generated by the frame of the terminal 4a to the other terminals 4b and 4c, the cell multiplex communication device 1a sets up a 1: N communication path 2a in advance. Thereby, the one-to-N communication path 2
a is connected to the cell multiplex communication device 4 via the trunk line 3a.
b, the cell is transmitted to the cell / frame conversion unit 11 and the copied cell is placed in the subsequent cell multiplex communication device 4.
c, and each cell is input to the cell / frame converter 11 from the 1: N communication path 2a in the subsequent cell multiplex communication device 4c.

In the cell multiplexing communication devices 4b and 4c, when cells are sequentially received by the respective cell / frame converters 11, the cells are assembled and converted into the original frames, and the converted frames are supplied to the frame transmitter 12. . The frame transmitting units 12 of the cell multiplex communication devices 1b and 1c transmit the received frames to the terminals 4b and 4c, respectively. When a broadcast is transmitted from the terminal 4b to the other terminals 4a and 4c, the frame / cell conversion unit 10 of the cell multiplex communication device 1b is used.
Are transmitted to the cell multiplex communication devices 1a and 1c by the same operation as described above using the 1: N communication path 2b, and are received by the terminals 4a and 4c. Terminal 4c to Terminal 4
Broadcasting is similarly performed for a and 4b using the one-to-N communication path 2c to realize bidirectional broadcasting, and one-way broadcasting can be performed using a part of this configuration. it is obvious.

FIG. 2 shows a second principle configuration of the present invention. A terminal provided with an application corresponding to an existing digital leased line in a frame relay network using a frame for performing logical multiplexing relay (referred to as a relay frame). The following is the principle configuration for realizing the broadcast using.

In FIG. 2, reference numerals 4a to 4c denote terminals having an application corresponding to a dedicated digital line for performing communication using an existing frame, similarly to the reference numeral 4 in FIG.
a to 5c denote a frame relay multiplex communication device having a function of relaying by frame multiplexing and a frame switching function;
Numerals 0 to 52 denote components provided in each frame relay multiplex communication apparatus. Numeral 50 denotes a frame / relay frame converter for converting a frame from the terminal (a frame such as an HDLC procedure) into a relay frame for frame relay. Is a relay frame that converts the relay frame to the original terminal frame.
A frame converter 52 for controlling transmission of frames from a plurality of terminals to the terminals;
Reference numeral 6c denotes a relay in the frame relay multiplex communication device or between the frame relay multiplex communication devices, which is one or a plurality of 1: N communication paths for transferring data from the terminal to a plurality of opponents. It is transmitted in a relay frame,
In the frame relay multiplex communication device, the frame is copied and transmitted to one or a plurality of accommodation terminals, and also relayed to the next frame relay multiplex communication device. 7a,
A relay line 7b connects between frame relay multiplex communication devices.

In the second principle configuration, when a broadcast is transmitted from the terminal 4a to the other terminals 4b and 4c, a frame (a frame such as an HDLC procedure) from the terminal 4a is transmitted to the frame / relay frame converter 50. , Logical multiplexing is performed, the frame configuration is converted, and converted into a relay frame relayed between frame relay multiplex communication devices. For a frame transmitted from the terminal 4a, a 1-to-N communication path 6a for transmitting to the other terminals 4b and 4c in the frame relay multiplex communication device 5a is set in advance.

As a result, each of the relay frames on the one-to-N communication path 6a is sent to the frame multiplexing communication device 5b via the relay line 7a. Is relayed in the direction of the subsequent frame relay multiplex communication device 5c.
Each relay frame is input to the relay frame / frame converter 51 from the communication path 6a.

In each of the communication devices 4b and 4c, when each relay frame / frame converter 51 receives a relay frame, it converts the relay frame into the original frame and outputs the converted frame to the frame transmitter 52. Each frame transmission unit 5 of the frame relay multiplex communication device 5b, 5c
2 transmits frames to the terminals 4b and 4c, respectively.
When transmitting a broadcast from the terminal 4b to the other terminals 4a and 4c, the same operation as described above is performed using the 1: N communication path 6b from the frame / cell converter 50 of the frame relay multiplex communication device 5b. Are transmitted to the frame relay multiplex communication devices 5a and 5c, respectively, and are received by the terminals 4a and 4c. The broadcast is similarly performed from the terminal 4c to the terminals 4a and 4b using the 1: N communication path 6c.

[0032]

FIG. 3 shows the configuration of an embodiment of unidirectional broadcasting according to the first principle of the present invention, and FIG. 4 shows the first embodiment of the present invention.
Is a configuration of an embodiment of bidirectional broadcasting according to the principle of the above. In each of the embodiments shown in FIGS. 3 and 4, 53 cells are used as fixed-length cells.
An example will be described in which an ATM (Asynchronous Transfer Mode) cell having a byte length (consisting of a header of 5 bytes and an information field of 48 bytes) is used.

FIG. 3 is a diagram showing one-way branch service.
1 shows an example in which a terminal having two transmitting functions and a terminal having only two receiving functions are accommodated. In the figure, reference numerals 1a to 1c are the same as those of the same reference numerals in FIG. 40
a is a transmitting terminal having a transmitting function, 40b and 40c are receiving terminals having a receiving function, 2a is a one-to-two communication path, 20b,
20c is a one-to-one communication path, and each cell multiplex communication device 1
In a to 1c, 10 is a frame / cell conversion unit, 11 is a cell / frame conversion unit, 12 is a frame transmission unit, 13 is a cell switch unit that performs processing such as cell relaying and switching, and 14 is a cell that is transmitted. A path management unit that manages logically multiplexed communication paths.

Each of the terminals 40b, 40c from the transmitting terminal 40a
When performing a one-way broadcast, the setting of a one-to-two communication path 2a is registered in advance between the transmitting terminal 40a and each of the terminals 40b and 40c. This registration is performed by the cell multiplex communication devices 1a, 1
The settings for realizing the communication path 2a are made for each of the cell switches 13 and the path management sections 14 for b and 1c. The specific configuration of the one-to-two communication path 2a is as follows.
This is shown in FIGS. 5 and 6 described later. On the other hand, in order to transmit a response corresponding to the broadcast between the receiving terminal 40b and the receiving terminal 40c toward the transmitting terminal, one-to-one communication paths 20b and 2
0c is set between the transmitting terminal 40a. This registration is similarly performed for each path management unit 14 of the cell multiplex communication devices 1a, 1b, 1c.

When the transmitting terminal 40a transmits broadcast data, the frame / cell converter 10 of the cell multiplex communication device 1a transmits the broadcast data.
Is converted into cells and transmitted to the terminals 40b and 40c using the communication path 2a. In the cell multiplex communication device 1b accommodated by the reception terminal 40b, the cell relayed from the cell multiplex communication device 1a is transmitted to the cell / frame conversion unit 11 for the reception terminal 40b and the next cell multiplex communication device 1c. Is copied and transferred. cell/
After the frame conversion unit 11 restores and converts the frame to the original frame, the frame transmission unit 12 performs order control on the frame from another communication path and transmits the frame to the receiving terminal 40b.
In this example, the order control function does not work because there is no other transmitting terminal. The next-stage cell multiplex communication device 1c transfers the relayed cell to the cell / frame converter 11 corresponding to the terminal 40c. After the original frame is restored and converted by the cell / frame conversion unit 11, the frame transmission unit performs order control on the frame from another communication path and transmits the frame to the reception terminal 40c.

In the receiving terminals 40b and 40c, the transmitting terminal 4
0a is returned with a reception confirmation or the like. The frame transmitted from the receiving terminal 40b is converted into a cell by the frame / cell conversion unit 10, and the cell multiplex communication device 1a is transmitted through the communication path 20b.
Is forwarded to Similarly, the frame transmitted from the receiving terminal 40c is converted into a cell by the frame / cell converter 10, and is transferred to the cell multiplex communication device 1a via the cell multiplex communication device 1b via the communication path 20c.

In the cell multiplex communication apparatus 1a, the communication path 20
After the cells from b and 20c are restored and converted to the original frames by the cell / frame conversion unit 11, the frame transmission unit 12 controls the order between the frames from the reception terminals 40b and 40c and transmits the frames to the transmission terminal 40a. I do. In an actual communication application, the receiving terminal 40b and the receiving terminal 40
Although c does not transmit a frame, the frame transmitting unit 12 of the cell multiplex communication apparatus 1a performs order control such as a FIFO (First-In First-Out) method by queue control, for example. In this way, the same broadcast communication as the one-way branch service between a plurality of receiving terminals can be performed by one transmitting terminal.

Next, FIG. 4 shows an example in which three transmission / reception terminals having both transmission and reception functions are accommodated on the premise of a bidirectional branch service. In FIG. 4, 1a to 1c,
2a to 2c, 3a and 3b are the same as those of the same reference numerals in FIG. Reference numerals 4a to 4c denote terminals (transmission / reception terminals) having both transmission and reception functions. 10 to 14 in each of the cell multiplex communication devices 1a to 1c are the same as those of the same reference numerals shown in FIG.

In FIG. 4, a terminal 4a is connected to another terminal 4b,
When the broadcast data is transmitted to the switch 4c, the path management units 14 of the cell multiplex communication devices 1a, 1b, and 1c preliminarily make a one-to-two communication path 2 for the broadcast to each switch unit 13.
The settings of a, 2b, and 2c are registered.

When the terminal 4a transmits broadcast data, the frame received by the frame / cell converter 10 of the cell multiplex communication apparatus 1a is converted into a cell, and the terminals 4b and 4c are accommodated using the communication path 2a. Cell multiplex communication device 1b, 1c
Sent to. In the cell multiplex communication device 1b accommodating the terminal 4b, the cell relayed from the cell multiplex communication device 1a is copied to the cell / frame conversion unit 11 for the terminal 4b and the next cell multiplex communication device 1c. Transfer. Cell / frame converter 1 of cell multiplex communication apparatus 1b
After the frame is restored and converted into the original frame in step 1, the frame sending unit 12 performs order control on the frame from another communication path and transmits the frame to the terminal 4b. In the case of bidirectional communication, the frame from the terminal 4c may be transferred via the communication path 2c, and the frame sending unit 12 performs order control such as FIFO (First-In First-Out) by queue control. And sends it to the terminal 4b.

In the next stage, the cell multiplex communication apparatus 1c converts the relayed cell into a cell / frame converter 1 for the terminal 4c.
Transfer to 1. After restoring and converting to the original frame by the cell / frame converter 11 of the cell multiplex communication device 1c,
The frame sending unit 12 controls the order with respect to the frame from another communication path and transmits the frame to the terminal 4c. Also in this case, there is a possibility that a frame from another communication path 2b may be transferred, and the order is controlled. In this way, broadcast communication between three transmitting / receiving terminals equivalent to the conventional two-way branch service is possible via each of the cell multiplex communication devices 1a to 1c.

The one-to-N communication paths 2a to 2c when N = 2 shown in FIGS. 3 and 4 use an ATM standard point-multipoint connection PVC (Permanant Virtual Channel) or SVC (Switched Virtual Channel). 5 and 6 show an embodiment thereof.

FIG. 5 shows a configuration of a first-to-N communication path according to the first embodiment of the first principle, and shows an example of a one-to-three communication path when N = 3. 2a and the one-to-two communication paths 2a to 2c in FIG. 4 can be configured according to the same principle.

In the first embodiment shown in FIG. 5, reference numerals 1a to 1d denote cell multiplex communication apparatuses, 2a denotes a terminal 4a and other terminals 4b to 4d.
1: N communication path between (in this example, 1: 4 communication path),
Reference numerals 3a to 3c denote relay lines between the cell multiplex communication devices, and 4a to 3c.
4d is a terminal accommodated in each cell multiplex communication device. In this example, four terminals 4a to 4d are provided,
One-to-N transmission from the cell multiplex communication device 4a in which the terminal 4a is accommodated to the cell multiplex communication devices 4b, 4c and 4d.
When the communication path 2a is formed, the cell copy processing unit 130 is arranged on the one-to-N communication path 2a in each of the cell switch units 13 (not shown) of the intermediate cell multiplex communication devices 4b and 4c.

The cell copy processing unit 130 of the cell multiplex communication device 1b is connected to the communication path 2a via the trunk line 3a and generates one copy for a cell received from the preceding cell multiplex communication device 1a. , This is a cell multiplex communication device 1
b to the terminal 4b side, and transmits the original cell to the adjacent cell multiplex communication device 1c. The adjacent cell multiplex communication device 1c performs the same processing and sequentially relays the data, and transfers the cells of the data transmitted from the terminal 4a to the terminals 4b to 4d.
, A one-to-N communication path can be realized. In the method of the first embodiment, duplicate cells are not transmitted on the trunk line to save traffic on the trunk line. On the other hand, when the relay band is sufficient, the method of the second embodiment shown in FIG. 6 can be adopted.

FIG. 6 shows the configuration of the second embodiment of the 1: N communication path corresponding to the first principle. Embodiment 2 of the one-to-N communication path in FIG. 6 is also an example in the case of N = 3, and in FIG.
Reference numerals 1 to 3d, 3a to 3c, and 4a to 4d represent the same reference numerals in FIG. 5, and 131 denotes the cell multiplex communication device 1a.
The cell copy processing units 20 to 22 are individual communication paths set by the number of correspondent terminals to be broadcast from the cell multiplex communication apparatus 1a, and constitute a one-to-N communication path as a whole.

In the case of the second embodiment of the one-to-N communication path, the communication paths 20 to 22 are used as one-to-N communication paths extending from the cell multiplex communication device 4a accommodating the terminal 4a to the cell multiplex communication devices 4b, 4c and 4d. Is set, and the cell copy processing unit 131 is arranged in each of the communication paths 20a to 20c.
The cell copy processing unit 131 copies a plurality of cells of the data for broadcast from the terminal 4a (the number of broadcast parties) and transfers each of the cells via the communication paths 20a to 20c. The cells are transferred to the individual cell multiplex communication devices 1b to 1d by the communication paths 20a to 20c, respectively, and each cell is converted into a frame (a cell / frame conversion unit is not shown) and received by the terminals 4b to 4d.

FIG. 7 shows a frame / cell converter (FIGS. 3 and 4).
10) shows the configuration of the first embodiment. Is a block configuration; Shows a processing flow of the processing device. FIG. 8 is an explanatory diagram of the relationship between frames and cells.

FIG. , 100 and 105 are interface units for terminating a physical interface of communication,
101 is a frame reception processing unit, 102 is a processing device, 10
Reference numeral 3 denotes a memory, and 104 denotes a cell processing unit.

The operation of the frame / cell converter according to the first embodiment will be described. The interface unit 100 of each frame / cell converter 10 in the cell multiplex communication apparatus receives a frame such as an HDLC procedure from an existing terminal.

FIG. 8 is a diagram for explaining frame / cell conversion according to the ATM standard AAL5. As shown in FIG. 8, a frame received from a terminal has "01111110" at the beginning and end.
And a format including an FCS (frame check sequence) before the last flag.

This frame is sent to the frame reception processing unit 101
, And is stored in the memory 103, and an interrupt is sent to the processing device 102. In the first embodiment,
In the frame receiving process, as shown in FIG.
AAL5 (ATM Adaptation Layer
r5: Connection-based data transfer)
S-PDU (CP common part protocol data unit: C
ommon Part CS Protocol Data Unit). In this format, padding (Padding) and a trailer (8 bytes) are added to the data portion excluding the flag (F) and the FCS before and after the frame. Here, the padding is dummy data having a number of bytes such that the entire byte length of the CPCP-PDU becomes an integral multiple of 48 bytes. The 8-byte content of the trailer is
Two bytes are the frame length of this CPCS-PDU, and four bytes are CRC-32 (a 32-bit cyclic redundancy).
Check-sequence), 2 bytes are reserved. The frame of FIG. 8 is stored in the memory 103.

The processing device 102 includes the frame reception processing unit 10
When receiving an interrupt indicating completion of reception from the memory 10, the memory 10
3 is confirmed, and the memory 10
The instruction of cell formation is given together with the address of the frame data of No. 3 (B in FIG. 7).

The cell processing unit 104 reads out the designated frame data (FIG. 8) from the memory 103 in 48-byte units, and adds a header (H) to each 48-byte data (information field). 8, a standard ATM cell of 53 bytes is created, sequentially output to the interface unit 105, and output from the interface unit 105 to the switch unit (13 in FIGS. 3 and 4). In addition,
VPI (virtual path identifier) / VC of cell header (H)
As I (virtual channel identifier), the same as the communication path set in the cell switch unit 13 by the path management unit 14 is set.

FIG. 9 shows a cell / frame converter (FIGS. 3 and 4).
11) shows the configuration of the first embodiment. Is a block configuration; Shows a processing flow of the processing device. FIG. , 110 and 115 are interface units for terminating a physical interface of communication, 111 is a cell reception processing unit,
112 is a processing device, 113 is a memory, and 114 is a decellularization processing unit.

When receiving the cell shown in FIG. 8 from the switch unit (13 in FIGS. 3 and 4), the interface unit 110 of each cell / frame conversion unit 11 in the cell multiplex communication apparatus, Received and processed in memory 1
13 when the reception of each cell is completed.
Raise the interrupt for. The reception processing unit 111 writes the data in the memory 113 excluding the header of each cell. The processing device 112 that has received the interrupt checks the cell data in the memory 113 and checks whether all the cells constituting the continuous frame have been received. If all the cells have been received, the processing unit 112 The decelerating process is instructed. The decellularization processing unit 114 reads out the designated cell data from the memory 113, performs decellularization processing, and transmits the cell data to the next frame transmission unit (12 in FIGS. 3 and 4) via the interface unit 115. The decelerating processing unit 1
In FIG. 14, 48-byte data (information field) of each cell in FIG. 8 is stored in the memory 113. The memory 113 assembles them, performs processing other than padding and trailer processing, and in the next stage frame transmission unit, starts the process. , A flag (F) is added thereto, and a frame with the FCS and the flag (F) added to the end is created and transmitted to the terminal. FIG. 10 shows a processing sequence of each device when the frame / cell converter (FIG. 7) and the cell / frame converter (FIG. 9) of the first embodiment are used. FIG. 10 shows a processing sequence when broadcast data is transmitted from the terminal 4a to the terminal 4b via the cell multiplex communication devices 1a and 1b. As shown in FIG. 10, the frame / cell conversion unit of the first embodiment converts the frame into a cell after completely receiving the frame into the buffer (memory), and the cell / frame conversion unit after completely receiving the cell into the buffer (memory). Since the conversion is performed into frames, the processing load on each conversion unit is small, but the delay is large from end to end, so that the configuration is suitable for the case where the delay is less affected by the delay and the speed of the terminal line is high.

In this embodiment, the frame / cell conversion unit converts a cell after completely receiving the frame from the terminal, but in order to reduce the delay time, the head data of the frame is transmitted in parallel with the reception of the frame. A method is also conceivable in which the cells are sequentially transferred into cells.

FIG. 11 shows the configuration of a second embodiment of the frame / cell conversion unit (10 in FIGS. 3 and 4) and the cell / frame conversion unit, and FIG. 12 shows the processing flow of the processing unit of the frame / cell conversion unit. is there. In the second embodiment, the frame / cell converter immediately creates and transmits cells from the terminal without passing through the buffer (memory), and the cell / frame converter also converts the cells into frames without passing through the buffer. I do. When the frame / cell conversion unit detects all "1" s indicating an idle state when no data is transmitted from the terminal, it deactivates the communication path, notifies the other party of the state, and transmits the cell. I stopped it.

FIG. 10 ′ is a frame / cell conversion unit according to the second embodiment; Reference numeral 11 'denotes a cell / frame conversion unit according to the second embodiment, which does not include a buffer (memory) and performs processing of transmitted / received data in a transparent form.

FIG. Frame / cell converter 1
At 0 ', 100 to 102, 104, and 105 correspond to A.0 in FIG. The frame / cell conversion unit 10 according to the first embodiment shown in FIG.
, And reference numeral 106 denotes an idle detection unit.

In FIG. Frame / cell converter 1
The operation of 0 'will be described.
The frame received by the interface unit 100 transmits data through the idle detection unit 106 and detects the idle state, and raises an interrupt to the processing device 102 when the idle state starts and ends. The signal indicating the idle state is a terminal that transmits and receives an existing frame (40a to 40a in FIG. 3).
40c, 4a to 4c in FIG. 4 are all "1" signals transmitted when data is not transmitted. Example 1 above
Although the idle state signal is not used in the configuration (FIG. 7), the idle state signal is used in the second embodiment.

That is, the processing device 102 that has received the interrupt
When the idle state is recognized, the communication path to which the transmission data from the interface unit 105 is transferred is set to the inactive state, and when the idle state is not set (when the head flag of the frame from the terminal is detected), the communication path is disabled. Is activated. This state is transmitted from the processing device 102 of the frame / cell conversion unit 10 'to the path management unit 14 of the cell multiplex communication device.
(See FIGS. 3 and 4), and the path management unit 14 is transferred to another cell multiplex communication device connected by a 1: N communication path using a known management cell. The path management unit 14 of another cell multiplex communication device can recognize the state by receiving this.

When not in the idle state, the communication path is activated, and the cell processing section 104
A process is performed to continuously convert the data transmitted through the cell into cells, and the data is transmitted via the interface unit 105.

FIG. At 110, 111,
114 and 115 are the same as those in FIG. Corresponds to each unit of the same reference numeral of the cell / frame conversion unit 11 of the first embodiment, and corresponds to a configuration without the processing device 102 and the memory 113 in the first embodiment. In the cell / frame conversion unit 11 'of the second embodiment, the cell received via the interface unit 110 is received by the cell reception processing unit 111,
14. The decellling processing unit 114 performs decelling processing while receiving cells, and
15, the next frame transmission unit (1 in FIGS. 3 and 4).
Send to 2).

The processing shown in FIG. Of the frame / cell conversion unit. At the start of the process, the communication path state is set to the active state (S in FIG. 12).
1) Waiting for an interrupt (S2). In this state, when an interrupt from the idle detection unit (106 in FIG. 11) occurs, the communication path state is set to the inactive state (S3 in FIG. 12). Subsequently, a time T (for example, 0.1 sec) is set in the timer (S4), and a predetermined short time t ₀ (for example, 5 m) is set.
t-t ₀ (t to the timer waiting for the passage of s) represents the last time the timer value, initially t = T) to set the (same S5). Next, it is determined whether t ≦ 0 (S6 in FIG. 12). If no, it is determined whether there is an interrupt from the idle detection unit (S7).
If there is an interrupt, the process returns to step S4 because the device is still in the idle state. T is set in the timer again. If there is no interrupt from the idle detection unit (at the start of the frame), the process returns to step S5 to update the timer time. I do. If t is determined to be 0 or less in step S6, the communication path state is set to the active state (S1 in FIG. 12). As described above, the idle state is checked in the cycle of the minute time t ₀ during the period of the time T, and when the idle state disappears, the communication path is activated again by the time lag of the time T. As a result, it is possible to avoid a situation where the broadcast receiving side overlaps with the reception of a cell from another cell multiplex communication apparatus.

FIG. 13 shows a processing sequence between the respective devices when the frame / cell converter and the cell / frame converter according to the second embodiment shown in FIG. 12 are used. FIG. 13 shows a case where broadcast data is transmitted from the terminal 4a to the terminal 4b via the cell multiplex communication devices 1a and 1b. in this way,
According to the second embodiment, since the bit string on the line is directly converted into cells and transferred regardless of the presence or absence of a frame, the delay time can be reduced as compared with the case of the first embodiment (FIGS. 7 and 9). . In addition, since the communication path is immediately deactivated in the idle state, useless cell transfer can be prevented.

When the frame / cell conversion method of the second embodiment is used, the cell multiplex communication apparatus of the communication partner receives cells from a plurality of terminals via a plurality of communication paths in the cell / frame conversion unit. The transmitting unit (12 in each of the cell multiplex communication devices in FIGS. 3 and 4) needs to detect the communication path state which broadcast path is transmitting the broadcast data and switch the data to be transmitted to the terminal side. .

FIG. 14 shows the configuration of the third embodiment of the frame / cell converter (10 in FIGS. 3 and 4), and FIG. 15 shows the third embodiment of the cell / frame converter (11 in FIGS. 3 and 4). Is shown.

In the third embodiment, the frame / cell converter immediately creates and transmits a cell from the terminal without passing through a buffer (memory), and the cell / frame converter also transfers the cell without passing through the buffer. Although the second embodiment is common to the second embodiment in that the frame is converted into a frame, the second embodiment deactivates the communication path and notifies the other party's cell multiplex communication device when it enters an idle state. Then, cell transmission was stopped, and an idle signal was generated when the other party detected this state.

FIG. Is a block configuration; Is the processing flow of the processing device; In the above, 10 ″ is the frame / cell conversion unit of the third embodiment, 100, 102, 104.
To 106 are the frame / cell converters of the second embodiment (FIG. 1)
1A. ) Correspond to the same reference numerals.

In the frame / cell conversion unit 10 ″ shown in FIG. 14, the data of the frame received by the interface unit 100 is converted by the idle detection unit 106 into the cell processing unit 1.
At the same time, the idle state is detected, and an interrupt is sent to the processing device 102 upon the start and end of the idle state. Upon receiving the interrupt and recognizing the idle state (S2 in FIG. 14B), the processing device 102 instructs the cell processing device 104 not to convert the data received from the idle detection unit 106 into cells and not transmit the data. (S3 of B. of FIG. 14). Unless there is a cell transmission stop instruction from the processing device 102, the cell conversion processing unit 104 performs a process of continuously converting data transmitted from the idle detection unit 106 into cells, and transmits cells via the interface unit 100.

FIG. Is a block configuration; Is the processing flow of the processing device; , 11 ″ is the cell / frame conversion unit of the third embodiment,
Reference numerals 4 and 4 correspond to the same reference numerals of the cell / frame conversion unit (B. in FIG. 11) of the second embodiment. Reference numeral 116 denotes an idle which generates a continuous "1" signal indicating an idle state to the terminal. The generation unit.

In the cell / frame conversion section 11 ″ in FIG. 15, the cell reception processing section 11
The cell received at 1 is transferred to the decellularization processing unit 114. The cell reception processing unit 111 monitors continuous cell reception, and raises an interrupt to the processing device 112 when no cell is received. When the processing device 112 receives this interrupt (S2 in FIG. 15B), the idle generation unit 116
Is instructed to generate an idle signal (S3). Also, it instructs the decell processing unit 114 to receive an idle signal corresponding to data for one cell from the idle generation unit and send it to the interface unit 115 (S4 in FIG. 15B). After waiting for the time required to transmit the data, the process proceeds to the next interrupt wait (S5).

The de-cell processing section 114 is the cell reception processing section 1
The cell receiving unit 11 performs a decelling process on the cell received from the communication unit 11 and sends an idle signal from the idle generation unit 116 to the interface unit 115 when there is no cell reception.

FIG. 16 shows a processing sequence between the respective devices when the frame / cell converter and the cell / frame converter of the third embodiment shown in FIGS. 14 and 15 are used. FIG. 16 shows that the broadcast data is transmitted from the terminal 4a to the cell multiplex communication devices 1a and 1b.
Is transmitted to the terminal 4b via the. When one frame is transmitted from the terminal 4a and becomes idle, the frame / cell converter 1 of the cell multiplex communication device 1a
When the idle state is detected at "0", the cell transfer is stopped.
The cell / frame converter 11 "of the cell multiplex communication device 1b on the other end generates an idle signal and transmits it to the terminal when no cell is received.

In the third embodiment, the second embodiment (FIG. 1)
Since only the frame portion is transferred as compared with the configuration of 1), the bandwidth occupation on the trunk line can be reduced, and this is an effective method even when the trunk line is relatively slow. In this case as well, as in the second embodiment, the frame transmission unit (12 in each cell multiplex communication device in FIGS. 3 and 4) identifies which communication path is transmitting the broadcast data, and It is necessary to switch the data to be sent to the side.

Although the configurations of the first to third embodiments have been described as the cell / frame conversion unit and the frame / cell conversion unit, conversion matching the communication system for performing cell relay is possible. Only the function capable of transferring the same frame data is required, and any frame / cell converter and cell / frame converter may be used as long as they have the same function.

FIG. 17 shows the configuration of an embodiment of unidirectional broadcasting according to the second principle of the present invention, and FIG. 18 shows the configuration of an embodiment of bidirectional broadcasting according to the second principle of the present invention. FIG. 17 shows one-way broadcast communication by the cell multiplex communication apparatus shown in FIG. 3 realized by a frame relay multiplex communication apparatus. , A configuration in which a receiving terminal having only two receiving functions is accommodated.

In FIG. 17, 40a is a transmitting terminal having a transmitting function, 40b and 40c are receiving terminals having a receiving function,
5a to 5c are frame relay multiplex communication apparatuses, 6a is a one-to-two communication path of frame relay, and 60b and 60c are one-to-one communication paths.
Communication path, and each frame relay multiplex communication device 5a
In 5c, 50 is a frame / relay frame converter, 5
1 is a relay frame / frame conversion unit, 52 is a frame transmission unit, and 53 is a frame relay processing unit that performs processing such as frame relay.

First, a one-to-two communication path 6a is set between the transmitting terminal 40a and each terminal. Receiving terminal 40b, 4
0c is a one-to-one communication path 60b, 60c for transmitting a response to the broadcast to the transmitting terminal 40a.
Is set in the frame relay processing unit 53 of each frame relay multiplex communication device.

In each of the embodiments shown in FIGS. 17 and 18, the standard frame format of the frame relay of the frame relay multiplex communication device is the first flag (F),
It comprises an address part, user data, FCS, and a flag (F) at the end. The address part in this is DLCI
(Data Link Connection Identifire) and control bit information are included, and a logical multiplex communication path is specified by the DLCI. In addition, the one-to-N communication path for performing the broadcast is a designated PVC (Permanen
t Virtual Circuit: Fixed connection of other party or SVC (Swit
ched Virtual Connection), and an embodiment is shown in FIG. 19 described later.

After each path is set, when the transmitting terminal 40a of FIG. 17 transmits broadcast data, the frame relay multiplex communication device 5a converts the frame received by the frame / relay frame converter 50 into a relay frame. Communication path 6
The data is transmitted to the frame relay multiplex communication devices 5b and 5c accommodating the terminals 4b and 4c by using a. In the frame relay multiplex communication device 5b accommodating the receiving terminal 40b, the relay frame relayed from the frame relay multiplex communication device 5a receives the relay frame / frame converter 51 for the receiving terminal 40b and the next frame relay multiplex communication device 5b.
The same relay frame is copied and transferred to c.

In the relay frame / frame converter 51 of the frame relay multiplex communication device 5b, after restoring and converting to the original frame, the frame sending unit 52 controls the order with the frame from another communication path. Transmit to terminal 40c. In this example, the function of order control does not work because there is no other transmitting terminal. The frame relay multiplex communication device 5b at the next stage transfers the relayed frame to the relay frame / frame converter 51 for the terminal 40b. The relay frame / frame converter 51 restores and converts the frame to the original frame, and the frame transmitter 52 controls the order with respect to the frame from another communication path, and performs the terminal control.
0c.

The receiving terminals 40b and 40c
Return the reception confirmation etc. to a. The frame returned from the receiving terminal 40b is converted into a relay frame by the frame / relay frame converter 50 of the frame relay multiplex communication device 5b, and is transferred to the frame relay multiplex communication device 5a via the communication path 60b. Similarly, the frame from the receiving terminal 40c is also converted into a relay frame and transferred to the frame relay multiplex communication device 5a via the communication path 60c. In the frame relay multiplex communication device 5a, the communication paths 60b,
After the relay frame from 60c is restored and converted by the relay frame / frame conversion unit 51, the frame transmission unit 52 controls the order between the frames from the terminals 40b and 40c and transmits the frame to the transmission terminal 40a. A terminal 40b having a communication application corresponding to the actual one-way branch service,
The frame 40c does not transmit a frame for acknowledgment at the same time, but the frame transmission unit 52 performs order control such as a FIFO method by queue control, for example. In this manner, one-way broadcast communication equivalent to the existing one-way branch service can be performed via the frame relay multiplex communication device.

In FIG. 18, reference numerals 4a to 4c denote terminals having transmission / reception functions, 5a to 5c denote frame relay multiplex communication devices, and 6a to 6c.
Reference numeral 6c denotes a frame relay one-to-two communication path. Reference numerals 50 to 53 in each of the frame relay multiplex communication devices 5a to 5c are the same as those of the same reference numerals in FIG.

In FIG. 18, terminal 4a is connected to another terminal 4a.
When transmitting broadcast data to b and 4c, a one-to-two communication path 6a is set in advance to the frame relay processing unit 53 of the frame relay multiplex communication devices 5a, 5b and 5c. Also,
The one-to-two communication paths 6b and 6c are set similarly. When the terminal 4a transmits the broadcast data, the frame is converted into a relay frame by the frame relay multiplex communication device 1a and transferred via the one-to-two communication path 6a by a configuration similar to that described with reference to FIG. After being restored and converted to the original frame, each frame relay multiplex communication device 5b,
5c is transmitted from the frame transmission unit 52 to the terminals 4b and 4c. In this case, each frame relay multiplex communication device 5
In the case of bi-directional broadcasting, the frame transmitting unit 52 of the communication terminal 6b or 5c transmits the frame from the terminal 4a and the frame from the other terminal 4c or 4b, respectively, to the corresponding one-to-two communication path 6c or 6a. There is a possibility that the frame is transmitted at the same time via the terminal, and the frame transmitting unit 52 performs order control such as a FIFO method by queue control and transmits the terminal 4b or 4c. In addition, the frame relay multiplex communication device 5
The terminal 4a accommodated in a can also receive reception confirmations and the like from the other terminals 4b and 4c by performing the order control in the frame transmission unit 52.

As described above, the broadcast communication between the three transmitting / receiving terminals equivalent to the two-way branch service can be performed via the frame relay multiplex communication device. Although there is no particular standard for the 1: N communication path passing between a plurality of frame relay multiplex communication devices, any one of PVC or SVC can be realized, and FIG. This is an example.

In the example of FIG. 19, four frame relay multiplex communication apparatuses 5a to 5d are provided,
To 4d are accommodated, and relay lines 7a to 7c are provided between the respective frame relay multiplex communication devices. When broadcasting data from the terminal 4a to the other terminals 4b, 4c and 4d, in FIG. 19, as in the case of the cell multiplexing system shown in FIG.
The frame copy processing unit 530 in the frame relay processing unit 53 (see FIGS. 17 and 18) copies the relay frame to form a one-to-N communication path (N in this example).
= 3) is realized.

The method of copying a relay frame is shown in FIG.
In the method of copying in each frame relay multiplex communication device for each relay as described in the above, it is also possible to use a method of copying multiple relay frames first in the source frame relay multiplex communication device and then relaying independently. it can.

FIG. 20 shows an embodiment of the frame / relay frame converter (50 in FIGS. 17 and 18).
Is a block configuration; Shows a processing flow of the processing device.
A. of FIG. , Reference numerals 500 and 505 denote interface units for terminating a physical interface of communication, 501 denotes a frame reception processing unit, 502 denotes a processing device, 503 denotes a memory, and 504 denotes a frame transmission processing unit.

The operation of the embodiment of the frame / relay frame converter will be described.
The interface unit 500 of the relay frame conversion unit 50
A frame such as an HDLC procedure is received from an existing terminal.
This frame is subjected to reception processing by the frame reception processing unit 501, written into the memory 503, and an interrupt is sent to the processing unit 502 when the reception of the frame is completed. Upon receiving the interrupt, the processing device 502 checks the frame data in the memory 503, and also checks the frame transmission processing unit 504.
, An address in the memory 503 is added and a frame conversion instruction is issued. The frame transmission processing unit 504 reads out the instructed frame data from the memory 503, converts the frame data into a relay frame, and sends the converted relay frame to the frame relay 1: N communication path via the interface unit 505. .

When a frame from a terminal is converted into a relay frame, for example, when a frame shown in FIG. 8 is received from the terminal, an address portion (DLCI or the like) is added to the head except for the flag (F) before and after the frame. ) To add F
After calculating CS and setting it at the rear, a flag (F) is added before and after to form a relay frame (variable length).

FIG. 21 shows the structure of an embodiment of the relay frame / frame converter (51 in FIGS. 17 and 18).
Is a block configuration; Shows a processing flow of the processing device.
A. of FIG. , 510 and 515 are interface units for terminating a physical interface of communication, 511 is a frame reception processing unit, 512 is a processing device, 513 is a memory, and 514 is a frame transmission processing unit.

The operation of the embodiment of the relay frame / frame converter will be described. The relay frame received by the interface unit 510 of each relay frame / frame converter 51 in the cell multiplex communication apparatus is received by the frame reception processing unit 511. , And write to the memory 513 and raise an interrupt to the processing unit 512 when the reception is completed. The processing device 512 that has received the interrupt confirms the frame in the memory 513, and instructs the frame transmission processing unit 514 to perform frame conversion together with the address of the frame data in the memory 513. The frame transmission processing unit 514 responds to this instruction and
3 to convert the relay frame in the memory into the original frame, and transmit the frame via the interface unit 515.

FIG. 22 shows a processing sequence between the respective units including the frame / relay frame converter and the relay frame / frame converter shown in FIGS. FIG.
Shows a case where broadcast data is transmitted from the terminal 4a to the terminal 4b via the frame relay multiplex communication devices 5a and 5b.

When broadcasting data from an existing terminal through this frame relay multiplex communication device, the format of the relay frame is not particularly limited, and the same frame data as the frame from the terminal is used by the frame relay multiplex device. There is no limitation on the format of the relay frame as long as it has a function of converting the original frame to a format that matches the relay frame and transferring the original frame to the partner terminal. Therefore, as shown in the above embodiment (FIGS. 20 to 22), the method of transferring the relay
Not only a method of converting a frame into one relay frame and transferring it, but also a method of converting one frame from a terminal into a plurality of short relay frames and transferring the frame can be used.

In each of the data broadcasting via the cell multiplex communication device according to the first principle of the present invention and the data broadcasting via the frame relay multiplex communication device according to the second principle of the present invention described above, a plurality of terminals It is not possible for the frame to be transferred at the same time because of the operating conditions of the terminal's communication application. It is desirable to be able to automatically cope with a communication application on the terminal side without having to do so. For this purpose, it is necessary to control the transmission order of frames from a plurality of terminals in a multiplex communication device by some method.

FIG. 23 shows the configuration of the first embodiment of the frame transmitting section, which can be applied to each multiplex communication apparatus according to the first principle and the second principle of the present invention. The principle of the first embodiment is to perform transmission order control by queue control.

In the figure, the frame transmitting unit corresponds to the reference numeral 12 in FIG. 1 or the reference numeral 52 in FIG. 2, but the reference numeral 12 is used here. 120a to 120 inside the frame sending unit 12
Reference numeral c denotes an interface unit that receives data transmitted from a plurality of terminals from the corresponding communication paths and receives converted data into frames, 121a to 121c denote frame reception processing units, 122 denotes a transmission queue, and 123 denotes a transmission queue. Interface section.

Each of the interface units 120a to 120c is connected to a cell / frame conversion unit or a relay frame /
A frame converted from a cell or a relay frame generated and transferred based on a frame transmitted from each of the other terminals by the frame conversion unit is input. The frame reception processing units 121a to 121c transfer the frames input from the corresponding interface units 120a to 120c to the transmission queue 122. In the transmission queue 122, the frames transferred from each frame reception processing unit are connected to the queue. In this case, the transmission queue 122 stores the FIFO (First
The frame is extracted from the queue in accordance with an In First Out) method or a predetermined extraction order control, and transmitted to the terminal via the interface unit 123. It should be noted that the queue system of the first embodiment includes the frame / cell converter and the cell / frame converter shown in FIGS. 7 and 9 and the frame / relay frame conversion and the relay frame / frame shown in FIGS. This method is suitable for the conversion method.

FIG. 24 shows the structure of the frame transmitting section according to the second embodiment. In the second embodiment, the cell multiplex communication apparatus shown in FIG.
This is applied when the frame / cell conversion unit shown in (1) is provided, that is, when the communication path state is notified from the transmission source cell multiplex communication device to the broadcast partner cell multiplex communication device.

In FIG. 24, reference numeral 12 'denotes a frame transmitting unit according to the second embodiment, and reference numerals 120a to 120c and 121a to 121
Reference numerals c and 123 are the same as those of the same reference numerals shown in FIG. Reference numeral 124 denotes a processing device, and reference numeral 125 denotes a frame selection unit.

In the second embodiment, the frame receiving unit 121
a to 121c correspond to the corresponding interface units 120a to 120c.
120c, the frame is received by the frame selection unit 12c.
Transfer to 5. The processing device 124 checks the state of each communication path, and issues an instruction to the frame selection unit 125 to transmit the frame of the communication path that has been activated first. At this time, if all the communication paths are inactive, data of any one of the communication paths may be transmitted. However, if a plurality of communication paths are active, the data becomes active first. Is controlled to select the communication path that was set. Frame selection unit 125
Then, a communication path for transferring a frame is selected in accordance with an instruction from the processing device 124 and transmitted to the terminal via the interface unit 123.

FIG. 25 shows the structure of the third embodiment of the frame transmitting section. The third embodiment is a cell multiplex communication apparatus having a frame / cell conversion unit and a cell / frame conversion unit shown in FIGS. 14 and 15, that is, a system that does not transmit a cell when an idle state is detected from a terminal. Applied in some cases.

In FIG. 25, reference numeral 12 "denotes a frame transmission unit of the third embodiment, 120a to 120c, 121a to 121
c and 123 are the same as those of the same reference numerals shown in FIGS. 23 and 24, and the description is omitted. Reference numeral 126 denotes a bit AND processing unit.

The frame receiving units 121a to 121c receive frames (including idle signals) via the corresponding interface units 120a to 120c, and transfer them to the bit AND circuit unit 126. In the bit AND processing unit 126,
A process of calculating a logical product of a plurality of input data in bit units is performed, and the result is transmitted via the interface unit 123.

In the communication application of the terminal which is the premise of the present invention, when no frame is transmitted, an idle signal (all "1") is transmitted.
When there is no frame even in the frame restoration process of the cell / frame conversion unit of (1), since the process of transmitting an idle signal to the terminal is performed, the input to the bit AND processing unit 126 is a maximum of one frame information and other Of idle signals. Since the idle signal is a bit signal of all “1” in bit units, as a result of the logical AND operation, at most one frame information is transferred as it is.

The frame transmitting section is required to have a function of automatically controlling the order of transmitting frames from a plurality of terminals, and the function is not limited to the first to third embodiments as long as the function is provided. .

[0109]

According to the present invention, a terminal provided with a communication application for performing data broadcasting on the premise of a conventional dedicated digital line branching service can be changed to a cell relay or a frame relay without changing its protocol and operation method. Can be accommodated in a communication network with a logical multiplexing relay system, and can perform one-way or two-way broadcasting. You can continue to use existing communication applications.

Further, it is possible to shift from the time-division multiplex relay system of the communication network to the logical multiplex relay system, which has not been possible in the past, and realize cost reduction by integrating lines and effective use of bandwidth by logical multiplex. be able to.

[Brief description of the drawings]

FIG. 1 is a diagram showing a first principle configuration of the present invention.

FIG. 2 is a diagram showing a second principle configuration of the present invention.

FIG. 3 is a diagram showing the configuration of an embodiment of unidirectional broadcasting according to the first principle of the present invention.

FIG. 4 is a diagram showing a configuration of an embodiment of bidirectional broadcasting according to the first principle of the present invention.

FIG. 5 is a diagram showing a configuration of a 1-to-N communication path according to the first principle in a first embodiment;

FIG. 6 is a diagram showing a configuration of a one-to-N communication path according to a second embodiment corresponding to the first principle;

FIG. 7 is a diagram illustrating a configuration of a first embodiment of a frame / cell conversion unit.

FIG. 8 is an explanatory diagram of frame / cell conversion according to ATM standard AAL5.

FIG. 9 shows a cell / frame cell converter (1 in FIGS. 3 and 4);
FIG. 1 is a diagram illustrating a configuration of Example 1).

FIG. 10 is a diagram illustrating a processing sequence of each device when the frame / cell conversion unit and the cell / frame conversion unit according to the first embodiment are used.

FIG. 11 is a diagram illustrating a configuration of a frame / cell conversion unit and a cell / frame conversion unit according to a second embodiment.

FIG. 12 is a diagram depicting a processing flow of a processing device of the frame / cell conversion unit;

FIG. 13 is a diagram illustrating a processing sequence between devices when a frame / cell conversion unit and a cell / frame conversion unit according to the second embodiment are used.

FIG. 14 is a diagram illustrating a configuration of a frame / cell conversion unit according to a third embodiment.

FIG. 15 is a diagram illustrating a configuration of a third embodiment of the cell / frame conversion unit.

FIG. 16 is a diagram illustrating a processing sequence between devices when a frame / cell conversion unit and a cell / frame conversion unit according to the third embodiment are used.

FIG. 17 is a diagram showing a configuration of an embodiment of unidirectional broadcasting according to the second principle of the present invention.

FIG. 18 is a diagram showing a configuration of an embodiment of bidirectional broadcasting according to the second principle of the present invention.

FIG. 19 is a diagram showing an embodiment of a 1: N communication path using frame relay.

FIG. 20 is a diagram illustrating a configuration of an embodiment of a frame / relay frame conversion unit.

FIG. 21 is a diagram illustrating a configuration of an embodiment of a relay frame / frame converter.

FIG. 22 is a diagram showing a processing sequence between devices including a frame / relay frame conversion unit and a relay frame / frame conversion unit.

FIG. 23 illustrates a configuration of a frame transmission unit according to the first embodiment.

FIG. 24 illustrates a configuration of a frame transmission unit according to a second embodiment.

FIG. 25 shows a configuration of a third embodiment of a frame transmission unit.

FIG. 26 is an explanatory diagram of a one-way branch service of a dedicated digital line.

FIG. 27 is an explanatory diagram of a bidirectional branch service of a dedicated digital line.

[Explanation of symbols]

 1a to 1c Cell multiplex communication device 10 Frame / cell conversion unit 11 Cell / frame conversion unit 12 Frame transmission unit 2a to 2c One-to-N communication path 3a, 3b Relay line 4a to 4c Terminal

Claims (11)

[Claims] 1. A data transmission system in which a terminal having a function of transmitting and receiving a frame corresponding to a branch service of an existing dedicated digital line is accommodated in a cell multiplex communication device constituting a logical multiplexing network and broadcasts between a plurality of terminals. In the broadcast system, a cell multiplex communication device accommodating a broadcast source terminal relays a cell corresponding to the source terminal to each cell multiplex communication device accommodating a plurality of broadcast destination terminals. A communication path is set, a frame / cell converter for converting a frame from a terminal into a cell and transmitting the cell to the 1: N communication path in each of the cell multiplex communication apparatuses, and a cell from the 1: N communication path. A data broadcast system comprising: a cell / frame converter for converting a frame; and a frame transmitter for transmitting the converted frame to a terminal. 2. A cell multiplex communication apparatus according to claim 1, wherein a plurality of cells accommodating a plurality of reception-only terminals serving as broadcast destinations are transmitted from a cell multiplex communication apparatus accommodating a transmission-only terminal serving as a broadcast transmission source. A plurality of cell multiplex communication apparatuses accommodating the reception-only terminal, which set a 1-to-N communication path for relaying cells to the multiplex communication apparatus, respectively return a reception acknowledgment with the transmission source terminal. A one-way broadcast by setting a one-to-one communication path. 3. The cell multiplexing communication apparatus according to claim 1, wherein each cell multiplex communication apparatus accommodating the plurality of terminals relays a cell to a plurality of cell multiplex communication apparatuses accommodating a plurality of terminals to which broadcasts are respectively transmitted. Respectively, and each cell multiplexing communication apparatus accommodating a source terminal of the one-to-N communication path transmits the one-to-N communication path from the frame / cell conversion unit.
Each cell multiplexing communication device that transmits broadcast data from the communication path and accommodates a terminal on the receiving side of another 1-to-N communication path transmits the frame converted from the cell by the cell / frame conversion unit to a frame transmission unit. By controlling the sending order,
A data broadcasting method in which a frame is transmitted to an accommodated terminal to perform bidirectional broadcasting. 4. The one-to-N communication system according to claim 2, wherein a cell converted from a frame from a transmission source terminal is relayed to a cell multiplex communication apparatus in which each destination is accommodated.
A data broadcasting method comprising: providing a cell copy processing unit for copying a cell on a communication path, and transmitting the cell-copied data to a terminal and a cell multiplex communication device at a subsequent stage of the communication path. 5. The cell multiplex communication apparatus according to claim 2, wherein the one-to-N communication path includes a cell multiplex communication apparatus accommodating a source terminal and a cell multiplex communication apparatus accommodating another destination terminal. A N-to-one communication path for individually connecting the devices, and a cell copy processing unit for copying N cells converted from the frame at the transmission source of the one-to-N communication path; A data broadcasting method, wherein each cell is transmitted by the N one-to-one communication paths. 6. The apparatus according to claim 1, wherein the frame / cell converter of the source cell multiplex communication device, when detecting a signal indicating an idle state from a terminal, sets the 1: N communication path to an inactive state. When the idle state ends, the 1: N communication path is activated, each state is notified to each cell multiplex communication apparatus accommodating the destination terminal, and each cell / frame conversion accommodating the destination terminal is transmitted. A data broadcasting system for performing a conversion operation in response to the notification. 7. The apparatus according to claim 1, wherein the frame / cell converter of the source cell multiplex communication device includes an idle state detector for detecting an idle state of the transmitting terminal, and the idle state detector detects the idle state. A data broadcasting method for stopping cell formation by a signal, wherein each cell / frame converter accommodating the destination terminal generates a signal indicating idle when detecting that no cell is received. . 8. A terminal having a function of transmitting and receiving a frame corresponding to a branch service of an existing dedicated digital line is accommodated in a frame relay multiplex communication device constituting a logical multiplexing network, and a plurality of terminals perform broadcasting. In the data broadcasting method, the frame relay multiplex communication device accommodating each of the source terminals relays a relay frame corresponding to the source terminal to each frame relay multiplex communication device accommodating a plurality of broadcast destination terminals. Set up a 1: N communication path,
A frame / relay frame conversion unit for converting a frame from a transmission source terminal into a relay frame suitable for frame relay and transmitting the frame to the one-to-N communication path; A data broadcasting method comprising: a relay frame / frame converter for converting a relay frame from a path into a frame; and a frame transmitter for transmitting the converted frame to a terminal. 9. The frame relay multiplex communication apparatus according to claim 8, wherein a plurality of reception-only terminals accommodating a plurality of reception-only terminals serving as broadcast destinations are transmitted from a frame relay multiplex communication apparatus accommodating a transmission-only terminal serving as a transmission source of broadcasts. A one-to-N communication path for relaying a relay frame is set in the frame relay multiplex communication device, and each of the plurality of frame relay multiplex communication devices accommodating the reception-only terminal receives acknowledgment with the transmission source terminal. A one-way communication by setting a one-to-one communication path for returning the data. 10. The frame relay multiplex communication apparatus according to claim 8, wherein each of the plurality of frame relay multiplex communication apparatuses accommodating the plurality of terminals relays to a plurality of each frame relay multiplex communication apparatus accommodating a plurality of terminals to which the broadcast is to be transmitted. Each one-to-N communication path for relaying a frame is set, and each cell multiplexing communication apparatus accommodating the terminal of the transmission source of the one-to-N communication path transmits the one-to-N communication path from the frame / relay frame conversion unit to the one-to-N communication path. Each frame relay multiplex communication apparatus that transmits broadcast data and accommodates a terminal on the receiving side of another one-to-N communication path transmits the frame converted from the relay frame by the relay frame / frame conversion unit to a frame transmission unit. A data broadcasting method in which a transmission order is controlled, a frame is transmitted to an accommodated terminal, and bidirectional broadcasting is performed. 11. The one-to-N communication path according to claim 9, wherein a relay frame converted from a frame from a source terminal is relayed to a frame relay multiplex communication apparatus in which each destination is accommodated. A data broadcasting system, further comprising a relay frame copy processing unit for copying a relay frame, and transmitting the copied relay frame to a terminal and a cell multiplex communication device at a subsequent stage of the communication path.