AU620176B2 - Method of performing data communication between plurality of data terminals - Google Patents

Description

i- 1 620176 S F Ref: 114016 FORM COMMONWEALTH OF AUSTRAL PATENTS ACT 1952 COMPLETE SPECIFICATION

(ORIGINAL)

FOR OFFICE USE: Class Int Class D 0 .4 4 I 0 G Complete Specification Lodged: Accepted: Published: Priority: Related Art: Name and Address of Applicant: NEC Corporation 33-1, Shiba Minato-ku Tokyo

JAPAN

Address for Service: Spruson Ferguson, Patent Attorneys Level 33 St Martins Tower, 31 Market Street Sydney, New South Wales, 2000, Australia Complete Specification for the invention entitled: Method of Performing Data Comnunication Between Plurality of Data Terminals The following statement is a full description of this invention, including the best method of performing it known to me/us 5845/4 L1_I~ Abstract of the Disclosure According to a method of performing data communication between a plurality of data terminals, data transmission/reception controllers are respectively arranged between data terminals and an electronic exchange.

A plurality of destination addresses are combined with data to be transmitted. Each data transmission/reception controller transmits received data to a data terminal 1connected thereto when the received data includes a destination address thereof, while transferring data 0 10 including another destination address to a data transmission/reception controller designated by this another destination address.

0 44 4 4 0 0 00- 0480 0 0 0 i r, Specification Title of the Invention Method of Performing Data communication between Plurality of Data Terminals Background of the Invention The present invention relates to a method of performing data communication between a plurality of data terminals by using an exchange.

In the present information-oriented society, the way of acquiring and communicating necessary information is one of the important factors in all fields of activity. In this situation, data communication is performed to transmit/receive data between a plurality of data I* 15 processing units. Various types of data communication are available, ranging from small-scale communication used for, online technical computation in universities and research institutes, and production management in factories, to large-scale communication on a nationwide o. .20 basis used for, seat reservation of railways. When data communication is to be performed, in order tq perform smooth communication between a plurality of data processing units, a communication system is used.

Fig. 4 shows a conventional communication system.

A data terminal 11 constituted by, a personal computer is connected to a data transmission/reception controller 12. The data 1Atransmission/reception controller 12 serves to receive transmitted data, display the data on the data terminal 11, and transmit data output from the data terminal 11 to another data terminal. The data transmission/reception controller 12 is connected to a line interface section 16 of an electronic exchange 15 through transmission and reception'lines 13 and 14. Similarly, a data terminal 18 is connected to a data transmission/reception controller eve, 19. The data transmission/reception controller 19 is i~ 0 10 connected to the line interface section 16 through :transmission and reception lines 20 and 21. A data V terminal 24 is also connected to a data transmission/reception controller 25. The data transmission/reception controller 25 is connected to the line interface section 16 through transmission and t t Ilt reception lines.

The electronic exchange 15 comprises the line interface section 16, a line connection data receiving V section 27, and a line control section 28. When a specific data terminal is to perform data communication with another data terminal, the line interface section 16 interconnects the transmission and reception lines of the data transmission/reception controllers, respectively, connected to these data terminals. In addition, the line interface section 16 serves as a data line for transmitting number data, which is output from the specific data terminal so as to call another data terminal, to the line control section 2 7

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28. The line control section 28 receives the number data through the line connection data receiving section 27 so as to control a line connection operation of the line interface section 16.

In the conventional data communication, when, for example, transmission/reception of data between the data terminal 11 and the data terminal 18 is performed in the following manner. Note that each data terminal includes a computer, and data output and display operations, and the 1 0 like are performed by the computer. However, the following description is based on the assumption that all these 0'1 operations are performed by the data terminals.

Number data for designating the data terminal 18 to be called, which will transmit/receive data, is manually '0 15 dialed and output from the data terminal 11. The data transmission/reception controller 12 receives this number data, and transmits it to the line connection data

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receiving section 27 connected to the line interface section 16. Upon reception of the number data from the line connection data receiving section 27, the line control section 28 inquires whether the data terminal 18 cqan respond to it or not. If the terminal 18 can respond, the transmission line 13 of the data transmission/reception controller 12 is connected to the reception line 21 of the data transmission/reception controller 19 through the data transmission line 30. In addition, the reception line 14 of the controller 12 is connected to the transmission line 3 i: ii of the controller 19 through the data reception line 31.

Upon completion of this connection, transmission/reception of necessary data is performed between the data terminals 11 and 18.

After the data transmission/reception is completed, the data terminal 11 is operated to output data for disconnecting the data transmission and reception lines 30 and 31 to the line control section 28. When the line control section 28 is disconnected, data communication is completed.

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0~t 00 0, 044o 00 1 0000 1o 0 10 As described above, in the conventional system, data communication is performed between a pair of data terminals. Data communication with another data terminal requires another similar operation after the current data 15 communication is completed.

For this reason, even if communication of the same data is performed between a plurality of data terminals, transmission/reception of data is performed by connecting a pair of terminals in a one-to-one correspondence. When communication of the same data is to be performed between a plurality of data terminals, all the data terminals are called, and line connection of the line interface section is repeatedly performed for each data terminal. Therefore, these operations are time-consuming.

In addition, an operation time may be prolonged because of erroneous dialing or the like for calling a data terminal.

4 -2 A one-way communication scheme for transmitting data from a single data terminal to a plurality of data terminals is realized in the form of multi-address calling used for a facsimile system. However, responses from a plurality of data terminals to a single data terminal (for example, acknowledgement or negative acknowledgement) cannot be performed.

Summary of the Invention It is, therefore, an object of the present .0 invention to provide a method of performing data communication which allows accurate and quick transmission/reception of the same data, two-way communication of the same data, between a plurality of data terminals.

o O o on o 00 o 0 0s 0 ii i.~ ii ij i i i, -t o° 15 In order to achieve the above object, there is 0o provided a method of performing data communication between a plurality of data terminals, in a data communication system including a plurality of data terminals for performing transmission/reception of data, and an 0n%; oa 000S 20 electronic exchange for performing line connection between at least one specific data terminal of the data terminals and other data terminals upon a request from the one specific data terminal, wherein data transmission/reception controllers are respectively arranged between the data terminals and the electronic exchange, a plurality of destination addresses are combined with data to be transmitted, and each of the data transmission/reception 5 controllers transmits received data to a data terminal connected thereto when the received data includes a destination address thereof, while transferring data including another destination address to a data transmission/reception controller designated by this another destination address.

Brief Description of the Drawings Figs. 1 to 3 are views for explaining an embodiment of the present invention, in which 0 Fig. 1 is a block diagram showing a communication o system according to the embodiment of the present invention, Fig. 2 is a flow chart for explaining an operation of a data transmission/reception controller, and o 15 Fig. 3 is a view showing a data format; and o° Fig. 4 is a block diagram showing a conventional communication system.

ii o oct Detailed Description of the Preferred Embodiment o, 0 An embodiment of the present invention will be CIO d 0 0,0 20 described in detail below.

o Fig. 1 explains the principle of a commi nnication system according to an embodiment of the present invention.

A data terminal 51 is connected to a data transmission/reception controller 52. The controller 52 serves to receive data sent from another data terminal, display the received data on the data terminal 51, and transmit data output from the data terminal 51 to another 6 data terminal in accordance with a flow chart shown in Fig. 2. The data transmission/reception controller 52 is connected to a line interface section 56 of an electronic exchange 55 through a reception line 53 for receiving data and a transfer line 54 for transferring data. Similarly, a data terminal 58 is connected to a data transmission/reception controller 59. The controller 59 is connected to the line interface section 56 through a

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reception line 60 for receiving data transferred from the controller 52. In addition, a transmission line (not shown) of the controller 59 is connected to the line iA *r interface section 56. This transmission line is used to transmit data when transmission/reception of data is performed with respect to another data terminal.

Similarly, a data terminal 61 is connected to a data transmission/reception controller 62. The controller 62 is connected to the line interface section 56 through a reception line 63 and a transmission line (not shown). In addition, the data transmission/reception controllers 52, 59, and 62 are connected to a response data interface section 65 of the electronic exchange 55 through E common response data line 64.

In the electronic exchange 55, a computer interface section 66 is connected to the line interface section 56 through a line connection data receiving Lection 67 and a line control section 68. The response data interface section 65 is connected to the computer interface 7 C C-C- V section 66 through a response data receiving section 69 and a response data transmitting section A computer 73 is connected to the computer interface section 66 through two data lines, a line connection data line 71 and a response data line 72. The computer 73 supplies a line connection command to the electronic exchange 55 in accordance with line connection data senfit from one of the data terminals. The computer 73

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V also has the function as a data terminal for transmitting/receiving data to/from each data terminal.

The line connection data line 71 is a data line for transmitting data which is used by the computer 73 to control line connection of the interface section 56. The response data line 72 is a data line which is used by the computer 73 when it serves as a data terminal for performing transmission/reception of data between the data i terminals 51, 58, and 61, and receives response data therefrom. The computer 73 is connected to a data receiver through a data transmission line 74. The data receiver 20 75 is connected to the line interface section 56 of the electronic exchange Data transmission/reception by the system of the embodiment having the above-described arrangement will be described below. Especially, a case will be described, wherein the computer serves as a data terminal and performs data transmission/reception between other data terminals.

8 4 Transmission/reception of the same data with a plurality of data terminals In this case, data which is received by the data receiver 75 from the computer 73 through the data transmission line 74 is transmitted to data terminals 51, 58, and 61 through the corresponding data transmission/reception controllers 52, 59, and 62. For this purpose, the data receiver 75 must be connected to the controllers 52, 59, and 62. The computer 73 controls line connection of the line interface section 56 through the line control section 68 in the following manner.

The computer 73 outputs, through the data line 74, line connection data for connecting the data receiver to the data transmission/reception controller 52. This V K 15 line connection data is received by the line connection data receiving section 67 through the computer interface section 66, and is input to the line control section 68.

SThe line control section 68 connects the data receiver which is connected to the line interface section 56, to the reception line 53 of the controller 52 through a data reception path 77 on the basis of the received line connection data. Subsequently, the computer 73 outputs line connection data for connecting the controller 52 to the controllers 59 and 62. As a result, the data transmission paths 78 and 79 ronnected to each other in the same manner as described With this operation, 9 rj i 1 i

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i t 77the connection between the data receiver 75 and the controllers 52, 59, and 62 are completed.

When the line connection process of the line interface section 56 is completed in the above-described manner, the computer 73 transmits the same data to all the data terminals 51, 58, and 61, and the corresponding data terminals display this data. This data is received by the data receiver 75 through the data transmission line 74.

The data received by the data receiver 75 is output to the .0 line interface section 56, and is received by the data transmission/reception controller 52 through the data #Ir Itt 19 reception path 77 and the reception line 53. When the controller 52 confirms that the received data is directed to its data terminal, it sends the data to the data terminal 51. At the same time, the controller 52 transfers the data to the data transmission/reception controller 59 through the transfe7 line 54, the data transmission path 78, and the reception line 60 in accordance with steps 103 and 104 in Fig. 2. In addition, the controller 52 transfers the received data to the data transmission/reception controller 62 through the transfer line 54, the data transmission path 79, and the reception line 63 in accordance with steps 105, 106, and 107 in Fig. 2. 'iii eontrollers 59 and 62 respectively supply these received data to the data terminals 58 and 61. The data terminals 51, 58, and 61 display the data transmitted from the computer 73. Note that in Fig. 2, if it is

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i B 10 12 determined in step 103 that the received data is not directed to a given connected data terminal the data terminal 59 in this case), the flow shifts to step 105. If it is determined in step 105 that the destination address coincides with that of a data terminal other than the connected data terminal, the flow shifts to step 106. If NO in step 105, the control operation of the computer 73 is ended. The control operation is also ended when a o9 transmission line for the data is not present.

Upon reception of the data from the computer 73, -o, 0p the data terminals 51, 58, and 61 output responses to the received data as response data to the data transmission/reception controllers 52, 59, and 62, respectively. The controllers 52, 59, and 62 respectively transmit the received response data to the electronic exchange 55 through the common response data line 64. The electronic exchange 55 receives this response data through the response data interface section 65, and outputs it from the computer interface section 66 through the response data

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receiving section 69 and the response data transmitting section 70. Tie output response data is receivedby the computer 73 through the response data line 72.

After data transmission/reception with the data terminals 51, 58, and 61 is completed, the computer 73 outputs line connection data for disconnecting the data reception path 77 and data transmission paths 78 and 79 of the line interface section 56. This line connection data 11 ta'-M;

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is received by the line connection data receiving section 67 through the line connection data line 71 and the computer interface section 66 of the electronic exchange i 55, and the line control section 68 disconnects the data reception path 77 and the data transmission paths 78 and 79.

Note that all or some of the data reception path 77 and the data transmission paths 78 and 79 may be *0f a disconnected depending on the contents of received data, a 0 0 lapse of time after data is transmitted, or a reception It state of received response data. For example, if data 1 requiring no response data is transmitted, the data K transmission path 77 and the data reception path 78 and 79 are disconnected upon completion of data transmission.

These lines may be disconnected after a lapse of predetermined time, whether response data needs to be received or not.

a Transmission/reception of the same data between a single terminal and other terminals When the data terminal 51 supplies, to the data transmission/reception controller 52, line connection data necessary for connection to the data terminals 58 and 61, the controller 52 transmits it to the electronic exchange through the data response line 64.

The electronic exchange 55 receives the line connection data through the response data interface section and outputs it from the computer interface section 66 12 through the response data receiving and transmitting sections 69 and The output line connection data is received by the computer 73 through the response data line 72.

Subsequently, the computer 73 controls the line interface section 56 through the line connection data line 71, the computer interface section 66, the line connection data receiving section 67, and the line control section 68 on the basis of the line connection data, as described above, thereby performing the required line connection operation.

0 0444 o oo 0 000 0 4 40 000 0 o 044 0444 4o 0 Q o wo 4 4 4 4 a4044 c4t In this case, in Fig. 1, data which is input to the data terminal 51 together with destination addresses is received by the data transmission/reception controller 52, 15 and is transferred to the data transmission/reception controllers 59 and 62 through the transfer line 54, the data transmission path 78 and 79, and the data reception lines 60 and 63. As a result, the data is transmitted to the data terminals 58 and 61 corresponding to the destination addresses in accordance with the flow chart in Fig. 2.

When response data is required for the transmitted data, the data terminal 51 transmits response request data to the data transmission/reception controller 52 and to the electronic exchange 55 through the response data line 64.

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9 49 90 9 0'r_ 9~ 9l 9r 99 0i 9#1 99g9 9 0999 146 In addition, the data terminals 58 and 61 respectively output responses to the received data, as response data, to the data transmission/reception controllers 59 and 62. The controllers 59 and 62 transmit the received response data to the electronic exchange through the common response data line 64 (see steps 101 and 102 in Fig. The electronic exchange 55 receives the response request and the response data through the response data interface section 65, and outputs them from the 10 computer interface section 66 through the response data receiving section 69 and the response data transmitting section 70. The output response data is received by the computer 73 through the response data line 72. Upon reception of the response data from the respective data 15 terminals 58 and 61, the computer 73 edits these response data into one response data, and transmits the edited data to the data receiver 75 through the data transmission line 74. The response data received by the data receiver 75 is then received by the data transmission/reception controller i. 52 through the reception line 53 and hence received by the data terminal 51 as a destination.

When data transmission/reception between the data terminal 51 and other data terminals 58 and 61 is completed, the computer 73 outputs line connection data for disconnecting the data reception path 77 and the data transmission paths 78 and 79 of the line interface 56, thus disconnecting the transmission and reception paths.

I I 14 I LI Note that all or some of the data reception path 77 and the data transmission paths 78 and 79 may be disconnected depending on a lapse of time after response request data is received or a reception state of received response data.

Data transmission/reception with specific data terminals Assume that the data receiver 75 and the data transmission/reception controller 52, and the data aoo 0 4.44 transmission/reception controllers 52, 59, and 62 are o connected through the interface section 56, as described +above.

044 For example, part of transmission data may be transmitted to all the data terminals, and the remaining 15 portion may be transmitted to specific data terminals.

o, Alternatively, data transmission to specific data terminals may be required while data transmission/reception is a o~ performed with all the data terminals and the line 0 interface section 56 is connected.

4444 20 Fig. 3 shows data to which destination addresses are added.

A case will be described below, wherein data transmission/reception is to be performed with only the specific data terminals 51 and 61 in a state in which the line interface section 56 is already connected. The computer 73 writes messages for designating the specific data terminals 51 and 61 at the destination addresses, adds 15

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400e0 o .0 .3 0 .0 .3 00 03 them to the data, and outputs the resultant data. The data to which the destination addresses are added is received by the data receiver 75 through the data transmission line 74, and is transmitted to the data transmission/reception controller 52 through the data transmission path 77 of the line interface section 56 which has already been connected.

The controller 52 checks whether the destination addresses added to the data have a message for designating the data terminal 51, and transmits the received data to the data 10 terminal 51. The controller 52 checks whether the destination addresses have a message for designating another data terminal, and transmits the data, through the data transmission path 79, to the controller 62 which is connected to the data terminal 61 which is designated by 15 the message.

(ii) Data transmission/reception without line connection of the line interface section 56 A case will be described below, wherein the computer 73 performs data transmission/reception with only a specific data terminal, the data terminal 58. The computer 73 outputs line connection data for connecting the data receiver 75 to the data transmission/reception controller 59. This line connection data is transmitted to the line control section 68 of the electronic exchange through the line connection data line 71. The line control section 68 connects the data receiver 75 to the reception 16 7i ;I line 60 of the controller 59 through the data reception path in accordance with the line connection data.

When the above-described line connection process is completed, the computer 73 outputs data to be transmitted to the data terminal 58. This data is received by the data receiver 75. Subsequently, the data is transmitted to the data transmission/reception controller 59 through the reception line 60, and hence o o, transmission/reception of the data is performed with the 10 data terminal 58.

o 0 n the above-described embodiment, connection of the line interface section and transmission methods of data to be transmitted are selected depending on whether the same data is to be transmitted to data terminals, and a 15 line connection state of the line interface section.

4 °However, the present invention is not limited to this. For example, the data receiver and a specific data Itransmission/reception controller, and the specific data btransmission/reception controller and the specific datadata transmission/reception controller and other data transmission/reception controllers are always connected to each other through the line interface section, regardless of whether data to be transmitted to the respective data terminals are the same or not.

Furthermore, in the above-described embodiment, data transmission/reception between the computer serving as a data terminal and other data terminals has been described. However, transmission/reception of data can be t; 17 performed between data terminals other than the computer.

In this case, line connection data is supplied from a specific data terminal to the computer through a corresponding data transmission/reception controller and the response data line. In accordance with this line connection data, the computer designates the line control section to perform line connection for allowing transmission/reception of data between corresponding data no9 terminals. The transmission and reception lines of a 0 10 specific data terminal are respectively connected to the 4. reception and transmission lines of another data terminal in the line interface section, thus performing data transmission/reception therebetween.

As has been described above, according to the present invention, since the lines of a plurality of data terminals can be simultaneously connected to each other upon designation by the computer, the same data can be transmitted to a plurality of data terminal by one data transmission operation. Hence, erroneous connection of terminals can be minimized. In addition, the time required jl for data transmission/reception can be shortened., 18-

Claims (4)

1. A method of performing data communication between a plurality of data terminals, in a data communication system including a plurality of data terminals for performing transmission/reception of data, and an electronic exchange for performing line connection between at least one specific data terminal of said data terminals and other data terminals upon a request from said one specific data terminal, wherein data transmission/reception controllers are respectively arranged between said data terminals and said electronic exchange, a plurality of destination addresses are combined with data to be transmitted, and each of said data transmissioin/reception controllers transmits received data to a data terminal connected thereto when the received data includes a destination address thereof, while transferring data including another destination address to a data transmission/reception controller designated by said i 15 another destination address.

2. A method according to claim 1, wherein said data communication system includes a computer connected to said electronic exchange, so that when a transmission request is output from said one specific data terminal to said computer, said computer controls said electronic exchange to perform line connection between a data transmission/reception controller connected to said one specific data terminal and other data Stransmission/reception controllers designated by the requested designated addresses, and the data including the plurality of destnaton addresses is subsequently supplied to said other data transmission/reception controllers designated by the requested destination addresses via connections established in the electronic exchange.

3. A method according to claim 2, wherein when response data is required in accordance with the data to be transmitted,, response data which are prepared by said respective data terminals on the basis of the received data are sequentially supplied to said computer through said electronic exchange, and edited into one response data by said computer, and said one response data is subsequently supplied to said data terminal which transmitted the data. HRF/0532y T S r j cl- _Ic I~ I ~1

4. A method of performing data communication between a plurality of data terminals, in a data communication system, said method being substantially as described with reference to Figs. 1 to 3 of the accompanying drawings. DATED this SECOND day of JULY 1991 NEC Corporation Patent Attorneys for the Applicant SPRUSON FERGUSON r 0 HRF/0532y %la -w 14qqN T