FR2534429A1 - Method of exchanging and routing information and switching circuit between a terminal and an item of data circuit terminal equipment, for radiowave transmission. - Google Patents

Abstract

The invention relates to the implementing of a system for communication by radiowave transmission for data transmission. It relates to an installation enabling a terminal 18 to directly control the radiowave transmission of data to one or more selected terminals, possibly different, from one data group to the next. A circuit 28 according to the invention makes it possible to transmit information from the terminal 18 and from its peripherals 20, 22 placed remotely, to the data circuit terminal equipment 10 via a simple telephone line of the switched network 26. Application to switching systems simultaneously serving fax machines and terminals of the screen-keyboard type.

Description

 The present invention relates to a method for exchanging and routing information between a terminal comprising at least two peripherals operating with different formats, and a data circuit termination equipment for Hertzian transmission.

The invention also relates to a switching and adaptation circuit intended for the implementation of such methods.

 It should therefore be noted that, in the present document, the expression "Hertzian transmission" generally designates the use of any communication system comprising a transmitter and at least one receiver distant from each other; the Hertzian transmission thus carried out is also called unidirectional since operating only in the transmitter to receiver and multipoint direction since the same transmitter can transmit information simultaneously to several receivers.

 It should also be noted that, in the present specification, the expression “data circuit termination equipment” designates all the modules necessary for the exchange of information between a terminal directly connected to the switched network and the transmitter or the Hertzian transmission receiver. The same data circuit termination equipment can advantageously ensure the exchange of information with several terminals to which it is connected by the switched telephone network or a dedicated line.

The distance between a terminal, a data circuit termination device, a transmitter or a receiver can be as large as necessary.

 Currently, the use of wireless data transmission is becoming more and more important; very generally, these are links between a transmitter and a single receiver, a point-to-point unidirectional link. There are also known devices which allow the establishment, from a single point-to-point link, of a certain number of paired data channels of peripherals using the same given format; the operator uses either one or the other of the available communication channels.

 The invention relates to the extension of the possibilities for operating wireless data transmission systems, this extension relating on the one hand to the facilities for addressing data and, on the other hand, to the increase in the number of users. concerned.

 The extension relating to the facilities for addressing data, therefore for selecting the recipient (s), is obtained by the use of data circuit termination equipment enabling dialogue with a terminal comprising two different peripherals, and the routing of data via the network.

 More specifically, the terminals currently used do not have the possibility of transmitting selectively and simultaneously from the switched network data to one or more other terminals, in particular by Hertzian transmission. However, it is sometimes very advantageous to transmit information intended for numerous recipients at the same time, information which is otherwise not received by those who are not recipients.

The data circuit termination equipment implemented according to the invention comprises a device enabling a terminal having peripherals corresponding to the different data formats to supply the addressing information of the terminals receiving the data.
The data circuit termination equipment comprises a device processing the information corresponding to the various peripherals. The data of a peripheral being in relation with the data of another peripheral and the passage from one to the other peripheral being carried out by a management module included in the device.

 The second extension made possible by the invention is the increase in the number of users. In fact, the peripherals of the transmission terminals are generally expensive. The least expensive are the keyboard-screen type devices, the graphics type devices being, on the contrary, very expensive.

 In addition, "point to point" data transmissions are generally more expensive than "multipoint" transmissions intended for several receivers simultaneously. According to the invention, the association of a device of the short-screen keyboard-screen type, for example of the "MINITEL 'type, with a Type III fax machine, allows the formation of a terminal having both the possibilities of a visual, a keyboard and a graphic terminal and using only industrially developed elements on a large scale whose cost can therefore be reduced.

 Regarding transmission costs, they are divided by the number of effective recipients of the same message since it is transmitted only once.

The association of the two peripherals in the terminal does not require any modification according to the invention. An additional device, a telephone handset, is advantageously associated with the two peripherals.

 It should be noted that, in the present specification, the term "terminal applies to a device capable of being connected to a remote device by means of a communication system.

 According to the invention, all the adaptation operations which are necessary because of the use of different formats in radio transmission and in the peripherals, are ensured by a single circuit connected, on the one hand, to the switched network so that it allows exchanges with remote terminals and, on the other hand, with conventional transmission or reception equipment, which itself can be located remotely.

 It should be noted that, in the present specification, the term "format" characterizes the coding of the information. Thus, the expression "character format" designates a character code, and the expression "vibrate format designates a data code formed, by for example, segments of bit strings representative of graphical data or their analysis.

 According to the invention, a switching and adaptation circuit ensures the passage from one format to the other or from one peripheral to the other when the content of the information exchanged requires it.

More specifically, the invention relates to a method for exchanging information between a terminal comprising at least two peripherals operating with different formats and a data circuit termination equipment operating in at least two different formats of data and intended, moreover, to the transmitter or to a receiver of a hertzian transmission system, the processing of the data of one format is, moreover, associated with the data of another format, the said method being characterized in that it comprises
- the establishment of a communication, by a single transmission line, between the terminal and the data circuit termination equipment, by connection of a first peripheral to the corresponding module of the data circuit termination equipment , this module being capable of processing the data corresponding to a first format,
- exchanging data in a first format between the first peripheral and the data circuit termination equipment,
the connection of the second module of the data circuit termination equipment in place of the first module of this same equipment, the second module being capable of processing data having a second format different from the first,
- the connection of a second peripheral to the transmission line instead of the first peripheral, the second peripheral being intended to exchange data having the second format,
- the adaptation of the data exchange modalities having the second format between the data circuit termination equipment and the second peripheral,
the exchange of data in a second format between the second peripheral and the data circuit termination equipment, and
- release of the data transmission line.

 It is advantageous that the data circuit termination equipment is connected first to the first peripheral and allows an exchange of information which includes in particular the list of recipients and possibly other data then directly controls access to the system. Hertzian transmission.

 The connection of the module of a first format or module of a second format to the module of a second format or module of a first format is preferably carried out automatically at the level and by the data circuit termination equipment at the end of data exchange between a peripheral and the data circuit termination equipment.

 The adaptation of the terms of exchange advantageously includes the determination of the resolution, the format of the document, etc.

 It is very advantageous for the first peripheral to be of the visual type, for example a "directory terminal" and for the second peripheral to be of a test forming type, preferably a teletypewriter, for example a group III fax machine or "Mass Market". ".

 It is advantageous that certain operations are carried out by an operator. Thus the establishment of the communication is normally executed (except in automatic reception) by an operator. The latter can, in addition, ensure the connection of the second device in place of the first, after the data circuit termination equipment has switched from the module of one format to the module of another data format.

 In addition, it is desirable that an operator, having for example a telephone handset, controls the establishment of the communication and then the execution of the operations for switching from a first format to the second format, these latter operations being detected by suitable line tones.

The invention also relates to a switching and adapstation module intended to be associated with a data circuit termination equipment each accepting different data formats, this module comprising
- a switch having an input channel and at least two output channels, the switch being normally returned to the position in which the input channel is connected to a first output channel,
- a switch control member,
a circuit for adapting the data exchange conditions, mounted in a second output channel, and
- the input channel being intended to be connected to a single line of the switched or specialized network, and the output channels being intended to be connected to different modules of the data circuit termination equipment, this data circulating on these different exit routes having different formats.

 It is advantageous that the first output channel corresponding, for example, to the exchange of data with a display, comprises a modulator-demodulator, the switch then being controlled by signals transmitted by one or the other of the output channels.

 It is advantageous for the adaptation module to include a modulator-demodulator suitable for reception, for example data from a fax machine, and a circuit intended for interrogating a remote device, for example a fax machine, via the line, and determine the appropriate transmission procedure for that device and data circuit termination equipment accordingly.

 I1 is also desirable that the module includes a coupler mounted on an input channel and intended to ensure coupling to a telephone line of the switched network.

 It is also desirable to include in the data circuit termination equipment an automatic call equipment allowing the automatic transmission of data in a second format to a subscriber equipped with a fax machine.

 Thus, the implementation of the invention does not require any modification either of the user terminals or of the lines which are simply formed by the switched network. A simple switching and matching circuit is mounted at the input of the data circuit termination equipment.

 It is advantageous to integrate into the data circuit termination equipment a memory module capable of storing a sufficient number of information in the various formats so that it can be retransmitted later either to a destination terminal or to the sender of the Hertzian transmission system.

Other characteristics and advantages of the invention will emerge more clearly from the description which follows, given with reference to the accompanying drawings in which
FIG. 1 is a block diagram of an installation allowing the implementation of the method of exchanging information in transmission and in reception;
FIG. 2 schematically represents an example of a terminal produced in a known and useful manner for the implementation of the invention;
FIG. 3 is a block diagram of a switching and adaptation circuit according to the invention, and
FIG. 4 is a more detailed block diagram of an embodiment of a circuit of the type shown in FIG. 3.

 Figure 1 is a block diagram of an installation useful for the implementation of the invention. This installation includes data circuit termination equipment 10 connected to a transmitter 11 and two other data circuit termination equipment 100 and 900 respectively connected to receivers 110 (for 100) and 910 (for 900) of the transmission system. - Hertzian. Each data circuit termination equipment comprises for example two modules 12, 14; 120,140; 920, 940 allowing the processing of information according to the different formats; a management module 16 and in particular for switching between the modules 12 and 14 as well as the modules 160; 960 respectively for modules 120, 140; 920, 940.

 Each data circuit termination equipment also includes a communication module 17; 170; 970 in particular loads the exchange with the transmitter 11 or the receiver 110; 910 and controlled by the management module 16; 160; 960. It includes in particular the memory capacity necessary for the storage of information.

A terminal 18 comprises a first peripheral 20, for example a visual, very advantageously a "Minitel" directory terminal, and a second peripheral 22, advantageously a Type III fax machine, for example of the TC 103 type from MATRA, T60 from Thomson CSF, or "SAFAX" 2000 from
SAGEM, a switching device 24 allows the alternate connection of the terminal 18 to the line 26 which is advantageously an ordinary subscriber line of the switched network.

 A switching and adaptation module 28 is connected on the one hand to line 26 of the switched network and on the other hand to the data circuit termination equipment 10.

 Two other terminals 180, 980 each include a first peripheral 200, 1000, for example a display identical to peripheral 20 and a second peripheral 220, 1200, for example a Type III fax machine identical to peripheral 22, an identical switching device 160, 1060 to the device 24 allows the alternating connection of each terminal to the corresponding line 260, 860 of the switched network.

 A module 280, 1080 per terminal performs the switching and adaptation and is connected, on the one hand to the corresponding line 260, 860 of the switched network and on the other hand to each of the pieces of equipment 100, 900 for terminating the data circuit themselves connected to receivers 110, 910 of the Hertzian transmission system (9).

Each data circuit termination equipment 10, 100, 900 is not of the type currently used, formed by simple juxtaposition of the modules that compose it. In fact, the constitution of the data circuit termination equipment is original because it connects to a single line of the switched network, it makes it possible to communicate successively with several peripherals on the one hand, and with a transmission system.
Hertzienne on the other hand More precisely, each set of modules 12, 14; 120, 140; 920, 940 established, for each module 17; 160; 960 the correlation defined between the information of the peripheral groups 20, 22; 200, 220; 1000, 1200 and this, thanks to each management module 16; 170; 970
In the case where at least two terminals 180; 980 are in connection with two receivers 110; 910 through the data circuit termination equipment 100, 900, it is possible to transmit from the terminal 18 in a single message different information for each terminal 180; 980, the selection being only carried out at the terminal 18. Each terminal can therefore receive different data but also each peripheral 200, 220; 1000, 1200, or, for example, the directory terminal on the one hand and the fax machine on the other.

 Thus, other receivers can be used without modifying the principle of the invention or the operation of the installation.

 The circuits necessary for such an operation are well known to specialists and their operation is not repeated in detail in the present brief.

 The terminal 18 is represented in a more detailed form, in one embodiment, in FIG. 2. The visuals constitute the "directory terminals", well known today, comprising in addition to the visual 20, a switch 24 which allows the connection of the subscriber line 26 either on display 20 or on the outside line 30. Usually, this line 30 is connected to a telephone handset such as 34. In the terminal according to the invention, this line 30 is however connected to a switch 32 of a facsimile machine 22, the facsimile machine being normally held in the position in which the wires 30 and 36 are connected.

In this way, when neither the display 20 nor the facsimile machine 22 has been ordered, the telephone handset -34 is connected to the subscriber line 26.

 Each terminal 180; 980 is identical in principle to terminal 18.

 We now consider in more detail the switching and adaptation module 28 identical to the modules 280; 1080 and which is represented in the form of a block diagram in FIG. 3 and in more detail in FIG. 4.

 The switching and network adaptation module first comprises a line coupler 38, intended to ensure the connection with an ordinary line of the switched network or even a dedicated line. This coupler is connected to a switch 40. Two channels also come from the switch; the first is connected to a first modulator-demodulator 42 and the second to a second modulator-demodulator 44. The first output path leads to module 12 identical to modules 120 and 920 comprising in particular a circuit allowing dialogue with a peripheral of the type visual, for example a directory terminal. The second output channel comprises> in addition to the modulator-demodulator 44, an information / signaling switch 46, connected to a logic control circuit 48, and a circuit 50 for processing control characters or of a particular type. This second path leads to a connection 51 intended to be connected to the module 14 identical to the modules 140, 940, and responsible in particular for the processing of the data and their possible partial storage if necessary.

 The modulator-demodblator 44, the switch 46 and the logic circuit 48 constitute a circuit 52 described in more detail below. In the particular case considered, the connection 43 is connected via the processing module 12, identical to the modules 120; 920, to the communication module 17; identical to modules 160; 960 which manages exchanges with the transmitter module or the receiver module of the Hertzian transmission system 9.

In the embodiment considered, the switch 40 is normally recalled so that it ensures the connection of the coupler 38 to the modulator-demodulator 42. The switch 40 is controlled by the logic circuit 48 which indicates to it when it must switch. When circuit 48 controls the switch so that it connects the second channel, coded data can be exchanged between the fax machine and the processing module 14 identical to the modules 1409 940 and which exchanges information with the switching module 17 identical to the modules 160 ; 960
We now consider more precisely the operation of the circuit in FIG. 3. Subscriber A having the terminal shown in FIG. 2 wants to transmit information partly to a subscriber B and for the rest to a subscriber Cq both subscribers B and C also having a terminal as shown in FIG. 2.

 Subscriber A lifts the handset and dials the telephone number corresponding to the data circuit termination equipment. The switches 24 and 32 are in their position of direct connection of the handset to the line 26, and the switched network ensures the connection to the circuit 28, and more precisely to the coupler 38 and to the switch 40.

 This is in the position in which the coupler 38 is connected to the modulator-demodulator 42 so that, via the connection 43, the management circuit 16 is brought online. When it receives a first tone, the operator connects the directory terminal, in the form of a display 20, and the subscriber can exchange information with the processing module 12; for example, it can receive a distribution list comprising the respective "addresses" of subscribers B and C on the Hertzian transmission system. The operator then enters the code numbers corresponding to these addresses on the keyboard of the directory terminal and can optionally enter a message in the form of accompanying characters on the keyboard of the display 20. All of this information is, for example, stored in the processing module 12.

 At the end of the transmission of this information in the form of characters, the operator transmits the end signal by a special key on the display 20 and the management circuit 16 causes the switching from module 12 to module 14 for processing, ie circuit 42 to circuit 44; the operator having resumed listening to the telephone handset, notes that after all signal on the line has disappeared, a new tone appears to be generated by the correspondent and more specifically by the modulator-demodulator 44 and transmitted through circuits 40 and 38.

 The operator then connects the facsimile machine 22 to line 26, which then exchanges, with circuit 52, signals indicating the possible methods of transferring data between the facsimile machine 22 and the data circuit termination equipment 10. The the fax machine then selects a possible transmission mode and then orders the exchange. When the data is received by the facsimile machine, it is circuit 52 of the data circuit termination equipment which then controls the exchange.

 This exchange corresponds to the transmission of information entered by the fax machine on a sheet of paper placed by the operator on the corresponding area of the fax machine.

The data received in our example, by the data circuit termination equipment, is stored in the processing module 14
In a different example, the operator may wish to transmit different data to subscribers A and B; in which case, after a first exchange, in accordance with the preceding description (however striking only the address of A), the circuit 44 and the module 12 are again put on line with the terminal 20 which makes it possible to choose, for the second exchange, the address of subscriber B.

 At the end of these exchanges, which can be as numerous as desired, the circuit 52 then commands, by line 53 connected to the communication module 17, the start of the radio transmission phase by sending information from the modules 12 and 14 in a single message.

 On reception, and depending on whether the data circuit termination equipment 100 or 900 has recognized or not the address of the corresponding subscriber, an identical process, the information then coming from the receiver, will take place with the additional possibility of the subscriber to receive directly and automatically the data intended for the peripheral 220; 1200 of the facsimile type, that is to say the data sent from the facsimile machine 22.

 It should be noted, in FIG. 3, that the circuit 52 comprises only part of the logic circuit 48. This characteristic is explained in the remainder of this specification with reference to FIG. 4, It should also be noted that a circuit shown in dotted lines indicates the connection of a specific coupler which allows control of the switch 40 via the signals of the telephone channel, in a variant of the device according to the invention. Control of the switch by circuit 48 is then no longer necessary.

 We now consider the circuit shown in more detail in Figure 4. The elements bearing the same references as in the previous figures have the same meaning, Thus, the coupler, the switch and the modulatorsmododulators have the same role as before.

On the other hand, the configuration of the circuit 52 is detailed. The switch 54 used in transmission is connected to a logic circuit 64 for management and control by a circuit 66 generating a frame control polynomial and by a circuit 68 for constituting a frame. The switch 56 used in reception is connected to the logic circuit 64 by a frame analysis and control circuit 70 and by a frame validity control circuit 72. Lines 74 further connect the circuit 64 to circuits 76 which create and analyze the command field, create and analyze the information field (mEmoPisation) create and analyze the address field and create and analyze the command field in facsimile as well as correspondence and conformity tests.

 All of the elements of the circuit 52 shown in FIG. 4 can be constituted by a microprocessor circuit already developed as an element of group III facsimile machines, such as facsimile machines 22.

 The circuits 58 and 60 correspond to the circuit 50 of FIG. 3.

Circuit 58 is intended to identify and transform special characters. The circuit 60 is intended to detect and insert control characters. These two circuits are specially adapted to a particular treatment sometimes necessary in Hertzian transmission systems; standard formats (ASCII, etc ...) must then be strictly observed.

 When the circuit 52 is of the developed type for type III facsimile machines, it is inconvenient to modify the microprocessors of the circuit so that it provides control of the switch. In this case, it is preferable that a special control circuit 62 controls the switch 40.

This circuit then advantageously controls the signals of the two channels, close to the modulator-demodulators, so that it determines the appropriate moment of switching and controls the good progress of the operations.

The device described above does not require any modification of the transmission lines or of the terminals which are available to subscribers.

Only the switching and adaptation circuit is incorporated between the subscriber terminal connecting to the switched network and the access point (transmitter or receiver) of the Hertvian transmission system, this access point can be connected by a network public data transport.

 Although it has been indicated that circuit 52 is formed by different circuits, most of the functions of these can be fulfilled by a microprocessor and associated components such as random access memory, passive memory, etc.

 Although an embodiment has been described in which the switch 40 was controlled by a specific electrical circuit, it can also be controlled by tones circulating in the telephone line and picked up by a specific coupler, as suggested by the circuit indicated in dotted lines in Figure 3.

 Of course, the various elements are of a well known type adapted to the specifications set by the user country. For example, there are standards concerning the transmission of data in character format, the transmission of facsimile data, etc. In particular, the modulator-demodulators 42 and 44 are adapted to the speeds of the different signals. Likewise, the circuits 58 and 60 which together form a transcodeus are adapted to the particular nature of the transmission system. All of these adaptations are well known to those skilled in the art and are therefore not described in the present specification.

 It is understood that the invention has only been described and shown as a preferred example and that any technical equivalence may be made in its constituent elements without going beyond its ambit.

Claims (9)

1. A method of exchanging information between a terminal comprising at least two peripherals operating on the switched network or on a dedicated line, and data circuit termination equipment intended for connection to a radio transmission system; data in a format that can modify the characteristics of the transmission of all or part of the data.Characterized in that it includes  - establishing communication between the terminal (for example 18) and the data circuit termination equipment (for example 10) by a single data transmission line 26 by connection of a first peripheral (20) from the terminal to a first module (12) of the data circuit termination equipment (10), the data processed in this first circuit having a first format,  - the exchange of data between the first module (12) of the data circuit termination equipment (10) and the first peripheral (20),  - the connection of the second module (14) of the data circuit termination equipment (10) in place of the first module (12) to the transmission line (26), this second module (14) having data according to a second format different from the first,  - the connection of a second peripheral (22) to the transmission line instead of the first peripheral (20), the second peripheral (22) being intended to exchange data having the second format,  - the adaptation of data exchange methods having the second format between the data circuit termination equipment (10) and the second peripheral (22), and  - release of the data transmission line (26). 2. Method according to claim 1, characterized in that the data circuit termination equipment (for example 10) is connected first to the first peripheral (for example 20) and the exchange between the first module ( 12) and the first peripheral (20) comprises in particular the transmission of a list of possible recipients. 3. Method according to one of claims 1 and 2, characterized in that the connection of the first module (for example 12) to the second module (14) of the data circuit termination device (10) is preferably carried out automatically by the data circuit termination equipment (10) at the end of the data exchange between the first module (12) and the first device (20). 4. Method according to any one of claims 1 to 3 characterized in that the first device (for example 20) is a visual and the second device (for example 22) is of a type forming a test. 5. Method according to any one of claims 1 to 4, characterized in that it further comprises controlling the establishment of communication, as well as the disconnection of a first module (for example 12), the data circuit termination equipment (10) and the connection of a second module (14) of the data circuit termination equipment (10) to the line (26). 6. Switching and adaptation circuit intended to be connected to a local or remote Hertzian transmission system (9); which circuit being characterized in that it comprises  - a switch (40) having an input channel and at least two output channels, the switch being returned to the position in which the input channel is connected to a first output channel when it is in the state of rest,  - a switch control member (62), and  - a circuit (52) for adapting the data exchange methods, mounted in a second output channel,  - the input channel being intended to be connected to a single transmission line (26), and the output channels being intended to be connected to modules (12 and 14) processing the data differently, the data transmitted by the two channels with different formats. 7. The circuit as claimed in claim 6, characterized in that the first output channel comprises a modulator-demodulator (42) and in that the switch control member (62) is controlled by signals transmitted by one of the exit routes. 8. Circuit according to one of claims 6 and 7, characterized in that the adaptation circuit (52) comprises a modulator-demodulator (44) and a circuit (64) intended to communicate with a remote device by the intermediate of the transmission line (26) and to determine the modalities for the transfer of information accordingly. 9. Circuit according to one of claims 6 to 9 characterized in that it also comprises an automatic call equipment on a switched network mounted on the entry channel.