FR2790169A1 - Telephone line inter equipment double call ringing technique having specific frame transmission protocol inserted and transmission sequence detected/specific frame identification words added. - Google Patents

Abstract

The double call ringing technique between communication equipment across a telephone line has transmission protocol with a specific frame (21) carrying a repetitive symbol (22). During transmission the specific frame is detected and digital identification words are inserted in the identification signal.

Description

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  COMMUNICATION EQUIPMENT CALLING METHOD

  DURING A TRANSMISSION OF DATA IN PROGRESS AND

ASSOCIATED COMMUNICATION EQUIPMENT

  In the telecommunications sector, many telephone network operators now offer a double call service and

  a caller ID service.

  i0 The inquiry call service lets you notify an incoming call, or "call waiting", to a device, for example a fax machine, while the latter is in the middle of a telephone call, by a tone

specific appeal.

  The caller identification service allows a device, in the event of an incoming call, to receive caller identification data, namely its call number, without going off-hook, in other words without establishing with

  calling it a circuit type telephone communication.

  Equipment having access to both services, caller ID and inquiry call, can therefore, in the event of an incoming call, while it is already in the course of a telephone call, receive a call tone in

  instance and the caller's telephone number.

  When transmitting a fax between two fax machines, each fax machine executes a fax protocol, for example the T30 protocol, by exchanging protocol frames. This protocol notably includes a performance negotiation phase and a facsimile data transmission phase, with positive acknowledgments or

  negative, depending on the quality of the transmission.

  If a call is received by a fax machine with access to the caller ID service and the inquiry call service, while a fax transmission is in progress, the call waiting tone and especially the received caller ID information disrupts fax transmission. Such a disturbance, when it occurs during the fax image data transmission phase, risks

  loss of points or even entire lines of the fax.

  In short, the reception of the identification data and the call tone

  may affect the quality of the current transmission.

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  The present invention firstly aims to limit the risk of loss of useful data by the called equipment, in the event of an incoming call occurring during a data transmission in progress, due to the reception of identification data from the appellant. To this end, the invention relates to a method of calling a communication equipment by another communication equipment through a wired telephone network, in which, the equipment called being in the course of communication 1o, through said network telephone, for the transmission of data according to a transmission protocol, on the network side, identification data of the calling equipment is transmitted to the called equipment, characterized in that said transmission protocol comprising at least one specific frame comprising a repeating pattern part, on the network side, the transmission to the called equipment of said specific frame is detected and the repeating pattern part of the latter is inserted

  identification data of the calling equipment.

  The invention finally consists in spying, on the network side, the data transmission in progress of the called equipment in order to detect the transmission of a frame with repeating patterns, and in deliberately destroying some of these patterns, transmitted in a redundant manner, by transmitting caller ID information. The pattern is received at least one

  times by the called equipment which does not lose any useful information.

  In short, thanks to the invention, the quality of the transmission is not altered.

  Advantageously, on the network side, a call waiting tone is inserted.

  in the repeating pattern part of the frame.

  Thanks to this, the pending call is signaled to the called equipment, without

  alter the quality of the transmission.

  In a particular embodiment, on the network side, a specific preliminary tone is inserted into the repeating pattern part of the frame to ask the called equipment if it accepts to receive the data.

  identifying the calling equipment.

  Advantageously, on the called equipment side, the tone is detected

  preliminary and a response, acceptance or refusal tone is emitted.

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  Preferably, the specific frame is a V2 1 modulation frame.

  The invention also relates to communication equipment for implementing the above method, comprising means for receiving and transmitting data over a wired telephone network and means for executing a data transmission protocol, characterized by fact that it comprises means for detecting, during a data transmission in progress, a specific preliminary tone constituting a request for transmission of identification data of an item of equipment

io calling.

  The invention will be better understood using the following description of a

  particular embodiment of the calling method and of a particular embodiment of the communication equipment of the invention, in i5 with reference to the appended drawing in which: - Figure 1 represents a functional block diagram of the equipment of communication, according to the particular embodiment, and - Figure 2 represents information received and transmitted by the equipment of Figure 1, concomitantly with the reception of a protocol frame of

  fax, repetitive patterns.

  In the particular example of the description, the equipment of

  communication is a facsimile machine 20 connected by a wired link to a wired telephone communication network 100, in this case the switched telephone network (PSTN), and having access to a caller identification service and to a double service call, provided by an operator of the

telephone network 100.

  The inquiry call service allows the fax machine 20 to receive a call waiting tone, in the event of an incoming call occurring during a

communication in progress.

  The caller identification service enables the facsimile machine 20 to receive, in the event of an incoming call, caller identification data,

  in this case his telephone number.

  The facsimile machine 20 comprises a fax transmission and reception unit 1, connected by a wired link to a telephone line of the network 100, a modem 2, connected to the transmission and reception unit 1, a keypad for

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  input 3, a display screen 4, a buzzer 5, a print block 6 and a

  block 7 for managing incoming calls.

  The transmit and receive block 1 is for transmitting and receiving facsimile data in the form of analog signals. Modem 2 is intended, in transmission, to modulate data to be transmitted into analog signals and, in reception, to demodulate analog signals

  received in order to transform them into data.

  The "buzzer" 5 is intended to emit a call waiting beep, that is to say

  an audible signal to warn a user of a pending call.

  The incoming call management block 7 includes - a module 9 for detecting a call waiting tone and for controlling the buzzer 5, a module 10 for detecting a specific preliminary tone, constituting a request for transmission of the number telephone call from a fax machine calling, during a data transmission in progress, a module 1 1 for transmitting a response tone (acceptance or refusal) to a preliminary tone as explained below above, and a module 12 for intercepting the telephone call number of the

calling fax machine.

  The input keyboard 3 includes a key allowing a user to activate or deactivate a functionality for receiving the caller's call number, in the event of an incoming call occurring during a fax transmission in progress, in ordering in module 1 1

  to emit either an acceptance tone or a refusal tone.

  The facsimile machine 20 further comprises a block 8 for executing a facsimile transmission protocol, in this case the T30 protocol, and a central unit 13, to which all the elements described above are connected, and

  to control the operation of the facsimile machine 20.

  The method of calling the facsimile machine 20 by another facsimile machine 30 will

now be described.

  When the facsimile machine 30 is called, the called facsimile machine 20 is in communication with another facsimile machine, not shown, for the purpose of

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  fax data transmission, following the T30 fax protocol. The T30 protocol comprises frames, here of V21 modulation, comprising a header part with repeating patterns and a useful part. The repeating pattern part contains a pattern, also called "flag" by the skilled person, consisting of eight bits of value "7E", that is to say of hexadecimal value, and repeated for one second at speed from 300

  bits / second. The useful part contains useful information.

  We first place ourselves in the case where the functionality for receiving the caller's call number, in the event of an incoming call occurring during a

  fax transmission in progress, is activated.

  i5 On the telephone network 100 side, a spy device, in this case a PABX, monitors the current communication from the fax machine called 20, determines that it is a fax transmission, detects the transmission of a modulation frame. V21 21 to the called facsimile machine and locates the repeating pattern part 22 of this frame 21. The repeating pattern part 22 of the frame 21 should normally be received by the facsimile machine 20 during a period T, of duration substantially equal to

a second.

  The PABX inserts a call waiting tone 24 into the repeating pattern part 22 of the frame 21, transmitting the call waiting tone 24 to the facsimile machine 20, during period T. Upon receipt of this tone 24, the detection module 9 detects it and then commands the activation of the buzzer 5 which emits a call beep to signal the call

pending.

  Then, on the telephone network side 100, the automatic branch exchange inserts in the repeating pattern part 22 a specific preliminary tone 25 to ask the called facsimile machine 20 if it accepts to receive the telephone number of the calling facsimile machine 30, by transmitting the tone preliminary 25 towards the facsimile machine 20, during the period T. On the facsimile machine called 20, the detection module 10 recognizes and detects the preliminary tone 25, predefined in memory. The transmission module 11 then commands the transmission of an acceptance tone, during the

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  period T, under the control of the detection module 10, as well as

  activation of the interception module 12.

  On the network side 100, the PABX receives the acceptance tone and then inserts into the repeating pattern part 22 of the frame 21 a "CLIP" call 27 (Call Line Identification Presentation) 'call), containing the telephone number of the calling fax machine 30, by transmitting CLIP 27 to fax machine 20, during period T. On the fax machine side called 20, when receiving CLIP 27, the interception module 12 intercepts the fax telephone number

  calling 30 and controls its display on the screen 4.

  It should be noted here that the reception of the call waiting tone 24, the preliminary tone 25 and the caller's telephone number 27, as well as the emission of the response tone 26 occurring during the period T, disrupt the transmission of the repeating pattern part 22, destroying some of the transmitted "7E" patterns. However, these reasons being transmitted in large numbers, the fax machine called 20 receives at least

  one and therefore does not lose information.

  After having received the repeating pattern part 22, the called facsimile machine receives the useful part 23 of frame 21, then the following frames of the transmission.

fax machine.

  In the case where the functionality for receiving the caller's call number, in the event of an incoming call occurring during a fax transmission in progress, is deactivated, the facsimile machine 20 receives the call waiting tone then the preliminary tone, inserted in the patterned part of a frame V21 by the PABX of the telephone network 100, as previously explained. After reception and detection of the preliminary tone, the facsimile machine 20 emits a refusal tone to indicate to the automatic branch exchange that it refuses to receive the telephone number of the calling facsimile machine. The rest of the V21 frame is then transmitted and received normally. We could also consider automatically transmitting the caller identification data, without a preliminary tone to ask

  the equipment called if it agrees to receive them.

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  Finally, provision could also be made to signal a pending call to a user by visual signaling, for example by switching on a

  indicator light or by displaying a message on the fax screen.

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Claims (9)

  1- Method of calling a communication equipment (20) by another communication equipment (30) through a telephone network (100), in which the called equipment (20) being in communication, through said telephone network (100), for the transmission of data according to a transmission protocol, on the network side (100), transmission data 1o of the calling equipment (30) is transmitted to the called equipment (20) , characterized in that, said transmission protocol comprising at least one specific frame (21) comprising a repeating pattern part (22), on the network side (100), the transmission to the called equipment (20) of said said is detected specific frame (21) and the data is inserted into the repeating pattern part (22) thereof   1 5 (27) identifying the calling equipment (30).   2- The method of claim 1, wherein, network side (100), inserting a call waiting tone (24) in the repeating pattern part (22) of the frame (21).   3- Method according to one of claims 1 and 2, wherein, network side   (100), a specific preliminary tone (25) is inserted in the repeating pattern part (22) of the frame (21) to ask the called equipment (20) if it accepts to receive the data (27) d identification of the calling equipment (30).   4- The method of claim 3, wherein, on the called equipment side (20), said preliminary tone (25) is detected and a tone is emitted.   response (25), acceptance or refusal.   - Method according to one of claims 1 to 4, wherein, side   equipment called (20), the identification data of the calling equipment (30).   6- Method according to one of claims 1 to 4, wherein the weft   specific (21) is a V21 modulation frame.   7- Communication equipment for implementing the method of claim 1, comprising means (1, 2) for receiving and transmitting data through a wired telephone network (100) and means (8) 9 2790169   for executing a data transmission protocol, characterized in that it comprises means (10) for detecting, during a data transmission in progress, a specific preliminary tone (25) constituting a request for data transmission ( 27) identifying calling equipment (30). 8- Equipment according to claim 7, wherein there is provided means (1 1) for emitting a response tone, acceptance or refusal, in case   receiving said preliminary tone (25).   9- Equipment according to one of claims 7 and 8, wherein it is provided   means (12) for intercepting data (27) identifying a calling equipment (30).   10- Equipment according to one of claims 7 to 9, wherein it is   provided means (9) for detecting a call waiting tone (24).   i 1- Equipment according to one of claims 7 to 10, wherein it is   provided means (5) for audible signaling of a pending appeal.   12- Equipment according to one of claims 7 to 1 1, wherein it is   provided means for visual signaling of a pending appeal.