FR2765061A1 - Fraudulent use detector for telephone lines - Google Patents

Abstract

The fraudulent use detector is inserted in the telephone line between the telephone (1) and the communications centre. A detector (2) is connected to the telephone line circuit (9) near the telephone, and a second detector (3) is connected in the incoming line (10) prior to the detector. A logic circuit (4) measures the difference between the two signal flows, and switches an alarm (6) if a difference is detected.

Description

1i 2765061

  ELECTRONIC DEVICE FOR DETECTING FRAUDULEU USES

  SES OF A TELEPHONE LINE AND OF DETERRENCE AGAINST THESE USERS

TIONS

GENERAL PRESENTATION

  A large number of telephone devices are connected to the telephone network by two

  electric wires ensuring their functioning.

  These wires, also called "pairs", pass to the telephone exchanges by passing

  by more or less numerous regrouping points.

  The pair corresponding to a given telephone line is therefore accessible in several

  points and beyond the control of the subscriber of the phone to which it is officially assigned.

  It is therefore possible, and even easy, for a fraudster to connect his own telephone to a

  accessible point of the pair concerned and to use the line to its advantage.

  This action is sometimes called "installing a ramp".

  Unless attempting to use the line when this fraudster is acting, the holder of the line may

  not being aware of anything and not being able to detect fraud.

  It can also happen that this fraud causes significant consumption,

  putable, despite himself, to the owner of the line.

  The invention relates to an electronic device which, connected to a telephone line,

  allows its holder to detect, at the time it occurs, the possible fraudulent use

  leuse it and discourage fraudsters.

  The device can hinder this fraudulent use and help confuse the fraudsters.

  The invention can also constitute an instrument for detecting certain teleprints.

  phonic. The invention can also be used on telephone lines comprising more than

two active sons.

  CONSTITUENT ELEMENTS OF THE INVENTION

  The figures show symbolic representations of the elements thus constituting it

  as links between these elements.

  According to the practical embodiments of the invention, the shape of the device as well as

  the arrangement of the constituent elements may be significantly different from those shown

felt in the figures.

  Referring to Figure 2, the device according to the invention consists of: - An upstream activity detector (2);

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  - A downstream activity detector (3); - A logic circuit (4); - A switch (5);

- A signaling device (6).

  Each of the elements constituting the invention is designated by a name summarizing its main function. The telephone line to be protected against fraudulent use is divided into two parts:

  - The upstream line (9), corresponding to the part of the line between the tele-

  phonic (1) and the place where the line is separated; - The downstream line (10) between the separation of the line to be protected and the end of the pair

  assigned to the subscriber in question, generally in the telephone exchange (11).

CONNECTIONS

  With reference to the figures representing the invention, the connections (otherwise called

  nexions), indicated on these, between the elements constituting it are connections which can

  be carried out by electrical conductors.

  They can also be carried out by any other means making it possible to transmit

  electrical impulses, such as, for example, electromagnetic induction.

  These connections can be direct from element to element, or indirect via one or

  several other elements whether or not constituting the invention.

  Two elements are said to be "connected" to each other when electrical signals can

  can be passed between them in one direction, in the other, or in both directions.

  The connections between elements are represented in the figures by a single line the

joining each other.

  The elements of the invention are connected together according to the following diagram: - The upstream line (9) is connected to the switch (5); - The downstream line (10) is also connected to the switch (5); - The upstream activity detector (2) is connected to the upstream line (9) and to the logic circuit (4); - The downstream activity detector (3) is connected to the downstream line (10) and to the logic circuit (4); - The logic circuit (4) is connected to the signaling device (6), the upstream activity detector (2), the downstream activity detector (3) and the switch (5);

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  - The switch (5) is connected to the upstream line (9), the downstream line (10) and the circuit

logic (4).

  - The signaling device (6) is connected to the logic circuit (4).

FUNCTIONS

  The constituent elements of the invention exchange with each other, using the connections

  described above, electrical signals, which can correspond to orders or to information

mations.

  Each element responds with defined actions to the various signals or orders it receives.

  The main functions of each of the elements constituting the invention are the following:

  tes: - The activity detectors (2) and (3) detect, at any time or punctually,

  the activity on the lines to which they are connected and address the logic circuit (4) if-

  general corresponding to the activities detected; - The logic circuit (4), a true "brain" of the invention, delivers to the switch (5) orders resulting from the analysis of the signals received from the activity detectors (2) and (3). These orders

  can be for example "open" or "close". This logic circuit also delivers or-

  dres to the signaling device (6), resulting from the same analysis. These orders can be by

  example "activate reporting" or "do not activate reporting".

  - The switch (5) obeys the orders of the logic circuit (4). To the signals corresponding to the "open" command, it responds with complete or partial isolation (in other words, disconnection) of the

  upstream and downstream lines (9) and (10) and those corresponding to the "close" order, it responds with the con-

  nexion of these lines between them. The connection of the upstream and downstream lines (9) and (10) then allows the

  normal operation of the telephone line.

  - The signaling device (6) obeys the orders of the logic circuit (4). To the signals corresponding to the order "activate the signaling", it responds by implementing the signaling systems, examples of which are given in the rest of the text, to those corresponding to the order "do not activate the signaling" it responds by remaining inactive Secondary functions can be assigned to each of the elements

  the invention according to the various possible variants in the operation thereof.

GENERAL OPERATION

  The general operation of the invention is as follows: - The logic circuit (4) receives, from activity detectors (2) and (3), signals indicating the state of the activity of the upstream line (9) and from the downstream line (10) and analyzes them;

  - The logic circuit (4) controls, depending on the result of this analysis, the switching

  tor (5) or the signaling device (6);

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  - The switch (5) connects the upstream and downstream lines (9) and (10) between them when the logic circuit (4) commands it, in the event, for example, of an attempt to use the telephone apparatus (1 ) by the designated user of the incoming line or telephone call; - The signaling device (6) is activated when the logic circuit (4) commands it, ie when only the downstream line (10) is active and it is not a call telephone

incoming picnic.

  A line is said to be "active" when it, or one of its portions, is used to con-

  duire electrical signals intended either to switch a call (following the composition of a number

  méro), either to transmit messages (telephone conversation, fax, etc.), or to implement other functions related to the use of the line (off-hook the handset to obtain

dial tone, etc.).

  Is called "Incoming call" or "Incoming telephone call" the call, by a third party and to

  from the network, the telephone set (s) (1).

  Is called "Registered User" or "Line Holder" the person or persons who can

  access the telephone set (1).

  The logic circuit (4) can establish the connections described above, and the various elements

  ment of the invention can operate, for example according to the following logic table:

LA9 LA10I DA2 DA3 DS6 LA9 / LA10

  Without activity Without activity State O State O Not activated Not connected Activity Without activity State 1 State O Not activated Connected Without activity Activity State O State 1 Activated Not connected Activity Activity State 1 State 1 Not activated Connected Without activity Ringing State O State 2 Not activated Connected The reading to be made of the table is as follows: 1st line: LA9 designates the upstream line (9); LA10 designates the downstream line (10); DA2 indicates the activity detector (2); DA3 indicates the activity detector (3); DS6 indicates the signaling device (6);

  LA9 / LA10 indicates the state of the connection between the upstream line (9) and the downstream line (10).

Following lines:

  Each line indicates a particular state of the device according to the invention.

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  Each box indicates the state in which the part of the invention designated at the top of the column in which it is found is, among these states, we can cite: - "No activity": no activity on the line concerned; - "Activity": activity on the line concerned; - "Ringing": activity linked to an incoming call; - "State0": no activity detection; - "Etatl": activity detection; - "State2": detection of incoming call (ringing); This operating logic can also be described as follows (the

  stages of each case are, except exception or simultaneity, written in chronological order

  sequence logic): Case N I: In the event of an incoming call The activity detector (3) detects and recognizes the incoming call (the ringing signal) and sends the specific signal corresponding to the logic circuit (4); The logic circuit (4) recognizes this specific signal and commands the switch (5) to connect the upstream and downstream lines (9) and (10) to each other; The regular user of the line can then use it normally;

  At the end of this use, the device returns to case N 2.

  Case N 2: Absence of activity on the upstream and downstream lines (9) and (10) The logic circuit (4) commands the switch (5) to maintain the upstream lines and

  downstream (9) and (10) disconnected from each other or, depending on the case or the manufacturing methods, do not

  see no order to connect these lines together.

  Case N 3: Attempt to use the telephone set normally (1) The upstream activity detector (2) sends to the logic circuit (4) the signal or signals indicating activity on the upstream line (9); The logic circuit (4) commands the switch (5) to connect the upstream and downstream lines (9) and (10) to each other; The switch (5) provides this connection and the device (1) can be used;

  At the end of this step, the device returns to case N 2.

  Case N 4: Attempted fraudulent use on the line (10)

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  The downstream activity detector (3) sends to the logic circuit (4) the signal or signals indicating activity on the downstream line (10), activity different from that linked to an incoming call; The upstream activity detector (2) sends to the logic circuit (4) the signal or signals indicating the absence of activity on the upstream line (9); The logic circuit (4) activates the signaling device (6);

  At the end of this step, the device returns to case N 2.

  All operating variants compared to the logic presented above can-

may be admitted.

  The signals processed and delivered by the logic circuit (4) as well as those produced and processed by the various elements of the invention are electrical signals which can be for example

binary type.

  Some of the elements of the invention can for example react to an absence of signal

electrical in their connections.

  The STATE 0 described above can for example be obtained following a lack of current

  in the connections between the elements constituting the invention, the STATE 1 has a presence of

  rant, and STATE 2 to a combination of the two states described above.

  The opposite of the case described in the preceding paragraph can also be implemented.

  The same applies to the activation of the signaling device (6) and the switch (5).

VARIANTS

  Grouping of elements According to certain particular manufacturing methods, all or part of the elements constituting

  the invention can be integrated into each other by manufacturing.

  The elements constituting the invention can also be grouped in a single box 13 comprising the sockets (14) and (15) necessary for quick connection on the upstream lines

and downstream (9) and (10).

  Figure 4 illustrates the latter possibility.

  Activity detection modes Activity detection on each of the upstream and downstream lines (9) and (10) can be performed

  by detecting the closure of the electrical circuits constituting them.

  In the latter case, it is possible for example to measure, periodically or permanently, the electrical resistance existing between the wires constituting the line, the latter being considered to be active as soon as this resistance is less than a certain value (circuit closure) .

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  Measuring the resistance drop per unit of time can also be an event

  triggering for activity detectors (2) and (3).

  Activity detection on the upstream and downstream lines (9) and (10) can also be done using

  "listening" to the electrical signals conducted by these lines.

  The electrical signals conducted by telephone lines and corresponding to the activities of their users are in fact specific to them. They are located for example in

  frequency ranges easy to define.

  The activity detectors (2) and (3) can be designed to detect the specificities of these

  signals and to enter "State 1" or "State 2" as soon as this detection is made.

  Injection of signals or messages on the downstream line Figure 1 shows a variant of the device according to the invention for which the device

  signal (6) is connected to the downstream line (10).

  In this case, the signaling device (6), when activated by the logic circuit (4),

  can inject, on the downstream line (10), specific signals or messages.

  These signals may, for example, be interference signals making it difficult to

payment held by the fraudster.

  They can also be voice messages, for example warning the fraudster and

  his contact for the discovery of fraud.

  These messages can be dissuasive enough to discourage the fraudster (s) from

  continue to use the line equipped with the invention.

  The logic circuit (4) can, in order to obtain the maximum effectiveness of the message delivered and according to certain manufacturing methods, activate the signaling device (6) only at the start of the

  conversation between the fraudster and his interlocutor.

  This start of conversation can, for this, be recognized by the downstream activity detector (3).

  Recording and processing of telephone numbers

  FIG. 3 shows another variant of the device according to the invention equipped with a recording

call number finder (12).

  This call number recorder (12) is activated by the logic circuit (4), for example at each activity detected on the downstream line (10) and can store the dialed call numbers

by the fraudster (s).

  The call number recorder (12) can also include a function allowing

  to synthesize in the form of a voice message, the numbers he has recorded.

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  The call number recorder (12) can be consulted, possibly from the telephone apparatus (1) and with the use of the logic circuit (4), by the assigned user of the

telephone line.

  This knowledge of the telephone numbers dialed by the fraudsters can be a determining factor in helping the regular user of the line to confuse them. The voice synthesis of the stored number can also be included in the message

  injected by the signaling device (6) on the downstream line (10).

  This latter function can constitute an additional deterrent.

  The voice synthesis of the recorded numbers, possibly accompanied by other information

  For example, the date, time and duration of each call can also be accessed.

  ble to the assigned user of the line from the telephone set (1).

  The call number recorder can operate using electronic microprocessors

  tronic. Various variants The signaling device (6) can also trigger, when activated, the switching on of one or more other devices such as for example a device for recording the

  conversation (tape recorder or other), an alarm, etc.

  The invention can operate using the electric current supplied by the power line

  on which it is or by another source, autonomous or not.

  The invention can be incorporated, by construction, into the telephone apparatus (1).

  Certain constituent elements of the invention, or all of them can function

  using electronic microprocessors.

  The efficiency of the invention is improved when the entire upstream line (9) and under the

line holder control.

  FIG. 5 shows a variant of the invention for which the upstream line (9) can include

  carry several telephones (1).

  In the latter case, the operation of the invention is the same as in the case where

  the telephone apparatus (1) is unique.

  The invention can be equipped with all other accessories such as for example a device (16) whose function is to control the starting and stopping of the operation of the invention.

  The device (16) can, for example, be a switch connected to the logic circuit (4).

  The invention could then work, for example, by following the logic table below: ou2! [Lnp 9.fl! UI moleST! LUnl md spuetuoO3 luie9 snîlup soa '(9g) J! L! Sodsip np saww xnop sol luenb! Puî 91 (CI omwlu! Ouuol -oD ei op solnllpo sol 'wuop9oJd nrolqm np olloo onb owuowlso nuolqm ao op amlool oi seloeuuoo A! LoB UONOlel3 0 el3 e! JeuUOS91A! ^! Pe sues Z UOe loo SOO sel! 0 el: R3 e,! A! IpV 91! AIV Z UO! LiSOd

  .......: .................................. ........ .................... DTD: .................... DTD: se8peuuoo @A! Bp uoN O 1eRî O 1ER 91! A! PD @! A! Pe sues 3 UOi! SOd o .......

  .................................................. ....................... DTD: ......................... ................................................ DTD: ......................................... seOpeuuoO 9A! Ipe UON 0 1el3 0 leQ3 eIA! A: suesu 1! A! PV z uo! llsOd..DTD:

  .................................................. ....................... DTD: ......................... ................................................ DTD: ...........................................; ...... .......... DTD: seaepeuuoO9A!; Oe UON0 lel30 1El 91! AlDe sues9l! A! 0e suesz UoII! SOd seGlPeuuoo? A! Pe UONZ el3 0 el3! Jouuosol! A! Pe suesI uo! L ! SOd

  .................................................. ....................... DTD: ......................... ........................................., _..... DTD: .................., ............................... ........: .............. DTD: .... DTD: sO ep.uuoD9A! Pe UON il lelR 914! A! 1DV? 1! A! 1DVI, uo! L! SOd

  .................................................. ....................... DTD: ......................... ................................................ DTD: .................... DTD: seeloeuuos UON A ^! PV I lel30 le3 91! ^! APV91! ^! Pe suesI uo! 1! Sod seQ9loeuuoO e ^ Aoe UONO leR3I 1eR3 el! ^ A! E sues l! ^ AlV, uo0I! Sod

  .................................................. ....................... DTD: ......................... ................................................ DTD: .................... DTD: seç1oeuuoo UON 9Ale UON0 el3 o 1eR?, A! IDe SUES91! A! 10: e suesI Uo! 1! SsOd 0 vL1I6v1 9SO vat zva0 oI 6Vl 9 W

19099LZ 6

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Claims (1)

CLAIMS CLAIM 1: Device for detecting fraudulent use of a telephone line, characterized by the fact that it comprises: - An upstream activity detector (2); - A downstream activity detector (3); - A logic circuit (4); A switch (5); - A signaling device (6). The device is also characterized by the fact that the telephone line concerned is separated into two parts, the upstream line (9) and the downstream line (10) and by that: -The upstream activity detector (2) is connected to the upstream line (9) and to the logic circuit (4); - The downstream activity detector (3) is connected to the downstream line (10) and to the logic circuit (4); - The logic circuit (4) is connected to the signaling device (6), the upstream activity detector (2), the downstream activity detector (3) and the switch (5); - The switch (5) is connected to the upstream line (9), the downstream line (10) and the logic circuit (4). - The signaling device (6) is connected to the logic circuit (4). The device is finally characterized by the fact that its operation is as follows: - The logic circuit (4) receives, from activity detectors (2) and (3), the signals indicating the state of the activity of the upstream line (9) and the downstream line (10) and analyzes them; - The logic circuit (4) controls, according to the result of this analysis, the switch (5) or the signaling device (6); - The switch (5) connects the upstream and downstream lines (9) and (10) between them when the logic circuit (4) commands it, in the event, for example, of an attempt to use the telephone apparatus (1 ) by the designated user of the incoming line or telephone call; - The signaling device (6) is activated when the logic circuit (4) commands it, ie when only the downstream line (10) is active and it is not a call incoming telephone. : 01 NOLLVDIN3A9X (ZI) loddep o-i9umu op maQnsiouo unp, d.nb, so l!, Nb ao ed 9s.uoleo 8, s I suoio.Apua ^ ol sop munl uolQs jî! Sods! I: 6 NOLLVDIGWANP SZ ( 01) IrA ^ au! L eI ms xnuoA soaQssow sop '^ Alop so.!, Nbsol ol oopfu (9) luow -alu.s Qpj.l! Sods.pa onb l anb aoa ed 9suoae.eo L uo.luo! puatol el uolps j.isods! G: 8 NOLLVDICINAgN 'Àu o! l oo.ms sonbg! 3ods so2ussow sop no xnmeus sop plofiu! i1!, nb oo l.d (b,) Qnb.ol.mnl. ol oed DA ^ .iog iso I!, nbsaoI 'Io (01) IA ^, oug! l ei g1? IoouIuoo so (9) luoaoreus oZ -is op ju! wsods.pi anb oo.ed os.u9oireo 9 g I suonteo. puQaOl sap munj uOliS Jti! sods! I: L NOLLVDICNKAg ouf! l ouoo xns uongsl. ln oun, sQnbîj! 3ods sonbuoolI xnmuuis op uogomgp 1l red oej; sa (01) reA QuS. I t [ms., IAi xop uo! Îool, p g1 onb ao sed os.uilopmo b, V 1 SUo, OpUIAQI sap saunl uolSj! .L! Sods! S: 9 NOIIVDIGN3AM "Àluemlnsuoo gI jlmo. [Np QmtnuLaj ri op uo! Lojap e.lmd ol.j lso (01) ^ gAg oU! Stn s' l lolpS uonoolp g1 onb oo.ed? Suoueso f7 e I suo !. o.! puoAlI sop ounl uolas jî.! lsods (I: S NOIIVDIIN3AIt -uTml.suoo l raeoal! o np amluuoj BI ap uonoogPp el.ed al.js (6) louO au.SI g1 ms !! A ^ Pap 01 uon.olgp g1 anb ao xed s.lu1o3BXe l, I SUO! lo.pUQAQJ sop munl uolosjl! sods (I: t, NOIIVDIGNASg uoorutnsuoo ird saont xns sun sol soa1i. u. luos lumu! .suoo al sluwtup sap ed no tnoo onb ao.rd osu01ot. Mo 7 no I suoil.A [puQo. sop ounl UOlS jW! sods! G: ú NOILVDIA- 'S se9peuuo 9AI! PB UON Z Me3 o el3 eUeuuOS 91! AI! pE sUes. ...................!. 1 ............................ ..... CLMF: seepeuuoo eAi1ce UON k. Le; j L. ieR3 8l! AI e! ^ V ......................... ................................................ CLMF: ........ .......................................... .... CLMF: seDepuuoo UON 9A! DV I., E3 o el3 9,! A! 1oV, l! A! Pe sUes. ................... .................. .....................! ........ ._. ........... CLMF: seqPeuuoo QAêIe uOl Q 1iei3 je! Al! Pe sUes .......................... ............................................... CLMF:. ......................... ......................... .CLMF: seepeuuoo UON ^! UON o leR3 O 1e3 91! ^! De sues?! A3 ^! DE sues O0lri11 / l 9SO úCV ZV0 OIl1 6VI: lurA! Ns anb.fol nsIlqn ol uolos imoojjos luowuuuoaouoj uos op i! 1. [Lp ol onb ood 9suogjrm I uo. lo. [puAo ^ gi uOlOs j. !! sods! G: Z NOLLVDICNgATg 19099_Z. he 12 2765061   Device according to Claim 9, characterized in that the call number recorder (12) includes a function making it possible to synthesize, in the form of a voice message, the numbers that he recorded. CLAIM 11:   Device according to one of Claims 1 to 10, characterized in that the electrical energy   necessary for its operation is supplied by the electrical voltage of the telephone network. CLAIM 12:   Device according to one of Claims 1 to 10, characterized in that the electrical energy   necessary for its operation is supplied by an external source, other than the electrical voltage phone network. CLAIM 13:   Device according to one of Claims 1 to 12, characterized in that it is integrated, by   construction, to the telephone set (1). CLAIM 14:   Device according to one of Claims 1 to 13, characterized in that the signals processed   and delivered by logic circuit (4) as well as those produced and processed by the various elements of   the invention are binary electrical signals. CLAIM 15:   Device according to one of Claims 1 to 14, characterized in that the elements constitute   killing the invention are grouped in a single box (13) comprising the sockets (14) and (15)   necessary for quick connection on the upstream and downstream lines (9) and (10). CLAIM 16:   Device according to one of Claims 1 to 15, characterized in that it operates using of electronic microprocessors. CLAIM 17:   Device according to one of Claims 1 to 16, characterized in that it comprises more   several telephone devices (1), connected to the upstream line (9). CLAIM 18:   Device according to one of claims 1 to 17 characterized in that it comprises a device   positive (16) allowing its operation according to the following logical table: SOe1OOUUOD9PAIPB UONO 1813O) 183 OIJSUUO5E) 1! A! 1O8 SUES3 UO !! sOd .s ..?! .. uu .......? .. 9 .. u ... N ... 0 .......... 0 .. !! ...............   .....!. p ..................................., ... v .. ........ uo.so '.. CLMF: suuoo gA.le UONO 13 Q.3 13 9..A! a. 9.! AI.V. UO,!. SO ..   se euuoo ..................... u ............. q ........... 3 ..? .. I .... .V ...... us ....! .......................... .... OU .............. Qo ....... o.   . U se9l08uu039AiIDB UONO 181Q 3 91! A! 1O8 SuU IISO3 UOIjSOd 9e910euu03 9) AI1Oe UON O le1: 1 O l1813? E! A! 1D8 sues 91! A! 1D8 sues 3 UOi1! SOd u91o ue9) e1: 1l *! JOuuos91! ^! 10th sues1. uo! 1! SOdl ...........................................:. ............ .CLMF: ............, .............,. O., .... .............,. 1 ...................... CLMF: .....: .... .......... o .............., ........................ ............. CLMF: ....... Se @ 100UUOQgAQOS UON i. îe; jj 183 91! A! 1SUV? 1! A! 1Vj. UOW1SOd .. CLMF:   ................................... e..uu ....? ...... ... OU ............... CLMF: ..! .................... p ..... ...................! ........................ CLMF: .. uo. ..o .............. CLMF: Se9PGUUOO UON V I.813O 1813 @ 1! A! S VIA! 13 sues UON! lSOd se @ poeuuoo ^! o8e UONo 3 l 813 91 ! A! 1OS sueS 91! A! 1oVj UOI1ISOd SeG oeUoo UON 9 A1 ^ 0o UON O 1813 Q l181 91! A! 1DB suBs 91! A! 1oe sues j uoIlIsod 01'lI / 6Vl 9SO úVG MO Ol.i 6V; 91, 1,9099zL ú1