MXPA99010381A - Enhanced identification system - Google Patents

Abstract

A method and an identification system for communicating between a reader (10) and a plurality of transponders (1, 2, 3) are disclosed. The reader (10) has a transmitter (11) for transmitting a signal and each transponder (1, 2, 3) includes a receiver for receiving the reader signal and a transmitter for generating a transponder signal. When the reader (10) recognises a transponder signal from one of the transponders (1) it immediately issues a mute instruction, muting all other active transponders (2, 3) and passing control to the said transponder (1), without the need for a specifically timed acknowledgement to the said controlling transponder (1). The reader (10) may issue a single disable/wakeup instruction which disables the controlling transponder (1) returning control to the reader (10) and reactivated all muted (but not disabled) transponders (2, 3).

Description

IMPROVED IDENTIFICATION SYSTEM Description of the invention: This invention relates to a method for identifying a plurality of repeaters, each of which transmits data at intervals to a receiver. The invention also relates to an identification system comprising a plurality of repeaters and a receiver, and with the repeaters and receivers themselves. The invention is further related to method and apparatus for improving the identification systems described in EP 494,114 A and EP 585,132 A. Identification systems are known in which a plurality of transmitters, typically repeaters, are activated by a signal of power (or an "interrogation signal") and then transmits response signals, which usually contain identification data, to a receiver, which typically forms part of the interrogator. The signals can be transmitted in various ways, including electromagnetic energy, for example radio frequency (FR), infrared (IR), and coherent light, and sound, for example ultrasound. For example, the transmission can be achieved by the actual emission of RF energy by the repeaters, or by the modulation of the reflectivity of an antenna of a repeater, resulting in variable amounts of RF energy in the interrogation signal that REF .: 31762 is being reflected or redispersed from the repeater antenna. GB 2,116,808 A describes an identification system in which individual repeaters are programmed to retransmit data in a pseudo-random manner. The synchronization signals of the repeaters in this identification system are derived from a crystal oscillator, thereby making the repeaters expensive to manufacture. EP 467,036 discloses another identification system which uses a pseudorandom delay between the repeater data transmissions. In this example, the linear recursive sequence generator is seeded by the identification address of the repeater to make the pseudorandom delay as random as possible. EP 161799 A describes an interrogator / repeater system in which an interrogator transmits an interrogation signal to a plurality of repeaters present in the interrogation field. Repeater layer transmits the response signal consisting of a uniquely coded identification number. The interrogator then retransmits the signal it has received and each encoding repeater identifies the signal and verifies the data against its own identification number. In the event that a particular repeater recognizes its own code, that repeater discontinues the response signal or adjusts to receive additional instructions (all others have to turn off). If interference occurs because two or more repeaters are transmitting at the same time, the interrogator waits until a valid signal is received. EP 494112 A describes another interrogator / repeater system in which an interrogator transmits an interrogation signal to a plurality of repeaters present in the interrogation field. An example of the identification system comprises an interrogator or reader which transmits interrogation signals at a power of approximately 15W and at a frequency of approximately 915 MHZ to a number of passive repeaters. The repeaters derive a power supply of power in the interrogation signal, and modulate a portion of the energy received from the interrogator with an identification code to generate a response signal, which is transmitted back to the interrogator. EP 585,132 A discloses another interrogator / repeater system in which the repeaters are provided with local synchronization means which depend on the voltage of the power supply derived from the interrogation signal, thus causing the clock frequencies of the different repeaters vary in a relatively broad way. The interrogator is adapted to detect the successful reception of a response signal from any repeater and to derive a synchronization signal from the response signal. The interrogation signal can then be modified in a synchronized manner with a particular repeater. The repeater can use separate receiving and transmitting antennas, or a single antenna can be used for both reception and transmission. If a single antenna is used, the response signal can be generated by modulating the reflectivity of such an antenna; if separate receiving and transmitting antennas are used then a modulator is required which redirects the energy of the receiving antenna to the transmitting antenna. Alternatively, the repeater can be powered independently and can generate its own response signal. The system described in the aforementioned patent application causes each repeater to wait for a random or pseudo-random period after receiving an interrogation signal from the interrogator, before transmitting its own response signal. The successful identification of any repeater is indicated by a brief interruption or other modification of the interrogation signal, very close to the excitable reception of a response signal from any particular repeater. This acts as an interruption signal for the relevant repeater. Random or pseudorandom delay in the generation of response signals, in response to repeated interrogation signals, ensures that all repeaters will eventually be identified by the interrogator. In general, if the transmissions of two repeaters overlap or overlap, the transmissions become contaminated and therefore are lost, since the receiver can distinguish the separate transmissions. In this way, the system must make each repeater transmit repeatedly until the entire transmission takes place in a "silent" time and is successfully received by the interrogator. Any repeater must obtain a silence time which is as long as the total length of the data flow to be transmitted. As shown in Figure 1, there is a considerable waste of time in systems employing such an unlocking and delaying algorithm. EP 689 151 A2 describes another interrogator / repeater system in which the RFID connection terminal transmits a transmission signal request (RTT) and waits for a recognition signal from the network controller before attempting to transmit data. The disadvantage with such a system is that the connection terminal must wait, and decode, an appropriately synchronized permission before attempting to transmit data, thereby adding unnecessary complexity to the connection terminal and leading to a waste of considerable time in the cycle. transmission. If the connection terminals have local synchronization means (as described in detail in EP 585,132 A) the synchronization and the duration of the recognition instruction must be derived from the local synchronization means of the connection terminal that is transmitting the signal RTT. Since the RTT signal must necessarily be too short to provide the suggested advantages, the network controller must be able to extract the synchronization of very little information. This adds unnecessary complexity to the network controller. An object of this invention is to provide a very simple, improved identification system with enhanced recognition of data signals. It is also an object of this invention to remove the waste of time, to improve the speed to identify a plurality of repeaters without adding unnecessary complexity to the identification systems. Another object of the present invention is to provide an identification system in which the waste of time due to contamination of the transmission is considerably reduced while still providing a reasonably fast connection terminal transmission cycle. According to a first aspect of the invention, there is provided an identification system comprising a reader that includes a transmitter to transmit a signal and a plurality of repeaters, each repeater includes a receiver to receive the signal from the reader and a transmitter to generate a repeater signal, characterized in that upon recognizing a repeater signal from a repeater the reader immediately issues a silent instruction, silencing all other repeaters and passing the control to the repeater, without the need for a synchronized recognition specifically to the control repeater. According to a second aspect of the invention, there is provided a method for identifying a plurality of repeaters, which comprises transmitting a reader signal, and each repeater receiving the signal from the reader, characterized in that upon recognizing a repeater signal from a repeater the The reader immediately issues a silent instruction, silencing all other active repeaters and passing the control to the repeater, without the need for a specific synchronized recognition to the control repeater. In a further aspect of the invention, there is provided a repeater comprising receiving means for receiving a reader signal, transmission means for transmitting a repeater signal containing data which define the repeater therefore in a set of repeaters, two or more repeaters can transmit their repeater response signals in response to receiving the signal from the reader, characterized in that the repeater is provided with control means, so when recognizing a silent instruction in the reader signal, all repeaters assets in the group except one are silenced and control passes to a repeater, without the need for synchronized recognition specifically of the control repeater. In a further aspect of the invention there is provided an integrated circuit for use in a repeater, comprising receiving means for receiving a signal from the reader, transmission means for transmitting a repeater signal containing data which identifies the repeater therefore in a set of repeaters, two or more repeaters can transmit their repeater response signals in response to receiving the signal from the reader, characterized in that it is provided with control means, so when recognizing a mute instruction in the signal of the reader, all active repeaters in the set except one are silenced and the control passes to a repeater, without the need for a synchronized recognition specifically to the control repeater.

In a further aspect of the invention there is provided a reader comprising transmission means for transmitting an interrogation signal to at least one repeater, at a time when at least one other repeater can transmit in response to the interrogation signal, and receiver means for receiving a response signal from a repeater, characterized in that upon recognizing a repeater signal from the repeater the reader immediately emits a silent instruction, silencing all active repeaters, and passing control to the repeater, without the need for a specifically synchronized recognition of the repeater of control. The silent instruction may take the form of a total or partial interruption of the reader's signal, or some other modification of the reader's signal. Alternatively, the silent instruction may be a separate signal transmitted by the reader, for example at a frequency which differs from the signal of the reader. An acceptance instruction may be sent after the signal from the repeater has been received successfully by the reader. The acceptance instruction may be similar in nature to the silent instruction, such as a total or partial interruption or other modulation of the reader's signal. Alternatively, the acceptance instruction may be transmitted at a frequency which differs from the reader's signal; such frequency may also differ from the frequency of the silent instruction. The acceptance instruction may also have a duration different from that of the silent instruction, or be formed by repeating the silent instruction within a predetermined period, for example using simple or double pulses. The silent instruction can silence the rest of the active repeaters by stopping the random wait cycle of the repeaters until either is reset or reset by another instruction. If the random waiting cycles of the remaining active repeaters are stopped by the silent instruction, the acceptance instruction can also instruct the remaining active repeaters in the reader field to restart the existing random wait cycles. Alternatively, the acceptance instruction may cause the remaining active repeaters to start new random waiting cycles. The silent instruction can simply silence a repeater by inhibiting the transmission repeater. Any repeater that reaches the end of this random waiting cycle is inhibited - so as not to transmit the repeater signal. For example, the silent instruction may be to set an indicator and when the repeater reaches the end of this random waiting cycle check to see if the indicator was set before the transmission. The inhibition of the repeater can be readjusted by the acceptance signal or readjusted after a predetermined time. The acceptance instruction may also act as a disabling instruction, disabling the repeater which has recently been transmitted either permanently, for a predetermined period of time or until its readjustment. In this way a single acceptance instruction can be used to disable a repeater which has been successfully identified, and to instruct the rest of the connection terminals that remain silent to continue with the existing random wait cycles, or to start over. The repeaters may, instead of being reactivated by an acceptance instruction for the control repeater, remain silent for a predetermined period of time. The random wait cycle of the repeaters may include a delay equal to the length of a repeater signal; if a disable instruction is used then the delay may also include the period for the reader to transmit the disable instruction. If they are repetitive employees with local synchronization means (as described in detail in EP 585, 132 A mentioned above), the acceptance instruction, if used, can be synchronized by the particular synchronizing means of the control repeater. The frequency and duration (ie synchronization) of the interrogator's instructions may be present in the interrogator at the time of manufacture or installation. The synchronization can be set in an optimization phase, for example after installation or synchronization can be optimized in an initial interrogation and used in subsequent interrogations. If the repeaters within the interrogation field are programmed with unique codes, the acceptance instruction can be eliminated altogether, and the repeaters can therefore provide the continuous survival of the items to which the repeaters are attached. If all repeaters are programmed with the same code and the disable instruction is used, the number of repeaters within the interrogation field can be counted. The repeaters can be used as "presence connection terminals", and indicate the number of items to which repeater repeaters are attached, and the response code can therefore be very simple. The selective use of the acceptance signal can provide greater flexibility to an identification system.

Repeaters and interrogators, such as those described in EP 494,114 A and EP 585,132A (all the contents of which are incorporated herein by reference), can be adapted to produce repeaters and interrogators according to the invention. The invention will now be described in greater detail. Subsequently, specific, non-limiting modalities are described herein, with reference to the accompanying drawings in which: Figure 1 is a simplified representation of data transmissions of a repeater of the prior art; Figure 2 is a simplified block diagram showing an interrogator and three repeaters according to a first embodiment of the invention; Figure 3 is a simplified representation of an interrogator and a number of repeaters; Figure 4 is a block diagram of a repeater according to the first embodiment of the invention; Figure 5 shows a synchronization diagram of a repeater according to the first embodiment of the invention; Figure 6 shows a flow chart for a repeater according to the first embodiment of the invention; Figure 7 shows a detailed diagram of a range detector circuit for the first embodiment of the invention; Figure 8 shows a circuit for the interrogator of the first embodiment of the invention: Figure 9 shows a synchronization diagram of a repeater according to a second embodiment of the invention; Figure 2 shows an example of the RFID system comprising a reader 10, which includes a transmitter 11 with a transmission antenna lia and a receiver 12 with a reception antenna 12a. The transmitter (11, lia) transmits a power signal (the signal from the reader) to a number of passive repeaters (connection terminal 1, connection terminal 2 and connection terminal 3). Each repeater includes a dipole antenna, the two poles of which are indicated by 4 and 5. The repeaters within the field of the reader are able to derive a power supply of the energy in the signal from the reader using the capacitor C and the diode D. The code generator 6 and the logic circuit 7 generate a signal using the Manchester code, which is transmitted to the reader, modulating a portion of the energy received from the reader using the modulator 9 connected between the poles of the antenna 4 and 5. The repeaters have local synchronization means (as described in detail in EP 585,132 A mentioned above). When receiving power, each repeater executes a random waiting cycle before transmitting a signal. If a signal is received the reader issues a silent instruction. The silent instruction may consist of a short interval (a partial or complete interruption) in or another modification of the signal. Other active repeaters within the reader field become temporarily mute by transmitting the silent instruction, which is recognized as giving control to another repeater. The reader issues an acceptance instruction (disable / wake instruction) once the repeater signal has been received free of noise or interference. Since the repeaters have local synchronization means (as described in detail in the aforementioned EP 585,132 A) the synchronization and duration of this instruction is synchronized with the local synchronization means. The random waiting cycles of these repeaters are - reactivated by this deactivate / awaken instruction. Figure 3 represents the signal of the reader and the responses of the repeaters. The signal from the reader 20 is fed at time t0, after which the repeaters within each field of the reader are powered and the random waiting cycles begin. In the example shown in Figure 3, the connection terminal 1 transmits a signal 20 at a time ti. The reader recognizes a repeater signal and, interrupting the reader signal at time t2, produces the silent instruction 21 which stops the random waiting cycles of the connection terminals 2- and 3. When the connection terminal 1 has completed the transmission of the signal 20 the reader issues an instruction 22 at time t3. In the example shown in Figure 3, the connection connection terminals 2 and 3 are temporarily silenced by the transmission of instruction 21 to time t3. The connection terminals 2 and 3 are instructed to summarize the random wait cycle with the transmission of the disable / wake up instruction 22, which also disables the connection terminal 1 until it is removed from the field. In this figure, the reading process is then successfully completed by the connection terminal 3 followed by the connection terminal 2. Figure 4 shows, in the form of a sketch, the terminal that can be used with the reader of Figure 2 and Figure 5 shows a synchronization diagram for the signal paths marked in Figure 4. The connection terminal includes a dipole antenna, the poles of which are shown as 60 and 61. A code generator 62, when enabled by a logic circuit 64 modulates a transistor Ql with a code, using the code of Manchester (signal 77). The synchronization of the code generator is derived from a local oscillator 66. Diodes DI and D2 in combination with a capacitor Cl supply power to the connection terminal. The oscillator is disconnected from the random timeout generator when FF1 or FF2 is in the reset state (signals 70 and 72). FF1 is only set when the connection terminal is powered and readjusted when the connection terminal is interrupted after being read successfully. FF2 is in the reset state when the connection terminal is silenced and the steady state of the power supply when the connection terminal is in its normal operating mode. When the connection terminal initially receives the signal from the reader FF1 will be in the fixed or adjustment state. In the power supply of the logic circuit 64, it triggers the random wait time 63 to select a reading value and start a downward count. The interval detector circuit 65 is able to detect the presence or absence of the reader signal by means of the diode D3 and, if there is an interruption or interval in the signal of the reader, the duration of the interval. The 'interval detector circuit is shown in greater detail in Figure 7. A long interval (a disable / awaken instruction) will set FF2 and a short interval (silent instruction) will reset FF2. Therefore a range of reader disable / wake is detected by means of a range detector which sets FF2, which allows the random time-out generator to work. The random timeout generator indicates (signal 75) the end of the downcount of the logic circuit 64 which then enables (signal 75) the code generator 62 to modulate the transistor Ql with the code. The logic circuit also inhibits the interval detector circuit during the time that the connection signal takes to transmit the signal. If, during the descending count, a silent interval of the reader is received (passing the control to another repeater) the interval detector changes the FF2 to the reset state, thus disconnecting the oscillator (signal 73) and pausing the counting falling. FF2 remains in the reset state until another pulse is received from the reader (the disable / wake interval which disables the control repeater). The random standby synchronizer then continues the count down until the repeater signal is transmitted or another mute interval is received. If the reader issues a properly synchronized disable / awaken interval once the repeater signal has been received by the reader free from noise or other interference. The interval detector circuit detects this interval and indicates the presence of this interval to the logic circuit 64. Whenever this interval occurs at a predetermined time after the end of the repeater signal, for example the clock pulse 5 after the end of the code, logic circuit 64 (signal 71) will reset to FF1. FF1 (signal 72) disconnects the oscillator until it is readjusted, and in this case after removing the field connection terminal and allowing the capacitor Cl to discharge sufficiently. If it is not necessary for the connection terminals to be interrupted after successful detection of the repeater signal, the flip-flop FF1 and the switch SW1 can be omitted completely from the connection terminal. Figure 6 shows a flow diagram of the connection terminal operation illustrated in Figure 4. The interval detector circuit 65 is shown in more detail in Figure * 7. When a range appears in the interrogation (a silent interval) ), the output of D3 becomes low. The edge detector circuit 102 detects a falling edge at the output of D3, which in turn resets FF2. The output of the ORIENTATION gate 100 for then pulses from the oscillator 66 to the counter 101. When the counter reaches a sufficient value to make Q4 high, FF2 is set. When the output of D3 becomes high again (at the end of the silent interval) the counter is reset. If the interval is short, the counter 101 resets before Q4 can become high. FF2 resets at the beginning of the interval and remains in this condition after the interval. If the interval is long, FF2 will remain readjusted at the beginning of the interval. When the counter 101 has counted enough for Q4 to be high, FF2 is fixed and remains in this fixed state after the interval. Figure 8 shows a circuit for interrogation. The transmitter 110 produces a continuous wave signal of fr the reader which is transmitted to the connection terminals via the circulator 111 and the antenna 112. The signal of the connection terminal is received by the antenna 112 and is passed via the circulator 111, to separate the signal from the transmitter, the mixer 113, which extracts the signal from the low frequency code, and the low pass filter 114. The mixers 113 mix the signal from the connection terminal with a portion of the transmitted reader signal extracted by the divider 118 thereby generating the baseband signal which is fed to the filter 114. The filter outputs are then amplified 119 and the rectified complete wave 121. The resulting signal is then amplified and passed, via a division circuit by two 125 to the microprocessor 126. The microprocessor can interrupt the signal of the reader with a short or long interval, using the short monostable 127 or the monostable and 128, the AND gate 129 and the switch 130. Referring to FIG. 9, in a second embodiment of the invention the interrogator is adapted to provide a dual impulse arousal or acceptance instruction and a single pulse for the silent instruction. The repeater is adapted to distinguish between signals. In particular, in the repeater the details of the interval detector circuit 68 are adapted to detect the occurrence of one or two "short" pulses of the same duration and provide the signal from Set 5 to FF2 after the occurrence of the two pulses and the signal to readjust R to FF2 when an impulse occurs. It should be appreciated immediately by those skilled in the art that the functionality of the connection terminals and the reader can be achieved in numerous different ways. For example, the connection terminals, instead of deriving power from the reader signal, can be powered by a small battery. In a further mode, the integrated circuit of the repeater has read / write capabilities. The instructions sent from the reader to the repeater can take the form of coded instructions included in the silent instructions and / or acceptance. For example, if the mute and / or acceptance instructions are in the form of interruptions in the reader signal, the encoded instructions may be present in the intervals in the reader signal defined by those interruptions. In the previous modalities the reader, when recognizing the signal of a repeater, immediately emits a silent instruction, silencing all the other active repeaters, and passing in control to the repeater. Preferably, the silent instruction is transmitted as soon as the reader recognizes it, or there is a high probability that the reader has recognized a valid signal from the repeater. In one embodiment, the first few pulses in the repeater signal may have a unique formula or feature, thereby allowing the reader to quickly distinguish whether or not the received signal comes from the repeater or conversely is the opposite of spurious noise. It is noted that in relation to this date, the best method known to the applicant to carry out the aforementioned invention, is that which is clear from the present description of the invention.

Claims (106)

CLAIMS Having described the invention as above, the content of the following claims is claimed as property.

1. An identification system comprising a reader that includes a transmitter for transmitting a signal a plurality of repeaters, each repeater includes a receiver for receiving the signal from the reader and a transmitter for generating a repeater signal, characterized in that when recognizing a repeater signal of a repeater, the reader immediately emits a silent instruction, silencing all other active repeaters, and passing the repeater control, without the need for a synchronized recognition specifically to the control repeater.

2. The identification system according to claim 1, characterized in that the silent instruction comprises a modulation of the reader signal.

3. The identification system according to claim 1, characterized in that the reader issues an acceptance instruction after the signal of the control repeater has been successfully displayed by the reader.

4. The identification system according to claim 3, characterized in that the acceptance instruction comprises a modulation of the reader signal.

5. The identification system according to claim 2 or 4, characterized in that the modulation comprises a total interruption of the signal of the reader.

6. The identification system according to claim 2 or 4, characterized in that the modulation comprises a partial interruption of the signal of the reader.

The identification system according to claim 2 or 3, characterized in that the instruction is the signal transmitted independently of the signal of the reader.

8. The identification system according to claim 4, characterized in that the acceptance instruction uses the same modulation of the reader signal as the silent instruction.

9. The identification system according to claim 8, characterized in that the acceptance modulation has a duration different from the silent modulation.

The identification system according to claim 1, characterized in that the silent instruction comprises a short interruption in the reading signal and the acceptance instruction comprises a longer interruption in the signal of the reader.

The identification system according to claim 1, characterized in that the repeater includes a random waiting synchronizer, which triggers the transmission of the repeater signal after the random waiting cycle has been completed.

The identification system according to claim 11, characterized in that if a repeater receives a mute instruction before starting to transmit a repeater signal, the random wait cycle of the repeater is stopped.

The identification system according to claim 12, characterized in that the random waiting cycle of the repeater is restored by means of an acceptance instruction issued by the reader.

The identification system according to claim 12, characterized in that the random waiting cycle of the repeater is readjusted by an acceptance instruction issued by the reader.

15. The identification system according to claim 12, characterized in that the random waiting cycle of the repeater is readjusted after a predetermined period of time.

16. The identification system according to claim 11, characterized in that if_ a repeater receives a silent instruction before starting to transmit a repeater signal, the repeater is inhibited so as not to transmit the repeater signal at the end of the random waiting cycle. .

The identification system according to claim 1, characterized in that the reader issues a disabling or deactivation instruction after the control repeater signal has been successfully received by the reader.

18. The identification system according to claim 17, characterized in that the control repeater is permanently disabled by a disable or deactivate instruction.

19. The identification system according to claim 17, characterized in that the control repeater is disabled for a predetermined period of time after disabling the instruction issued.

20. The identification system according to claim 17, characterized in that the control repeater is disabled by the disable or deactivate instruction until it is reset.

21. The identification system according to claim 1 or 3, characterized in that the repeaters include local synchronization means.

22. The identification system according to claim 21, dependent on claim 3, characterized in that the reader synchronizes the acceptance instruction with the local synchronization means to control the repeater.

23. The identification system according to claim 1, characterized in that each repeater generates the same repeater signal.

24. The identification system according to any of claims 1 to 23, characterized in that the circuit in the repeater is in the form of an integrated circuit that has read / write capabilities.

25. The identification system according to claim 24, characterized in that the instructions sent from the reader to the repeater include encoded instructions incorporated in the silent instructions.

26. The identification system according to claim 24 or claim 25, dependent on claim 3, characterized in that the instructions sent from the reader to the repeater include encoded instructions incorporated in the acceptance instruction.

27. The identification system according to claim 25 or claim 26, characterized in that the silent and / or acceptance instructions are in the form of interruptions in the reader signal, the coded instructions are present in the intervals in the signal of the reader defined by those interruptions.

28. The identification system according to claims 5, 6, 10 or 27, characterized in that each repeater includes a detector circuit of the length of the interval to determine the length of interruption of the signal of the reader.

29. The identification system according to claim 28, characterized in that the interval length detecting circuit detects a mute instruction and pauses the random waiting cycle.

30. The identification system according to claim 29, characterized in that the detection circuit of the interval length detects an acceptance instruction and allows the random waiting cycle to resume.

31. A method for identifying a plurality of repeaters comprising transmitting a signal from the reader, and each repeater receiving the signal from the reader, characterized in that upon recognizing a repeater signal from a repeater, the reader immediately issues a silent instruction, silencing all the other active repeaters, and passing the control to the repeater, without the need for a synchronized recognition specifically to the control repeater.

32. The method according to claim 31, characterized in that an acceptance instruction is issued by the reader after the control repeater signal has been successfully received.

33. The method of compliance with the claim 31, characterized in that the transmission of the repeater signal by each repeater is triggered after a random wait cycle has been completed.

34. The method according to claim 31, characterized in that if a mute instruction is received by a repeater before starting to transmit its repeater signal, the random wait cycle of the repeater is stopped.

35. The method according to claim 34, characterized in that the random waiting cycle of the repeater is restarted by means of an acceptance instruction issued by the reader.

36. The method according to claim 31, characterized in that if a mute instruction is received by a repeater before starting to transmit a repeater signal, at the end of the random waiting cycle the repeater is inhibited to not transmit the repeater signal.

37. The method according to claim 31, characterized in that the disabling or disabling instruction is issued by the reader after the control repeater signal has been successfully received by the reader.

38. The method according to claim 31, characterized in that the control repeater is permanently disabled or deactivated by a disable or deactivate instruction.

39. The method according to claim 31, characterized in that when a repeater detects a mute instruction the random wait cycle pauses.

40. The method according to claim 39, characterized in that when a repeater detects an acceptance instruction, the random waiting cycle is resumed.

41. The method according to any of claims 31 to 40, characterized in that the repeater circuit is in the form of an integrated circuit having read / write capabilities.

42. The method according to claim 41, characterized in that the instructions sent from the reader to the repeater include encoded instructions incorporated in the silent instructions.

43. The method according to the claim 41 or claim 42, when dependent on claim 32, characterized in that the instructions sent from the reader to the -repeater include encoded instructions incorporated in the acceptance instruction.

44. The method of compliance with the claim 42 or claim 43, characterized in that the mute and / or acceptance instructions are in the form of interruptions in the coded reader instructions being present in the intervals in the reader signal defined by those interrupts.

45. A repeater comprising receiving means for receiving a signal from the reader, the transmission for transmitting a repeater signal containing data which identify the repeater, so in a set of repeaters, two or more repeaters can transmit their response signals of the repeater in response to reception of the signal from the reader, characterized in that the repeater is provided with control means, so that upon recognizing a silent instruction in the reader signal, all repeaters active in the set except one are silenced and the control passes to the repeater, without the need for a synchronized recognition specifically to the control repeater.

46. The repeater according to claim 45, characterized in that the silent instruction of the reader comprises a modulation of the signal of the reader and the repeater has detection means for recognizing the modulation.

47. The repeater according to claim 46, characterized in that the repeater control means can detect an acceptance instruction in the reader signal after the control repeater signal has been successfully received by the reader.

48. The repeater according to claim 47, characterized in that the acceptance instruction comprises a modulation of the reader signal.

49. The repeater according to claim 46 or 48, characterized in that the modulation comprises a total interruption of the signal of the reader.

50. The repeater according to claim 46 or 48, characterized in that the modulation comprises a partial interruption of the signal of the reader.

51. The repeater according to claim 46 or 48, characterized in that the instruction is the signal transmitted independently of the signal "of the reader

52. The repeater according to claim 48, characterized in that the acceptance instruction uses the same modulation of the read signal that the silent instruction

53. The repeater according to claim 48, characterized in that the acceptance modulation has a duration different from that of the silent modulation

54. The repeater according to claim 48, characterized because the silent instruction comprises a short interruption in the signal of the reader and the instruction of acceptance comprises a long interruption in the signal of the reader.

55. The repeater according to any of claims 45 to 54, characterized in that the repeater includes a random standby synchronizer which triggers the transmission of the repeater signal after a random wait cycle has been completed.

56. The repeater according to claim 55, characterized in that if a repeater receives a mute instruction before it has begun transmitting a repeater signal, the random wait cycle of the repeater stops.

57. The repeater according to claim 56, characterized in that the random wait cycle of the repeater is reset by an acceptance instruction issued by the reader.

58. The repeater according to claim 56, characterized in that the random waiting cycle of the repeater is readjusted by an acceptance instruction issued by the reader.

59. The repeater according to claim 56, characterized in that the random wait cycle of the repeater is reset after a predetermined period of time.

60. The repeater according to claim 55, characterized in that if a repeater receives a mute instruction before it has begun transmitting a repeater signal, the repeater is inhibited to not transmit the repeater signal at the end of the random wait cycle.

61. The repeater according to claim 45, characterized in that the control repeater is permanently disabled or deactivated by a disabling or deactivating instruction of the reader after the control repeater signal has been successfully received by the reader.

62. The repeater according to claim 45, characterized in that the control repeater is disabled or deactivated for a predetermined period of time after the disabling or disabling instruction is issued.

63. The repeater according to claim 45, characterized in that the control repeater is disabled or deactivated by the disable or deactivate instruction until its reset.

64. The repeater according to claim 45 or 47, characterized in that the repeater includes local synchronization means.

65. The repeater according to claim 64, when dependent on claim 47, characterized in that the reader synchronizes the acceptance instruction with the local synchronization means of the control repeater.

66. The repeater according to any of claims 45 to 65, characterized in that the circuit on the repeater is in the form of an integrated circuit that has read / write capabilities.

67. The repeater according to claim 66, characterized in that the instructions sent from the reader to the repeater include encoded instructions incorporated in the silent instructions.

68. The repeater according to claim 66 or claim 67, when dependent on claim 47, characterized in that the instructions sent from the reader to the repeater include encoded instructions incorporated in the acceptance instruction.

69. The repeater according to claim 67 or 68, characterized in that the silent and / or acceptance instructions are in the form of interruptions in the reader signal, the encoded instructions are present in the intervals in the reader signal defined by those interruptions.

70. The repeater according to claim 50, characterized in that each repeater includes a detector circuit of the length of the interval to determine the length of the interruption in the signal of the reader.

71. The repeater according to claim 70, characterized in that the detecting circuit of the length of the interval detects a mute instruction and pauses the random waiting cycle.

72. The repeater according to claim 71, characterized in that the detection circuit of the length of the interval detects an acceptance instruction and allows to resume the random waiting cycle.

73. An integrated circuit for use in a repeater, comprising receiving means for receiving a reader signal, transmission means for transmitting a repeater signal containing data which define the repeater, so in a set of repeaters, two or more repeaters can transmit their repeater response signals in response to receiving the signal from the reader, characterized in that it is provided with control means, so that upon recognizing a silent instruction in the reader signal, all the Active repeaters in the set except one are silenced and the control passes to a repeater, without the need for a synchronized recognition specifically to the control repeater.

74. The integrated circuit according to claim 73, characterized in that the silent instruction of the reader comprises a modulation of the signal of the reader and the integrated circuit has detection means for recognizing the modulation.

75. The integrated circuit according to claim 74, characterized in that the circuit control means can detect an acceptance instruction in the reader signal after the control repeater signal has been successfully received by the reader.

76. The integrated circuit according to claim 75, characterized in that the acceptance instruction comprises a modulation of the reader signal.

77. The integrated circuit according to claim 74, characterized in that the modulation comprises a total interruption of the signal of the reader.

78. The integrated circuit according to claim 74, characterized in that the modulation comprises a partial interruption of the signal of the reader.

79. The integrated circuit according to claim 46 or 48, characterized in that the instruction is the signal transmitted independently of the signal of the reader.

80. The integrated circuit according to claim 75 or 76, characterized in that the silent instruction comprises a short interruption in the signal of the reader and the acceptance instruction comprises a long interruption in the signal of the reader.

81. The integrated circuit according to any of claims 73 to 80, characterized in that the circuit includes a random standby synchronizer which triggers the transmission of the repeater signal after a random wait cycle has been completed.

82. The integrated circuit according to claim 81, characterized in that if a circuit receives a silent instruction before it has begun to transmit a repeater signal, the random wait cycle of the repeater is stopped.

83. The integrated circuit according to claim 81, characterized in that the random waiting cycle of the repeater is reset by an acceptance instruction issued by the reader.

84. The integrated circuit according to claim 81, characterized in that the random waiting cycle of the repeater is readjusted by an acceptance instruction issued by the reader.

85. The integrated circuit according to claim 81, characterized in that the random waiting cycle of the repeater is reset after a predetermined period of time.

86. The integrated circuit according to claim 82, characterized in that if a repeater receives a mute instruction before it has begun to transmit a repeater signal, the repeater is inhibited by the circuit to transmit the repeater signal at the end of the random wait cycle .

87. The integrated circuit according to claim 73, characterized in that the control repeater is permanently disabled or deactivated by a disabling or deactivating instruction of the reader after the signal of the repeater has been successfully received by the reader.

88. The integrated circuit according to claim 73, characterized in that the control repeater is disabled or deactivated for a predetermined period of time after the disabling or disabling instruction is issued.

89. The integrated circuit according to claim 75, characterized in that the control repeater is disabled or deactivated by the disable or deactivate instruction until its reset.

90. The integrated circuit according to claims 73 to 89, characterized in that the circuit includes local synchronization means.

91. The integrated circuit according to any of claims 73 to 90, characterized in that the integrated circuit has read / write capabilities.

92. The integrated circuit according to any of claims 74 to 91, characterized in that it includes a detector circuit of the length of the interval to determine the length of the interruption in the signal of the reader.

93. The integrated circuit according to claim 92, characterized in that the detection circuit of the length of the interval detects a silent instruction and pauses the random waiting cycle.

94. The integrated circuit according to claim 92, characterized in that the detection circuit of the length of the interval detects an acceptance instruction and allows the random waiting cycle to be resumed.

95. A reader comprising transmission means for transmitting an interrogation signal to at least one repeater at a time when at least one other relay can transmit in response to the interrogation signal and receiving means for receiving a response signal from a repeater, characterized in that in recognizing a repeater repeater signal the reader immediately emits a silent instruction, silencing all other active repeaters, and passing control to the repeater, without the need for a specific synchronized recognition to the control repeater.

96. The reader according to claim 95, characterized in that the silent instruction comprises a modulation of the reader signal.

97. The reader according to claim 95, characterized in that the reader issues an acceptance instruction after the control repeater signal has been successfully received by the reader.

98. The reader according to claim 97, characterized in that the acceptance instruction comprises a modulation of the reader signal.

99. The reader according to claims 93 to 96, characterized in that the modulation comprises a total interruption of the reader signal.

100. The reader according to claims 93 to 96, characterized in that the modulation comprises a partial interruption of the reader signal.

101. The reader according to claims 93 to 96, characterized in that the instruction is the signal transmitted independently of the signal of the reader.

102. The reader according to claim 97, characterized in that the acceptance instruction uses the same modulation of the read signal as the silent instruction.

103. The reader according to claim 97, characterized in that the acceptance modulation has a duration different from that of the silent modulation.

104. The reader according to claim 97, characterized in that the silent instruction comprises a short interruption in the signal of the reader and the acceptance instruction comprises a long interruption in the signal of the reader.

105. The reader according to any of claims 92 to 104, characterized in that the reader transmits the silent instruction as soon as the reader recognizes, or there is a high probability that the reader has recognized, a valid signal from the repeater.

106. The reader according to any of claims 93 to 106, characterized in that the reader is adapted to distinguish the first few distinguishing pulses in the repeater signal as a signal from a repeater.