EP1354468A1

EP1354468A1 - Method and device for secure data recording and monitoring

Info

Publication number: EP1354468A1
Application number: EP02700372A
Authority: EP
Inventors: Philippe Dubus
Original assignee: Assmann Telecom
Current assignee: Assmann Telecom
Priority date: 2001-01-26
Filing date: 2002-01-22
Publication date: 2003-10-22
Also published as: WO2002060169A1

Abstract

The invention relates to a method for monitoring at least one satellite station by means of a centralised monitoring station and for secure data recording, wherein: said satellite stations are outside the local network (LAN) of the centralised station; the centralised station is adapted for at least temporary connection with each of a number of satellite stations; the centralised station monitors multiple satellite stations and, for each of said stations, records data corresponding to a monitored object such that a reproduction of the monitored object can be produced; the monitoring of said satellite stations is carried out in real time. The invention also relates to a monitoring and recording device used to carry out said method.

Description

METHOD AND DEVICE FOR SECURE DATA MONITORING AND RECORDING

The present invention relates to a method of monitoring at least one satellite station by a centralized monitoring and secure data recording station, and the device enabling the method to be implemented.

An increasing number of data that can be considered important or sensitive or confidential are exchanged between various people or organizations. For a large part of this data, it is necessary to carry out a recording which can serve as reproduction, proof, quality control, removal of doubt, etc. Different types of recorders of known types make it possible to make recordings fulfilling these different roles. Such recorders are physically located near the data source to be recorded, and are operated and maintained by users.

This type of configuration has several drawbacks. First of all, users must be trained to know how to use the machine correctly, in all circumstances. Sometimes training must be repeated at regular intervals to take into account the arrival of new employee-users or simply to update the knowledge of occasional users. The daily management of the device is also a source of many concerns for certain non-specialized users, in particular during emergencies or crises, situations which are frequent with this type of device.

On the other hand, in the event of a breakdown or technical difficulty requiring the intervention of a specialist, a certain amount of time is necessary before the intervention can be carried out. This type of intervention involving the displacement of a specialist involves a significant cost. On the other hand, once a user has purchased a recorder of a given type with a certain capacity and a certain configuration, it may prove difficult to manage the changes in the needs of this user. For example, it may be necessary to change some do modules the device, which involves moving a specialist for a technical intervention. Sometimes, we can only note the technical obsolescence of the device: we must then consider replacing it with another more adapted to the new environment. All this involves significant costs, in some cases even before the costs of acquiring the first device are amortized.

Maintaining the device in operational conditions involves maintenance operations by specialists. This also involves costs and sometimes causes periods of unavailability of the device.

This type of configuration, in which a recorder is placed close to the data source, on the other hand provides undeniable advantages as regards security. The device being physically in the premises of the user, this one can constantly make sure of its effective operation, to be certain that the data are indeed recorded. He can also ensure his safety, for example by controlling the access of people who will be in physical contact with the device. Users of such devices generally appreciate proximity and physical contact with the device. This type of physical contact gives a deep sense of security, the psychological importance of which often exceeds technological reality. This is easily understood by considering on the one hand that the users are not themselves specialists in the technical field in question and on the other hand that to be incontestable, the recordings must imperatively be inviolable.

Such recording devices, of analog or digital type, are therefore common today for recording telephone conversations in certain environments where the content of the information can be of a vital nature, such as for example in police stations. , gendarmerie, fire department, ambulance, etc. These devices are now entering more widely in financial institutions, for example for recording financial or commercial transactions, etc. Here again, the requirements in terms of confidentiality and security are of fundamental importance. In addition, with the boom in transactions on public networks such as the Internet, the need for traceability is growing rapidly. Indeed, both merchants and consumers, increasingly need intangible, neutral and tamper-proof evidence to settle any disputes related to the content of the transactions carried out. Today, the recording of transactions, when it is carried out, is done with standard, non-secure IT media, which does not guarantee the inviolability of data. In addition, the data is recorded by the merchant and at the merchant. In the event of a dispute, the consumer may find himself perplexed and disoriented in a situation which is a priori disadvantageous.

The present invention aims to avoid such drawbacks. It also aims to propose a method and / or a device allowing a great flexibility of evolution and adaptation.

To this end, the invention proposes a method for monitoring at least one satellite station by a centralized monitoring and secure data recording station, in which:

said satellite stations are outside the local area network (LAN) of the centralized station;

the centralized station is adapted for at least temporary connection with each of a plurality of satellite stations;

the centralized station monitors a plurality of satellite stations, records for each of them the data corresponding to a monitored object so as to be able to constitute a reproduction of the monitored object;

-the data of the resulting registration being unalterable, and therefore not repudiable. Thanks to such a method, the monitoring of the monitored satellite stations is advantageously carried out remotely by a specialized operator. The operator of the monitored satellite station no longer has to worry about the technical aspects linked on the one hand to the hardware and software infrastructure, and on the other hand to the recording and / or recovery of the data. He no longer has to worry about managing and storing recording media such as cassettes, labeling and storing them in a safe place, such as in a safe. The risks of identification, management or loss of error are also eliminated.

Maintenance and service can be centralized. Redundancy (for example doubling or tripling of equipment) in order to guarantee continuity, security and the quality of monitoring and recording is facilitated, even increased and less expensive since it is carried out centrally rather than multiple times within from each satellite station. A centralized support service (of the “hot line” type) may also be available. Centralization minimizes equipment, maintenance, staff training and various interventions at satellite stations. It is also easier to adapt and develop a given installation as a function of parameters that may need to vary over time, for example the volume or size of the object monitored and / or its nature.

Monitoring of the satellite station preferably involves recording the monitored object on a continuous basis. According to an advantageous alternative embodiment, in the field of recording telephone calls, the "blanks" (the moments of silence during conversations) and / or the idle times between calls are advantageously managed during the recording of so as to minimize / optimize the memory space used, while reconstituting them during a re-listening.

Time-outs are therefore not recorded as such. It is the time stamp data which allows the sequence of events to be reconstructed (duration, time, date, etc.). Timestamping notably makes it possible to precisely identify calls, to locate or find them, and possibly to save recording capacities, regardless of whether they are magnetic, optical or other media.

Other coordinates may be provided for recording, such as the source of the data, such as for example the coordinates of the caller for telephone calls, its location, or any other identifiable parameter.

Advantageously, the monitoring of said monitored satellite stations is carried out in real time.

The monitored object preferably corresponds to the data relating to the communications received and / or sent by the monitored satellite station.

For example, the monitored object corresponds to the data relating to the communications (audio, visual, written or codified) received and / or sent by the monitored satellite station.

For example, the monitoring and recording of data from a monitored satellite station such as the police station, gendarmerie, fire department or ambulance, etc., makes it possible to reconstruct the chronology of information or technical data such as telephone communications made by example over a given period of an hour or a day, etc. Listening to a specific recording is particularly advantageous, for example to hear a misunderstood emergency call, whether for reasons of poor quality of the communication, or simply because the caller does not speak clearly. Such a situation is indeed common and normal in the case of urgent calls such as for a fire, an accident, or any other situation requiring the rapid intervention of a rescue team. It can also be radio communications such as communications intended for controlling air, nautical or underwater traffic, rail, space, etc.

The method according to the invention preferably provides means for locking the recorded data preventing modification of the latter.

Locking data, that is, the inability to modify data, can be an important part of user security. Locking can be either bilateral (data cannot be modified from a satellite station or from the centralized station), or unilateral (data cannot be modified either from a satellite station or from the centralized station), according to a pre-established configuration .

The elements implemented, as well as the centralized operator, can be subject to certification, guaranteeing user safety. Certification of data locking can be an important part of a security guarantee.

The recorded data is inviolable, thus providing a high level of security, which can be used for example for the purposes of judicial authentication.

For example, the security of the recording can be ensured by an encryption means. Advantageously, proprietary type encryption is used.

Otherwise, or alternatively, the recording means may include an anti-intrusion system, protecting the data, or an intrusion detection system, indicating that an unauthorized third party has attempted to enter the memory, or access the recorded data. Thanks to one or more of these means of known type, or using equivalent means, the unalterability or inviolability or securing of data can be ensured. According to an advantageous variant, the object monitored corresponds to elements of a technical or physical nature. Thus, the method according to the invention makes it possible to take into account any information, data, event, parameter, situation or context of a technical or physical nature likely to be of interest to be traced in order to provide elements of analysis or proof .

According to an advantageous embodiment, the monitored object corresponds to technical data. It may be information of a technical nature or physical parameters that it is often desirable to verify, either for security purposes or in the context of the control of a system, machine, etc. For example, the monitored object corresponds to the data associated with an alarm system, a relay, a control system, a physical parameter such as temperature, speed, pressure, power, flow, time , electric current (voltage, amperage), spatial or geographic coordinates, or the signal from a radar, etc. In the context of more complex systems generally involving a plurality of parameters, several objects or sub-objects, or even all of them, can be monitored. It may for example be a monitoring system for a thermal or nuclear power station, a dam, a water purification station, a monitoring or medical monitoring system, etc.

The data of the monitored object consist for example of audio and / or visual information, such as for example the data coming from a video surveillance system of a public place.

According to another advantageous example, the data of the monitored object consists of written or coded information of the written message type.

For example, it may be instructions or orders (such as a stock market order) sent to an intermediary, such as for example a financial intermediary of the broker, banker, insurer type, etc. Here again, data inalterability can play a major role. This can thus reassure a client in the event of a telephone order, since there is then recorded and tamper-proof proof of the identical content of the order. An unsatisfied client can then prove the nature of his request. If the recording is carried out by a third party, advantageously certified, then all the conditions are met so that the evidence can be used in the event of a dispute before a court, or in the event of an investigation.

Advantageously, the reproduction of the monitored object allows the faithful reconstruction of the technical or physical elements subject to the monitoring.

For example, in the case of monitoring communications (audio, visual, written or codified) received and / or sent by the monitored satellite station, the recording made allows the replay of all conversations and / or the reissue of all messages, intended for the monitored satellite station. Advantageously, communications from the satellite station are also monitored. The nature of the reconstitution or restitution of the object monitored may vary according to the case or needs and / or according to the very nature of the technical or physical elements monitored. For example, voice data can easily be reconstructed in audio or audio form. Written data can be reconstructed in written form (by printing or display on a screen). Other types of parameters such as temperature, alarms, thresholds, etc., can preferably be reconstituted in the form of information (with any corresponding units or scales), for example in the form of a list making it possible to recognize said parameters, instead of transforming them back into their original nature (temperature, pressure, etc.).

The nature of the reconstruction can also be in another form. For example, audio elements can be reconstructed in written form.

The traceability of the elements is advantageously ensured by associating with the recorded data all the coordinates essential for the precise identification of the context. For example, the origin of a telephone call or a communication, the identification of a machine that has collected data such as a measurement, a parameter, the time stamp, etc. The reproduction is advantageously organized in the form of identified files.

A file includes for example the identification of the caller (such as telephone number, IP address, or other) the timestamp of the communication, the duration, the content of the communication (telephone conversation, data file, etc. ). These elements can be reconstructed chronologically, according to the sequence of arrival of the data at the monitored satellite station. Optionally, one can choose to recover only a portion of the data, corresponding for example to a more important element.

According to various alternative embodiments, the data of a monitored satellite station, recorded by the centralized station, can for example be accessible only from the centralized station, or even from the centralized station and / or from at least one other station, such as by example a satellite station, a listening station, etc.

According to another advantageous embodiment, the data of a monitored satellite station, recorded by the centralized station, cannot be modified either by the centralized station or by a satellite station.

Since the data cannot be modified unilaterally by a monitored satellite station or by the centralized station, they can be used for the authentication of facts related to this data, or for the removal of doubts. This can be important for example during an investigation in order to verify the authenticity of technical or physical elements such as for example the data corresponding to communications between two parties. For example, it may be necessary to verify the content of a stock market order that a potential client claims is poorly executed, partially completed, or even not completed at all. It can sometimes be useful to check or control the response time of a rescue team, for example between the time of a telephone call for an intervention request and the actual arrival of the team on the scene of the intervention. According to the invention, the connection between the monitored satellite stations and the centralized station is advantageously carried out via a public network. Data thus circulates via a common network to a plurality of users. To prevent unauthorized persons from collecting data from a satellite station, it is advantageously secure, for example by encryption, or any other system or method making it possible to secure the transport and / or accessibility of the data.

Said public network can be the telephone network, the cable, the electrical network, a cellular telephone network, a satellite communication network, etc. Public network also means a private network to which a large number of people can access or connect, or a private network covering a large geographic area, as opposed to a private network with limited and monitored access, as for example in a single network. or a small group of substantially neighboring buildings.

According to an advantageous variant, the recorded data are accessible only to authorized persons.

This embodiment allows complete confidentiality at the satellite stations. Data from a satellite station can therefore only be retrieved by one or more authorized persons from that same satellite station. Access to third parties via the central station or another satellite station (not authorized) is restricted or impossible.

The connection between the centralized station and each of the satellite stations can be in substantially continuous mode or in “shared time” mode.

According to the first of these modes, the connection is substantially permanent or continuous between the centralized station and a plurality of satellite stations. According to the second mode, the connection is alternately, from a first satellite station to the centralized station, then from a second satellite station to the centralized station, etc. The alternation can be managed for example sequentially, or on demand, depending on access priorities such as the importance of traffic or data flow.

The temporal succession of the events corresponding to the sequence of these events in real time can be reconstructed during a processing intended to recover the data, with a possible preprocessing or formatting making it possible to better present the data.

According to another advantageous embodiment, the data are temporarily recorded in a temporary storage station connected to the monitored satellite station, for subsequent transmission to the centralized station.

Thanks to the use of a delocalized buffer, for example at the level of a given satellite station, which can allow the recording of data for a given period, it may subsequently be possible to send the data to the centralized station in the form of blocks or in any other form of preprocessing aimed for example at facilitating the transmission and / or recording thereof at the centralized station, or even to facilitate securing. Such a configuration can also prove useful in order to guarantee continuity of surveillance in the event of a breakdown or technical difficulty in a public network ensuring the connection between a satellite station and the centralized station.

Alternatively, a buffer can be used to serve a plurality of satellite stations.

The buffer data corresponding to a timeout period are preferably locked, or unalterable, as described above.

Access to the buffer data can, as described above, be accessible or not by the corresponding satellite station and / or by the centralized station. According to another advantageous embodiment, the data is of the type suitable for transmission via a global network.

For example, it is IP type data, or any other protocol suitable for an Internet type network.

According to an advantageous exemplary embodiment, the data of a monitored satellite station, recorded by the centralized station, are accessible by the same monitored satellite station but cannot be modified from this station.

This makes it possible to carry out immediate replay, in a simple and particularly rapid manner, as is often necessary, for example in rapid intervention services such as firefighters, police, ambulance, etc.

According to another advantageous embodiment, at least one satellite station is a mobile type station.

For example, it is a mobile station with access by satellite, radio (with earth stations), cellular, etc. This type of station corresponds, for example, to emergency vehicles for the population such as the police, firefighters, etc.

According to another advantageous embodiment, the data are also accessible from one or more other stations (listen-back station).

Such a replay station can advantageously allow the availability of certain data to other authorized users, or to the same users when the latter are outside their usual satellite station. It is advantageously a mobile station, with access by satellite, radio (with earth stations), cellular, etc.

The present invention also provides a device for monitoring at least one satellite station by a centralized monitoring and recording station. secure data, comprising at least one satellite station through which data which can be recorded transit and at least one centralized station, suitable for recording said data from the satellite station, in which the satellite stations are linked to the centralized stations by a network public, centralized stations being capable of exercising a substantially continuous monitoring of said satellite stations in order to permanently record said data. Data can either only pass through the satellite station (and then come from other sources), and / or can come from the satellite station.

The monitoring of said monitored satellite stations is preferably carried out in real time.

According to an advantageous embodiment, the monitored object corresponds to the data relating to the communications received and / or sent by the monitored satellite station.

According to an alternative embodiment, the monitored object corresponds to elements of a technical or physical nature.

Preferably, means for locking the recorded data prevent modification of the latter.

The invention further provides a satellite station through which data capable of being recorded pass, said station being capable of being connected in a substantially continuous manner to a centralized station in order to transmit said data in substantially real time for the purpose of registration by said centralized station.

The invention further provides a centralized station capable of carrying out substantially continuous monitoring of at least one satellite station in order to record the data passing through this station. The invention will now be described using the attached single figure, illustrating an example configuration according to the invention of a centralized station connected by a public network to a plurality of monitored satellite stations.

A centralized station 10 is connected to a plurality of monitored satellite stations 20 via a network 30. The centralized station comprises at least one data input / output means 11 with the outside, of modem type, allowing to establish links with satellite stations. At least one data recording means 12 is also provided within the centralized station. It preferably has a large storage capacity, a high level of reliability and an ability to quickly find and restore the information requested. In order to guarantee a high level of reliability and security, a recording means is advantageously provided with capacities allowing the multiplication or duplication of the recordings, either for the total duration of the recording or even for a limited period of time.

The central station can be configured in various ways. For example, a recording means 12 can be dedicated to a single satellite station. In a variant, a recording means is associated with a plurality of satellite stations.

A management system 13, such as for example a computer or a network of computers possibly supplemented by a server, makes it possible to configure the operating modes and to carry out the management of the hardware, software and data. This allows efficient management, for example, of data flows, recordings, data recovery, communications or data exchanges with outside the centralized station, etc.

A satellite station 20 comprises at least one unit to be monitored 40. It is preferably an element playing a key role with respect to the object to be monitored, whether it is data relating to communications, physical or mechanical parameters, etc. In the example illustrated, a communication module 24 (telephone type or the associated telephone line) can serve as a unit for monitor, if the object to be monitored consists of voice communications exchanged between the operator of the module 24 and for example any interlocutor located outside the satellite station. The example illustrated comprises a second unit to be monitored 40, which consists of a programmable controller 26.

A management system 23, such as for example a computer or a network of computers possibly supplemented by a server 22, makes it possible to configure the operating modes and to carry out the management of the hardware, software and data of the satellite station. . This makes it possible to efficiently manage, for example, data flows, recordings, data recovery, communications or data exchanges with the outside of the satellite station, etc.

A possible satellite recording module 25, connected to the satellite station, can serve as local support by means of centralized recording 12. The module 25 can be integrated either directly within a satellite station or even be located at a level intermediary between the satellite station and the centralized station.

If the satellite station is complex, it may possibly include a private network 21 or LAN, access to which is preferably restricted to only authorized persons. This network allows the integration and management of a multiplicity of parameters, of the same type or of different types, at different points, etc.

A network 30, preferably public, serves as a communication link between the satellite station and the centralized station, in order to establish the links between the two. These links can be continuous or temporary, depending on the type of configuration, the data flow and depending on whether or not a satellite recording module 25 is used at the satellite station.

According to an advantageous variant, provision is made for a duplication of the public network 30. For example, the wired telephone network constitutes the basic network; the cellular telephone network (or any other type of radio or wired network) constitutes the secondary or alternative network, likely to be used for example in the event of a breakdown or unavailability of the basic network. This secures the continuity of communication between the satellite stations and the centralized station.

The device and the monitoring and recording method according to the invention operate as described below. A monitored satellite station 20 serves as a hotspot for at least one parameter or element of a technical or physical nature.

In the example illustrated, the parameter in question relates to the data relating to telephone communications preferably established between at least one communication module 24 and the exterior of the satellite station. In the example illustrated, a programmable controller 26 manages another type of object, such as for example one or more alarm systems placed at points to be monitored, such as for example banks, shops, offices, apartments or residences.

The scent 22, connected to the module 24 and to the automaton 26, makes it possible to transmit the data of the object or objects being monitored to the centralized station 10. In order to allow true monitoring, the communication between the monitored satellite station 20 and the centralized station 10 is preferably established continuously. According to an illustrated alternative embodiment, at least one satellite recording module 25 is provided at the satellite station. This module makes it possible to record the data relating to the objects monitored for a pre-established duration, depending for example on the storage capacity of the module. The data are then transmitted by the network 30 to the centralized station 10.

The use of a satellite module 25 can make it possible to carry out a local recording for subsequent transmission of the data to the station 10, in order for example to avoid having to establish permanent communication between the satellite station and the centralized station. According to an advantageous variant, this same module can be used for duplication of the recording. According to another variant, it serves as a safety relay, in the event of communication failure between the satellite station and the centralized station for example.

The management of the recorded data, whether in a module 25 or at the centralized station, can be carried out in several ways, depending on the context and the requirements. The monitored object can thus be accessible either only at the original satellite station, or in another satellite station (listening station), or only at the centralized station, or in several of these stations. Data can be locked to limit access to only authorized persons, either to one or more stations. Limiting access to the monitored object notably makes it possible to guarantee that the recorded data will not be modified. Of course, other security devices, either of the software or hardware type, can contribute to this aspect.

The recording makes it possible to reproduce or reconstruct the data of the monitored object. Such reproduction or reconstruction may be necessary in several types of situations. For example, in the case where the monitored satellite station 20 is a population rescue service station such as a police, gendarmerie, fire, ambulance, etc. station, it may prove useful to recover data from a telephone call from a distressed citizen, who left a message difficult to understand.

Also in the example illustrated, the controller 26 may have detected an alarm situation which one wishes to verify by reproducing the recorded data.

Claims

1. Method for monitoring at least one satellite station by a centralized monitoring and secure data recording station, in which:

-the data of the resulting registration being unalterable.

2. Method for monitoring at least one satellite station by a centralized monitoring and secure data recording station according to claim 1, in which the monitoring of said monitored satellite stations is carried out in real time.

3. Method for monitoring at least one satellite station by a centralized monitoring and secure data recording station according to one of claims 1 or 2, in which the monitored object corresponds to the data relating to the communications received and / or sent by the monitored satellite station.

4. Method for monitoring at least one satellite station by a centralized monitoring and secure data recording station according to one of claims 1 or 2, in which the object monitored corresponds to elements of a technical or physical nature.

5. Method for monitoring at least one satellite station by a centralized monitoring and secure data recording station according to one of claims 1 to 4, in which means for locking the recorded data prevent modification of the latter.

6. Method for monitoring at least one satellite station by a centralized monitoring and secure data recording station according to one of claims 1 to 5, in which the data of a monitored satellite station recorded by the station centralized, can only be accessed from the centralized station.

7. Method for monitoring at least one satellite station by a centralized monitoring and secure data recording station according to one of claims 1 to 5, wherein the data of a monitored satellite station, recorded by the station centralized, are accessible from the centralized station and / or from at least one other station.

8. A method of monitoring at least one satellite station by a centralized monitoring and secure data recording station according to claim 7, wherein said at least one other station is a satellite station.

9. Method for monitoring at least one satellite station by a centralized monitoring and secure data recording station according to claim 7, wherein said at least one other station is a listening station.

10. Method for monitoring at least one satellite station by a centralized monitoring and secure data recording station according to one of the preceding claims, in which the connection between the monitored satellite stations and the centralized station is carried out via a public network.

1 1. Method for monitoring at least one satellite station by a centralized monitoring and secure data recording station according to one of the preceding claims, in which the recorded data are accessible only to authorized persons.

12. Method of monitoring at least one satellite station by a centralized monitoring and secure data recording station according to one of claims 1 to 1 1, wherein the connection between the centralized station and each of the satellite stations is in substantially continuous mode.

13. Method of monitoring at least one satellite station by a centralized monitoring and secure data recording station according to one of claims 1 to 1 1, wherein the connection between the centralized station and each of the satellite stations is in timeshare mode.

14. Method for monitoring at least one satellite station by a centralized monitoring and secure data recording station according to one of the preceding claims, in which the data is temporarily recorded in a temporary storage station connected to the station. monitored satellite, for subsequent transmission to the centralized station.

15. Method for monitoring at least one satellite station by a centralized monitoring and secure data recording station according to one of the preceding claims, in which the data is of the type suitable for transmission via a global network.

16. Device for monitoring at least one satellite station by a centralized monitoring and secure data recording station, comprising at least one satellite station through which data capable of being recorded pass through and at least one centralized station, suitable for recording said data from the satellite station, in which the satellite stations are linked to the centralized stations by a network, the centralized stations being capable of exercising a substantially continuous monitoring of said satellite stations in order to permanently record said data.

17. Device for monitoring at least one satellite station by a centralized monitoring and secure data recording station according to claim 16, in which the monitoring of said monitored satellite stations is carried out in real time.

18. Device for monitoring at least one satellite station by a centralized monitoring and secure data recording station according to claim 16 or 17, in which the monitored object corresponds to the data relating to the communications received and / or sent by the monitored satellite station.

19. Device for monitoring at least one satellite station by a centralized monitoring and secure data recording station according to one of claims 16 to 18, in which the object monitored corresponds to elements of a technical or physical nature. .

20. Device for monitoring at least one satellite station by a centralized monitoring and secure data recording station according to one of claims 16 to 18, in which means for locking the recorded data prevent modification of the latter.

21. Satellite station specially adapted for the implementation of the monitoring method according to one of claims 1 to 15, said station being capable of being connected in a substantially continuous manner to a station centralized in order to transmit said data in substantially real time for recording purposes by said centralized station.

22. Centralized station specially adapted for implementing the monitoring method according to one of claims 1 to 15, said station being capable of exercising substantially continuous monitoring of at least one satellite station in order to record the data. passing through this station.