ITMI20111993A1 - DISTRIBUTED DATA WIRELESS ACQUISITION SYSTEM - Google Patents

Description

Description of the patent application for industrial invention entitled:

"Distributed Acquisition System

wireless data "

TECHNICAL FIELD

The present invention relates to data acquisition systems and, in particular, to acquisition systems which use a plurality of sensors.

TECHNIQUE NOTE

Referring, for example, to acquisition systems for seismic monitoring, there may be the need to distribute a large number of sensors (several thousand) to be connected to a central control and data storage device over a large area to be monitored. The current wired system includes sensors, typically geophones or accelerometers, connected to the central apparatus by means of cables (fiber optic, coaxial cables or other) which can reach a total length and weight such as to make the system extremely expensive and complex. maintenance.

Therefore, data acquisition systems have been studied aimed at minimizing the use of transmission cables.

The document US-A-2007-0025307 describes a network of sensors for geophysical acquisitions (oil exploration). In this document it is proposed to adopt a radio technology and a wired technology in cooperation.

Document US-A-2 001-02 8313 describes a distributed architecture for real-time monitoring based on technology for GPRS / GSM cellular networks and location via GPS.

The following scientific documentation is useful for the complete understanding of this description:

[1] S. Savazzi and U. Spagnolini, "Wireless Geophone Networks for high density land acquisitions: technologies and future potential," The Leading Edge, Special Section: Seismic Acquisition, pp. 259-262, July 2008.

[2] ECMA-368 Standard: High Rate Ultra Wideband PHY and MAC Standard. Second Edition, December 2007, ECMA International.

[3] I.F. Akyildiz, Weilian Su, et al. "A survey on sensor networks", IEEE Comm. Magazine, vol. 40, no. 8, pp. 102-114, Aug. 2002.

[4] A. Batra, J. Balakrishnan, "Design of a Multiband OFDMSystem for realistic UWB channel environments," IEEE Trans.on Micro. Theory and Tech., Vol. 52, no. 9, pp. 2123-2137, Sept. 2004.

[5] I. Dermikol, C. Ersoy, F. B. Alagoz, "MAC Protocols for Wireless Sensor Networks: a survey," IEEE Comm. Magazine, pp. 115-121, April 2006.

[6] IEEE 802.15.4-2006, "Part 15.4: Wireless Medium Access Control (MAC) and Physical layer (PHY) Specifications for Low-Rate Wireless Personal Area Networks (LR-WPAN)". Standard, IEEE.

SUMMARY

The Applicant has noted that the methods indicated above do not appear satisfactory because they are unable to effectively combine different conflicting needs: the high number of sensors to be used, the need to limit the use of wiring and ensure robustness and reliability of the acquisition system. in the presence of interference, maintaining acceptable levels of energy consumption.

The aim of the present invention is therefore to make available a data acquisition system that overcomes, at least in part, the problems mentioned above.

This and other objects are achieved by means of a data acquisition system according to claim 1. The dependent claims define other possible embodiments.

BRIEF DESCRIPTION OF THE FIGURES

In order to better understand the invention and appreciate its advantages, some non-limiting exemplary embodiments thereof will be described below, with reference to the attached figures, in which:

Figure 1 is a schematic view of an embodiment of a data acquisition system comprising a control and storage unit, sensor devices and telecommunication devices;

Figure 2 shows an example of embodiment of a sensor device of said system;

figure 3 shows an example of embodiment of a telecommunication device of said system;

Figure 4 shows a structure of a frame which can be used by the data acquisition system in sending data and / or control signals;

Figures 5A and 5B refer to some steps relating to a method of registering a device in a subnet of the data acquisition system.

DETAILED DESCRIPTION

Figure 1 shows an example of a data acquisition system 1000. In particular, the data acquisition system 1000 can be used for monitoring activities, for example, for the following applications:

- environmental monitoring for the control of air, water pollution, temperature, weather conditions

monitoring for the prevention and / or detection and / or management of natural disasters (for example: landslides, earthquakes, fires, etc.);

- seismic monitoring;

- urban and / or industrial monitoring, video surveillance, urban traffic control, industrial process control;

- monitoring for advanced navigation systems, assisted navigation for the disabled;

- monitoring in medical applications for the optimization and improvement of medical care in hospitals, remote monitoring of patients.

In the following, the acquisition system 1000 will be described with reference, in a non-limiting way, to the particular application relating to seismic monitoring.

The particular data acquisition system 1000 shown in Figure 1 comprises: a plurality of sensor and / or transmission devices (indicated generically with the symbol WS), at least one control and data storage apparatus SU and, for example, at least one device for WSG telecommunication.

The plurality of sensor and / or transmission devices WS is organized in such a way as to be divided into two sub-pluralities which have distinct characteristics

These sub-pluralities include: a sub-plurality of WSC management sensor devices (represented in the figure with a black dot), with the role of coordinating and aggregating the received data and a sub-plurality of WSU network sensor devices (represented in figure 1 with a circle surrounding a point) coordinated by the WSC management devices,

Both the WSC sensor management devices (hereinafter referred to as "manager devices") and the network sensor devices (hereinafter referred to as "network devices") are configured to provide measured data and are capable of operating, for example, according to a first telecommunication method.

This first method provides for a short-range radio (ie wireless) telecommunication with ultra-broadband technology.

Figure 2 schematically shows a possible structure of a WSU network device; this structure is similar to that of the WSC management devices.

In greater detail, and with reference to Figure 2, the WSU network device can comprise, in particular, one or more sensors or detection units 1, suitable for detecting data relating to physical quantities to be monitored and an acquisition and communication apparatus 9 The sensors 1 are capable of supplying electrical signals, typically of the digital type, representative of a measured physical quantity. According to the example referring to seismic monitoring, the sensors 1 can be geophones or accelerometers. The sensors 1 are connected to the acquisition and communication apparatus 9 by means of a suitable wiring 10.

The acquisition and communication apparatus 9 comprises a digital data acquisition module 11 (ACQ), for example including an analog-digital converter, connected to the sensor 1, a memory unit 12 (M) and a first short-range transceiver apparatus 2 (SR-Rx / Tx). The memory unit 12 (M) is, for example, a memory card with a memory capacity of the order of tens of Mbytes.

The first short-range transceiver apparatus 2 is configured to operate according to the first telecommunication mode defined above to transmit / receive signals that can carry the data corresponding to the physical quantities measured by the sensor 1 or other types of signals, such as for example check.

This first short-range transceiver device 2 is, for example, a radio board in UWB 3-10 GHz or 60 GHz technology.

The WSU network device, and the WSC manager one, can also be equipped with a satellite location receiver apparatus, for example, GPS (Global Positioning System).

Furthermore, the network device WSU is optionally equipped with an external antenna 6 (for example toroidal) connected to the first short-range transceiver apparatus 2 and with a power supply battery 7 (BATT). Alternatively, the network device WS and / or the sensor 1 can be powered by photovoltaic panels.

It should be noted again that the above description with reference to Figure 2 is also valid for the WSC management devices, however it should be noted that according to a particular embodiment, the WSC management devices can be without the sensor 1 and therefore be communication and aggregation of data that do not carry out measurements.

As regards the organization of the plurality WS of sensor and / or transmission devices, the data acquisition system 1000 in the example of Figure 1 comprises a plurality of networks such as: a first network A, a second network B, a third network C and a fourth network D, each associated with a relative telecommunication device WSG which acts as a collection gateway.

Within each of these networks A-D, a plurality of sub-networks can be identified including a sub-plurality of WSU network devices (which act as end nodes) coordinated by the same management device WSC which therefore acts as a coordinator . The coordinator is able to aggregate and regenerate the data received from the devices he coordinates and then retransmit them; moreover, the coordinator provides the signaling necessary for the functioning of the network of which he is coordinator.

In particular, within each subnet the WSU network devices, coordinated by the WSC management devices, can be organized according to a star topology.

For example, with reference again to Figure 1, consider the second network B which comprises a first sub-network B1 formed by two network devices WSU-1 and WSU-2, coordinated by the manager device WSC1, and a second sub-network B2 formed by two other WSU-3 and WSU-4 network devices coordinated by the WSC-2 manager device. The first subnet B1 and the second subnet B2 are of the star type.

In the star topology, a WSC manager device is at the center of the star at the top of which are the WSU network devices. It should be noted that, for example, the WSU network devices can also be organized according to a tree or cluster topology in which the WSU network devices constitute end nodes and the WSC management devices assume the role of repeater nodes according to a higher hierarchical level up to to the connection with the WSG telecommunication device.

In addition, the WSC manager devices of each A-D network are organized by adopting a mesh network topology. Depending on the overall size of the area to be monitored, the usable mesh topology can be of the partially connected type or of the completely connected type. In figure 1, the possible connections are indicated by double arrows and WSC management devices appear to form partially connected meshes.

Each WSC manager device is such as to act as a coordinator for a given number of WSU network devices and can also operate as a repeater (regenerative relay) for other WSC manager devices, for example in the event that the mesh topology is partially connected. The WSC management devices also communicate with the WSG telecommunication devices, while this is not allowed for the WSU network devices which, moreover, are not enabled to communicate with each other directly (in peer-to-peer mode) but only through specific WSC handler devices.

The WSU network devices, in addition to the detection of external measurements, take care of the transmission of the measured data to the relative WSC manager device and of a "time-stamp" signal which allows to indicate an instant in time for the aggregation of the data and the 'processing in real time at the WSC management device.

With reference to Figure 3, an embodiment example of the WSG telecommunication device will be described below which comprises a second short-range transceiver apparatus 3, an interface device 4 and a long-range transceiver apparatus 5 (LR-Tx / Rx). The interface device 4 is configured for converting the digital signal received by the short-range transceiver apparatus 3 into a signal suitable for long-range transmission.

According to a further embodiment, one or more of the WSG telecommunication devices can also comprise a respective sensor (not shown) similar to that included in the WSU network devices or in the WSC management devices. The further sensor, if present, is connected to the second short-range transceiver device 3 by means of a possible relative acquisition module similar to module 11 i figure 2. The second short-range transceiver device 3, included in the WSG telecommunication devices it is configured to communicate with the first short range transceiver apparatuses 2 of the WSC management devices, according to the aforementioned first mode and which fall within the relative operability range. Furthermore, the second short-range transceiver apparatus 3 is such as not to allow direct wireless communication with the control and data storage apparatus SU.

In particular, for the purposes of the present description, the expression "short range transceiver apparatuses" means that the apparatuses are suitable for communicating within a radius of between 10 and 30 meters in conditions of visibility and for outdoor installations.

Furthermore, the "Ultra Wide Band" technology, known per se, is a radio technology (ie wireless) with signals having a frequency greater than or equal to 3 GHz and with a band used greater than 500 MHz and for example, between 500 MHz and 1.5 GHz.

According to a particular embodiment, the modulation of the OFDM type (Orthogonal Frequency-Division Multiplexing) is used as ultra-broadband technology, more particularly, of the MB multiband type: MB-OFDM. MB-OFDM technology involves the use of the frequency hopping technique which ensures connectivity by switching a signal, for which there were significant attenuations or disturbances, from a certain carrier frequency to another frequency.

The ECMA-368 protocol is one of the standards defined to support MB-OFDM technology at the physical layer. MB-OFDM technology allows to manage a minimum transmission speed of tens Mb / s up to a maximum of 480 Mb / s, at distances of 10 meters.

The long range transceiver apparatus 5, included in the WSG telecommunication device, is configured to operate, for example, in accordance with a second long range telecommunication mode. Long-range communication means wireless communication capable of covering distances greater than 30 meters and, in particular, greater than 100 meters, for example, up to 1km.

According to a particular embodiment, the second long-range telecommunication mode is of the broadband type (Wide Band) and in particular, of the WiFi type (with frequencies equal to 2.4 Ghz), but it can also operate at the frequency in ISM band 868 MHz / 910 MHz or in the VHF spectrum at 450-500 Mhz.

The long range transceiver apparatus 5, included in the WSG telecommunication devices, is configured to communicate wirelessly with the SU control and data storage apparatus, and allows direct wireless communication with at least one other WSG telecommunication device for long range transceiver 5.

The interface device 4 makes it possible to convert the data format received by the second short-range transceiver apparatus 3 into the data format compatible with long-range transmission. This is obtained through the extraction, by means of an extraction module 13 (PYL-EXTR), of the information content (payload) from a signal provided by the second short-range transceiver 3 and the transfer to the long-range transceiver apparatus 5, by means of an encapsulation module 14 (PYL-INC), and vice versa.

In accordance with the example described, the WSG telecommunication device is also equipped with a second memory card (not shown) for storing data (buffering) and with a satellite location receiver apparatus for example, GPS (Global Positioning System ). In addition, the WSG telecommunication device can be equipped with an antenna for short-range signals 8 and an antenna for long-range signals 15.

The SU control and data storage apparatus is configured to operate in the second long range radio telecommunication mode and is therefore capable of communicating with the WSG communication apparatuses. The control and data storage apparatus SU is structured to collect the data received from all the communication apparatuses WSG and is able to control the data acquisition system 1000, by means of the exchange of suitable messages.

Operation

The communication between the devices included in the data acquisition system 1000 takes place according to a packet switching technique. For example, the sensor 1 of the WSU-1 network device carries out measurements by obtaining measured data that it transmits to the outside, by means of its first short-range transceiver device 2. The data measured by the WSU-1 network device is received by the WSC-1 manager device that transmits them WSC-2 manager device, which aggregates, regenerates and transmits them to the WSG telecommunication device of the second network B.

According to an optional operating mode, the WSC-2 manager device can perform lossless or partial loss compression of the aggregate signal received by the WSC-1 manager device.

In particular, the characteristics (frequencies, powers, band used) of the first short-range telecommunication mode are such as to reduce or completely avoid interference between the signals arriving at the WSC management devices and at each WSG telecommunication device.

The use of the MB-OFDM technique allows to obtain a significant spatial reuse of radio resources and therefore to reduce / eliminate interference in a particularly effective way. The WSG communication apparatuses send the data they have received and stored to the control and data storage apparatus SU.

Note that, moreover, there is a difference between WSU network devices and WSC management devices with regard to network information: WSC management devices have the task of propagating network information by periodic transmission of "beacon" frames ( in English 'beacon frames'), while this functionality is inhibited for WSU network devices.

The network information transmitted through the beacon frames are, for example: the number of WSU network devices next to the transmitting WSC manager device, the status of the power supply battery of each network device of which a WSC manager device is coordinator, the list of reservations of the transmission resources in terms of number and position of time slots reserved for the transmission of the measured data within the frame structure.

As for the MAC (Medium Access Control) level, i.e. the level of the ISO / OSI stack relating to access to the media, the WSC management devices can be based, for example, on the ECMA-368 standard. According to this standard, each WSC manager device is able to transmit signals according to a frame structure in which both the measured data and the data necessary for network signaling are inserted. The latter are transmitted through beacon frames positioned within a specific sub-portion of the frame (Beacon Period, hereinafter also referred to as BP). The beacon frame is transmitted inside a beacon slot, that is a time unit whose length is such as to allow the sending of the data necessary for the signaling.

Note that the WSC cluster management sensor devices are configured to collect the measured data from the WSU network sensor devices and organize their resources through a fully distributed mechanism. This mechanism called distributed beaconing is made possible by the ECMA-368 standard and allows the creation of a mesh network between the WSC management devices. The fact that communication is possible between WSC management devices and not between WSU network devices represents a difference with respect to networks compatible with the ECMA368 standard.

Figure 4 shows by way of example the structure of the frame similar to that of the ECMA-368 standard, except for differences which will be indicated below.

Access to the medium is divided into super-frames (superirames) such as: a Beacon Period, a Guaranted Time Slot (GTS) containing guaranteed access time slots dedicated exclusively to the transmission of measured data and a collision access period (CAP) .

As already mentioned, unlike devices operating according to the ECMA 368 standard, WSU network devices cannot transmit data within the Beacon Period. In this way the use of resources is reduced, decreasing the overall energy consumption for the 1000 data acquisition system (since the latter is mainly due to the energy consumption measured during the reading of the Beacon Period).

Each WSC sensor device device is instead responsible for transmitting beacon frames with periodicity given by the superframe in figure 4. The WSU network sensor devices are instead suitable for receiving the beacon frame transmitted by the reference WSC manager device for synchronization recovery and for acquiring information relating to the monitoring status To avoid collisions within the Beacon Period, the WSU network devices are authorized to transmit data and control / signaling frames only during the sub-portion of the frame called CAP (Contention Access Period), in which access to the transmission medium through the random access mechanism only (not guaranteed).

As already described, the protocol specifications for WSG telecommunication devices can be based on the ECMA-368 standard. In particular, the WSG telecommunication devices have a MAC address and a Beacon Period beacon frame reserved and known to all the WSC management devices. In addition, the WSG telecommunication devices implement the following procedures (which extend their functionality with respect to both standard ECMA 368, both to WSC and WSU network manager devices):

a) procedure for spreading the framing structure (BP / GTS / CAP intervals);

b) procedure for generating control / propagation messages on the downlink section, eg START / STOP and Hibernate commands;

e) management / allocation procedure of the beacon slots in the superframe (the first slot after the signaling slots is reserved for the WSG telecommunication devices); see the super-frame structure of figure 4.

It should be noted that, according to this embodiment, the MAC protocol described here can integrate the main functions of the ECMA-368 standard (support of high transmission speed and real-time transmission), with the more specific ones relating to the IEEE 802.15 standard. .4 (low power consumption, high network scalability).

In particular, the definition of a network architecture based on coordination by full-function devices (WSC) and reduced function devices (WSU) is, for example, a characteristic of the 1000 acquisition system manageable in part similar to the IEEE 802.15.4 standard.

Now refer to the access modalities to the Beacon Period by the WSC management devices. This access to the Beacon Period by the WSC managing devices is managed, for example in a centralized way by one of the WSC managing devices which has the task of transmitting the beacon frames in a specific position (beacon slot) within the indicated Beacon Period. such as Highest Occupied Beacon Slot (HOBS).

Unlike the provisions of the ECMA368 standard, the access of a new WSC manager device to the use of the Beacon Period is based on an exchange of messages within signaling slots with reference to the frame structure of figure 4. This access comprising the steps of: sending a request message for a new beacon slot by a WSC manager device and waiting for a response message from the WSC manager device whose beacon slot occupies the HOBS position.

In this regard, reference is made to an example described with reference to Figures 5A and 5B. A manager device indicated in figures 5A-B as "DEV D", makes a request for insertion (REQ D) in the Beacon Period using one of the two signaling slots allocated before the start of the Beacon Period (Signaling Slots).

For the subnet considered in this example, another manager device indicated as "DEV C" covers the role of HOBS since the associated beacon slot is the closest to the final section of the Beacon Period (HOBS Highest Occupied Beacon Slot). The VIS-C subplot represents the Beacon Period vision for the DEV C management device.

The DEV C managing device therefore has the task of assigning the beacon slot immediately following its own to the DEV D managing device. The assignment obtained by communicating to other members authorized to access that Beacon Period (DEV A and DEV B managing devices) the position of the new slot occupied by the DEV D management device. This communication takes place through the periodic exchange of beacon frames and in particular by suitably modifying a portion of the beacon frame called Beacon Period Information Element (BPOIE), indicated in figure 5A as BPOIE (C). The whole operation has, for example, a total duration of 3x65.5ms (3 superframes).

Figure 5B shows the structure of the Beacon Period Information Element transmitted by the DEV D management device, BPOIE (D), at the end of the assignment procedure. Furthermore, figure 5B shows the subframes VIS-C and VIS-D which represent the vision of the Beacon Period for the manager device DEV C and for the manager device DEV D, respectively, at the end of the assignment procedure.

It should be noted that, as already mentioned, the WSG telecommunication devices are such as to transmit network information using a reserved beacon slot and therefore they do not participate in the Becon Period access procedure described for the WSC management devices.

According to another particular embodiment, the telecommunication devices WSG and the management devices WSC are respectively equipped with a receiver of a satellite navigation system, for example, of the GPS type.

Instead, all or part of the WSU network can be without a satellite navigation system receiver and can alternatively be equipped with a location software module capable of allowing an autolocation procedure that is not based on satellite signals.

In particular, the WSU network devices, not equipped with a GPS module, can measure the arrival times (Time of Arrivai) of the signal, i.e. measure the time interval used by a signal transmitted by a WSC management device or by a WSG telecommunication device (whose position is known through the GPS receiver they are equipped with) to reach the sensor device considered.

On the basis of three or more of these signal arrival time measurements, the localization module, by executing known triangulation algorithms, can determine the geographic coordinates of the considered WSU network device.

The WSU network devices then make their position available to the telecommunication device WSG, through the management devices WSC, making this information available to the control or data storage apparatus SU, and therefore to the operators.

Figure 4 shows within the CAP super-frame the position of the localization frame, called the localization frame intended to contain the information relating to the position, while some uplink slots are dedicated to the transmission of measured data (for example seismic data - Seismic Data).

It should be noted that although the above description refers to two telecommunication modalities, short range and long range, the data acquisition system 1000 could operate, according to another embodiment, according to only one of these telecommunication modalities. . With reference to the case in which only short range mode is used, the SU control and data storage apparatus is such as to operate at short range and the role played by the WSG telecommunication devices can be performed by those WSC management devices that occupy a higher hierarchical level. These management devices WSC, of higher hierarchical level, are connected in short range mode with the control and data storage apparatus SU, without the need to carry out conversions between different telecommunication modes.

The embodiments described are extremely advantageous.

The use of a short range UWB technology combined with the use of a long range technology allows you to manage data acquisition over large territories with a large number of sensors (for example, 3000 per km), avoiding collisions and with correct synchronization of the transmitted data.

The organization that provides management devices that coordinate the network devices, thus also operating as aggregators and repeaters, for example with tree or star topologies, makes it possible to cover large areas by optimizing energy consumption.

In particular, the efficient management / self-configuration of the Beacon Period used by the 1000 data acquisition system allows a reduction in the energy absorbed with a consequent limitation of overall dimensions and costs.

The use of the signaling slots for the registration procedure of the managing devices has the advantage of keeping the overall size of the Beacon Period under control, thus avoiding complex and difficult to control phases of contraction and expansion of the Beacon Period. This allows on the one hand to maximize the number of WSC management devices that can be registered within the Beacon Period, and on the other hand to minimize the energy consumption of the latter.

The possibility of carrying out a self-localization procedure by the WSU network sensor devices, without being equipped with a GPS receiver, allows a further reduction of dimensions and costs.

The skilled person, in order to satisfy specific contingent needs, can make numerous additions, modifications or replacements of elements with other functionally equivalent embodiments to the above-described embodiments of the data acquisition system, without however departing from the attached claims.

Claims (10)

CLAIMS 1.Data acquisition system (1000) comprising: a plurality of sensor and / or transmission devices (WSC, WSU) configured to provide measured data with wireless technology and according to a first telecommunication mode of the short-range radio type; a control and data storage apparatus (SU) adapted to receive the data provided by said plurality of devices (WSC, WSU) and configured to operate in a second long-range radio type telecommunication mode; at least one telecommunication device (WSG) structured to convert signals / data from the first to the second mode and vice versa, allowing an exchange of data / signals between said plurality of devices and said apparatus; wherein the plurality of sensor and / or transmission devices includes managed devices (WSU) and manager devices (WSC) configured to operate as coordinators of a subnet of managed devices; the management devices being organized in an at least partially connected mesh topology and being enabled to communicate with said at least one telecommunication device (WSG). System according to claim 1, wherein: the managing devices (WSC) are configured to communicate with further devices managing the plurality of devices; the management devices (WSC) are enabled to transmit network information relating to a subnet of managed devices of which they are coordinators within a beacon data frame (BP); the managed devices (WSU) being disabled for the transmission of said network information and being disabled from the transmission / reception of measured data to / from other managed devices. System according to at least claim 2, wherein the plurality of devices includes a first manager device configured to manage a request for access to the beacon data frame by a second manager device by exchanging signals within a time slot of report. 4. System according to claim 1, wherein the first telecommunication mode is ultra-broadband and preferably includes transmissions through an OFDM-Multibanda technology compatible, for example, with the ECMA368 standard and the second telecommunication mode is the broadband technology, Wide Band. 5. System according to claim 1, wherein at least part of the management devices and part of the managed devices form a star or tree subnet. System according to claims 1 and 2, wherein the first manager device (WSC) is configured for: allocate transmission resources to managed devices (WSU); receiving data / signals from the managed devices, regenerating them and transmitting them to said at least one telecommunication device (WSG); transmit further data in specific signaling slots for registration purposes for access to network services and for transmission within the beacon data frame. System according to claim 1, wherein each of the managed devices (WSU) includes a sensor unit (1) structured to provide data representative of a measured physical quantity. System according to at least claim 1, wherein: each of said management devices (WSC) includes a receiver module of a satellite navigation system configured to provide a position of the relative cluster management device; each of said managed devices (WSU) includes a module for calculating its position based on the analysis of the arrival times of signals coming from a plurality of cluster management devices; each managed device being structured to provide its calculated position to the managing device to which it is associated. System according to claim 1, wherein: each managed device each manager device comprises a relative first transceiver apparatus (2) configured to operate according to the first mode; the telecommunication device (WSG) includes: a second transceiver apparatus (3) configured to operate according to the first mode; a third transceiver apparatus (3) configured to operate in accordance with the second mode and with the control and storage apparatus; an interface (4) for interfacing the second and third transceiver apparatus. the telecommunication device (WSG) can transmit network information in a reserved time slot called telecommunication device. System according to at least claim 1, configured for at least one of the following types of monitoring: - environmental monitoring to control air, water pollution, temperature, weather conditions, - monitoring for the purpose of prevention and / or detection and / or management of natural disasters; - seismic monitoring; - urban and / or industrial monitoring, video surveillance, urban traffic control, industrial process control; - monitoring for advanced navigation systems, assisted navigation for the disabled; monitoring in medical applications for optimization, improvement of medical care in hospitals, remote monitoring of patients.