Classifications

• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
  • G01S5/00—Position-fixing by co-ordinating two or more direction or position line determinations; Position-fixing by co-ordinating two or more distance determinations
  • G01S5/02—Position-fixing by co-ordinating two or more direction or position line determinations; Position-fixing by co-ordinating two or more distance determinations using radio waves
  • G01S5/0295—Proximity-based methods, e.g. position inferred from reception of particular signals
  • G01S5/02955—Proximity-based methods, e.g. position inferred from reception of particular signals by computing a weighted average of the positions of the signal transmitters
• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
  • G01S5/00—Position-fixing by co-ordinating two or more direction or position line determinations; Position-fixing by co-ordinating two or more distance determinations
  • G01S5/0009—Transmission of position information to remote stations
  • G01S5/0018—Transmission from mobile station to base station
  • G01S5/0036—Transmission from mobile station to base station of measured values, i.e. measurement on mobile and position calculation on base station
• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
  • G01S5/00—Position-fixing by co-ordinating two or more direction or position line determinations; Position-fixing by co-ordinating two or more distance determinations
  • G01S5/02—Position-fixing by co-ordinating two or more direction or position line determinations; Position-fixing by co-ordinating two or more distance determinations using radio waves
  • G01S5/0205—Details
  • G01S5/0242—Determining the position of transmitters to be subsequently used in positioning
• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
  • G01S5/00—Position-fixing by co-ordinating two or more direction or position line determinations; Position-fixing by co-ordinating two or more distance determinations
  • G01S5/02—Position-fixing by co-ordinating two or more direction or position line determinations; Position-fixing by co-ordinating two or more distance determinations using radio waves
  • G01S5/0257—Hybrid positioning
  • G01S5/0268—Hybrid positioning by deriving positions from different combinations of signals or of estimated positions in a single positioning system
• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
  • G01S5/00—Position-fixing by co-ordinating two or more direction or position line determinations; Position-fixing by co-ordinating two or more distance determinations
  • G01S5/02—Position-fixing by co-ordinating two or more direction or position line determinations; Position-fixing by co-ordinating two or more distance determinations using radio waves
  • G01S5/0278—Position-fixing by co-ordinating two or more direction or position line determinations; Position-fixing by co-ordinating two or more distance determinations using radio waves involving statistical or probabilistic considerations

Definitions

• the present invention belongs to the field of geolocation.
• the invention relates to a method and a device for geolocation of a broadcast beacon of a wireless communication system.
• a broadcast beacon of the communication system can be configured to repeatedly send a broadcast message to terminals of the wireless communication system which are within range of the broadcast beacon, that is to say which are sufficiently close to the broadcast beacon to receive and decode the broadcast message.
• the broadcast message includes an identifier of the broadcast beacon.
• the terminals are configured to send, in response to receipt of the broadcast message, an association message to the access network.
• the association message includes the identifier of the broadcast beacon extracted from the received broadcast message.
• the association message also usually includes an identifier of the terminal, although this is not essential for the invention.
• An association message sent by a terminal provides information to the access network that said terminal is within range of the broadcast beacon, that is to say in a geographical area close to the broadcast beacon. Such arrangements can have different applications.
• the geographical position of the broadcast beacon may not be initially known by the access network, for example if it was acquired by a client without this client indicating to the operator of the access network to which place he plans to install the broadcast beacon.
• a receiver it is of course possible to integrate a receiver into a broadcast beacon.
• a satellite positioning system such as GPS (“Global Positioning System”), in order to be able to determine in real time the position of the broadcast beacon.
• GPS Global Positioning System
• such a solution increases the cost of the broadcast beacon and is not always functional, in particular if the broadcast beacon is positioned in a place where the signals transmitted by the satellites are not received.
• the objective of the present invention is to remedy all or part of the drawbacks of the prior art, in particular those set out above.
• the present invention relates to a method of geolocation of a broadcast beacon of a wireless communication system.
• the broadcast beacon is configured to repeatedly transmit a broadcast message to at least one terminal of the wireless communication system.
• the broadcast message includes an identifier of the broadcast beacon.
• the terminal is configured to send, in response to receipt of the broadcast message, an association message to an access network of the communication system.
• the association message includes the identifier of the broadcast beacon extracted from the received broadcast message.
• the association message sent by the terminal can be received simultaneously by several base stations of the access network.
• the geographical position of the broadcast beacon is determined as a function of the geographical position of at least one base station of the access network, called a “reference base station”, the geographical position of which is known and having received the message. association issued by the terminal.
• association messages can be sent by one and the same terminal or else by several different terminals having received a broadcast message from the beacon to be geolocated.
• reference base stations can be considered to determine the geographic position of the broadcast beacon.
• the reference base stations can correspond to:
• the different messages considered can be sent by a single terminal at different times (for example in response to several different broadcast messages received from the broadcast beacon), or else by several different terminals (in response to a single broadcast message, or in response to several different broadcast messages received from the broadcast beacon).
• the invention may further include one or more of the following characteristics, taken in isolation or in any technically possible combination.
• the geographical position of the broadcast beacon is further determined as a function of a measurement carried out for each reference base station of a value representative of a level of radio link quality between the terminal and said reference base station.
• the radio link in question corresponds to the link established between the terminal and the reference base station for the transmission of this message.
• the geographic position of the broadcast beacon is a weighted average of the geographic positions of the reference base stations.
• Each geographical position of a reference base station is weighted by a coefficient whose value is representative of the level of radio link quality between the terminal and said reference base station.
• the geographic position of the broadcast beacon is determined using a machine learning algorithm as a function of the measurements made and as a function of the geographic positions of the reference base stations.
• a group of several association messages are considered to determine the geographic position of the broadcast tag.
• Each association message considered was sent by a terminal of the communication system in response to a broadcast message received from the broadcast beacon.
• Each association message considered has been received by at least one reference base station.
• the geographic position of the broadcast beacon is determined as a function of a geographic position of the broadcast beacon estimated for each message in the group.
• a virtual measurement is calculated for each reference base station from the measurements made for said reference base station for the various association messages received by said reference base station.
• the geographical position of the broadcast beacon is then determined as a function of the virtual measurements obtained and the geographical positions of the reference base stations.
• the geographic position of the broadcast beacon is a weighted average of the geographic positions of the reference base stations.
• Each geographical position of a reference base station is weighted by a coefficient whose value is representative of the virtual measurement calculated for said reference base station.
• the geographic position of the broadcast beacon is determined by an automatic regression learning algorithm as a function of the measurements made and as a function of the geographic positions of the reference base stations.
• the present invention relates to a computer program product comprising a set of program code instructions which, when they are executed by one or more processors, configure the processor or processors to implement a method of geolocation of a broadcast beacon according to any one of the preceding embodiments.
• the present invention relates to a server of a wireless communication system.
• the wireless communication system includes a broadcast beacon configured to repeatedly transmit a broadcast message to at least one terminal of the wireless communication system.
• the broadcast message includes an identifier of the broadcast beacon.
• the terminal is configured to send, in response to the reception of the broadcast message, an association message intended for an access network of the communication system.
• the association message includes the identifier of the broadcast beacon extracted from the received broadcast message.
• the association message sent by the terminal can be received simultaneously by several base stations of the access network.
• the server is connected by a communication link to the base stations of the access network.
• the server is configured to implement a method of geolocation of the broadcast beacon according to any one of the preceding embodiments.
• the present invention relates to an access network of a wireless communication system.
• the access network includes a plurality of base stations and a server as previously described.
• FIG. 1 a schematic representation of a wireless communication system comprising at least one terminal and an access network comprising a plurality of base stations and a broadcast beacon,
• FIG. 2 a schematic representation of the main steps of a geolocation process for a broadcast beacon according to the invention
• FIG. 3 a schematic representation of the main steps of a first particular embodiment of a geolocation method according to the invention
• FIG. 4 a schematic representation of the main steps of a second particular embodiment of a geolocation method according to the invention
• FIG. 5 a schematic representation of the main steps of a third particular embodiment of a geolocation method according to the invention.
• FIG. 6 a schematic representation of the main steps of a fourth particular embodiment of a geolocation method according to the invention.
• FIG. 7 a schematic representation of a model used by a machine learning algorithm implementing a geolocation method according to invention.
• the present invention finds a particularly advantageous application, although in no way limiting, in wireless communication systems of the Internet of Things type (loT, for “Internet Of Things” in the English literature) or of the M2M type (English acronym). Saxon for "Machine to Machine”).
• FIG. 1 schematically represents a wireless communication system 10, comprising one or more terminals 20 and an access network 30.
• the access network 30 comprises several base stations 31 and a server 32 connected to said base stations 31.
• the data exchanges are essentially one-way, in this case on an uplink from the terminals 20 to the access network 30 of said wireless communication system 10.
• the planning of the access network 30 is often carried out such that a given geographical area is simultaneously covered by several base stations 31, such that a message sent by a terminal 20 can be received by several base stations 31.
• a message sent by a terminal 20 can be received by several base stations 31.
• the same message sent by the terminal 20 can be received, decoded, and processed by several base stations 31 (and not only by a single base station with which the terminal is associated).
• Each base station 31 is adapted to receive messages from terminals 20 which are within its range.
• a message sent by a terminal 20 includes in particular an identifier of the terminal making it possible to identify said terminal 20.
• Each message thus received is for example transmitted to the server 32 of the access network 10, possibly accompanied by other information such as an identifier of the base station 31 which received it, a value representative of the quality of the radio signal carrying the message, the central frequency on which the message was received, a date on which the message was received, etc.
• the server 32 processes, for example, all the messages received from the different base stations 31.
• the wireless communication system 10 is, for example, a low power consumption wireless wide area network known by the term LPWAN (acronym for “Low Power Wide Area Network”).
• LPWAN Low Power Wide Area Network
• Such a communication system without wire is a long-range access network (greater than one kilometer, or even greater than a few tens of kilometers), with low energy consumption (for example an energy consumption during the transmission or reception of a message less than 100 mW, or even less than 50 mW, or even less than 25 mW), and whose data rates are generally less than 1 Mbits / s.
• Such wireless communication systems are particularly suitable for applications involving connected objects.
• the wireless communication system 10 may be an ultra-narrowband communication system.
• ultra narrow band (“Ultra Narrow Band” or UNB in English literature) is meant that the instantaneous frequency spectrum of the radio signals emitted by the terminals has a frequency width of less than two kilohertz, or even less than one kilohertz. .
• Such a system makes it possible to significantly limit the power consumption of the terminals when they communicate with the access network.
• the system 10 further comprises at least one broadcast beacon 33.
• the broadcast beacon 33 is configured to repeatedly send a broadcast message to the terminals 20 of the wireless communication system 10 which are within range of the beacon. broadcast 33, that is to say which are sufficiently close to the broadcast beacon 33 to receive and decode the broadcast message.
• the broadcast message includes an identifier of the broadcast beacon 33.
• the terminals 20 are configured to send, in response to the reception of the broadcast message, an association message intended for the access network 30 of the communication system 10. .
• the association message includes the identifier of the broadcast beacon 33 extracted from the broadcast message received.
• the association message can also include the identifier of the terminal 20.
• the geographical position of the broadcasting beacon 33 is sought.
• One or more base stations 31 correspond to reference base stations BS Ref .
• a BS Ref reference base station is a base station 31 of the access network 30, the geographical position of which is known and which has received an association message sent by the terminal 20 in response to the reception of a message from broadcast emitted by the broadcast beacon 33.
• a single terminal 20 is shown.
• This terminal 20 is located inside a zone 35 of coverage of the broadcasting beacon 33, in other words it is within range of the broadcasting beacon 33, that is to say it is sufficiently close to the broadcast beacon 33 for receiving and decoding the broadcast message.
• the terminal 20 is located within a coverage area 34 of two different BS Ref reference base stations. In other words, the terminal 20 is sufficiently close to each of these two reference base stations BS Ref so that the association message sent by the terminal 20 in response to the reception of a broadcast message from the beacon 33 can be received and decoded by said reference base stations BS Ref . It should be noted that nothing prevents, in order to implement a method of geolocation of the broadcasting beacon 33, from considering several different terminals 20 which would be located in the zone 35 of coverage of the broadcasting beacon 33.
• the server 32 can in particular be used to implement all or part of a method for geolocation of the broadcast beacon 33.
• the server 32 comprises a processing circuit comprising one or more processors and storage means ( magnetic hard disk, electronic memory, optical disk, etc.) in which a computer program product is stored, in the form of a set of program code instructions to be executed in order to implement at least part of the steps of a method of geolocation of a broadcast beacon 33 of the wireless communication system 10.
• the processing circuit of the server 32 comprises one or more programmable logic circuits (FPGA, PLD, etc.), and / or one or more specialized integrated circuits (ASIC), and / or a set of discrete electronic components , etc., adapted to implement steps of the geolocation method.
• the server 32 includes software and / or hardware means for implementing a geolocation method according to the invention.
• FIG. 2 schematically represents the main steps of a method 100 for geolocation of the broadcast beacon 33.
• the geolocation method 100 comprises in particular a step 101 of determining at least one reference base station BS Ref whose geographical position is known and which has received an association message sent by at least one terminal 20 in response to the reception of a broadcast message sent by the broadcast beacon 33.
• the server 32 can in fact determine which base stations 31 have received an association message comprising the identifier of the broadcast beacon 33 (a base station which receiving such an association message can in fact transmit said message to the server accompanied by an identifier of the base station).
• the method 100 then comprises a step 102 of determining the geographical position of the broadcasting beacon 33 as a function of the geographical position of each reference base station BS Ref determined in step 101.
• the server 32 has access to a database comprising the geographical positions of a whole set of base stations 31 which can then play the role of reference base stations BS Ref .
• the geographical position of the broadcast beacon 33 can be determined in step 102 as being the geographical position of said reference base station BS Ref .
• the geolocation precision of the broadcast beacon 33 is relatively low.
• the geographical position of the broadcast beacon 33 can be defined in step 102 as being an average of the geographical positions of the different communication stations.
• geographical position is understood to mean, for example, a system of two coordinates corresponding to the latitude and the longitude. An average geographic position calculated between several geographic positions will then have for latitude the average value of the latitudes of the various geographic positions and for longitude the average value of the longitudes of the various geographic positions. None prevents, however, also considering a third coordinate corresponding to an altitude above sea level.
• the value representative of the quality of the radio link used is a received power level (“Received Signal Strength Indicator” or RSSI in English literature) measured for a base station 31 for a signal carrying a message transmitted by a terminal 20. It should however be noted that other values representative of the quality of the radio link could be used, such as for example signal attenuation, a signal to noise ratio of the signal (“Signal on Noise Ratio” or SNR in English literature) or a quality indicator of the communication channel (“Channel Quality Indicator” or CQI) . The choice of a particular value representative of the quality of the radio link constitutes only one variant of the invention. It should also be noted that the measurement can be carried out either directly by the base station which received the message, or indirectly. by the server 32 on the basis of information supplied by the base station which received the message.
• FIG. 3 schematically represents the main steps of a first particular embodiment of the geolocation method 100 according to the invention.
• this first particular embodiment we consider a single association message sent by the terminal 20 in response to a broadcast message from the broadcast beacon 33, and received by several reference base stations BS Ref . An RSSI measurement of the power level with which the association message is received is then performed for each BSR ef reference base station used.
• Step 201 is identical to step 101 described above with reference to Figure 2.
• step 202 an RSSI value is measured for each reference base station BS Ref determined in step 201 for the association message considered.
• step 203 the geographical position of the broadcast beacon 33 is determined not only as a function of the geographical position of each reference base station BS Ref determined in step 201, but also as a function of the RSSI values measured at l. 'step 202 for these reference base stations BS Ref .
• the geographical position of the broadcast beacon 33 is determined as being a weighted average of the geographical positions of the reference base stations BS Ref , each geographical position of a reference base station BS Ref being weighted by a coefficient whose the value is representative of the quality level of the radio link (that is to say the value of RSSI in the example considered) established between the terminal 20 and said reference base station BS Ref during the exchange of the message association considered.
• - K is the number of reference base stations BS Ref used to determine the geographical position of the broadcast beacon 33
• Z k is the known geographical position of a reference base station BS Ref of index k
• - Zc is the determined geographical position of the broadcasting beacon 33.
• Each weighting coefficient a k is for example calculated according to the expression below:
• - rssi k is the measurement of the received power level (RSSI measurement) performed for the reference base station BS Ref of index k,
• - Y is a normalization factor whose value is constant. Note that the same symbol g is used hereafter in different mathematical expressions to represent a normalization factor. However, the value of the normalization factor may vary from one expression to another.
• the RSSI measurement is expressed in dBm (power ratio in decibels between the measured power and one milliwatt).
• the RSSI metric is a negative value. The greater the absolute value of the RSSI measurement, the lower the measured received power level. Conversely, the smaller the absolute value of the RSSI measurement, the stronger the measured received power level.
• Such arrangements make it possible to determine the geographical position of the broadcasting beacon 33 as a function of the geographical positions of the reference base stations BS Ref while favoring the reference base stations BS Ref for which the association message in question has been received. with a high RSSI level. In other words, to determine the geographical position of the broadcast beacon 33, greater confidence is given to the reference base stations BS Ref which have received the association message considered with a high RSSI level.
• the geographical position of the broadcasting beacon 33 using a machine learning algorithm based on a pre-established model from measurements of RSSI level or RSSI level differences.
• the model is for example constructed during a learning phase by associating known geographic positions with values of weighting coefficients such as those described by the expression [Math. 2]
• the machine learning algorithm is configured to determine, during a search phase, a geographical position of a broadcasting beacon from the model thus constructed and from values of weighting coefficients calculated for base stations reference having received a particular association message associated with said broadcast beacon.
• FIG. 4 schematically represents the main steps of a second particular embodiment of the geolocation method 100 according to the invention.
• a group of several association messages (Msg # 1, Msg # 2, ... Msg #N) are considered to determine the geographical position of the broadcast beacon 33.
• Msg # 1, Msg # 2, ... Msg #N are considered to determine the geographical position of the broadcast beacon 33.
• Each association message considered has been received by at least one reference base station BS Ref .
• an RSSI measurement of the radio link is carried out for said base station when the association message is received.
• a determination of at least one reference base station BS Ref which has received said message d association considered (step 401). This determination of at least one reference base station BS Ref for a particular message is identical to step 201 described previously with reference to FIG. 3 for the first particular mode of implementation. Also, for each association message considered, an RSSI measurement of the power level with which said association message was received is performed for each of the reference base stations BS Ref having received said association message (step 402) . This determination of an RSSI measurement for each reference base station BS Ref for a particular message is identical to step 202 described previously with reference to FIG. 3 for the first and for the second particular mode of implementation.
• FIG. 5 schematically represents the main steps of a third particular embodiment of the geolocation method 100 according to the invention.
• This third particular embodiment is based on the second particular embodiment previously described with reference to FIG. 4.
• the step 501 of determining, for each association message considered, at least a reference base station, and the step 502 of determining, for each association message considered, an RSSI measurement for each reference base station having received said association message are respectively identical to steps 401 and 402 of the second particular embodiment described with reference to FIG. 4.
• This third particular embodiment further comprises a step 503 in which, for each association message considered, an estimated geographical position of the broadcast beacon is determined, as well as a step 504 in which the geographical position of the broadcast beacon is determined as a function of the various positions estimated at step 503.
• the estimated geographical position of the broadcast beacon 33 can be determined as being the average of the geographical positions of the reference base stations BS Ref having received said association message.
• this average can be weighted as a function of weighting coefficients whose values are representative of the RSSI measurements measured for the reference base stations having received said association message.
• the estimated geographical position Z m, x of the broadcast beacon 33 can be defined by the expression below:
• K m is the number of reference base stations BS Ref having received the association message with index m
• k is the weighting coefficient associated with the reference base station of index k
• weighting coefficient a m, k can be defined according to the expression below:
• rssi m k is the received power level measurement (RSSI measurement) for the reference base station BS Ref with index k for the association message with index m
• y is a constant normalization value
• the geographical position Z x of the broadcasting beacon 33 can for example be defined as a simple average of the geographical positions thus estimated:
• M is the total number of association messages considered.
• the estimation made for a particular message in step 503 of the geographical position of the broadcast beacon 33 and / or the final determination in step 504 of the geographical position of the broadcasting beacon 33 could also be carried out using a machine learning algorithm, for example an algorithm of the data partitioning type ("data clustering" in the English literature). Also, other weighting factors than the RSSI measurement could be taken into consideration to determine weighting coefficients for the different BS Ref reference base stations.
• FIG. 6 schematically represents the main steps of a fourth particular embodiment of the geolocation method 100 according to the invention.
• This fourth particular embodiment is based on the second particular embodiment previously described with reference to FIG. 4.
• step 602 of determining, for each association message considered, an RSSI measurement for each reference base station BS Ref having received said association message are respectively identical in steps 401 and 402 of the second particular embodiment described with reference to FIG. 4.
• This fourth particular embodiment further comprises a step 603 in which a virtual measurement is calculated for each reference base station BS Ref from the RSSI measurements carried out for said reference base station for the various association messages. received by said reference base station.
• the virtual measurement calculated for a reference base station BS Ref can correspond to a simple average of the RSSI measurements carried out for said reference base station for the various association messages received by said reference base station, this which can be translated by the expression below:
• Vrssi k is the virtual measurement calculated for a reference base station BSR ef of index k
• step 604 the geographical position of the broadcasting beacon 33 is determined as a function of the virtual measurements thus obtained and as a function of the geographical positions of the reference base stations BS Ref .
• the geographical position Z x of the broadcast beacon 33 can for example be defined as a weighted average of the geographical positions Z k of the K reference base stations BS Ref .
• each geographical position of a reference base station is weighted by a weighting coefficient representative of the virtual measurement calculated for said reference base station:
• association messages When several association messages are considered to determine the position of the broadcasting beacon 33, as is the case for example for the embodiments described with reference to FIGS. 4 to 6, it is possible, for each message association, to take into account the RSSI level with which a terminal 20 received the broadcast message which led to the transmission of said association message (the measurement can for example be included in the association message by the terminal). It is then possible to weight each association message according to the RSSI measurement associated with it. For example, it is possible to give a greater weighting coefficient (and therefore greater importance) to an association message with a higher RSSI metric.
• the geographical position of the broadcasting beacon 33 is determined by an automatic regression learning algorithm as a function of the measurements made and as a function of the geographical positions of the reference base stations BS Ref .
• Figure 7 shows an example of a model used by the machine learning algorithm.
• the model corresponds to a matrix of characteristics stored in a database accessible by the server 32.
• the machine learning algorithm is configured to generate a regression function to determine the geographic position (longitude, latitude) of a broadcast beacon from this feature matrix.
• Each row of the matrix corresponds to a broadcast beacon of the communication system 10.
• a group of P association messages comprising the identifier of the broadcast beacon 33 received by the access network,
• the first 3N columns of the characteristic matrix correspond respectively to the RSSI measurement, the longitude and the latitude of N reference base stations BS Ref having the largest RSSI measurement values for a first association message.
• Columns (3xN + 1) through 6xN correspond to similar values for a particular second message.
• the columns ((P-1) x (3xN) +1) to Px3xN correspond to similar values for a particular P th message. Note that if some characteristic matrix values are not available (eg if there are less than N identified reference base stations for a given association message) default values can be used. Also, other characteristics specific to each base station can be added in the matrix of characteristics, for example the altitude of the reference base station, or the environment in which it is located (urban, mountainous, maritime environment , etc.).
• distribution beacons to be geolocated correspond to diffusion beacons whose geographic position is known.
• the P association messages of the same line correspond to association messages received (possibly from different terminals) during a certain period of time
• different lines associated with the same broadcast beacon correspond to different periods of time (and therefore to different sequences of association messages received during said periods of time).
• the P messages of the same line correspond to association messages sent by one and the same terminal for a certain period of time
• different lines associated with the same base station correspond to different terminals (and possibly at different time periods too).
• the regression function can be used to predict the geographic position of a broadcast beacon on the one hand from the model stored in the database and on the other hand from the RSSI measurements taken. for a group of association messages.
• Different types of regression machine learning algorithms can be used, such as, for example, algorithms of the “Decision tree forest” type (“Random forest” in the English literature) or of the “Gradient improvement” type ( “Gradient boosting” in Anglo-Saxon literature ”).
• a selection of N reference base stations BS Ref having the largest measured RSSI values is carried out for each message considered. It should however be noted that it is possible to make a selection of N reference base stations or of P association messages according to different criteria. For example, the P association messages and the N base stations could be selected to maximize the number of common base stations having received the P association messages. According to another, the P association messages and the N base stations could be selected to maximize the spatial diversity of the base stations.
• the present invention achieves the objectives set.
• the invention makes it possible to geolocate a broadcast beacon of a wireless communication system in a simple and inexpensive manner, without it being necessary to modify the various elements of the system in software and / or hardware.

Landscapes

• Physics & Mathematics (AREA)
• Engineering & Computer Science (AREA)
• General Physics & Mathematics (AREA)
• Radar, Positioning & Navigation (AREA)
• Remote Sensing (AREA)
• Mathematical Physics (AREA)
• Theoretical Computer Science (AREA)
• Probability & Statistics with Applications (AREA)
• Mobile Radio Communication Systems (AREA)

Applications Claiming Priority (2)

Publications (1)

Family

ID=68988016

Family Applications (1)

Country Status (3)

Family Cites Families (4)

• 2019
  • 2019-10-10 FR FR1911223A patent/FR3101957B1/fr active Active
• 2020
  • 2020-10-09 WO PCT/EP2020/078368 patent/WO2021069638A1/fr unknown
  • 2020-10-09 EP EP20789097.1A patent/EP4226173A1/de active Pending

Also Published As

Similar Documents

Legal Events