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
  • G01S1/00—Beacons or beacon systems transmitting signals having a characteristic or characteristics capable of being detected by non-directional receivers and defining directions, positions, or position lines fixed relatively to the beacon transmitters; Receivers co-operating therewith
  • G01S1/70—Beacons or beacon systems transmitting signals having a characteristic or characteristics capable of being detected by non-directional receivers and defining directions, positions, or position lines fixed relatively to the beacon transmitters; Receivers co-operating therewith using electromagnetic waves other than radio waves
  • G01S1/703—Details
  • G01S1/7032—Transmitters
  • G01S1/7038—Signal details
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04W—WIRELESS COMMUNICATION NETWORKS
  • H04W64/00—Locating users or terminals or network equipment for network management purposes, e.g. mobility management
• • 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
  • G01S1/00—Beacons or beacon systems transmitting signals having a characteristic or characteristics capable of being detected by non-directional receivers and defining directions, positions, or position lines fixed relatively to the beacon transmitters; Receivers co-operating therewith
  • G01S1/02—Beacons or beacon systems transmitting signals having a characteristic or characteristics capable of being detected by non-directional receivers and defining directions, positions, or position lines fixed relatively to the beacon transmitters; Receivers co-operating therewith using radio waves
  • G01S1/08—Systems for determining direction or position line
  • G01S1/44—Rotating or oscillating beam beacons defining directions in the plane of rotation or oscillation
  • G01S1/54—Narrow-beam systems producing at a receiver a pulse-type envelope signal of the carrier wave of the beam, the timing of which is dependent upon the angle between the direction of the receiver from the beacon and a reference direction from the beacon; Overlapping broad beam systems defining a narrow zone and producing at a receiver a pulse-type envelope signal of the carrier wave of the beam, the timing of which is dependent upon the angle between the direction of the receiver from the beacon and a reference direction from the beacon
  • G01S1/58—Narrow-beam systems producing at a receiver a pulse-type envelope signal of the carrier wave of the beam, the timing of which is dependent upon the angle between the direction of the receiver from the beacon and a reference direction from the beacon; Overlapping broad beam systems defining a narrow zone and producing at a receiver a pulse-type envelope signal of the carrier wave of the beam, the timing of which is dependent upon the angle between the direction of the receiver from the beacon and a reference direction from the beacon wherein a characteristic of the beam transmitted or of an auxiliary signal is varied in time synchronously with rotation or oscillation of the beam
• • 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
  • G01S5/0269—Inferred or constrained positioning, e.g. employing knowledge of the physical or electromagnetic environment, state of motion or other contextual information to infer or constrain a position
• • 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
  • G01S1/00—Beacons or beacon systems transmitting signals having a characteristic or characteristics capable of being detected by non-directional receivers and defining directions, positions, or position lines fixed relatively to the beacon transmitters; Receivers co-operating therewith
  • G01S1/70—Beacons or beacon systems transmitting signals having a characteristic or characteristics capable of being detected by non-directional receivers and defining directions, positions, or position lines fixed relatively to the beacon transmitters; Receivers co-operating therewith using electromagnetic waves other than radio waves
• • 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
  • G01S1/00—Beacons or beacon systems transmitting signals having a characteristic or characteristics capable of being detected by non-directional receivers and defining directions, positions, or position lines fixed relatively to the beacon transmitters; Receivers co-operating therewith
  • G01S1/72—Beacons or beacon systems transmitting signals having a characteristic or characteristics capable of being detected by non-directional receivers and defining directions, positions, or position lines fixed relatively to the beacon transmitters; Receivers co-operating therewith using ultrasonic, sonic or infrasonic waves
  • G01S1/76—Systems for determining direction or position line
  • G01S1/82—Rotating or oscillating beam beacons defining directions in the plane of rotation or oscillation
• • 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
  • G01S2205/00—Position-fixing by co-ordinating two or more direction or position line determinations; Position-fixing by co-ordinating two or more distance determinations
  • G01S2205/001—Transmission of position information to remote stations
  • G01S2205/008—Transmission of position information to remote stations using a mobile telephone network
• • 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
  • G01S5/16—Position-fixing by co-ordinating two or more direction or position line determinations; Position-fixing by co-ordinating two or more distance determinations using electromagnetic waves other than radio waves
• • 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
  • G01S5/18—Position-fixing by co-ordinating two or more direction or position line determinations; Position-fixing by co-ordinating two or more distance determinations using ultrasonic, sonic, or infrasonic waves

Definitions

• This invention faces the problem of determining geographical co-ordinates in the context of mobile communications networks .
• the determination of the geographical co-ordinates (absolute and/or relative) of a mobile terminal in the framework of a communications network can be advantageous as it can be used in a broad range of services such as, for example, location billing, calls for help, indication of distances and/or paths between the current position of a mobile terminal and places or destinations, etc.
• location techniques are known, based on the triangulation of several Base Ter ianal Stations (BTS) received by the mobile terminal and/or GPS systems.
• BTS Base Ter ianal Stations
• Object of this invention is to provide a solution which, in the embodiment preferred at the moment, is capable of overcoming the problems outlined above and meeting the above- mentioned confidentiality needs.
• the invention also regards the mobile terminal equipped to operate as a consequence ⁇ Brief Description of Drawings
• FIG. 2 schematically illustrates the architecture of a system in accordance with the invention
• - figure 3 illustrates the criteria for carrying out a geographical location operation including a mobile receiver operating according to the invention, in the form of a flow diagram
• - figures 4 and 5 are two diagrams explaining the manner in which some of the steps in the flow diagram in figure 3 are actuated. Best mode for Carrying Out the Invention
• Figure 1 schematically illustrates the terms of the problem currently indicated in geometry as "resolution of a triangle” .
• the transmitters 1 and 2 can typically be included in X mobile telephone system of the cellular type, or of the type destined for ensuring microcell or picocell coverage, in accordance with the DECT standard, for example .
• transmitters 1 and 2 are also easy to place inside buildings so as to ensure coverage of spaces S selected in any manner.
• the angular coding of the radiation emitted is such that space S is scanned cyclically. All of this occurs concomitantly with a corresponding variation of at least one characteristic of the radiation emitted on the basis of the angle instantaneously formed by the main irradiation direction with respect to a reference direction.
• the above-mentioned reference direction is made up of the straight line identified by the positions occupied by the transmitters 1 and 2 situated at the distance d. These positions can in fact be identified for references purposes as points A and B in figure 1.
• the above-mentioned scanning of the space S can be actuated both with mechanical means, for example using respective antennas with high directionality characteristics to which a traverse movement is given, or - in accordance with the solution preferred at the moment - using antennas Tl and T2 operating in accordance with the techniques of , the type currently known as "phased array" .
• the radiation emitted by the antenna during the cyclical scanning movement is concentrated at every moment in a principle irradiation lobe with, for example, an opening value at -3 dB of around 5-10° for example.
• each of the transmitters 1 and 2 is subjected to a modulation or encoding such as to vary at least one characteristic of the radiation on the basis of the position instantaneously reached by the above-mentioned scanning movement .
• the above-mentioned result can be obtained by subjecting the frequency emitted by the transmitters 1 and 2 to a modulation law of the type
• f 2 f 20 + ⁇ f 2 (II) for transmitter 2.
• Values and ⁇ are representative of the corresponding magnitudes shown in figure 1, that is, by the angle instantaneously formed by the direction of alignment from sources 1 and 2 and from the segments which connect the mobile receiver respectively to transmitter 1 and 2.
• both the angle ⁇ and the angle ⁇ are between the value 0 and the value ⁇ /2 (90°) , where the value 0 corresponds to ⁇ alignment direction of the two transmitters 1 and 2.
• the amplitude ' of the scanning or transverse movement can be greater however, being equal to 180° for example.
• This variant lends itself in a particularly advantageous manner to use in combination with the 1MB (Ultra Wide Band) transmission technique, instead of the CDMA technique commonly used in traditional location systems.
• 1MB Ultra Wide Band
• the UWB technique has the advantage that it uses extremely low powers and has high immunity to echoes .
• the flow diagram in figure 3 illustrates a possible configuration modality for receiver 3 for the purposes of exploiting the variation in the characteristics of the radiation emitted by the transmitters 1 and 2 to permit determination of the geographical co-ordinates of the place in which the mobile terminal 3 is found within space S .
• the receiver 3 "reads" the signals received respectively by transmitter 1 and by transmitter 2.
• the receiver is generally able to distinguish between the two emissions as a function of the two different frequency ranges used.
• each of the values fi and f 2 is preferably obtained as mean (or central) value of a possible range of variation in accordance with the criteria best illustrated (with reference to transmitter 1) in figures 4 and 5.
• the mobile receiver 3 - supposed for simplicity to be in 'a fixed position - is in any case illuminated by each transmitter 1 or 2 not simply for an instant (t x in figure 5) but for a certain time interval (t' x ; t" x ) .
• the frequency emitted by the transmitter (and received by the receiver 3) varies, for example between a value f x and a value f" x . This typically occurs with a ramp pattern of the type illustrated in figure 5.
• the corresponding value used for location purposes can be made up, for example, of the mean or central value assumed by the code during the time interval in which the mobile receiver 3 is illuminated by the transmitter 1 or 2.
• the set of operations described corresponds in practice to taking the values fi and f 2 of formulae (I) and (II) seen above and corresponding to the point in which the mobile receiver 3 finds itself at that moment.
• receiver 3 Knowing the values fio, f 2 o, ⁇ fi and ⁇ f 2 (as they have been memorised previously and/or received by the transmitters 1 and 2) the receiver is able to implement formulae (I) and (II) in the subsequent ' steps 103 and 104, so as to deduce the angle values a and ⁇ which identify the geographical ⁇ coordinates of receiver 3.
• receiver 3 has the information available regarding its location within the limits of space S, that is, the data which (knowing the ' distance d from the transmitters 1 and 2) permit the "resolution" of the triangle identified by transmitters 1 and 2 as well as by receiver 3 itself.
• this information resides in receiver 3 and can therefore be made available to the system which transmitters 1 and 2 are part of only as an effect of transmission of the information from transmitter 3 to the system. This can occur in accordance with current modalities in the context of mobile communications systems, for example as an effect of transmitting the data from receiver 3 towards the base station or base stations to which it is connected at the time (not necessarily corresponding to transmitters 1 and '2)-, for example by means of messages in SMS (Short Message Signalling) format.
• SMS Short Message Signalling
• receiver 3 may decide (e.g. on the basis of an order K given at the moment or memorised previously by the user of the mobile receiver) regarding the possibility of proceeding with location within the limits of space S.
• step 105 If the outcome of step 105 is negative (the user of the mobile receiver 3 has decided not to be located) control of the receiver simply evolves upstream from step 101, so as to repeat the operations described previously.
• receiver 3 transmits the values of angles and ⁇ to the radio communications system it is part of, or rather the values of the corresponding geographical co-ordinates obtained - in accordance with known criteria - as an effect of the transformation of the above-mentioned angular ⁇ coordinates into a system of co-ordinates of a different kind, of the Cartesian type, for example.
• these operations can be made up, for example, by orders for billing based on position (location billing) , calls for help, indications of distances and/or paths between the current position of the mobile receiver and various places or destinations, etc.
• the operation of the receiver 3 evolves towards a final step indicated as 108, as far as the carrying out of operations for determining geographical co-ordinates are concerned.
• This datum is then associated with a database, managed in the framework of the system, which identifies the corresponding absolute position values (latitude and longitude) of the mobile receiver 3.
• location can be carried out directly by receiver 3, while still having information available regarding the distance d, as it has been received by the system for example.
• the configuration of receiver 3 for the purposes of actuating the operating mode shown schematically by the flow diagram in figure 3 can take place both by providing specific hardware components, in mobile terminal 3, or by appropriate programming of programmable elements already available in receiver 3 itself.
• Such a set-up at software level can be achieved advantageously, for example, by means of programming codes (program code means) entered at the level of what is known as the SIM CARD or, possibly, by means of codes loaded remotely into the mobile terminal and coming from the mobile communications system it is part of.
• programming codes program code means

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• Physics & Mathematics (AREA)
• Engineering & Computer Science (AREA)
• General Physics & Mathematics (AREA)
• Radar, Positioning & Navigation (AREA)
• Remote Sensing (AREA)
• Computer Networks & Wireless Communication (AREA)
• Electromagnetism (AREA)
• Signal Processing (AREA)
• Mobile Radio Communication Systems (AREA)
• Radar Systems Or Details Thereof (AREA)

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Publications (1)

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Cited By (5)

Citations (6)

• 2000
  • 2000-05-04 IT IT2000TO000417A patent/IT1320072B1/it active
• 2001
  • 2001-04-26 AU AU58736/01A patent/AU5873601A/en not_active Abandoned
  • 2001-04-26 WO PCT/IT2001/000205 patent/WO2001084175A1/en active Application Filing

Patent Citations (6)

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