FR2968883A1 - METHOD AND SERVER FOR LOCATING A MOBILE TERMINAL - Google Patents

Abstract

Method for locating a mobile terminal (2) accessing a telecommunication network (1) implemented by a location server (3), comprising: a step of obtaining a first location information of the mobile terminal (2), characterized in that it comprises: a step of selecting a group of referent terminals (4) in a list of referent terminals (4) of known location, as a function of said first location information; a step of determining a second location information of the mobile terminal, as a function of signals transmitted by wireless links between on the one hand the reference terminals (4) and the mobile terminal (2) and on the other hand fixed stations (6) of said telecommunication network.

Description

BACKGROUND OF THE INVENTION The invention relates to the field of locating a mobile terminal. The GPS (for "Gl7ba / Ponaitibning SKsten,") offers a satellite tracking technique that can locate a mobile herminal with a precision of about 20 meters, but this has the disadvantage of not allowing a localization of a mobile terminal 10 located inside a building, because the wavelength used by the signals emitted by the satellites does not enter buildings.When the mobile terminal to be located is a mobile phone, other techniques These can be used in addition to or instead of the satellite location, such as cell identification (""), triangulation or time differential, as the wavelengths used may inside buildings, it is possible to locate a mobile phone inside a building, but the accuracy of the location is usually a to the accuracy of a satellite location. Other localization techniques are based on the detection of WiFi access points or a femtocell access point. In this case also, it is possible to locate a mobile phone located inside a building but the accuracy of the location is limited. In addition, for a telecommunication operator who wishes to offer a location solution to its subscribers, this solution involves deploying a large number of femtocells, which represents a significant cost. There is therefore a need for a locating technique which makes it possible to locate a mobile terminal precisely, even within a building.

OBJECT AND SUMMARY OF THE INVENTION The invention aims to meet this need by proposing a method of locating a mobile terminal accessing a telecommunications network implemented by a localization server, comprising a step of obtaining a a first location information of the mobile terminal. This locating method comprises: a step of selecting a group of referent terminals in a list of reference terminals of known location, as a function of tacit first information of loceilsation, - a step dn~~ tanninaUOOdune a: leu xieme inrorrnation The invention also provides a location server for an accessing mobile terminal, according to the invention provided by the French Patent Office. to a telecommunication network, comprising means for obtaining a first location information mobile henninal.This location server comprises: - means for selecting a group of referent terminals in a list of reference terminals known location , according to said first location information, - means for determining a second location information of the mobile terminal, as a function of signals transmitted by wireless links. between the reference terminals and the mobile terminal on the one hand and fixed stations of said telecommunications network on the other. The first location information can be obtained using one of the techniques mentioned in the introduction, which offers limited accuracy. However, the invention proposes to locate a mobile ternoinal with reference to at least one nearby reference hermit. This allows a very precise location. In one embodiment, the step of determining a second location information comprises: a step of determining, in the reference terminal group, the closest reference terminal of the mobile terminal, as a function of said signals, and a step of determining a second location information of the mobile terminal, as a function of a location information of the nearest referent terminal determined. In this case, the invention allows a very precise location of the mobile terminal, with reference to the location of the nearest reference Uerminal. For example, in the case of a building in which each room contains a reference terminal, the nearest referent terminal determined is normally the reference terminal located in the same room as the mobile terminal. It is therefore possible to determine in which room of the building is the mobile terminal. In the case of a building in! Equel only some parts contain a reference terminal, the accuracy is less. However, it remains possible to determine, for example, the group of adjacent rooms or the floor where the mobile terminal is located. Thus, the accuracy is high compared to the localization techniques discussed in the introduction. In practice, the accuracy of the location depends on the mesh of reference terminals. Moreover, thanks to the step of obtaining a first location information of the mobile terminal and at the step of selecting a group of referent terminals, it is sufficient to search the nearest reference terminal of the mobile terminal in a group of limited size, and not in the whole list of referring terminals. The Games Information Center / LoLoO may be located in the vicinity of the second, the second, or the second. In one embodiment, the locating method comprises a step of determining whether a terminal belongs to the group of referent terminals from the terminal of the terminal group. a subscriber identification. This embodiment makes it possible in particular to take advantage of a dialing standard making it possible to distinguish between types of objects. The first location information may be an identification of a cell of said telecommunication network. The step of obtaining a first location information mobile terminal may include obtaining a location area code stored in association with an identification of said mobile harminal in a local subscriber register or a subscriber register visitors of said telecommunications network. In the two aforementioned cases, the step of obtaining a first location information of the mobile terminal can be easily implemented. In particular, it can be implemented in an existing cellular network without requiring substantial modification of the network. The step of selecting a group of referent terminals may include consulting a database which contains, for each reference terminal of the list of referent terminals, a first location information of the referring terminal. Correlatively, the invention proposes a telecommunication network comprising a location server according to the invention and a plurality of referring terminals, in which the location server has access to a database which contains, for each of said reference terminals, a first location information of the referent terminal and a database which contains, for each of said referent terminals a second location information of the referent terminal. These databases make it easy to implement the step of selecting a group of referent terminals with the first location information of the referring terminals, and to assign as second information of the mobile terminal the second location information of the terminal. reference berminal nearest. The aforementioned databases may for example comprise a local subscriber register and a visitor subscriber register for the first location information and a complementary database for the second location information. The mobile terminal and the referring terminals may each be equipped with a subscriber identification card used to identify the terminal considered in the network.

35 n ~ unkobcnu / assoda ~ on u / \ 2 idcnUhcati-nn said te ~ n ~ ina! Obi | c. Thus, the invention can also be implemented in a network. The invention also relates to a computer program comprising instructions for carrying out the steps of a localization method according to the invention when said program is executed by a computer. . This program can use any programming language, and be in the form of source code, object code, or intermediate code between source code and object code, such as in a partially compiled form, or in any other form. another desirable form. The invention also relates to a recording medium or information carrier readable by a computer, and comprising instructions of a computer program as mentioned above. The recording media mentioned above may be any entity or device capable of storing the program. For example, the medium may comprise storage means, or a ROM, for example a CD ROM or a microelectronic circuit ROM, or a magnetic recording medium, for example a floppy disk or a disk. hard. On the other hand, the recording media may correspond to a transmissible medium hal which an electrical or optical signal, which can be conveyed via an electric or optical cable, by radio or by other means. The program according to the invention can be downloaded in particular on an Internet type network. Alternatively, the recording media may correspond to an integrated circuit in which the program is incorporated, the circuit being adapted to execute or to be used in the execution of the method in question.

BRIEF DESCRIPTION OF THE DRAWINGS Other features and advantages of the present invention will emerge from the description given below, with reference to the accompanying drawings which illustrate an embodiment having no limiting character. In the figures:

FIG. 1 represents a telecommunication network in which a localization method according to one embodiment of the invention can be implemented; FIG. 2 represents a location server of the network of FIG. 1, and FIG. 3 represents the main steps of a localization method according to one embodiment of the invention.

The network of a telecommunication network 1 comprises a location server 3, a network, a network, a network, a network, a network, a network, a network, a network, and a network. the mobile switching center 8 / MG [for "M & B Switching Center"], a plurality of reference terminals 4 located inside buildings 5, base stations 6 (BTS for "Base Tranceiver Station") connected to base station controllers 7 (BSC for "Base Station 5 Controller") In Figure 1, only three base stations 6 and one base station controller 7 are shown, but of course the telecommunication network 1 can be The base station controllers 7 are connected to the switching center of the mobile service 8. In a known manner, the switching center of the mobile service 8 has access in particular to a register 8A of local subscribers (HLR for "Home 1cvatiznReg / ster ") and to a register 8B 10 of the subscribers (VLR "Wsitor 1oca / iov / Reg / ster") containing, in particular, a location area code for each of the mobile terminals 2 present in the telecommunications network 1. The telecommunications network 1 further comprises a database 3A forming register 3A referent terminals. This database 3A is either integrated in the local subscriber register 8A or the visitor subscriber register 8B or is independent and physically separated from these two registers. Each of the mobile terminals 2 is equipped with a subscriber identification card, for example SIM type (for "Sü / scnber / be9tity Module") and can establish wireless links with the base stations 6. The mobile terminals 2 are for example mobile phones. As is known, such a subscriber identification card serves to identify the barminal and / or the subscriber 20 considered in the telecommunications network 1 and provides by interrogation a subscriber identification, for example in the form of alphanumeric code and / or number. Each of the reference terminals 4 is also equipped with a subscriber identification card and can establish links without hl with the base stations 6. The referent terminals 4 are for example fixed phones, fax machines, desktops , home gateways type ADSL box, computer peripherals (printer, ...). The presence of a SIM card in a referral terminal 4 makes it possible, for example, to use an antitheft system or a remote management service. In the context of the present description, the term "reference teneral" refers to a terminal identified as belonging to a set of referent terminals. The distinction between a mobile terminæl 2 and a referent terminal is, according to a first variant, by analysis of the subscriber identification provided by the subscriber identification card inserted in the harnninal considered. Subscriber identification card numbering standards are high in many countries, while the number of newcomers is 35%. dS of xunee / oi ~ Uon p ~ nnuibon ~ on!]! / onx ~ m dIli: ~ J ~ cabm. d ~! a co ~~ '5 !;' to solve onedishnc '/ uo between, d the cards iu "~' ~ dnhno :, 'd ~ d ~ ~ ~ ~ ~ n dr`. (uxn, ^ sv / mbii` tmn ~ m1. "dawn pi L It is advantageous that the referential terminal database 3A will be able to manage these new numbering standards and the referent terminals will use these future standards 'object M2M' or standards. close to these standards 'M2M object' to distinguish between simple objects (which require a location search for example) and the objects 5 which will serve as referents.In a second variant, usable in the absence of such a standard the database 3A only references the list of the terminals of the telecommunications network 1 which are part of the set of reference terminals From a subscriber identification, it is thus possible to determine if a terminal is a reference terminal, by querying the database 3A 10 for a record concerning a terminæl associated with such a subscriber identification. If a registration hel is found, it is concluded that this terminal is a referring terminal. In the opposite case, it is concluded that this terminal is not a reference terminal.

Such a reference terminal is supposed to remain permanently in a room of a building 5, but can be moved into the room. In FIG. 1, a building 5 is shown in the equation, each room containing a reference berminal 4, and another building 5 in which only certain rooms contain a reference terminal 4. For a reference hsl hen, two separate pieces of information about The location of this reference terminal is stored in association with a subscriber identification. The location server 3 is a computer server for locating the mobile terminals 2. I! may be a location specific computer server. As a variant, the location server 3 is integrated with another piece of equipment of the telecommunications network 1, for example at the switching center of the mobile service 8. The location server 3 has access to the database 3A of the referent terminals 4 and than the local subscribers' register 8A (HLR) and the register 8B of the visitor subscribers (VLR). The local subscriber register 8A (HLR) and / or the visitor subscriber register 8B (VLR) includes a list of terminals accessing the telecommunication network. For each terminal there is stored in association with a subscriber identification, a first location information. The local subscriber register 8A (HLR) and / or the register 8B of the subscribers 30 (VLR) thus contains a first location information for the reference terminals 4 referenced in the database 3A. This first location information is a location information used for the location of bernninol within the telecommunication network and the routing of

35 xizhooda! Zcd ~ sabon esi! ~ Arexemp ~ e ~ ~ code ~~ OR ~ u posic ~ o ~ ~ q ~ og / ~ ~ uedu i ~ rr: i '/ a ~ mnunka \ icu ~ 1.' no The database 3A contains the list of reference terminals 4 of the telecommunication network 1 and, for each reference banner 4, in association with each other. with a subscriber identification of this reference terminal, a second location information. Optionally this database 3A, also contains in association with a subscriber identification of this reference harnoinal, the first location information. The second location information is a location information complementary to the first location information and which, unlike the first location information, is not necessary or used for the purposes of routing communications to the terminal considered. The second location information is for example a location within a building, a city, or more generally a specific space. It can be based on any location system: GPS position (Glocal Positioning System), postal address, coordinates in a three-dimensional space, etc. This second location information may also be representative of a hardware environment in which the terminal in question is located: it identifies or describes a hardware object located near the reference terminal: printer, fax, photocopier, beverage dispenser, room a building, etc., when the referring terminal is in a building; or street, monument, park, public furniture, fountain, metro station, bus station, etc., when the reference terminal 20 is outside a building, in a city or a natural area; and / or it identifies or describes (network alias, network address, type of equipment, manufacturer, model, etc.) the equipment (printer, fax, photocopier, beverage dispenser, etc.) integrating and / or constituting the terminal referent. This second location information is thus more precise than the first location information and / or gives additional information with respect to that provided by the first location information. In the embodiment described here, the second location information is composed of the postal address of the building 5 in which is located the reference home 4, a floor number and a room number (for example office or room number). Figure 2 shows the location server 3 in schematic form. The location server 3 presents the hardware architecture of a computer and comprises in particular a processor 9, a root memory 10, a random access memory II and a communication interface 12. The processor 9 allows the execution of stored computer programs in the memory r 10, using the RAM 11. The communication interface 12 allows 35 ronm / a ~! Vc / with other equiprements. Figure 3 ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~~ by the execution of a computer program mernc in the m / .e dead 10. 8 The location server 3 executes a preliminary configuration phase B] in which it records in the register 8A and / or 8B a first location information for each of the referring terminals. This information is recorded as the terminals of this group connect to the telecommunications network 1. The first location information 5 is, in a known manner in the cellular networks, obtained by the location server 3 by application of a mobile terminal location technique in the telecommunication network. This first location information is typically a location area code. The location server 3 further determines, from a subscriber identification 10 obtained by interrogating the subscriber identification card of this terminal, whether a terminal connecting to the network belongs to the group of referent terminals. One of the two variants described above is usable: use of a numbering specific to the referent terminals or query of the database 3A. The location server 3 additionally records, in the database 3A, for each reference bernninal belonging to this group of referent terminals a second location information. This second information provides information on the environment of the referring terminal (postal address, building, room, object nearby, etc.). This second location information may come from different sources: - refénantseux terminals, the location information being for example registered in the SIM card (or equivalent) during its allocation and may be requested by the database server 3A reference terminals or via a service platform dedicated to this task; such a platform remounts the information directly from the mobile to the entity making the request for location information by SMS, email, internet connection, etc. - One or more dedicated hosting servers, installed and secured by one or more network operators and inhernogaab! es from the telecommunications network 1 by the location server 3; such a hosting server containing the second geographical location information (address, building, floor, room, etc.) of the referring terminals, these info / mationsayanLété provided - by the operators of the networks containing these hosting servers, independently 30 or in cooperation, and / or - by merchants and / or manufacturers of devices (computers, faxes, electronic equipment) capable of serving as reference terminals; and / or by users of the location service according to the invention, via a server via an inscription on 111L? r -1: or [11.1il or by SMS. 35 The ~ oco [ScLion dxxk ~ [kin ~ e E1 where k, = + nxeur of 3 req'elle! Lc requet 3 Cet- '. \' Rfie a 9 Then, at l step E2, the location server 3 obtains a first location information from the mobile terminal 2. The first location information is for example the location area code of the mobile terminal 2, obtained by consulting the register 8A local subscribers or the As a variant, the first location information may be, for example, an estimate of the geographical position of the mobile terminal 2, obtained for example by a cell identification technique, a triangulation technique or a differential technique. These techniques are known to the person skilled in the art and it is not necessary to give a detailed description of them According to the first location information of the mobile terminal 2 obtained in step E2, the server of localization 3 selecti in step E3, there is a group of reference terminals 4 located near the mobile terminal 2. For example, in the case where the first location information of the mobile terminal 2 is the location area code of the mobile terminal 2, the location server 3 selects the referring terminals 4 which have the same location area code as the mobile terminal 2. As a variant, in the case where the first location information of the mobile terminal 2 is an estimate of the geographical position of the mobile terminal 2, the location server 3 selects the referring terminals 4 which are located in a vicinity of the mobile terminal 2, for example at most at a maximum distance determined. Then, in step E4, the location server 3 determines, in the reference terminal group 4 selected in step E3, the reference terminal 4 closest to the mobile terminal 2. For this purpose, the signals transmitted by links without hl between on the one hand the reference terminals 4 and the mobile terminal 2 and on the other hand base stations 6 are used. For example, it is possible to determine the closest referential hermit 4 of the mobile terminal 2 by using a triangulation technique and / or a time differential technique (these techniques are known to those skilled in the art and they it is not necessary to give a detailed description). The signals used here are for example those used in a standard way by the operators (GSM, etc.) during the establishment of a communication with the herminal and / or during a phase of localization of the terminal and / or during a connection phase of the hærnninal network.

Then, in step E5, the location server 3 determines a second mobile terminal time information 2, deduced from the second information of the terminal of the terminal e4 the most -in- step E4. Information-setting of termi'ul xno''on dc! OcaUsn \ ion of term / r This (10 distance to which is the mobile terminal 2 with respect to the terminal referent 4: "to 2 meters from piæurX" or "to2 In a variant, it is determined which are the three reference terminals closest to the ernnina! 2, the relative distance of the mobile terminal 2 is determined relative to the three closest reference terminals using a technique of time and triangulation differential above and the exact position of the terminal 2 is deduced. When a plane of the building or space in! equel is the three closest reference terminals is available, it can furthermore be indicated on this plan the position of the mobile terminal 2.

Finally, in step E6, the location server 3 sends a response to the request of the step E1, containing the second location information of the mobile terminal 2. The location method of FIG. mobile terminal 2 located inside a building 5, with reference to a location information of a reference terminal 4 located nearby. This allows a very precise location. For example, in the case of a building 5 in each equation, each room contains a reference numeral 4, the closest reference terminal 4 determined in step E4 is normally the reference terminal 4 located in the same room as the mobile terminal 2. It is therefore possible to determine in which room of the building 5 is the mobile terminal 2. In the case of a building 5 in which only some parts contain a 20 tertiary referent 4, the accuracy is less. However, it remains possible to determine, for example, the group of adjacent rooms or the floor where the mobile terminal Z is located. Thus, the accuracy is high compared to the localization techniques discussed in the introduction. In practice, the accuracy of the location depends on the mesh of referent terminals 4. Thanks to the aforementioned steps E2 and E3, it is sufficient to look for the reference terminal 4 the closest to the mobile terminal 2 in a group of limited size, and not in the entire database 3A referents terminals. Step E4 is therefore relatively easy to implement. The locating method makes it possible, for example, to precisely locate, inside a building, a lost person equipped with a mobile terminal 2. In addition, in an alternative embodiment, the telecommunications network 1 also includes reference terminals 4 located outside the buildings 5, which ensures a continuity of the location service.

Claims (13)

REVENDICATIONS1. Method of locating a mobile terminal (2) CLAIMS1. Method for locating a mobile terminal (2) accessing a telecommunication network (1) implemented by a location server (3), comprising: - a step (E2) of obtaining a first location information mobile terminal (2), characterized in that it comprises: - a step (E3) for selecting a group of referent terminals (4) in a list of referent terminals (4) of known location, according to said first location information; - a step of determining a second location information of the mobile terminal, as a function of signals transmitted by wireless links between on the one hand the referent terminals (4) and the mobile terminal (2) and on the other hand fixed stations (6) of said telecommunication network. 2. The locating method as claimed in claim 1, in which the step of determining a second location information comprises: a step (E4) of determining, in the group of referent terminals (4), the reference terminal (4) the closest to the mobile terminal (2), as a function of said signals, and - a step (E5) of determining a second location information of the mobile terminal (2), as a function of a location information of the reference terminal ( 4) the closest determined. 3. The locating method according to claim 2, wherein the second location information is representative of a hardware environment in which the nearest reference terminal is located. The locating method according to claim 3, wherein the second location information identifies or describes equipment in the equel is the nearest reference terminal. 5. The locating method according to claim 1, comprising a step (EO) of determining whether a terminal belongs to the group of referring terminals (4) from a subscriber identification. 6. The method of loca isotion according to claim 1, wherein the first information of N) cnl a identi ') cnton ci'a diet-1-senu telecommunication cell (1). 7. A method of locating according to claim 1, wherein the step (E2) for obtaining a first location information of the mobile terminal (2) comprises obtaining a location area code stored in association with an identification of said mobile terminal (2) in a register (8A) of local subscribers or a register (8B) of the visitor subscribers of said telecommunication network (1). 8. A method of locating according to claim 1, wherein the step (E3) for selecting a group of referent terminals (4) comprises consulting a database (8A, 8B) which contains, for each terminal referent (4) of the list of referent terminals (4), a first location information of the referent terminal (4). 9. The locating method according to claim 1, wherein said mobile terminal (2) and said reference terminals (4) are each equipped with a subscriber identification card used to identify the hsnninal considered in said telecommunications network ( 1), said first location information being stored within said telecommunication network (1) in association with an identification of said mobile terminal (2). A computer program comprising instructions for performing the steps of the locating method according to claim 1 when said program is run by a computer. Computer-readable information carrier having instructions of a computer program according to claim 10. 12. Location server (3) of a mobile lerminal (2) accessing a telecommunications network (1), comprising: - means (9, 10, 11, 12) for obtaining a first location information of the mobile terminal (2), characterized in that it comprises: - means (9, 10, 11, 12) for selecting a group of referent terminals (4) in a list of terminals [e / eots (4) of known location, according to said first location information, - means (9, 10, 11, 12) for determining a second location information-location of the island, depending on in ti ire in t. leeu, 35 / o [e / iis (4) and the term '' '' '' '' '' '' '' '' '' '' '' '' '' '' '' '' '' '' '' '' '' '' '' '' '' '' '' '' '' '' '' '' '' '' '' '' ''. Telecommunication network (1) comprising a location server (3) according to claim 12 and a plurality of referent terminals (4), in which the location server (3) has access to a database (8A, 8B). ) which contains, for each of said referent terminals (4), a first location information of the reference terminal (4) and a database (3A) which contains, for each of said referent terminals, a second location information of the referent herminol ( 4).