A process for indoor location of a mobile terminal equipped with a transceiver apparatus capable of communicating with a mobile cellular telecommunication network, through a system comprising at least one transmitter apparatus (5a-5g), present inside an indoor environment (6;A-G), and said mobile terminal equipped with at least one receiver apparatus, capable of receiving data transmitted by at least one of said transmitter apparatuses (5a-5g) present inside said indoor environment (6;A-G), and of relaying them to a locating station through said transceiver apparatus over said mobile cellular telecommunication network, comprising the following steps: a) at least one of said transmitter apparatuses (5a-5g) present in said indoor environment (6;A-G) transmits at least one identifier of a fixed calling terminal located in said indoor environment (6;A-G) in which said transmitter apparatus (5a-5g) is situated; b) said receiver apparatus of said mobile terminal receives said identifier of a fixed calling terminal transmitted by at least one of said transmitter apparatuses (5a-5g); c) said transceiver apparatus of said mobile terminal relays said identifier of a fixed calling terminal to said locating station through said mobile cellular telecommunication network; and d) said locating station locates said mobile terminal depending on said identifier of a fixed calling terminal received from said mobile terminal through said mobile cellular telecommunication network, by associating said identifier with a geographic address of said indoor environment (6;A-G) after consulting an existing database accessible to said locating station, said database comprising information associating said identifier with data relating to the geographic address of said indoor environment (6;A-G) where the transmitter (5a-5g) that transmitted it is situated, and wherein said identifier is associated with at least one fixed calling terminal of a fixed telephone network present within said indoor environment, wherein - in step b) said mobile terminal receives from said transmitter apparatuses (5a-5c) a plurality of different identifiers associated with different ones of said fixed calling terminals (8a-8c); - said mobile terminal selects one of said identifiers of a fixed calling terminal to be transmitted to said locating station among said plurality of different identifiers, said selected identifier being the one estimated as being transmitted by the transmitter apparatus nearest to said mobile terminal; and - step d) comprises associating said selected identifier of said nearest transmitter apparatus with a geographic address thereof through said database. a) at least one of said transmitter apparatuses (5a-5g) present in said indoor environment (6;A-G) transmits at least one identifier of a fixed calling terminal located in said indoor environment (6;A-G) in which said transmitter apparatus (5a-5g) is situated; b) said receiver apparatus of said mobile terminal receives said identifier of a fixed calling terminal transmitted by at least one of said transmitter apparatuses (5a-5g); c) said transceiver apparatus of said mobile terminal relays said identifier of a fixed calling terminal to said locating station through said mobile cellular telecommunication network; and d) said locating station locates said mobile terminal depending on said identifier of a fixed calling terminal received from said mobile terminal through said mobile cellular telecommunication network, by associating said identifier with a geographic address of said indoor environment (6;A-G) after consulting an existing database accessible to said locating station, said database comprising information associating said identifier with data relating to the geographic address of said indoor environment (6;A-G) where the transmitter (5a-5g) that transmitted it is situated, and wherein said identifier is associated with at least one fixed calling terminal of a fixed telephone network present within said indoor environment, wherein - in step b) said mobile terminal receives from said transmitter apparatuses (5a-5c) a plurality of different identifiers associated with different ones of said fixed calling terminals (8a-8c); - said mobile terminal selects one of said identifiers of a fixed calling terminal to be transmitted to said locating station among said plurality of different identifiers, said selected identifier being the one estimated as being transmitted by the transmitter apparatus nearest to said mobile terminal; and - step d) comprises associating said selected identifier of said nearest transmitter apparatus with a geographic address thereof through said database. - in step b) said mobile terminal receives from said transmitter apparatuses (5a-5c) a plurality of different identifiers associated with different ones of said fixed calling terminals (8a-8c); - said mobile terminal selects one of said identifiers of a fixed calling terminal to be transmitted to said locating station among said plurality of different identifiers, said selected identifier being the one estimated as being transmitted by the transmitter apparatus nearest to said mobile terminal; and - step d) comprises associating said selected identifier of said nearest transmitter apparatus with a geographic address thereof through said database.