A method for improved positioning of a mobile communication device, comprising the method steps of: a) providing position-related information in a plurality of first mobile communication devices , wherein the first mobile communication devices each have a receiving device which is adapted to receive positioning signals from a component of a navigation system; b) transmitting the position-related information from the plurality of first mobile communication devices to an evaluation device ; c) determining, by the evaluation device, supplemental position information in the form of integrity information and/or correction data associated with a first point in time on the basis of the received position-related information, wherein the evaluation device performs a curve fitting calculation on the basis of position-related information received by the evaluation device from the plurality of first mobile communication devices; d) providing position information associated with the first point in time in a second mobile communication device , the first mobile communication devices and the second mobile communication device being distinct devices; e) transmitting the supplemental position information associated with the first point in time from the evaluation device to the second mobile communication device; f) determining, in the second mobile communication device, the integrity of the position information provided in step d) for the first point in time on the basis of the supplemental position information; and/or re-determining, in the second mobile communication device , position information for the first point in time (ta n ) on the basis of the position information provided in step d) and associated with the first point in time (ta n ) and the supplemental position information associated with the first point in time (ta n ). a) providing position-related information in a plurality of first mobile communication devices , wherein the first mobile communication devices each have a receiving device which is adapted to receive positioning signals from a component of a navigation system; b) transmitting the position-related information from the plurality of first mobile communication devices to an evaluation device ; c) determining, by the evaluation device, supplemental position information in the form of integrity information and/or correction data associated with a first point in time on the basis of the received position-related information, wherein the evaluation device performs a curve fitting calculation on the basis of position-related information received by the evaluation device from the plurality of first mobile communication devices; d) providing position information associated with the first point in time in a second mobile communication device , the first mobile communication devices and the second mobile communication device being distinct devices; e) transmitting the supplemental position information associated with the first point in time from the evaluation device to the second mobile communication device; f) determining, in the second mobile communication device, the integrity of the position information provided in step d) for the first point in time on the basis of the supplemental position information; and/or re-determining, in the second mobile communication device , position information for the first point in time (ta n ) on the basis of the position information provided in step d) and associated with the first point in time (ta n ) and the supplemental position information associated with the first point in time (ta n ). <EOS>