Patent ID: 8712427

Claim:
A method of determining a local position of a first mobile radio communication terminal device in a radio cell of a radio network of a radio communication system, wherein the radio cell is fixed by a base station, the method comprising: before emitting a retrieval signal, emitting a preceding inquiry signal from the first mobile radio communication terminal device requesting that at least one mobile radio communication terminal device of a set of mobile radio communication terminal devices send an acknowledgement signal indicating a readiness thereof to participate in the determination of the local position of the first mobile radio terminal device, wherein the preceding inquiry signal is a broadcast radio signal, wherein the preceding inquiry signal comprises a first response time or accuracy parameter, or both; transmitting, from the first mobile radio communication terminal device, after receipt of the acknowledgement signal, a retrieval signal retrieving position information of the at least one mobile radio communication terminal device of the set of mobile radio communication terminal devices that sent the received acknowledgement signal while satisfying the first response time or accuracy parameter, or both conditions; transmitting position information by at least one radio signal from the at least one mobile radio communication terminal device of the set of mobile radio communication terminal devices that satisfied the response first time or accuracy parameter, or both conditions, the location of which is known either to the at least one mobile radio communication terminal device of the set of mobile radio communication terminal devices or to the radio network, and which is either in the radio cell or in another radio cell, the at least one radio signal being transmitted to the first mobile radio communication terminal device via either a direct radio connection or an indirect radio connection via the radio network; inferring a distance between the first mobile radio communication terminal device and the at least one mobile radio communication terminal device of the set of mobile radio communication terminal devices that satisfied the first response time or accuracy parameter, or both conditions on the basis of the signal propagation time of the at least one radio signal, wherein a second response time or accuracy parameter for the position information is a condition for the first mobile radio communication terminal device to use the radio signal from each of the at least one mobile radio communication terminal device of the set of mobile radio communication terminal devices that satisfied the first response time or accuracy parameter, or both conditions in the inferring of the distance.