Method of estimating a geographic location of a mobile device

A method of providing training data to a model for estimating a geographic location of a mobile device based on a plurality of signal measurements, the method comprising:

• obtaining one or more data records from a mobile device, wherein each data record comprises:
• a plurality of signal measurements and respective cell identifiers, and
• a corresponding measurement of the geographic location of the mobile device,
• wherein the mobile device is configured to communicate using a telecommunications network comprising a plurality of cells, wherein each signal measurement relates to a signal received by the mobile device from a cell of the plurality of cells attributed with the respective cell identifier;
• for each data record, generating an ordered list of signal properties comprising the plurality of signal measurements, wherein an index of each signal property in the ordered list of signal properties is correlated with a corresponding cell identifier assigned to the cell from which the signal was received, based on an index of the signal property in the ordered list of signal properties;
• and
• for each data record, providing the ordered list of signal properties and the corresponding measurement of the geographic location of the mobile device to the model.

A method of correlating each signal property in an ordered list of signal properties to a corresponding cell identifier based on an index of the signal property in the ordered list of signal properties, wherein the ordered list of signal properties is suitable for input to a model for estimating a geographic location of a mobile device, the method comprising:

• reading one or more data records, wherein each data record comprises a plurality of signal data entries, wherein each signal data entry corresponds to a signal received by a mobile device and wherein each signal data entry comprises:
• a signal measurement of the signal, and
• a respective cell identifier assigned to a cell from which the signal was received;
• for each data record of the one or more data records and for each signal data entry of the plurality of signal data entries in the data record, reading the cell identifier of the signal data entry;
• and
• for each unique cell identifier read from the plurality of signal data entries and from the one or more data records, correlating a signal property in an ordered list of signal properties with the corresponding unique cell identifier, based on an index of the signal property in the ordered list of signal properties.

A method of generating an ordered list of signal properties, the method comprising:

• reading a data record comprising a plurality of signal data entries, wherein each signal data entry corresponds to a signal received by a mobile device and wherein each signal data entry comprises:
• a received signal measurement of the signal, and
• a respective cell identifier assigned to a cell from which the signal was received;
• for each signal data entry of the plurality of signal data entries in the data record, populating a signal property in the ordered list of signal properties with the signal measurement of the signal data entry, wherein the updated signal property is correlated to the corresponding cell identifier of the signal data entry, based on an index of the signal property in the ordered list of signal properties.