Patent ID: 7633436

Claim:
A method for determining a location of a mobile terminal in a cellular communication network, the mobile terminal being configured to receive signals from satellites of a satellite-based positioning system, the method comprising: receiving, at the mobile terminal, signals from a plurality of satellites; measuring, at the mobile terminal, pseudoranges to the satellites at a time of signal reception; calculating the location of the mobile terminal based on parameters representing the measured pseudoranges; determining a quality measure associated with the location calculation; comparing the determined quality measure to a first predefined quality criterion; and recalculating, if the quality measure does not fulfill the first predefined quality criterion, the location of the mobile terminal with added correction for error in at least one parameter representing a parameter measured at the mobile terminal, wherein said calculating step uses a parameter for the time of signal reception measured at the mobile terminal, and said recalculating step involves correction for error in the parameter for the time of signal reception by using a transmission time offset parameter as an additional unknown parameter.