The positioning of a mobile station (MS) will become mandatory in the US to support wireless emergency calls in the near future. Also, lots of other applications are foreseen for the location service, when implemented. In this paper the authors study the feasibility of the Global System for Mobile Communications (GSM) and MS location. The TDMA based GSM system offers some inherent means of calculating the location of the MS. In the MS there is already implemented a set of measurement functions that can be used to locate the MS. We investigate the use of timing advance (TA) and observed timing difference (OTD).