Many applications appeared on the market after the spread of smartphones which requires acces to the position of the mobile phone, although many times subscribers do not want to use the GPS in their devices. For this, and for many other scenarios an alternative solution is required. This master thesis expounds the non – GPS based positioning methods in mobile systems, and compares three of them according to accuracy, based on measurements in a real environment and on computer implemented models. These three methods are the Round Trip Time method, which is based on the propagation delay of the signal spread in the radio channel, the also propagation delay based Time Difference of Arrival method, and the received signal strength method, which is based on the signal attenuation in the radio channel. It observes these methods in different types of environtment, so the comparison is evaluated from many points of view. Finally, it gives suggestions for the use of these methods, and for further opportunities.