In this section, we evaluateV-GPS layer by analyzing the real measurements collected on Android phones for two class of applications. One class of applications are related to navigation applications which constantly need precise location information in real time and other class of applications are location based services(LBS) as discussed in this paper which serve the need even with position errors ˜150 meters. During the experiments, we ran the same application with V-GPS on one smartphone and other without V-GPS in both stationary/least mobility and highly mobile environments. The experiments are run on phone until the battery is discharged to 25% on each phone while measuring the accuracy and battery consumption for every 15 minutes. We first evaluate the impact on energy efficiency, position accuracy and frequency of the type of sensors used at each sample in different scenarios. After that, we discuss the impact of V-GPS and overhead in V-GPS is analyzed.