SARAS calls the merchant web service when the application is started. It is not called again if the user does not change the location by at most 10km as the default value. In order to measure the impact of the frequency of calling web services, tests are conducted with different frequency values. For example, a test is conducted by calling the service in minutes intervals or calling at a lower location distance change in the drive mode. For 20 minutes, test merchant web service is called 20 times in the first test. In the drive mode, it was called 4-5 times depending on the location change. Figure 3(a) shows the increase of battery consumption when the web service call frequency increases. In the drive mode tests, 3G connection is used. Hence, CPU and power consumption values are higher than the other case.