Measuring user-induced randomness to evaluate smart phone performance in real environments

The radiated performance of a wireless device depends on its orientation and position relative to the user. In addition, the antenna performance is different on different devices and it depends on the device model. Hence, to understand the impact of the users behaviour on the device antenna and the resulting network performance an investigation of the device usage and signal quality is of high importance. This paper presents a first analysis of the orientation usage of wireless devices based on data gathered from 5 smart phones over a period of more than two months. The data was obtained from the built-in sensors in the phone, and includes angles of orientation, information about signal quality and the connected network. Some interesting trends regarding typical orientations of the phone are presented for both voice and data services. We believe that data of this type has the potential to be used for optimizing the device and the network performance, e.g., when the data is correlated with the experienced channel quality.