  Location service is one of the most widely used features on a smartphone.
More and more apps are built based on location services. As such, demand for
accurate positioning is ever higher. Mobile brand Xiaomi has introduced Mi 8,
the world's first smartphone equipped with a dual-frequency GNSS chipset which
is claimed to provide up to decimeter-level positioning accuracy. Such
unprecedentedly high location accuracy brought excitement to industry and
academia for navigation research and development of emerging apps. On the other
hand, there is a significant knowledge gap on the energy efficiency of
smartphones equipped with a dual-frequency GNSS chipset. In this paper, we
bridge this knowledge gap by performing an empirical study on power consumption
of a dual-frequency GNSS phone. To the best our knowledge, this is the first
experimental study that characterizes the power consumption of a smartphone
equipped with a dual-frequency GNSS chipset and compares the energy efficiency
with a single-frequency GNSS phone. We demonstrate that a smartphone with a
dual-frequency GNSS chipset consumes 37% more power on average outdoors, and
28% more power indoors, in comparison with a singe-frequency GNSS phone.
