The mobile network measurements have been performed
with our Android application, the NetworkCoverage App4. This
application was developed to gather measurements from various
devices, users, and locations. It consists of a service that
passively monitors system resources like GPS and the cell interface
and a component executing active measurements probing
the network performance by generating traffic on the cell or
WiFi interface.
The application passively monitors the local signal strength,
the network provider, and the used wireless access technology.
These measurements are linked to the time-stamped location
derived from the Android framework. The location is either
GPS-based, or based on information from available networks
using Google’s location API. Active measurements include
RTT and throughput measurements. The RTT measurements
are executed periodically in background, resulting in a large
number of samples. Throughput measurements are generally
only collected upon user request, as the data transfer might
cause additional data cost at the user’s end. The measurement
values are stored in a local SQLite database and later
transmitted to a data collection server for analysis.