Mobile network measurements - It´s not all about signal strength

Platforms for measuring cellular networks from mobile phones are very popular. Unfortunately, they all suffer from a simplistic approach and measurement errors, and questions how to interpret these measurements. One such error source is that it is easy to measure the signal strength but hard to draw exact conclusions from it. Our work focuses on understanding the measured signal strength and analyzing it´s relationship to enduser service quality. To study interesting causalities, such as the above, between different parameters we developed a measurement platform called Netradar for gathering information from mobile devices. We show the correlation between signal strength and TCP goodput in graphs and geographical maps, and the behavior depending on time of the day. We also discuss grouping of measurements to enable estimating the quality of connectivity in an area.