ERLANG: cell phone traffic map

This map shows cell-phone traffic intensity in real-time. The animation plays through the last 24 hours of activity change and stops longer at the current, real-time map. The traffic is calculated in "erlang," a dimensionless unit used in telephony as statistical measure of telecommunications intensities. The "erlang" describes the total traffic volume of one hour for each antenna. White displays higher, while black shows lower intensity of cell-phone usage.

HANDOVERS: call handovers between cells

This map computes origins and destinations of cell-phone calls passing through the city of Graz. The results shown are calculated anonymously on all calls, in a stastistically chosen order. The actual process of transferring calls from one cell-phone to another cell-phone is is called a "handover." The traces, represented as orange lines, start and end in the corresponding geographic areas of where the cell phones were used to make and receive calls.

TRACES: cell phone tracking

The Real-Time City map registers and visually renders the volume and geographic source of cell phone usage in Graz, thus showing a different layer in the use and experience of the city. The record of this movement has been collected, processed and finally displayed as set of dynamic traces showing their paths through the city on the same map. The orange traces displayed in this map show the physical location of the M-Graz exhibition visitors who voluntarily registered and allowed their cell phones to be tracked as they move through the city. The red lines retrace individual paths of movement, indicating the person's code number at the bottom of the page.

Send a blank SMS to 06646600317 and follow your traces while you move in the graz area

The Real-Time City maps register and visually render the volume and geographic movement of cell phone usage in the city of Graz. Our goal is to visualize the technologically driven urban dynamics that remain transparent to us in everyday life and to open up new ways of understanding the contemporary city. By creating and publicly displaying maps that closely follow the physical and electronic flux of the city in real-time, we try to illustrate urban phenomena that traditionally escape static mapping: movement, communication and comparative use of different parts of the city.

For more information, visit

SENSEable City Lab, MIT Carlo Ratti (coordinator),
Daniel Berry, Andrea Mattiello, Eugenio Morello, Andres Sevtsuk
Design team: David Lee, Xiongjiu Liao, Jia Lou, Sonya Y Huang, Daniel A Gutierrez
In collaboration with A1 - Mobilkom Austria
Thanks to www.gis.steiermark for providing the GIS data