Node placement

As depicted in the figure below, the DES-Testbed will span several buildings located on the campus of the Freie Universität Berlin. Currently, the computer science building is equipped with a network of about 40 mesh routers located on all three floors. The adjacent buildings are of similar height with at least one floor underground and two or three above.

The routers are deployed in a non-uniform manner to meet our requirements to create a topology that incorporates as many facets of real world installations. The following list includes some of these properties:

• Long linear chain of routers
• Area with high node degree and media access contention among routers
• Regions without coverage, creating holes in the network
• Unidirectional connections
• Multiple mesh clouds whose border routers do interfere with each other

These topologies can be configured on demand by switching particular subsets of routers off or by changing their parameters.

The official campus wide ZEDAT managed WLAN, called FUnkLAN, does exist in parallel to the DES-Testbed using the same wave band. This setup of course leads to additional media contention and possible media congestion. We consider this fact as a normal real world problem experienced in many installations. To ensure repeatability of experiments under equal conditions these will be done at night-shift when less interfering radio devices are operated.