Motivation and Area of Application. For documentation of communication networks like telephon networks normaly there are two different representations: a ground plan showing the exact coordinates of all net elements (man holes, trenches, cables cabinets, exchanges, . . . ), usually stored and managed in a GIS system,and a schematic plan containing the same information,but drawn in a schematic way,not properly scaled,but in an easier to understand way. Another kind of schematic maps are often used to display connections in a urban public transportation system: the arrangement of train stations shows some similiarity to geographic coordinates,but the main importance is to show an easy to understand drawing of the connection possibilities by using a more orthogonal drawing.