The study aimed at capturing and analyzing modern telecommunication networks with regard to their ecological environmental impacts. In order to make comparisons, different future scenarios were developed, which include technological developments and – as far as possible – changes in user behavior. The effective and prospective environmental impacts were calculated and evaluated by means of an LCA. As both the supply and the demand for telecommunications services are developing extremely dynamically, this detailed study should show a better understanding of the actual situation and possible development paths.