A Metropolitan-Scale Testbed for Heterogeneous Wireless Sensor Networks to Support CO2 Reduction. - Pablo Ezequiel Guerrero; Alejandro P. Buchmann; Kristof Van Laerhoven; Immanuel Schweizer; Max Mühlhäuser; Thorsten Strufe; Stefan Schneckenburger; Manfred Hegger; Birgitt Kretzschmar (GreeNets, 2012)