This paper describes energy consumption demographic data in operating real mobile networks. We examine published data from NTT DoCoMo, which is the largest mobile telecommunication operator in Japan and operating nation-wide 3G networks, and identify the most power consuming part is of radio access networks including base tranciever stations. We also investigate power consumption of terminals, and find that the consumption ratio of terminal v.s. networks is about 1:150. Our daily energy consumption per a customer is 0.83Wh/day for a terminal and 120Wh/day for the mobile network. The terminal side energy consumption is negligible in view of total CO2 emission though,limitation of its battery performance raises another issue called "energy starvation of mobile devices.'' The demographic data leads our discussion to (1) radio-on-fiber access network architecture as green networks and (2) thin client models as the key to sustain the evolution toward the future.