If network gear doesn't change, it will take much more energy to carry the amount of traffic users will produce by 2020, GreenTouch says. The conclusions of its study are based on forecasts that the amount of traffic on wireless networks will have multiplied by 88 times between 2010 and 2020, while wired access networks will grow about 10 times more busy and wired core networks will see traffic multiply by eight times.
One problem with current networks is that most of them are always on, even when not needed.
"For the most part, the energy consumption of the equipment is at the peak power, or very close to the peak power ... even when there is no load," Klein said.
GreenTouch has identified ways to solve that problem by making networks more adaptive, so components or entire systems can be shut down when not needed. This is similar to what vendors have promised is possible with server virtualization, where cores or systems could be turned off during periods of low demand. It effectively turns network resources into Lego blocks that can be added or removed as needed, Klein said.
"Even at the subsecond level, I can turn some of the equipment on and off very fast, and I save energy when I don't need all the bandwidth to handle the traffic," Klein said.
Wireless networks are the least efficient, according to GreenTouch. The technologies it has already identified could cut wireless networks' power consumption by 1,043 times, the group said. Shifting traffic from macro cells on towers to small cells indoors or at street level is one way to do this. However, that could leave even more pieces of equipment up and running without any traffic at some hours. The Lego-block approach, applied to wireless, could power down individual small cells or even change the power level of an antenna as needed, he said.
Wired access networks could be made 449 times more efficient and core networks could see a 95x gain by 2020, the group said. The optical technology that's widely used in wireline networks makes them more efficient than wireless already. Other technologies that could help to drive efficiency in the next seven years are Bi-PON (bit-interleaved passive optical networks), content caching and separation of the control and data planes of the network, according to GreenTouch.