Greentouch believes three key changes will make the difference to cellular networks' power hunger and CO2 emissions levels. These are the use of smaller, low power metrocells to add capacity in dense areas; wider infrastructure sharing; and techniques to match power consumption flexibly to the level of usage of the network at any time.
"We need to make resource usage proportional to the amount of traffic the network is handling," said Klein.
Smart antenna technologies will also be vital. Greentouch revealed first results of a key low energy project in 2011, demonstrating proof of concept base stations that use large arrays of up to 1,000 smart antennas to cut power consumption. The trial found that the energy needed to power each one dropped significantly as more were added, without impacting the range or capacity of the cell. The team was using fairly standard MIMO techniques, but harnessing the arrays not to boost capacity, but to reinforce a single transmission, creating a single strong beam from many low power signals.
There is work to be done on the fixed line side too. Key techniques will be the BIPON (bit interleaved passive optical network) protocol, which enables an optical network unit to recognize data destined for other units rather than processing it.
Greentouch was founded by Alcatel-Lucent's Bell Labs and has harnessed some of that legendary R&D group's expertise in areas like MIMO. Other firms whose labs and scientists are heavily involved include Samsung, Huawei, Freescale, Orange and IMEC. The organization describes its mission as a "five-year quest to achieve sustainable networking". Its members include operators, government agencies and research centers.