New technology makes residential fixed access networks more energy efficient

Telecommunication networks have become an integral part of today’s way of living. They allow us to surf the Internet, Skype, upload and download videos and data, etc. But they also consume a lot of electricity; a consumption that increases each year with approximately 10% (meaning that it doubles every seven years). 

In order to reverse that trend, researchers from iMinds - Ghent University joined the international GreenTouch™ consortium, which (in 2010) disclosed its plans to develop the roadmap of technologies that are needed to significantly improve the energy efficiency of communication and data networks. Following five years of research, the consortium recently announced during a public event that it has been successful in meeting that ambition. The researchers from iMinds - Ghent University contributed to the model that integrates a number of solutions to make residential fixed access networks 250 times more energy efficient than a state-of-the-art reference network in 2010.

Electricity consumption of telecom networks continues to grow

As winter approaches, the issue of blackouts is becoming a hot topic again – but we know that we can avoid disasters if we adapt our energy consumption to the supply of electricity. However, telecom networks do not (yet) seem to follow that logic: last year, researchers from iMinds - Ghent University published a study showing that the electricity consumption of telecommunication networks is subject to annual growth rates of about 10%.

"Today, we already need fifty nuclear power plants to meet global electricity needs of telecom networks," says Prof. Dr. Mario Pickavet, iMinds - Ghent University. "This is not scalable in the longer term. Hence, we investigated – along with fifty-odd other companies, universities and research centers in the GreenTouch™ consortium – which technologies are required to significantly improve the energy efficiency of communication and data networks."

Integrating technologies that help make residential fixed access networks 250 times more energy efficient

Despite the growing popularity of mobile data traffic, fixed access networks (using cable, DSL or fiber) continue to transport more than 85% of total telecom traffic – with volumes that continue to grow quickly. The challenge is clear: how can we prepare these networks to deal with greater loads of traffic, while making them more energy efficient?

"The energy consumption of conventional network technologies is directly linked to their capacity. As telecom networks are built to cope with peaks, rather than take into account users’ actual (average) bandwidth consumption, they are not energy efficient as a rule," says Dr. Bart Lannoo, iMinds - Ghent University. "That’s why GreenTouch™ developed new techniques, ensuring that network components (both at home and in the central office) only have to deal with those data that are relevant to them. As such, they no longer need to run at full power all of the time – reducing energy consumption of the whole network by a factor of four to five."

Linked to this, the researchers also investigated ways to put equipment (both at home and at the central office) in ‘sleep mode’ when it is not being used. Given the large numbers of connected devices at home, a considerable reduction in energy consumption can thus again be realized.

Finally, the iMinds - Ghent University researchers developed (in collaboration with their Bell Labs colleagues) a ‘green meter’ that took a closer look at the portfolio of GreenTouch™ technologies for fixed access networks, assessing their individual and collective impact on energy consumption and energy efficiency improvements.

"This 'green meter’ was crucial for the consortium to demonstrate that the energy efficiency of residential fixed access networks can indeed be improved with a factor of 250," states Thierry Klein, Chairman of the Technical Committee, GreenTouch™. “We are very pleased that we were able to call upon the expertise of the iMinds - IBCN - Ghent University researchers to realize this important breakthrough. This shows once again that Flemish telecom researchers are top-notch."