Energy-saving techniques in the spotlight at MWC24

Sustainability will be a hot topic once again at the annual industry gathering Mobile World Congress in Barcelona next week. A slew of news ahead of the event shows operators and the vendor ecosystem are working to advance network power-saving techniques to mitigate rising energy costs and meet carbon emission reduction targets. And some are making their way into operators’ mobile networks.

With the radio access network (RAN) accounting for around 80% of mobile network energy consumption, much of the energy reduction innovations are focused in this area.

Orange has announced that it will roll out a new “extreme deep sleep” power-saving solution from Nokia in the second half of 2024. Nokia claims the sleep mode, which is a feature in its latest AirScale radio access network (RAN) portfolio, can reduce radio unit consumption by a factor of eight. The “zero traffic, zero Watt” mode can detect when there is low traffic on the network and shut down certain parts of the radio unit hardware to save energy.

“Orange is combining smartly different technologies, including sleep-modes, to reduce the 5G network energy consumption without impacting customer experience,” said Arnaud Vamparys, Chief Technology & Information Officer for Europe at Orange.

He explained that the operator has already introduced many software algorithms that save network energy, such as “micro sleep mode” (micro-DTX) as well as switching off some mobile frequencies during low-traffic times, which are automated by Nokia’s Centralized Self-Optimizing Networks tools.

“We need further hardware innovations from our main network partners to reach the next level in 5G energy optimization. Leveraging these innovations, this new Extreme Deep Sleep mode is maximizing the proportion of hardware subsystems which disconnect from the power supply under low traffic conditions. The incremental gain on energy saving is significant,” he said.

When considering techniques for reducing network energy consumption, Vamparys said, “Smartly combined, these sleep mode software algorithms have delivered the best energy saving results so far.”

Ericsson has also introduced more energy-saving techniques. The Swedish vendor unveiled a swathe of new products ahead of MWC24, among which was an Automated Energy Saver software feature described as hitting “the sweet spot” between network performance and energy efficiency.

The feature is “autonomously executed via an intent defined by the communication service provider to adjust radio resources” for better use of energy.

From energy reduction to monetization

Another development to watch is a new concept from Nokia called the Virtual Power Plant. This is a software platform that can enable mobile operators to make money from their backup battery power supplies at their base stations. It can switch the power supply from the electricity grid to battery sources, which can lower energy costs. But because the battery backup is idle most of the time, as power cuts are rare, there is also an opportunity to contribute to “power reserve markets.”

According to Nokia, “an operator can use their backup batteries to run their base stations while maintaining normal operations or provide energy to the market instead of using the grid energy. This turns their battery backup power systems into an investment with a steady financial return.”

Furthermore, being part of an electricity grid’s reserve power can help the grid avoid power cuts and reduce CO2 emissions, the vendor explained.

Nokia has trialled the solution and hopes to make it available later this year.

Energy use on the edge

It’s not just the RAN that will be getting attention on the energy efficiency front. Reducing energy use in data centres, and those at the edge, is becoming more urgent driven in part by rise in artificial intelligence and AI model training that has driven demand for more capacity and evolving operator edge strategies.

The International Energy Agency (IEA) has forecasted that global data center electricity demand will double by 2026, exposing the size of the challenge for the sector.

According to STL Partners, edge data centre sustainability is “an overlooked concern” while progress has been made in traditional data centres. A recent report by STL, sponsored by precision liquid cooling specialist Iceotope, found that “advanced” edge sustainability strategies can reduce telco energy usage by 3% to 5% and one million tons of carbon dioxide equivalent of emissions. For a typical large operator group, this these strategies could save up to $40 million per year in energy costs, according to STL.

The report evaluated energy saving cooling technologies, including liquid-to-air and liquid-to-liquid precision liquid cooling, tank immersion, direct-to-chip water cooling, and specialized, ruggedized servers.

Iceotope, which will have a presence at MWC, uses precision liquid cooling in its KUL RAN telco server for low-latency RAN and 5G services. It says the solution can reduce energy consumption by 40%.

Nokia has also introduced a “liquid cooled” solution for baseband hotel sites that it claims can deliver 90% energy savings compared to “active air cooling.” When the waste heat from baseband hotels is used for other purposes, like heating buildings, this can cut carbon emissions by up to 80%.

Singtel has said it is working on cooling technologies, such as “direct-to-chip liquid or immersive cooling,” for its new AI data centers and to help meet its goal to be net zero by 2028.

The operator’s Nxera infrastructure subsidiary plans to build “green, sustainable and hyper-connected AI-ready data centres” in the Southeast Asia region and has partnered with NVIDIA as well as renewable energy providers in Singapore, Indonesia, Malaysia and Thailand for sustainable power sources.

“We are tackling this issue to balance the duality of enabling powerful technologies like AI but to do it sustainably and responsibly,” said Bill Chang, CEO of Nxera and Singtel’s Digital InfraCo, in an interview with Bloomberg.