As a new generation of technology replaces legacy networks, there are opportunities for increasing efficiency, and therefore, sustainability of networks. In the current shift from 4G to 5G, operators are also finding additional possibilities for better efficiency, through the use of cloud technology, the broader use of software, the targeted application of artificial intelligence and also the emergence of Open RAN.
In a session at the recent Telco Sustainability Forum, Nilmar Seccomandi David, Telefónica’s head of infrastructure and Dr. Femi Adeyemi, head of Fujitsu’s wireless business, offered their perspectives on the role of network transformation as it relates to sustainability.
Essentially, this came down to four areas.
Turn-down of legacy networks. Telefónica, which operates networks in a dozen countries, wants to switch off 2G and 4G networks as quickly as possible to save on both energy and maintenance costs, David said. But such transitions are far from simple. “We have to move based on the needs of the services we offer in each country, and with each technology,” he acknowledged.
Still, the reductions in energy use associated with network turn-downs can be significant. In Germany, Telefónica was able to turn down its 3G network two years ago, and it is seeing a 10% reduction in its total energy consumption as a result, according to David. The carrier has seen similar energy use reduction from turning down its 2G network in Uruguay, he said.
Meanwhile, Telefónica is also expanding its deployments of 5G, which is a far more efficient technology in terms of the energy used for the amount of traffic delivered. The network operator already covers most of the population in Germany and Spain, and it is working to deploy rapidly in countries like Brazil and Chile.
Changing energy sources along with network technology. As Telefónica works toward its goal of being net-zero by 2040, it is focused on intermediate goals, David said. Those include consuming 100% of its electricity from renewable sources by 2030, and to optimize its energy consumption per traffic unit by 90% by 2025. “This means we must both reduce energy consumption and transition to renewable energy resources,” he said.
Architecture changes, including the use of flexible compute resources. Adeyemi said that the increasing use of cloud and centralization in the RAN can both impact efficiency, by increasing flexibility. Centralized deployments of compute resources, rather than distributed baseband at each site, can enable more flexibility to use (or not use) network resources, based on traffic demand, he explained—and a “layered” approach can be taken provides an opportunity to direct network resources to where they are needed versus not needed. That can offer new monetization strategies, he added.
Using centralized and cloud-based architectures can also enable far more efficient network deployment and management, Adeyemi said. He pointed to the example of Boost Mobile (formerly Dish Wireless) in the United States, where using centralized computing infrastructure was a major factor in enabling the company to build out a national network in a relatively short period of time.
“Centralizing gives you better ability and visibility,” he said.
Applying new technology in the RAN. The Radio Access Network is the primary target for energy use reduction because it consumes so much of Telefónica’s overall energy. The company uses about 6 terawatts a year, David said—about the same as a small country like El Salvador or Luxembourg. About 60% of Telefónica’s energy is consumed in its mobile network RAN, another 30% from central offices that support its wireline network and network core, and another 10% from data centers and offices, David said.
According to David, Telefónica has reduced its energy consumption by about 9% over the past 10 years, even as its traffic has increased nine-fold. It has done this through multiple initiatives, including the deployment of 5G, which is about 85-90% more efficient than 4G on a basis of energy use per traffic unit.
Still, he said, the percentage of the company’s energy consumed by the RAN has risen from about 50% to about 60%.
“I believe that new technologies must … be more energy efficient by design,” he said, adding: “I see energy as one of the biggest priorities for vendors, and I hope these new technologies, including Open RAN, can help us to achieve our energy targets.”
David has a unique perspective on that energy-efficiency-by-design aspect, since he works on an Open RAN working group on sustainability within the O-RAN Alliance. He said that the difference between traditional RAN and Open RAN when it comes to energy consumption is likely to come down to software.
“I think the right question is where Open RAN can have a differentiation, comparing with traditional RAN,” he reflected. “For me, the answer is the software.” While virtualizing and centralizing baseband can have an impact, that only accounts for about 15% of the energy use of a site, he said. About 85% of energy usage at a site is due to the active antennas. Software that can optimize energy consumption in lower-traffic times and scenarios “could be the game changer for Open RAN,” David said.
For more insights from David and Adeyemi, watch the full session from Telco Sustainability Forum and more content on demand here.
