As operators invest in 5G sustainability, energy efficiency as a standalone target isn’t doesn’t take into account real-world networks
In both the contexts of driving global demand for energy and facilitating the reduction of consumption and attendant greenhouse gas emissions (GHG), the Information and Communications Technology (ICT) sector has a very important role to play. In an introductory presentation at the Telco Sustainability Forum (available on demand here), Senza Fili Principal Monica Paolini talked through 5G sustainability efforts, and drew an important distinction between a focus on reducing energy consumption and becoming more energy efficient while optimizing mobile networks to meet real world service demand.
By the numbers, ICT accounts for about 4% of global energy use and generates 1.4% of global GHG emissions. Mobile networks as a subset of ICT accounts for about 0.7% of global consumption with the radio access network (RAN) drawing at least more than 50% of that power. Comparing 4G with 5G on a per-bit basis at max capacity, 5G is clearly, and by design, more efficient than its predecessor. And, finally, the International Telecommunication Union (ITU) reckons that ICT, mobile network operators included, needs to cut GHG by 45% by the end of the decade to meet climate change goals laid out by its parent organization, the United Nations.
With that, back to Paolini: “To be energy efficient is actually not that hard,” she said. “What is really hard about it is to be energy efficient in the big context of optimizing your network…So the challenge is not to reduce energy consumption but to do so in a way that makes sense.” She made the point that mobile network power consumption has increased dramatically along with surging traffic demand—including from new types of internet of things (IoT) and enterprise networks as well as in service of nascent use cases—but not on a one-for-one basis. But, “That doesn’t mean we should just sit down and relax.”
Focusing in on the RAN where the bulk of power is consumed, Paolini noted that energy draw in the RAN is a function of end-to-end draw that begins in the core, traverses the transport network, then hits the RAN. In the RAN and system-wide, energy efficiencies are being had based on ongoing component evolution, disaggregation offering operations more supplier optionality, the move to cloud-native bringing resource pooling gains, and centralized/distributed RAN topologies offering more power management flexibility.
“When we look at energy efficiency, it’s tempting to think like 5G is more efficient than 4G and that is absolutely true…But in real networks that might or might not be the case,” Paolini said. She cited research from Ofcom and CommScope that delineated how variables like which spectrum is being used or how many transmit/receive elements are in a massive MIMO antenna array as influencing real world power consumption. It’s not as simple as 4G vs. 5G or vendor A vs. vendor B, she said. “We need a new approach to plan, test and monitor the network.”
Energy efficiency as a standalone target is not enough to achieve long-term sustainability, Paolini concluded. “Long-term sustainability is driven by a different and new way to approach energy efficiency which is not just simply reduced consumption. Although that’s always a good thing…in a vertical like wireless…we want to focus on energy efficiency, and that’s a long-term type of play. It requires a new mindset. We need to keep the two separate—consumption and efficiency. Efficiency is really where sustainability comes from.”
For 5G sustainability to be a durable, achievable goal,”We need to have a wider and more comprehensive view on how we bild, manage and monitor, and optimize wireless networks.”
Check out Paolini’s website for more on 5G sustainability and other key topics impacting mobile.
