Hoesung Lee, Chair of The Intergovernmental Panel on Climate Change said in a forward to the Climate Change 2022: Impacts, Adaptation and Vulnerability report released in February 2022: “This report is a dire warning about the consequences of inaction, it shows that climate change is a grave and mounting threat to our wellbeing and a healthy planet. Our actions today will shape how people adapt and nature responds to increasing climate risks.”
The telecommunications industry plays a critical role in helping industries respond to the risks by enabling them to operate more sustainably. There can be no green without digital. The digitalization of industry and society is key to making industries and communities more productive, less wasteful and more resource-efficient. In fact, GSMA research shows connectivity and digitalization can help other industries and society to reduce their emissions by up to 10 times more than the mobile industry’s own emissions.
But growth in digitalization will require communication service providers (CSPs) to grow capacity, which in turn focuses attention on how they decouple this from growth in energy use, or more precisely put, cut emissions per bit of data transmitted.
One approach is sustainable energy consumption, and several leading operators have signed the RE100 pledge to use 100% renewable energy. BT achieved its 2020 goal to purchase 100% renewable energy, as did Vodafone in Europe in 2021, whilst also targeting to achieve 100% renewable electricity globally by 2025.
As vital as it is to accelerate the adoption of decarbonized electricity, CSPs want to go further — and can do so by undergoing network transformation.
Access networks
Studies show that access infrastructure is the most energy-consuming segment in a network. The base station in the radio access network (RAN), for example, accounts for between 60-80% of energy consumption, while successive generations of technology—global systems for mobile (GSM) to LTE to 5G—are more energy efficient. These 5G upgrades are the perfect opportunity to look at legacy RAN and associated spectrum. In 2017, Vodafone decided to shut down its 3G network in Europe; by 2021, 96% of its traffic was on 4G and 5G, and Vodafone was able to reduce CAPEX as well as OPEX spend for energy and spectrum utilization.
In fixed networks, fiber-to-the-home (FTTH) is far more energy-efficient than legacy copper-based digital subscriber line (DSL) connectivity. Since 2007, fixed broadband power consumption has been reduced by 38% while speeds have increased by a factor of 64. This trend shows that the explosion in demand for connectivity does not necessarily need to lead to a massive increase in emissions; emissions have decreased in recent years since the shift from copper to fiber.
Chipsets are the primary driver of energy consumption in an access node, and with more power-efficient chipsets, CSPs can achieve smaller nodes that take up less space, use less power and need less cooling.
And like mobile technologies, successive generations of passive optical networks (PON) improve their energy efficiency. XGS-PON (10 Gigabit Symmetrical PON), for example, consumes twice the energy of GPON but delivers five times the capacity, so CSPs upgrading PON networks will also improve carbon footprint on a bits delivered per watt consumed basis. Geert Standaert, CTO at Proximus, has said that their massive-scale deployment of fiber in Belgium has resulted in a 75% energy-saving cost.
Backhaul
The mobile backhaul network also needs to use the most energy-efficient and sustainable technology. Traditional copper used in urban backhaul is being replaced by fiber, with the associated improvements in energy efficiency previously described.
Network convergence has been around as a concept for a long while, and the improved performance characteristics of the latest generations of PON make this a viable option for mobile backhaul. An urban FTTH network has the capacity to support mobile backhaul alongside residential broadband and is advantageously close to where 5G small cells are needed. A single converged network for mobile backhaul, business and residential broadband is more energy-efficient than separate networks since it reduces the number of cables laid and electronic equipment deployed.
Network operations
Recently, AT&T shared that it’s piloting liquid-cooled base station technology in a live network trial in Philadelphia, which could reduce cooling system energy consumption by up to 90% and base station CO2 emissions up to 80% compared to traditional active air-cooling systems.
Proximus is also taking some innovative approaches to network operations and business models to accelerate deployments, economic viability and improve sustainability. Network sharing is one example, where Proximus shares both mobile and fixed network infrastructure with other CSPs.
Avoiding duplicate networks while maximizing the use of existing assets has allowed Proximus to reduce energy consumption by 20% on its mobile network.
Proximus is also exploring innovative deployment techniques. Micro-trenching reduces the cost and carbon emissions, with less waste, backfill material and labor. Aerial fiber has the same advantages and uses the poles of electricity distributors, giving a faster and less disruptive way to draw fiber directly to radio cell sites, homes and businesses.
This is just one example of how network optimization offers another route to energy efficiencies.
Data centers
Cooling represents approximately half the energy consumed by data centers. Norwegian Construction company MIRIS uses liquid cooling for its data centers and reuses it in a local heating system, creating a clean and energy efficient process. Likewise, Iliad has adopted adiabatic cooling, a more energy efficient cooling process which uses a change in air pressure caused by volume expansion in all its data centers and expects that this will reduce power consumption.
It’s clear that in information and communications technology (ICT) the line between purpose and profit is disappearing and that business and environmental interests should be aligned.
Connectivity and digitalization play a critical role in the sustainable transformation of industry and society, enabling people and businesses to reduce their GHG emissions. Every network improvement program is an opportunity to increase sustainability with network modernization options described above producing real results for CSPs. The latest generations of mobile and fixed technology give CSPs more options than ever before and help make the world a more sustainable place.
