Policymakers worldwide are striving to combat climate change by maximizing energy efficiency in every economic sector, including communications. Balancing the growing demand for wireless connectivity with environmental sustainability is particularly challenging because the performance of wireless networks, in terms of coverage and capacity, depends on transmitted signal energy (i.e., signal power). Increased signal power helps overcome propagation and blockage losses that impact every wireless network but is clearly contrary to energy conservation goals. This dichotomy between the communications and sustainability objectives requires a comprehensive approach that leverages technological advances to deliver much needed connectivity while optimizing energy efficiency. The latest Wi-Fi® generation offers a solution.
One underpinning fact of the communication policy’s sustainability considerations is the majority of data-intensive use cases such as automation, cloud computing, e-health, remote learning, immersive reality and others are realized indoors. This fact presents policymakers with a unique opportunity to address growing demand for connectivity while minimizing networks’ energy consumption. Indoor connectivity relies predominantly on fixed broadband (e.g., fibre or cable) for delivery and Wi-Fi for distribution. As a result, significant sustainability advantages can be realized because the fixed/Wi-Fi deployments are highly localized and do not need to expend significant energy on signal propagation.
Indeed, fixed/Wi-Fi networks are 2.5x more energy efficient per megabyte transmitted than cellular networks. Unlike fixed/Wi-Fi, cellular networks (e.g., 5G) must propagate signals from distant cell-towers and penetrate building walls, expending extra signal energy just to reach end users. Similarly, an indoor cellular device’s signal to an outdoor cell station uses a disproportionate amount of energy just to overcome obstacles and distances in its propagation path, exacerbating environmental impact with increased recharge cycles, battery wear, and additional electronic waste.
The demand for connectivity indoors is further evidenced by most recent statistics indicating that fixed/Wi-Fi networks already deliver more than 80 percent of all broadband traffic in industrialized countries [1]. Governments are responding to this massive demand for indoor connectivity with increased fixed broadband deployments. In Europe, nearly 100% of EU households are set to be served with a fibre-to-the-home connection [2]. Similar efforts are underway in other countries [3]. With the prolific fixed broadband rollout, Wi-Fi becomes increasingly essential to national telecommunication infrastructures.
As with all wireless technologies, Wi-Fi functionality requires access to the radio spectrum. Radio frequency spectrum is a finite natural resource that is carefully administered by national regulators around the world. Deciding on the most beneficial use of frequency spectrum is not trivial, requiring balanced evaluation of competing priorities and resulting socioeconomic benefits. The rapid pace of wireless innovation can lead to spectrum management decisions before their environmental implications are fully understood. In the case of the 6 GHz, regulators need to decide whether to repurpose this spectrum for cellular deployments or to allow Wi-Fi access while preserving ongoing operations. The 6 GHz (i.e., 5.925-7.125 GHz) is the only spectrum that can accommodate optimal performance of the latest Wi-Fi generation, Wi-Fi CERTIFIED 7, which is designed to operate with wider (e.g., 160 MHz or 320 MHz) channels. Wi-Fi delivers increased data throughput rates, ultra-low and deterministic latencies, better mobility, and high densities of users/devices – but only with access to the full 6 GHz band. Recognizing this fact, regulators in several countries already expanded Wi-Fi access to the 6 GHz frequency band while in other countries, regulators continue to evaluate alternatives [4]. One factor that is gaining prominence in the 6 GHz decision making processes is the environmental consequences, particularly the impact on carbon footprint associated with alternative deployments in the upper 6 GHz band. The recent study, Sustainability Benefits of 6 GHz Spectrum Policy, offers a methodical analysis of this issue.
The study provides clear evidence that allowing Wi-Fi access to the entire 6 GHz band supports broadband connectivity objectives with a sizeable reduction in energy consumption compared to cellular networks. In this study, WIK-Consult analyzed two 6 GHz spectrum utilization scenarios in Europe. The first scenario assessed the impact of making the entire 6 GHz band available for Wi-Fi. In this scenario, fiber-to-the-home capacity was not constrained by a lack of spectrum for Wi-Fi, which in turn allowed for sufficient bandwidth to meet advanced indoor connectivity needs. The second scenario modeled assigning the upper portion of the 6 GHz band (6.425-7.125 GHz) to cellular networks, which limited the amount of spectrum available to Wi-Fi. The analysis confirmed that lack of spectrum access reduced Wi-Fi performance and increased data traffic congestion, which in turn, drove frustrated consumers from fixed/Wi-Fi connectivity to cellular networks. The forced transfer in the second scenario resulted in a 15% increased shift in traffic from fixed/Wi-Fi to 5G cellular, resulting in an estimated 16% higher energy consumption. It is estimated that the higher energy consumption resulted in an additional 3.2 megatons of CO2 emissions per year in Europe alone. According to WIK-Consult, similar increases in the CO2 levels can be expected in other parts of the world.
Wi-Fi technology excels in maximizing spectrum utilization with low-power radio techniques. But more importantly, the study highlights the significance of the 6 GHz policy decisions on the environmental impact.
Sources:
- See UK Ofcom International Broadband Scorecard 2023: Interactive Data, Section 4-Data Consumption
- See Europe’s Digital Decade: digital targets for 2030
- See U.S. Broadband Equity, Access and Deployment (BEAD) Program, also see APAC Fiber Deployment
- See Countries enabling Wi-Fi in 6 GHz (Wi-Fi 6E, Wi-Fi 7)
