Green 5G Lights the Way to a Low-Carbon Future

As the most energy-efficient wireless technology to date, 5G plays a pivotal role in cutting carbon emissions.

By Jiang Xudong, President of Huawei's SRAN Product Line
WinWin Issue 40

Although GSMA reports that telecommunications represent just 0.4% of global carbon emissions, operators have extended their green strategies from minimizing network-derived carbon emissions to boosting energy efficiency in vertical industries. Equipment vendors must therefore innovate green products and solutions to help operators build green 5G networks and achieve net zero goals while fulfilling growing demand for diverse services.

1.5°C threshold and 1:10 enablement

Climate change is one of the most pressing global challenges and one that will have a huge impact on future generations. In its latest report Climate Change 2021: The Physical Science Basis, the Intergovernmental Panel on Climate Change (IPCC) found that historically rare weather extremes have become much more common. For example, severe heat waves that happened only once every 50 years are now happening roughly once a decade. 

UN Secretary-General António Guterres warns that, "We are at imminent risk of hitting 1.5 degrees in the near term. The only way to prevent exceeding this threshold, is by urgently stepping up our efforts, and pursuing the most ambitious path."

Another GSMA report, The Enablement Effect, concludes that, "With a European and North American scope, mobile technologies had a 1:5 enablement ratio compared to the footprint of the industry in 2015." 

This means that one kWh of power consumed by mobile networks will lead to a 5-kWh reduction in electricity used by other industries. GSMA believes the ratio will rise to 1:10 by 2025.

As a reliable partner of operators on a global scale, Huawei will continue to develop efficient and green 5G networks to support their energy conservation and emissions reduction efforts.

Efficiency drivers 

Customer-driven efficiency gains

During more than 20 years of developing wireless technologies, we’ve prioritized developing green products and solutions geared to boosting network energy efficiency. The best innovations are customer-driven and based on understanding customer pain points before the development process begins.

Distributed Base Stations

In 2005, Huawei launched the first-ever distributed base station. By moving RF modules from indoor equipment rooms to outdoor sites closer to antennas, distributed base stations improve signal quality while reducing air-conditioning costs. They minimize cable loss and overcome insufficient space and cooling capacity.


Launched in 2007, the Huawei SingleRAN solution changed how sites are deployed and relaxed deployment requirements by enabling one RF module to work on multiple bands and support multiple radio access technologies. Operators could then more easily adapt to different access technologies, build converged networks, and smoothly evolve their networks. Using 50% less power than traditional solutions, SingleRAN was first deployed in Europe and is now mainstream worldwide, contributing heavily to energy savings and lower electricity bills.


Global operators want to deploy energy-saving software to reduce network energy consumption, but are also concerned about degraded network performance and user experience. This dilemma ended in 2018 when Huawei launched its unique energy-saving solution, PowerStar, which uses intelligence to help operators balance energy use and network performance. More than 70 operators have deployed the solution in live networks. In China, 800,000 sites are running PowerStar, saving 400 million kWh per year.

Green 5G 

The ITU has set the objective of reducing ICT carbon emissions by more than 45% by 2030. Many operators have announced their own carbon neutrality targets and action plans, including for 5G.

To more effectively support operators on their energy conservation and emissions reduction journeys, Huawei has introduced its integrated green site, green network, and green operations solution. We’ve moved to establish a green network assessment system based on energy efficiency and developed eight technological directions for building green 5G target networks. These measures will enable operators to build networks that deliver excellent performance and high energy efficiency, and thus support their carbon-neutrality strategies.

What makes a network green?

As networks develop at different stages, energy efficiency is a better measure than absolute energy use. In addition to proposing the Network Carbon Intensity (NCI) index, Huawei assesses the relationship between network demand growth and network energy consumption from the energy-efficiency perspective. The value of energy efficiency to operators is that it serves as a relatively fair and objective evaluation system that drives the industry to coordinate service traffic growth and a reduction in carbon emissions. 

Eight Directions 

In addition to standards for measuring green networks, a number of technological directions are necessary for operators to develop green 5G networks.

Direction 1: Multi-antenna RF reduces per-bit energy consumption and increases transmission efficiency. 5G AAU uses a multi-antenna, multi-channel architecture alongside spatial multiplexing to significantly boost system capacity. Signal phases and amplitudes can be tweaked to concentrate radio energy in narrower beams that point to users more precisely, increasing energy transmission efficiency and ramping up per-bit energy efficiency. Our test results show that the energy efficiency per bit of 64T64R modules is 20 times higher than it is in 4T4R modules. The AAU will become an essential tool for operators to meet constantly growing traffic demand from individuals and industries.

In addition to reducing AAUs' power consumption through innovation and the comprehensive application of expertise in multiple fields, Huawei has introduced a new approach to reducing AAU power consumption: extremely-large-scale antenna arrays. Through innovations in software (e.g., baseband algorithms) and hardware (e.g., antennas), extremely-large-scale antenna arrays maximize antenna utilization, improving both energy efficiency and coverage. In theory, Huawei's MetaAAU consumes 30% less power than a typical AAU when delivering the same coverage.

Direction 2: Ultra-broadband multi-band devices reduce energy consumption. Higher integration enables a device module to expand its RF capability from single to multiple bands and provide ultra-large bandwidth. This transforms site construction from the deployment of one band on one RRU or AAU module to one integrated module that supports multiple bands. Operators can use one module to provide various services that previously required multiple modules, lowering costs and overall energy consumption.

One of our customers in the Netherlands replaced two RF modules on 800 MHz and 900 MHz with one ultra-broadband RF module that can provide services on the 700 MHz, 800 MHz, and 900 MHz bands using the same amount of power. 

Direction 3: Hardware enhancement for nearly linear power usage changes with varying load levels to reduce low- and medium-low energy consumption. RF hardware transmits at higher efficiency as traffic loads increase. Refined, granular hardware sleeping mechanisms can shut devices down more responsively and at deeper levels when traffic loads are low, which wastes less power, increases the overall RF efficiency of hardware modules in low-traffic periods, and boosts device reliability.

Operators in China have demonstrated that deep hibernation can reduce power consumption by more than 60% in networks under a light load.

Direction 4: Simplified sites without equipment rooms and air conditioners. Air conditioning accounts for 30% to 40% of total site energy consumption. We have proposed two directions: 

Centralized BBU deployment can enable one air conditioner to cool multiple sites rather than one air conditioner cooling one site. Liquid-based and natural cooling methods are a good option for equipment rooms. China Unicom has saved 17,000 kWh of electricity in each of its sites per year through centralized BBU deployment. 

Outdoor equipment cabinets are the better choice. One site, one cabinet deployment and blade site deployment can replace one air conditioner at each site. With one site and one cabinet, cooling media works closely with heat-producing devices, facilitating precise and targeted cooling, which slashes energy consumption. Blade site deployment focuses on saving energy by mounting devices on poles, which maximizes the effect of natural cooling, producing a 60% to 97% increase in energy efficiency.

Direction 5: Linked site energy improves comprehensive energy efficiency. Power feeding and consumption systems, such as power supplies and transmission systems, are "dumb devices" that cannot sense each other, collaborate, or sense service load and running status, thus wasting energy and lowering efficiency.

Linking services to site power supply, storage, and use for increased efficiency is a major direction for green sites. Services and solar power, power supply, battery, the main grid, and temperatures should be linked to enable precise, real-time control on temperature and power operations in line with service loads to ensure efficient energy usage. 

Based on one of our cases in Greece, solar power can produce more than 50% of the total energy of a site linked to solar generators, substantially cutting carbon emissions.

Direction 6: Intelligence for energy-saving and network performance: Intelligent technologies can adapt spectrum and many other resources to real-time service changes and service scenarios in networks.

Launched in 2018, PowerStar was designed with intelligent technology to lower network energy consumption. This year, PowerStar2.0 adds a number of enhancements such as extending energy-saving periods from off-peak hours to all day, expanding three energy-saving dimensions to four, and narrowing KPI optimization down from days to seconds. Operators can double the energy-saving effect and deliver the same network performance.

The commercial deployment of PowerStar2.0 in China's Sichuan province has lowered energy consumption in mobile networks by more than 25%.

Direction 7: Switching services to 5G can maximize energy-efficiency advantages. 4G is 7 to 10 times more energy-efficient than 3G, and 5G is 20 times more efficient than 4G. Moreover, 5G’s energy efficiency will improve exponentially as it continues to evolve. 

Statistics on mobile networks in Hangzhou, China, show a 3.5-times increase in energy efficiency from 2019 to 2021, even though just 20% of network traffic is carried on 5G networks.

Direction 8: Full-lifecycle recycling reduces dependence on natural resources. Procedures like design, manufacturing, and transportation are equally important to a low-carbon future. In product packaging, for example, we’ve developed a dual-density expanded polypropylene (EPP) process. Two different-density materials can  improve cushioning and recycled materials can reduce the size and volume of packaging and materials used. 

These eight directions represent our E2E commitment to sustainability. We will continue to work closely with operators and partners to help operators build green 5G networks and enable vertical industries to use less energy and cut carbon emissions.