Bai Gang, Vice GM of RAN Products at ZTE, highlights the company's latest innovations in improving the energy efficiency of communication networks as complexity increases with the deployment of 5G services.

What are ZTE's key achievements in building green 5G networks?
ZTE has long committed to developing and deploying green and energy saving networks. The effort has become particularly critical in the emerging 5G era as operators reply on multiple radio access technologies using more RF units, which can significantly increase energy consumption. ZTE takes a holistic approach to reducing energy usage across its entire line of wireless and fixed assets.
We have long taken energy savings and consumption reduction as a key responsibility. By increasing technological efficiency, ZTE works with operators around the world to build green networks to fulfil its promise of Climate Action in response to the UN's Sustainable Development Goals (SDGs).
Over the past five years, we submitted more than 500 green 5G innovation patent applications. Our cutting-edge design of 5G active antenna units received the iF Design Award 2020. In addition, ZTE and China Telecom developed a smart energy-saving network platform called 5G Greener Telco, which won the Outstanding Catalyst—Impact for Society award from the TM Forum.

What's the impact on implementing energy savings solutions on operators' opex?
Energy consumption can represent as much as 20 to 40 per cent of an operator's total opex. ZTE's 4G and 5G network energy saving solution, PowerPilot, can achieve significant energy savings and lower opex. By identifying service types and their energy efficiency differences, PowerPilot can evaluate service requirements in real time and support the service with networks of higher energy-efficient to maximise energy efficiency in the entire network.
China Telecom and ZTE jointly put PowerPilot into commercial use in the city of Chengdu, resulting in 35 per cent, or 14 kWh, in network energy consumption saved per site on average per day.

Where have you been able to find the biggest reductions in energy consumption?
The cooling system, power distribution and the base station equipment are the three main RAN components, accounting for more than 50 percent of the total network energy consumption.
Using a distributed architecture for base stations, which is deployed in most cellular networks, energy consumption of the radio frequency unit accounts for more than 75 percent of base station equipment power usage. That is using a single band with three sectors. The percentage increases as the number of bands rises. ZTE focuses on the radio frequency unit, which is where we can find the biggest gains in power efficiency.

How does the efficiency of PowerPilot compare with conventional energy saving solutions?
Conventional AI-based energy saving options enable a more precise per-site energy saving policy based on site traffic and other site-related conditions to improve the efficiency and reduce the manpower required.
In the 5G era, this approach is not enough for mobile operators to deliver the much-needed energy savings. One important thing we can exploit is that different networks have different energy efficiencies, even those delivering the same type of services or running the same generation on different spectrum frequencies. By detecting the differences, PowerPilot directs the services to the optimal network or spectrum for higher network energy efficiency.
According to a model using typical network configurations, PowerPilot can save twice as much energy as conventional AI-based energy saving solutions.

The power savings possible in single-mode networks is significantly higher than for multi-mode and multi-frequency networks. Why is that and what is ZTE doing to change that?
Most mobile network operators run 2G, 3G and 4G networks, and increasingly 5G, at the same time. In most multi-mode and multi-frequency cellular network, service efficiency varies from mode to mode and band to band. Multi-mode is more complex than a single-mode network and more factors need be taken into consideration.
PowerPilot, the industry's first AI-powered service-aware energy savings solution, exploits differences in energy efficiency of different types of services, different networks or bands to deliver direct certain services to the most energy-efficient network, helping achieve the most efficient energy usage in multi-mode and multi-frequency networks without impacting network performance or the user experience.
If all services or users can be concentrated in part of the network or band, more energy can be saved by shutting resources down or putting them in deep sleep mode.

Beyond 5G networks, what actions are you advising customers to take with their 2G, 3G and 4G networks?
ZTE has been developing network energy saving technologies since the 2G era, enabling multi-dimensional and full scenario energy saving solution across all networks.
Wind Tre in Italy, which uses our solution, saves an average of 0.36 kWh per cell site per day for its entire networking covering 2G, 3G and 4G network with ZTE energy saving solution.
Depending on their existing networks, operators can deploy a basic or AI-based energy saving strategy as well other technologies, such as dynamic spectrum sharing to improve energy efficiency.

How many mobile operators you are working with to improve energy efficiency?
ZTE's network energy saving solutions are used in more than 20 networks, with some 600,000 sites deployed worldwide. Clients includes Wind Tre Italy, MTN South Africa, U-Mobile Malaysia, Telenor Pakistan, China Mobile, China Telecom and China Unicom.