Embracing Net Zero: Enhancing RAN Infrastructure with Superior Energy Efficiency

In recent years, the concerning effects of extreme weather events resulting from escalating temperatures have underscored the urgent need to address climate changes. Shen Jianda, the Vice President of ZTE Corporation, highlights the ongoing efforts ZTE in actively embracing the principles of green development and demonstrating a strong commitment to social responsibility. ZTE is dedicated to participating fully in global decarbonization initiatives, working towards the goal of achieving Net Zero CO2 Emissions.

To help telecom operators around the world achieve sustainable development in building end-to-end green, low-carbon and high-quality networks, ZTE has been actively engaging in the global transition to a decarbonized economy and has attained a position on the CDP 2023 ‘A List’ recently, placing in the top 2% of all participating companies for its outstanding corporate transparency and performance on climate change, as recognized by the global environmental non-profit CDP.

During the transition from 4G to 5G networks, ZTE has persisted to promoting sustainability in networks by enhancing the energy efficiency of their RAN network infrastructure, solutions, simplifying site architecture, and advancing performance through innovation.

Industry’s highest energy efficiency by Super-N 2.0:

One of their primary focuses is optimizing the network for maximum energy efficiency. Based on the statistics from GSMA intelligence, it’s known that RRU (remote radio unit) of the radio site consumes more than 50% of the service provider’s network energy consumption, and 80% power consumption of one RRU is costed by power amplifier (PA). To reduce the power consumption of PA is essential to the reduction of the total power consumption and electricity fees.

Deploying high-efficiency RRUs is crucial for introducing new spectrum and NR, boosting capacity, enhancing the user experience, while reducing power consumption.

In 2022, ZTE released RRU with the very efficient PA platform Super-N 1.0. Simply rely on this innovation, the RRU has 8 to 10 percentage points improvement in PA efficiency compared with traditional one, and a 20% reduction in the RRU power consumption, which has demonstrated leading performance in multiple project tests. The RRU series of the Super-N 1.0 platform have been applied in over ten projects worldwide, with a deployment of over 100,000 units, resulting in a significant reduction in energy consumption in the modernized network.

In MWC24, Super-N 2.0 platform is introduced with constant efficiency PA, to achieve up to 30 percentage points PA efficiency improvement compared to traditional technology, and a 35% reduction in RRU power consumption is achieved compared with industry standard level. Super-N 2.0 realizes the high level of power efficiency across all load levels, particularly in periods of low service demand. The power efficiency at a 10% service load is three times of traditional PAs, and 1.5 times at a 30% service load. When the load beyond 30%, the power efficiency goes almost constant at a very high level. There are three breakthroughs to enable this capability, the advanced architecture with even smaller and more densely packed PA transistor array, an “on-demand” adaptive activation method for the PA dies, and patent QNN-DPD (Quasi-neural network) algorithm for adaptive and precise matching online to the architecture. In a summary, the Super-N 2.0-based RRU can effectively decrease power consumption for customers across all levels of usage.

Industry’s first 0-bit 0-Watt:

In 2022, ZTE is the first vendor to support AAU (Active Antenna Unit) hibernation, which means in scenarios with no traffic, the AAU can be turned off only left 5W power consumption. This function has been activated on more than 300,000 AAUs in commercial networks to help telecom operators saving. In 2023, ZTE innovatively implements the hibernation function to RRU, to realize as low as 3W power consumption of RRU when there is no traffic.

For QCell, the pico RRU for indoor coverage, 0 watt at 0 bit is realized. The QCell can be turned-off and waked-up on-demand, when there is no traffic, it is turned-off in a second, and when there is access attempt, it can be waked-up as quick as seconds.

High resource utilization by RF pooling:

Considering the unbalanced traffic among different sectors, ZTE has developed RF pooling solution to fully utilize the RRU resources, absorbing more traffic without any impact of the cell performance and enhancing the radio utilization. ZTE has developed unique RF pooling solution to dynamically adjust output power among sectors to ensure an optimal user experience with very high radio efficiency. The RRU resources can be fully utilized, and the energy efficiency of bit/watt can be improved up to 20%.

Based on the unique 3-sector-in-one 12TR UBR, the idle output power of one sector can be shared with other sectors, effectively increasing the output power of each cell from 120W to 160W. Increased traffic not only leads to more efficient use of resources, but also enhances the user experience, particularly for those at the network edge.

Simple yet improved site energy efficiency through integrity site solutions:

Traditionally the cooling system in the radio equipment room also consumes a considerable amount of the total site energy consumption. Shifting some of this equipment outdoors, along with the increased deployment of outdoor poles, leads to reduced energy consumption for outdoor cooling. This approach also reduces power loss due to the conversion for power continuity, which can be further minimized with the deployment of state-of-the-art power solutions that have high conversion efficiency.

Based on this understanding, ZTE supports the all-on-pole site with outdoor BBU, pad RRU, pad power. By utilizing a modular framework with LEGO-style assembly to replace the traditional cabinet installation, the site solution eliminates the need for air conditioning and equipment room, which is suitable for rural coverage. It is possible to achieve green energy supply by using only two solar panels, realizing zero carbon site deployment. ZTE enables the sites to maintain the simplest while achieving extremely high efficiency.

To increase the use of renewable energy and reduce reliance on the grid or diesel generators for off-grid RAN sites, ZTE offers a new generation of sPV (Smart PhotoVoltaic) solution to support the rapid adoption of green and clean energy sources for station, cabinet, and pole sites. With each solar panel equipped with sPV modules and implementing MPPT (maximum power point tracking) for single components, the sPV solution offers more flexible configurations, saving space, while maximizing solar energy generation and effectively reducing the impact of shading. This has led to an overall improvement in power generation by over 20%.

Base station native AI enabling high-precision full-scene energy saving:

AI and ML (Machine Learning) techniques are applied to achieve precise network level energy saving strategy. Independent of network-level AI platforms, BS (base station) native AI enables real-time decision making of energy saving, balancing user experience and energy consumption with user location and services awareness. Network resources can be distributed optimally based on real-time needs with deep learning of service patterns by integrating native-AI into base stations.

Through verification in the 700M-2600M dual-layer 5G network, it has been demonstrated that BS native-AI enables co-coverage layer identification through grid knowledge base and realizes the minimization of wake-ups, ensuring that only cells with service demands are activated. Real-time resource scheduling optimization improves spectrum efficiency by 20%. The average increase of 30% in energy-saving duration leads to an additional 4-5 percentage point energy-saving benefit.

“Our efforts to advance towards a Net Zero future for operators have been significant”, Shen Jianda said. “By prioritizing sustainability and environmental consciousness, we have made substantial progress in developing eco-friendly solutions for the telecommunications industry. Through the implementation of Super-N 2.0 high-efficiency PA, innovative RF pooling solution and industry’s first 0-bit 0-watt, modular site architecture, renewable energy integration, as well as the introduction of BS native AI, we aim to drive the creation of a more sustainable and environmentally responsible network infrastructure. Aligned with Net-Zero-Emission goals, our goal shows our commitment to creating a greener, more sustainable future for society and civilization.”

Source: Mobile World Live