Introduction
Wireless networks power our connected world, but their energy appetite—especially in the Radio Access Network (RAN)—raises sustainability concerns. The RAN consumes 70–80% of cellular network energy (Ericsson, 2024), with 5G sites averaging 2.4–3.2 kW and 6G baselines projected at 3.0–4.0 kW due to denser deployments and higher frequencies (Samsung, 2025). Enter 6G: a game-changer promising greener networks through cutting-edge technologies like Symbol-Level Power Tracking (S-PT) and Faster-than-Symbol Power Tracking (F-SPT). This article breaks down RAN energy consumption and reveals how 6G paves the way for eco-friendly telecom.
1. RAN Energy Breakdown: What’s Powering the Network?
A 5G RAN site’s energy use varies by configuration, but here’s a typical snapshot:
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Total Site Power:
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5G: ~2.4–3.2 kW
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6G Baseline: ~3.0–4.0 kW
Source: Ericsson (2024)
Key Takeaway: The Radio Unit (RU) is the energy hog, driven by Power Amplifiers (PAs). Cooling systems, needed to manage PA heat, add to the load, spotlighting hardware efficiency as a priority for 6G.
2. Zooming In: The Power Amplifier Challenge
The RU’s 40–50% energy share hinges on PAs, which amplify signals for transmission. Here’s the RU breakdown:
Why PAs Drain Power:
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Efficiency Woes: Traditional PAs (e.g., silicon-based) run at 15–30% efficiency, losing 70–85% of energy as heat.
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Example: A 500W PA at 25% efficiency demands 2,000W input, with 1,500W wasted.
This inefficiency spikes in 5G’s mmWave bands and will worsen in 6G’s ultra-high frequencies (95–300 GHz), making PA innovation critical (Samsung, 2025).
3. 6G’s Green Solution: S-PT and F-SPT
6G tackles PA inefficiency with S-PT and F-SPT, as detailed in Samsung’s 6G Vision 2025.
3.1 How They Work
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Symbol-Level Power Tracking (S-PT): Adjusts voltage per symbol, matching PA output to signal needs. Efficiency: 65–70%.
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Faster-than-Symbol Power Tracking (F-SPT): Tweaks voltage within symbols, adapting to rapid signal changes. Efficiency: 75–80%.
3.2 Compared to Envelope Tracking (ET)
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ET: Tracks signal envelopes for 50–60% efficiency.
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S-PT & F-SPT: Offer finer control, slashing heat loss further.
Efficiency Table:
Impact: S-PT and F-SPT boost PA efficiency to 65–80%, cutting RU power by up to 60%.
4. Beyond PAs: 6G’s Holistic Green Strategy
6G’s sustainability isn’t just about PAs—network-wide innovations amplify savings:
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AI-Native Networks: Optimize resources with sleep modes. Savings: 20–30% site-wide (Nokia, 2024).
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Waveform Upgrades: OTFS waveforms enhance efficiency in dynamic settings. Gain: 15–20% RU reduction (Samsung, 2023).
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Upper Mid-Band (7–24 GHz): Balances coverage and capacity, reducing site density. Impact: Lower total energy use (Samsung, 2025).
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Virtualized RAN (vRAN): Cloud-based processing streamlines DU/CU tasks. Savings: Up to 25% site power (Samsung, 2023).
- 6G vs. 5G: Quantifying the Savings**
5G Baseline
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Site Power: 2.4–3.2 kW
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RU Power: 800–1,200W
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PA Power: 400–800W
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Global Use: ~10 million sites, 25–30 TWh/year
6G Savings
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Cumulative Effect:
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PA power drops from 400W to ~200W.
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Site power falls to 1.2–1.8 kW (40–50% less than 5G).
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Global Savings: 10–12 TWh/year, enough to power ~1.5 million homes.
6. Global Stakes
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RAN’s Role: PAs drive ~50% of RU power, so efficiency gains ripple site-wide.
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Scale: At 10 million sites, 6G could save 120 TWh yearly—equivalent to 15 million homes or 20 coal plants retired (Ericsson, 2024).
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Vision: By 2030, PA innovations, AI, and renewables could birth “zero-energy” RAN sites (Samsung, 2025).
7. Hardware or Software: The Green Key?
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Hardware (PAs): Delivers instant wins (e.g., 50–60% PA savings).
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Software (AI): Scales savings dynamically (e.g., 20–30% site-wide).
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Answer: Hardware lays the groundwork; software maximizes it. Both are vital.
What’s your view?
8. References
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Samsung. (2025). 6G Vision 2025.
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Samsung. (2023). 6G Power Reduction: Envelope Tracking.
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Nokia. (2024). 6G Networks: Energy-Efficient with AI/ML.
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Ericsson. (2024). 6G Energy Performance.
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Megatrends and Technologies towards 6G by Dr. Howard Benn, Samsung
Conclusion
6G redefines RAN energy use with S-PT, F-SPT, AI and more, targeting a 40–50% power cut. As telecom races toward sustainability, will hardware or software lead the charge? Share your thoughts!