The need for sustainable mobile networks is stronger today than ever before. Increasing operational costs, tightening environmental rules, and international commitments toward sustainable development are all compelling telecom operators, as well as infrastructure vendors, to repaint their perspective on how networks are created and powered. Since wireless infrastructure uses more than any other type of infrastructure in terms of energy use, the transition from 5G to 6G is an opportunity to make sustainability one of the prime considerations alongside speed and capacity.
According to ITU-R Recommendation M.2160 on the IMT-2030/6G Framework, sustainability remains one of the key aspirations, where mobile systems are expected to be designed so that they use minimum power, emit least greenhouse gases, and utilize their resources efficiently. Contrary to what happened in previous generations where energy efficiency was considered after the fact, 6G has the potential to incorporate green-by-design concepts from the start so as to deliver both excellent performance and little environmental impact.
Energy-Saving Features in 5G: Achievements and Limitations
Innovations such as RRC_INACTIVE mode, Idle Mode Signaling Reduction, Discontinuous Reception (DRX), Discontinuous Transmission (DTX), and Carrier Aggregation control helped reduce unnecessary signaling and lower energy use.
The later 5G releases enhanced on such features as:
- Dynamic SSB transmission control based on cell load.
- On-Demand SIB1 broadcasting.
- Cell switch-off and micro-sleep for base stations.
- Improved RRC_INACTIVE mobility.
- Partial activation of antenna ports.
- BWP operation for UEs.
- Dynamic PDCCH monitoring control.
- SCell dormancy in carrier aggregation.
- Low-power receivers for UEs.
However, some structural shortcomings exist: for instance, frequent SSB bursts (every 20 ms) allow only shallow sleep, and persistent antenna activation wastes energy even when traffic is low. Many legacy UEs are incapable of supporting these new modes of efficiency, and high-traffic scenarios still do not have robust network-level mechanisms for saving energy. These gaps necessitate a fundamental rethink of energy efficiency in 6G.
Less ON, More OFF is the Principle on Which 6G Is Built:
In 6G, energy efficiency will become a paramount design concern instead of a mere secondary feature. The phrase “Less ON, More OFF” becomes the banner under which unnecessary transmissions are done away with and base stations and UEs are put to sleep when at all possible.
Samsung Research finds three main enablers:
Carrier-Dependent Capabilities
6G introduces Energy-Saving Network Access (ENA), which dynamically controls SSB transmission.
Multi-toned SSBs: Normal (NM-SSB), Energy-Saving (ES-SSB), and On-Demand (OD-SSB) provide extremely flexible signaling in contrast to 5G-Fixed SSBs-on.
ES-SSB usually delays the transmission periodicity (e.g., 160 ms); the OD-SSBs are transmitted only on demand, reducing base station standby energy.
- Dynamic Time/Frequency/Spatial/Power Adaptation
Here, DSA is the active adaptation of the number of active antennas and beam directions based on real-time demand.
It avoids over-provisioning and wasting idle power and is particularly applicable for high-frequency bands in which power scales with antenna density.
- Energy-Aware Network Management and Exposure (EANF)
Interfacing with the central orchestration layer for real-time monitoring of energy consumption, in order to initiate power-aware policies for scheduling, load balancing, and carrier activation.
Further, in the realm of AI-RAN, better traffic predictions will enable the optimization of beam configurations and event-driven measurements, thereby also reducing signaling, and hence power consumption.
Energy Conservation for UEs in 6G
User devices remain at the core of the 6G energy-saving scheme. Network-UE joint power saving opens the way for more proactive strategies whereby the network predicts UE activity, traffic patterns, and battery status to join in coordinating wake-up intervals.
Some of these key innovations include:
- Ultra-low-power wake-up receivers that keep energy use at a minimum.
- Context-aware wake-up signals powered by ML techniques evaluating and adapting timing and frequency.
- Collaborative scheduling between the network and the UE to reduce idle consumption without degradation of user experience.
Performance and Energy Gains
Internal studies with 24-hour traffic profiles demonstrated:
- ENA cuts energy consumption by 43.37% at low traffic and reaches 20.3% average savings.
- DSA further reduces power consumption by another 14.4%, scaling the antenna ports with demand.
- Together, ENA + DSA can reach an energy saving of ~21.2% while also enhancing the user-perceived throughput (UPT) by up to 8.4%.
In this way, such results show that 6G energy savings are not just about switching off and saving power-they also include efficiency improvements and network responsiveness enhancements.
Conclusion:
Rather from being a small improvement, the 6G energy-saving vision represents a paradigm shift. Networks can enter low-power modes more frequently when ENA, DSA, and EANF cooperate, which minimises waste and maintains service quality. 6G offers faster and more dependable connectivity as well as a sustainable foundation for the upcoming ten years of wireless evolution by fusing AI-native intelligence, signalling innovation, and hardware flexibility.
(This article has been adapted and modified from content on Samsung.)
