The deployment of new 5G Radio Access Network (RAN) equipment alongside the introduction of 5G systems is expected to lead to a significant increase in energy consumption over the coming years. This increase will not only affect energy levels but also the overall costs associated with operating a 5G site. For mobile network operators (MNOs), RAN energy consumption is a critical component of operational expenditure (OPEX). Consequently, 5G MNOs and vendors are currently exploring various energy-saving techniques to mitigate this rise in consumption. These strategies are being analyzed from both technical and cost perspectives to identify the optimal solutions for each operator. So, now let us Explore Energy-Saving Techniques for 5G RAN along with Smart LTE RF drive test tools in telecom & RF drive test software in telecom and Smart Best wireless site survey software, site survey tools for wireless networks & Indoor cellular coverage walk testing tool in detail.
Factors Affecting 5G RAN Power Consumption
The overall cost of running a 5G network is heavily influenced by the system technology in use. Different hardware components, such as the Radio Unit (RU), Baseband Unit (BBU), and transport unit, contribute to the overall power consumption. In systems with active antennas, the antenna units themselves also consume power. Additionally, other elements of the base station infrastructure, such as power supply units (PSUs) and cooling or heating systems, play significant roles in determining power consumption levels.
Enhancing 5G RAN Energy Efficiency
One way to reduce 5G RAN energy consumption is through equipment re-engineering. Depending on the hardware’s lifecycle, operators may opt to replace existing equipment with new, low-energy consumption alternatives. Another approach involves strategic network planning, where operators optimize the physical placement of equipment or alter the geographical location of sites. Although finding new locations for base stations can be challenging, this strategy can still yield energy savings in certain scenarios.
Several other energy-saving techniques are also being explored. These include the dynamic adaptation of network resources to traffic load variations, scheduling policies that adjust bandwidth usage, and the use of adaptive power amplifiers, BBUs, and antennas. Additional methods involve Radio Resource Management (RRM), Artificial Intelligence (AI), and Machine Intelligence. Implementing sleep modes, where active hardware is turned on and off based on network resource needs, is another effective strategy. These techniques are detailed further in the following sections.
Key 5G RAN Energy-Saving Techniques
- Improving RF Unit Efficiency
Innovations in both hardware and software are being targeted to enhance RF unit efficiency. Telecom vendors continuously develop and introduce new product generations, focusing on improving power amplifier (PA) efficiency and RF and IF chip-level efficiency. Each new hardware generation, typically introduced every 5-8 years, aims to achieve a 5-10% improvement in total energy efficiency.
- One Radio for Three Sectors
A standard 3-sector site usually requires three radios. However, in this technique, one physical equipment is configured to serve all three sectors. This solution is suitable for low-capacity sites, as the output power of one RF unit is shared among the three sectors, leading to limitations in the downlink. The gNodeB can be upgraded to a standard configuration when traffic exceeds certain predefined thresholds.
- Symbol and Enhanced Symbol Power Saving
Power amplifiers consume static power even when no signal is transmitted. The symbol power-saving feature quickly shuts down PAs of symbols that do not contain data, reducing overall power consumption. Enhanced symbol power saving involves shaping downlink Physical Resource Blocks (PRBs) to the same transmission time intervals (TTIs), making more TTIs available for symbol power saving. This technique reduces network interference with minimal impact on latency.
- Dynamic Voltage Adjustment
Adaptive power adjustment modifies the PA working voltage based on the traffic load, increasing PA conversion efficiency. This technique reduces PA power consumption and improves overall e/gNodeB energy efficiency.
- M-MIMO Array-Related Sleep Mode
During low traffic scenarios, such as nighttime in stadiums or shopping malls, some channels of the RF module can be shut down. These channels can be dynamically reactivated based on traffic load and configured thresholds. Shutting down M-MIMO channels can save energy but may increase interference and affect edge user performance.
- Capacity Layer Shutdown
This feature transfers user equipment (UE) from a lightly loaded capacity layer to a basic layer of other cells, shutting down the capacity layer to save energy.
- M-MIMO RF Deep Sleep Mode
In low traffic conditions, when an Active Antenna Unit (AAU) is in sleep mode, PAs are turned off, leading to a 15-20% power reduction. With RF deep sleep mode, almost all AAU components can be shut down, achieving power reductions of up to 75%.
- MIMO Sleep Mode (8×8)
While this can save energy, it may reduce throughput and coverage, which can be compensated by increasing RF power.
- Multi-RAT Shutdown
In networks with multiple Radio Access Technologies (RATs), the Multi-RAT Shutdown feature shuts down cells of one or more RATs during low traffic periods. Coverage and service are provided by the remaining RATs, with shut-down RATs reactivated when traffic increases.
- Artificial Intelligence
Using traffic monitoring and machine learning, AI adjusts the timing for turning PAs on and off, optimizing energy consumption.
- BBU Sleep Mode
When parts of the RF equipment are inactive during low-traffic periods, the associated digital processing components in the BBU can also be put into sleep mode, saving approximately 40-50W of power.
Summary of 5G RAN Energy-Saving Strategies
Investing in power-saving technologies will help reduce the operating costs of 5G sites for mobile operators. However, it’s crucial that these energy-saving techniques do not compromise the overall user experience. Techniques should ensure that end-users receive the required throughput and coverage, with capacity reductions during low-traffic periods implemented without impacting system performance. Fast wake-up techniques should maintain user experience levels and Service Level Agreements (SLAs) during traffic surges. By carefully balancing energy efficiency and performance, operators can achieve significant cost savings while delivering high-quality 5G services. Also read similar articles from here.