PAC-ORAN: Power Saving CPU Scheduling Approach for Scalable Mobile UEs in Open RAN

Open RAN is a next-generation wireless network technology that promotes flexibility, cost efficiency, and interoperability through disaggregation and open interfaces. Energy efficiency remains a key challenge, especially in scalable deployments with many connected User Equipments (UEs), where dynamic power management at the gNodeB is critical. In this paper PAC-ORAN (Power-saving Adaptive CPU Scheduling for Open RAN) is proposed which is an advanced CPU scheduling algorithm evaluated with a large number of connected UEs to gNodeb. PAC-ORAN includes an advanced method using moving average adaptive threshold selection and dynamically adjusting CPU core states and frequency tuning based on real-Time CPU metrics. The evaluation of PAC-ORAN focuses on two key objectives: (1) Sustainability Goals: PAC-ORAN reduces CPU power consumption by 5% to 30%, lowers RAM power usage by 2% to 20%, and brings down CPU temperature by 2 to 3 degree Celsius. (2) Performance Goals: PAC-ORAN maintains bounded throughput even during power-saving operations and balances CPU frequency usage. The key contribution of this paper lies in the proposed PAC-ORAN algorithm tested on large number of connected UEs along with key findings from the PAC-ORAN algorithms impact on CPU and RAM power utilization as well as its impact on CPU temperature and frequency usage.