UE Centric DU Placement with Carrier Aggregation in O-RAN using Deep Q-Network Algorithm

Open Radio Access Network (O-RAN) provides the capability to efficiently distribute the RAN Network Functions (NFs) such as the Radio Unit (RU), Distributed Unit (DU) and Centralized Unit (CU) in O-RAN Cloud (O-Cloud) nodes using virtualization, automation, intelligence and open interface specifications. In addition, Carrier Aggregation (CA) technology enhances the throughput of the users by aggregating Component Carriers (CCs) and allocating one Primary Cell (PCell) and multiple Secondary Cells (SCell) to each user. Finding the DU NFs placement of each CC (PCell or SCell) while minimizing the number of used O-Cloud nodes and the average user end to end delay is our aim in this paper. Thus, we model the average delay and propose an algorithm using Deep Q Network (DQN) based Deep Reinforcement Learning (DRL) algorithm to find the solution to the problem. Simulation results demonstrate that our proposed scheme reduces the average end user delay and the number of employed O-Cloud nodes at least 90% and 20% with respect to the baselines.