Intelligent User Association and Scheduling in Open RAN: A Hierarchical Optimization Framework

Distributed deep reinforcement learning; functional splits; network slicing; open radio access network; user association; Functional split; Functionals; Hierarchical optimization; Network slicing; Open radio access network; Optimization framework; Radio access networks; Reinforcement learnings; User associations; Electrical and Electronic Engineering

Abstract :

[en] In the ever-evolving landscape of NextG wireless networks, Open radio access network (RAN) emerges as a transformative paradigm, revolutionizing network architectures and fostering innovation through its open, intelligent and disaggregated approach. By integrating RAN intelligent controllers (RICs), we can seamlessly implement machine learning (ML) algorithms to cater to diverse vertical applications and deployment environments without the need for intricate planning. However, this architecture suffers from two critical challenges: frequent handovers and load balancing amid varying traffic demands of different services in dynamic environments. To address these issues, this study proposes a joint intelligent user association, congestion control, and resource scheduling (IUCR) scheme. Aligning with the 7.2x functional split (FS) option recommended by the O-RAN Alliance, we present a hierarchical optimization framework incorporating heuristic methods, successive convex approximation (SCA), and a distributed deep reinforcement learning (DRL) approach across different Open RAN components, such as RICs and RAN layers. The simulation results convincingly demonstrate the superior performance of the proposed scheme compared to centralized approaches, validating its effectiveness.

Disciplines :

Computer science
Electrical & electronics engineering

Author, co-author :

KAVEHMADAVANI, Fatemeh ; University of Luxembourg > Interdisciplinary Centre for Security, Reliability and Trust (SNT) > SigCom

VU, Thang Xuan ; University of Luxembourg > Interdisciplinary Centre for Security, Reliability and Trust (SNT) > SigCom

Nguyen, Van-Dinh ; VinUniversity, Vinhomes Ocean Park, College of Engineering and Computer Science, Hanoi, Viet Nam

CHATZINOTAS, Symeon ; University of Luxembourg > Interdisciplinary Centre for Security, Reliability and Trust (SNT) > SigCom

External co-authors :

yes

Language :

English

Title :

Intelligent User Association and Scheduling in Open RAN: A Hierarchical Optimization Framework

Publication date :

November 2025

Journal title :

IEEE Transactions on Communications

ISSN :

0090-6778

eISSN :

1558-0857

Publisher :

Institute of Electrical and Electronics Engineers Inc.

Volume :

Issue :

Pages :

11574-11589

Peer reviewed :

Peer Reviewed verified by ORBi

Additional URL :

http://xplorestaging.ieee.org/ielx8/26/5497975/11095741.pdf?arnumber=11095741

Available on ORBilu :

since 22 October 2025

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