Conflict Management in the Near-RT-RIC of Open RAN: A Game Theoretic Approach

Abstract: Open Radio Access Network (RAN) was introduced recently to incorporate intelligence and openness into the upcoming generation of RAN. Open RAN offers standardized interfaces and the capacity to accommodate network applications from external vendors through extensible applications (xApps), which enhance network management flexibility. The Near-Real-Time Radio Intelligent Controller (Near-RT-RIC) employs specialized and intelligent xApps for achieving time-critical optimization objectives, but conflicts may arise due to different vendors' xApps modifying the same parameters or indirectly affecting each others' performance. A standardized Conflict Management System (CMS) is absent in most of the popular Open RAN architectures including the most prominent O-RAN Alliance architecture. To address this, we propose a CMS with independent controllers for conflict detection and mitigation between xApps in the Near-RT-RIC. We utilize cooperative bargain game theory, including Nash Social Welfare Function (NSWF) and the Equal Gains (EG) solution, to find optimal configurations for conflicting parameters. Experimental results demonstrate the effectiveness of the proposed Conflict Management Controller (CMC) in balancing conflicting parameters and mitigating adverse impacts in the Near-RT-RIC on a theoretical example scenario.