Physical Cell Identity (PCI) Conflict Detection

Continuously analyzes incoming UE measurement reports and X2/Xn neighbor relation data to identify PCI conflicts without manual intervention. The xApp cross-references reported PCIs against the RAN Network Information Base (R-NIB) to detect two distinct failure modes: PCI collisions (two neighboring cells sharing the same PCI) and PCI confusion (a cell having two neighbors with identical PCIs). Detection latency is typically under 100ms, enabling near-real-time resolution before user experience degrades.

Executes closed-loop remediation by selecting an optimal new PCI from the available pool and orchestrating the reassignment via the E2 interface. The algorithm considers multiple constraints:

• Avoids PCIs used by detected neighbors and neighbors-of-neighbors
• Respects PCI mod constraints for reference signal collision avoidance
• Minimizes impact on ongoing handover procedures
• Coordinates with Mobility Robustness Optimization (MRO) xApps to prevent conflicting parameter changes during reassignment

Employs distinct detection logic for each conflict type. PCI collision is identified when a UE reports a strong neighbor cell with a PCI already assigned to its serving cell, indicating overlapping coverage. PCI confusion is detected when the R-NIB topology graph reveals a cell with two neighbors sharing the same PCI, making handover target identification ambiguous. The xApp logs each event with cell identity, timestamp, and affected UEs for operational audit trails.

Leverages time-series forecasting models trained on historical PCI reassignment data and network topology changes to predict potential conflicts before they occur. The model ingests:

• Planned cell site additions from the Non-RT RIC
• Neighbor relation changes from Automatic Neighbor Relation (ANR) functions
• Traffic pattern shifts that may trigger new cell deployments This proactive approach reduces conflict occurrence by up to 70% compared to reactive-only methods.

Operates across heterogeneous RAN deployments by consuming standardized E2 service models (E2SM-KPM for measurements, E2SM-RC for control). The xApp abstracts vendor-specific PCI allocation logic behind the O-RAN RAN Function Exposure API, enabling consistent conflict detection regardless of whether the underlying gNB is from Ericsson, Nokia, Samsung, or other vendors. This eliminates the need for proprietary SON coordination gateways.

Maintains a comprehensive, time-stamped log of every detected conflict and remediation action in the R-NIB for operational visibility. Each record captures:

• Triggering event: UE measurement report or topology change
• Conflict type: Collision or confusion with affected cell identities
• Resolution action: New PCI assigned and reassignment timestamp
• Post-resolution validation: Confirmation that no new conflicts were introduced This data feeds into the O1 interface for FCAPS compliance and regulatory reporting.