A PCI collision occurs when two neighboring (geographically adjacent or mutually visible) cells are configured with the same Physical Cell Identity, causing UEs to be unable to reliably distinguish between them based on their synchronization and reference signals. This leads to degraded reference signal measurements, failed handovers, and potential interference between the two cells' signals. This is distinct from PCI confusion, where two non-adjacent cells that share a PCI are both neighbors of a third common cell, creating ambiguity during handover target selection even though the two same-PCI cells are not directly adjacent. The correct remediation for a PCI collision is a PCI replanning exercise, reassigning one of the conflicting cells to a unique PCI value that avoids both direct reuse with its neighbors and problematic modulo relationships that affect reference signal sequences. This is typically performed remotely via configuration management without requiring a site visit.

An 'Equipment Over-Temperature' alarm indicates internal temperature monitoring has detected conditions exceeding safe operating limits, which can lead to performance throttling or automatic protective shutdown of the affected hardware. Beyond inspecting the cooling system itself, a NOC engineer should check whether related environmental alarms are also present at the site, such as a cabinet door-open alarm (which disrupts climate control), a fan failure alarm, or an HVAC/air-conditioning fault alarm for the shelter or cabinet.
These correlated alarms often explain an over-temperature condition by pointing to a broader site environmental issue rather than an isolated equipment defect, helping correctly scope the response (for example, escalating an environmental/facilities issue rather than treating it purely as a RAN equipment fault).
The cell's PCI value, handover success rate, and NetAct license expiry date are entirely unrelated to thermal conditions and would not assist in diagnosing this alarm.

Remote Electrical Tilt (RET) units are Antenna Line Devices (ALDs) that communicate with the base station over the Antenna Interface Standards Group (AISG) bus. After a physical RET replacement, the appropriate remote verification is to confirm that the new device is discovered on the AISG bus, that it is communicating correctly with the base station's controller, and that its current tilt position can be read remotely and that tilt adjustment commands are correctly applied and reflected back. This confirms both the physical connectivity (cabling/bus communication) and functional operability (motor and position feedback) of the replaced unit.
The unit's color is irrelevant to functional verification, and while serial number changes are expected with replacement (a new unit will naturally have a different serial number, which should simply be recorded for inventory purposes), it is not itself a functional check. NR-ARFCN relates to radio carrier frequency configuration and has no relationship to RET device verification.

When a cell repeatedly raises and clears 'Cell Unavailable' alarms, and PRB utilization simultaneously drops to zero during exactly those same intervals, this pattern strongly indicates the cell is genuinely going out of service intermittently, rather than a display or reporting artifact. The investigation should focus on causes capable of producing repeated, short-duration outages: transport link instability (brief link flaps causing loss of the cell's connectivity), loss of synchronization reference (particularly significant for TDD 5G, where sync loss can force a cell to stop transmitting to avoid interference), or unexpected hardware resets/restarts of the baseband or radio unit, potentially linked to environmental issues such as overheating or power fluctuations.
NetAct UI theme settings, subscriber handset models, and the billing system are entirely unrelated to RAN service availability and would not explain this correlated alarm and KPI pattern. Correlating alarm timing with PM data and environmental/transport alarms is a key NOC diagnostic technique.

Voltage Standing Wave Ratio (VSWR) measures how efficiently RF energy transmitted by the radio unit is delivered into the antenna system versus being reflected back due to an impedance mismatch. A High VSWR alarm indicates a significant mismatch on a particular antenna branch or port, commonly caused by issues such as a damaged or loose feeder cable connection, a faulty or improperly seated RF connector, moisture
/water ingress into a connector, or physical damage to an antenna element. This is a radio-frequency hardware issue on the affected branch and is entirely unrelated to NetAct server storage, core network mobility functions, or billing systems. For NOC engineers, a persistent High VSWR alarm typically signals that a field visit may be needed to inspect and repair the physical RF connections or replace damaged hardware on that antenna line, since it is a physical-layer condition not resolvable through remote configuration alone.