Intermittent Roaming Drops Reported Only by One Floor
Users on the third floor report dropped voice calls and video freezes when walking between offices, but only on that floor. Other floors with the same AP model and controller configuration are fine. Monitoring shows third-floor APs have normal CPU, no channel changes, and client counts similar to other floors. However, RRM logs show the third floor's APs repeatedly changing transmit power, and a neighboring tenant's network appears on the same channels with strong RSSI in the corridor. The controller's minimum RSSI / band steering settings are default and identical fleet-wide.
1. Given identical configuration fleet-wide, what explains the floor-specific roaming problem?
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Identical configuration does not mean identical RF behavior. The differentiator is the RF environment on floor 3:
- A strong neighboring tenant network on the same channels raises noise and triggers RRM power changes; repeated power adjustments shift cell boundaries, so clients roam at unpredictable points and may stick to a distant AP or bounce between two.
- Default minimum-RSSI/band-steering thresholds are tuned for a quiet environment; under higher interference the same thresholds produce late or ping-pong roaming.
- Normal CPU and client counts rule out controller load; the problem is airtime and cell-edge instability, visible only where the neighbor's signal is strong (corridor).
The judgement: the fleet-wide config is a red herring; the floor-3 interference profile is the cause.
2. Propose monitoring steps to confirm the diagnosis and a configuration change scoped to floor 3.
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Confirm first:
- Spectrum/site analysis in the corridor to document the neighbor's RSSI and channel occupancy; compare to a clean floor.
- Client event logs for the affected clients: look for repeated roam events, retry spikes, and low-SNR associations at the moment of drop.
- RRM history correlating power changes with reported drop times.
Then, scoped to floor 3:
- Pin channels and power on floor-3 APs (disable or dampen RRM power changes) to stabilize cell boundaries, choosing channels that avoid the neighbor where possible.
- Tune minimum RSSI / band steering for floor 3 only, so clients are encouraged to roam earlier at the corridor edge.
- Re-validate with the same client walk test and monitoring; leave other floors unchanged so the change is attributable.
Avoid fleet-wide changes based on one floor's RF conditions.