Improving Call Quality: Dropped Calls, One-Way Audio, and Missed Calls on Passpoint

What's happening

Users on a Passpoint network experience call quality issues that aren't full connectivity failures — calls connect but drop during roaming, audio only works in one direction, or calls are occasionally missed even though the device shows a connected state.

Why this happens

Unlike full connectivity failures (device can't connect, or connects with no internet), these symptoms usually point to radio/roaming behavior rather than a hard configuration error. Common contributing factors:

• Poor roaming behavior between access points — as a device moves and needs to hand off from one AP to another, a slow or unstable handoff can interrupt an active call.
• RF interference or suboptimal channel selection, especially in the 5 GHz band, which can degrade call quality even when the connection technically stays up.
• Device-side network handling features (like iOS's "Wi-Fi Assist," which can silently switch a device to cellular mid-call in certain conditions) interacting poorly with Wi-Fi Calling.
• RADIUS accounting/interim update timers set too aggressively, which can cause brief session interruptions that manifest as call issues.

• Band or client load balancing features on the controller, which can force a device to switch bands or APs at an inopportune moment.

   

Troubleshooting steps (for your network/IT team)

1. Review roaming settings on your controller — enabling fast roaming/transition features (e.g. 802.11r / BSS Transition Management) can significantly improve handoff speed and reduce call interruptions during roaming.
2. Check DFS channel usage in the 5 GHz band. Extending available channels via DFS can reduce interference in congested environments, though DFS channels can occasionally trigger radar-avoidance channel changes — worth monitoring if you use them.
3. Review channel width and channel selection — narrower channels or manually assigned non-overlapping channels can sometimes outperform default auto-channel settings in dense deployments.
4. Consider tuning the minimum RSSI (signal strength) threshold required for a device to join or stay on an AP — a threshold around -72 dBm is a reasonable starting point for many environments, forcing devices to roam to a stronger AP sooner rather than clinging to a weak signal.
5. Check RADIUS interim accounting update timers. If set too frequently or too infrequently, this can affect session stability — moderate, consistent timing is usually best.
6. Disable band steering or client load balancing on the SSID/AP group used for Passpoint if you suspect it's interfering with active calls — these features are generally designed for data throughput optimization, not real-time voice stability.

7. On affected devices, check "Wi-Fi Assist" (iOS) or equivalent settings that allow automatic fallback to cellular — while usually helpful, this feature can sometimes cause unexpected mid-call behavior. Disabling it as a test can help isolate whether it's a contributing factor.

    

If the issue continues

If you've reviewed roaming, channel, and RADIUS timing settings and still see recurring quality issues, contact support with:

• What symptom is occurring (dropped calls, one-way audio, missed calls) and how often
• Which of the above you've already checked or adjusted

Our team can review your specific RF environment and controller configuration for further tuning.