Roaming Failures: Drops While Walking, Broken Calls

What it looks like

Typical cases: a nurse pushing a cart, a hotel guest on a call while walking, a forklift crossing zones. Voice breaks up, scanners need reconnecting, video calls freeze for seconds.

Likely causes

Ordered from most to least common:

• Sticky client: it stays on a fading AP below -75dBm until the link fails, then reconnects
• 802.11k/v/r disabled: the client does not know neighbour APs exist, so handover only happens on failure
• Uneven AP power: one AP reaches much further than the next, so clients naturally stick to the strong one
• Low rates still enabled: 1/2/5.5/11Mbps extend the apparent range and create false coverage
• Inconsistent SSID or security: different encryption across APs makes clients treat them as separate networks

Diagnostic steps

Follow in order.

• Use a Wi-Fi analysis app and walk the roaming path, recording signal before and after each handover
• Note the signal at handover: below -75dBm means a sticky client — go to step 3
• On the AC, disable the 1/2/5.5/11Mbps low rates on 2.4GHz and set a minimum rate floor on 5GHz
• Check that neighbouring APs transmit at similar power and turn the strongest down by 3–6dB
• Confirm every AP uses identical SSID and encryption, guest network included
• Verify the AC has pushed 802.11k/v/r; where clients lack r, at minimum enable k and v

Fix and prevent

Fix: disable low rates first, level the power between neighbours, then enable k/v/r. If individual clients still stick, that is client-side behaviour — mitigate by densifying so each cell is smaller. Prevent: design adjacent APs with similar cell radii and deliberately reduce power in dense areas instead of maximising reach.