ABC Company has a 2.4 and 5 GHz WLAN deployment supporting four bands in the 5 GHz range
(UNII 1, UNII 2, UNII 2e, and UNII 3). DFS functionality is enabled as required by the regulatory
domain. Band steering is also enabled to encourage dual-band clients to use frequency bands
with more capacity.
Your performance analysis shows that many dual-band VoWiFi client devices will move back and
forth between 2.4 and 5 GHz as the user roams throughout the building. All APs have 2.4 and 5
GHz radios enabled.
This “band hopping” behavior is viewed by network staff to be undesirable. What is the most likely
cause of the unpredictable client band selection behavior?
Interference from 5 GHz radar sources has increased frame corruption and retries on channels
36-48 in UNII 1.
5 GHz frequencies offer better RF penetration than 2.4 GHz, but 2.4 GHz offers more voice call
capacity and lower latency than 5 GHz.
The voice client does not support DFS, and therefore experiences some 5 GHz coverage holes
as it moves through the network.
The client’s band selection algorithm prefers 5 GHz, but band steering behavior usually steers
75-85% of client devices to 2.4 GHz.