You may find the following "Setting Up" Guide useful
separate Service Set Identifier (SSID) for the IP phone. However, if there is an existing SSID configured to support voice capable Cisco Wireless LAN endpoints already, then that WLAN can be utilized instead.
The SSID to be used by the IP phone can be configured to only apply to a certain 802.11 radio type.
It is recommended to have the IP phone operate on the 5 GHz band since it has many channels available and not as many interferers as the 2.4 GHz band.
Ensure that the selected SSID is not utilized by any other wireless LANs as that could lead to failures when powering on or during roaming; especially if a different security type is utilized.
Refer the following document wireless phone configuration