The BLE nodes operate in accordance to the IEEE 802.11 protocols. In particular the BLE nodes:

• do not interfere at all with the 5 GHz Wi-Fi networks because the BLE nodes use only the 2.4 GHz frequencies.
• do not interfere with Wi-Fi networks that use channels that don’t overlap with the channels used by the permanent Wi-Fi network. This means that if an existing Wi-Fi network uses channels from 1 to 6 and the Wi-Fi network is set to work on channel 11, there will be no interference between the 2 networks.
• the interference with other networks that share the same 2.4 GHz channel is minimal because the infrastructure is mostly passive (as explained in this page).