Hi Kazola, thank you for your reply.
802.11 transmitters have generally trasmitted power limited to a value lower than +20 dBm, in order to accomodate for antenna gain (a dipole , for example , has about 2 dB of gain).
I agree with your considerations about differences between BT and BTLE, but i'd like to know BT device class in the referred document in order to understand which will be the behavior with BTLE & WiFi in the same area , taking into account the differences between BT and BTLE.