How to calculate transmit power?

I want to calculate required transmit power (Pt) of a signal in 60 GHz to transmit 5 Gb of data across 10 meters. What other details are required to know to do so? plus formula to do so?Considering the free space path model.

 I think I need the baseline value i.e. Pt of 'x' is required to achieve 'y' gb data over 'z' meters. but what if my argument is that with increase in distance transmit power is not linearly increased. that is, rapid propagation loss with increase of distance which is generally the case with 60 ghz networks.
Thanks.