Can you add antenna gain ( dBi) plus gain of amplifier?

For a system with an antenna and a bidirectional amplifier. How do we specify the system gain? Can the antenna gain in dBi added to the amplifier gain. for wifi and wimax systems, What kind of input power can we expect going to the amplifier from the antenna in the recieve mode and o/p power in transmit mode back to the antenna? Please help me out with the following questions

Link budget specifies the output power at antenna connector plus antenna gain, which is part of the analysis.
In WLAN a maximum power of approx +18dBm is expected at antenna connector in TX mode, and approx -80dBm at antenna connector in RX mode, for a normal link connection

Look into the Friis transmission formula and link budgets as well for additional information and how to characterize your system.

Thanks for the information. I suppose for wimax and wifi systems the o/p power must be around +27 to +30 dBm which yields rates of 36 to 54 Mbps , which is the purpose of using the wifi system in the firt place. Please correct me if my reasoning is incorrect.

It seems to me the way you specify the system gain makes sense.

I have the same feeling.. but one question.. how to you intend to characterize multipath loss in your budget? -20,-40 dB as a role of thumb?

Regards,
Lupin

Needs to be emphasized are: the antenna gain is a circuit parameter, but his meaning and the amplifier gain should not be substitutes for one another, to the system Tx, Rx design comprehensive consideration.