Hi Carol & Hi Art,
Your questions are quite general and GSM planning & optimization is a vast arena. The best approach is to understand the hardware first and learning planning & optimization skills would be easier.
Carol, I did not get your question about checking the power o/p of an antenna system. Just remember that GSM antennas are passive device. whatever is the power o/p of your BSS is the power at your antenna apart from some system gain.
You can be specific in your questions. May be then i’d get a better idea of your queries.