If you want to know the radio TX power of a given AP, you need to reference the AP's data sheet and also the countries regulatory domain. You will not ever find a calculator to tell you how much coverage you will have. It is best to have a site survey performed which can determine what AP's, antennas, tx power, location, and how any AP's you need.
As far as using the vWLC, look at the doc Sandeep posted. You need to make sure your ESXi host has enough resources that is required per the document. The server matters, but the available resources that you can give that VM is important.
Transferring Crash file from standby: Login to the Active WLC in HA.
From CLI: (Cisco Controller) >transfer upload datatype crash (Cisco
Controller) >transfer upload filename (Cisco
Controller) >transfer upload mode tftp (Cisco Controller) >transfer
This is the start of a display filter cross reference between Wireshark
and OmniPeek. The 1st installment is a table of advanced filters. More
filters will be added as time allows. It is a living doc, so check back
for changes every so often Please feel f...