I need to make a scan of the wifi signals in the place where is the AP located. In other vendor this is called "wireless site survey" and it returns a list of the AP with their MAC Address and their RSSID and channel.
What you are describing is a post installation site survey.
You will need some site survey software, such as AirMagnet's Survey PRO or Ekahau's Site Survey Professional, to complete this. This applications allow you to import a floor plan and record information such as:
the changing RSSI for each BSSID as you walk around the survey area
Data rates (if your wireless client is associated to the WLAN)
Retry rates (if your wireless client is associated to the WLAN)