This link budget tool lets you quickly compute the free Space path Loss, Received Signal Strength, and Fade Margin between two ADTRAN APs. Distance will be entered in feet, or you may use GPS coordinates. The tool will take into account loss of feed cables, or additional loss for any components you may install.
Free Space Path Loss - Loss of RF signal as it travels through the air from AP to AP, assumes clear line of sight, no obstructions.
Received Signal Strength - The signal received at the radio.
Fade Margin - The design for a "Good" link is based on a minimum 10 dB fade margin. The fade margin is the difference between the received signal level and the receive sensitivity of the AP radio. For instance, the BSAP 1940 has a receive sensitivity of -72 dB for 802.11n transmission speeds. In order to achieve a fade margin of 10 dB we need to design for a received signal of -62 dB. The reason for the fade margin is to allow for unknown outside interference and still maintain an acceptable signal.
Note: This Excel tool utilizes macros to perform calculations, you must enable these macros to run in your Excel for the tool to function properly. A December 2014 Microsoft update caused issues for some users, see this link for details if you have problems running macros. http://support.microsoft.com/en-us/kb/3025036/en-us