A communication system operating with a center frequency of 900 MHz has a 20 Watt transmitter feeding a 21.6 dBi antenna array on top of a 50 m high tower through a cable with 5 dB loss. The receiving antenna is handheld at a height of 1.5 m, has a gain of 2.16 dBi, and feeds a matched receiver through a cable with 1 dB loss. To be understandable in the presence of noise, the minimum acceptable received signal power is -110 dBm.
a. Calculate the maximum range using free space path loss.
b. Calculate the maximum range using plane earth path loss.
c. Calculate the maximum range using Egli empirical path loss.