Question

19) A 1 GHz communications link is 1 km long, of which, 12 meters is foliage. Find the following: (a) the free- space loss, (b) the Weissberger model foliage loss, and (c) the Early ITU Model foliage loss

Answer 1

Given that: - a 1 GHz communications link = 1 km long 12 meters is foliage Now we can calculate (a) Free Space loss: - Now we can calculate the free space loss we have Free space loss = 20 log(4 pi R/lambda) where lambda = c/f Free Space loss = 20 log(4 pi times 1000 times 10^9/3 times 10^8) = 20 log[4 pi times 10^12 times 10^-8/3] = 20 log[4.18879 times 10^4] = 20 log(41887.9) Free Space loss = 92.44 dB \r\n Weissberger model foliage loss: - Now we can calculate Weissberger model foliage loss Then we have Foliage loss = 0.45 f^0.284 d = 0.45(10^9)^0.284 times 12 = 0.45 times 359.75 times 12 Foliage loss = 1942.65 dB This is the required Weissberger model foliage loss Early ITU Model foliage loss: - By Early ITU Model Foliage loss = 0.2(f)^0.3 d^0.6 = 0.2 times (10^9)^0.3 (12)^0.6 = 0.2 times 501.187 times 4.44 Foliage loss = 445.05 dB This is required Early