Question

A mobile base station (BS) in an urban environment has a power measurement of 15 µW at 175 m. If the propagation follows an inverse cube-power law (Section 3.2.2), what is a reasonable power value, in µW, to assume at a distance 0.7 km from the BS?

Answer 1

Answer:

The reasonable power will be "0.234 μW".

Explanation:

The given values are:

P = 15 μW

d = 175 m

As we know,

Propagation follows inverse cube power law, then

∴  $Power \ \alpha \ \frac{1}{d^3}$

⇒ $Power=\frac{K}{d^3}$

On substituting the estimated values, we get

⇒  $15\times 10^{-6}=\frac{K}{(173)^3}$

⇒  $K=15\times (175)^3\times 10^{-6}$

Now,

"P" at 0.7 km or 700 m from BS will be:

⇒  $P=\frac{K}{d^3}$

⇒  $P=\frac{15\times (175)^3\times 10^{-6}}{(700)^3}$

⇒  $P=0.234 \ \mu W$