Wednesday, February 13, 2008

Busting Some Myths About Wireless Technology

The general equation for calculating the clearance zone radius at any point P in the middle of the link is the following:

F_n = \sqrt{\frac{n \lambda d_1 d_2}{d_1 + d_2}}


Fn = The nth Clearance Zone radius in metres

d1 = The distance of P from one end in metres

d2 = The distance of P from the other end in metres

λ = The wavelength of the transmitted signal in metres

The cross section radius of the first Clearance zone is the highest in the center of the RF LoS which can be calculated as:

r = 72.05  \sqrt{{D} \over {4 f}}


  • r = radius in feet
  • D = total distance in miles
  • f = frequency transmitted in Gigahertz.

Or even:

r = 17.32  \sqrt{{D} \over {4 f}}


  • r = radius in metres
  • D = total distance in kilometres
  • f = frequency transmitted in gigahertz.