# how to calculate number of antennas

• May 21st 2011, 09:13 AM
moonnightingale
how to calculate number of antennas
My company is having a area of 3 square kilometers. I want to install antennas for wifi where each antenna covers radius of 300 feet. How many total antennas will be required to cover whole area of 3 square kilometers . Each antenna pattern will overlap with other around 10 Percent. I just need approximate answer. i dont need exact calculation.
• May 21st 2011, 09:31 AM
CaptainBlack
Quote:

Originally Posted by moonnightingale
My company is having a area of 3 square kilometers. I want to install antennas for wifi where each antenna covers radius of 300 feet. How many total antennas will be required to cover whole area of 3 square kilometers . Each antenna pattern will overlap with other around 10 Percent. I just need approximate answer. i dont need exact calculation.

An antenna with coverage radius of 300ft (~90m) will cover an area of of

$A \approx \pi \times 90^2 \text{m}^2 \approx 25500 \text{ m}^2$

So the number of stations with no overlap if that were possible would be:

$N=3000000/25500 \approx 118$

and allowing for 10% overlap will require appriximatly another 12 stations for a total of about 130 stations.

(I doubt you can get away with as little wasted coverage as this in practice)

CB
• May 21st 2011, 09:19 PM
moonnightingale
ok thanks capt black. i m always confused with square Km concept. If i say area of my rectangle is 4 square kilometer, does this mean that its sides are 2 km and 2 km

am i rightt
• May 22nd 2011, 05:50 AM
CaptainBlack
Quote:

Originally Posted by moonnightingale
ok thanks capt black. i m always confused with square Km concept. If i say area of my rectangle is 4 square kilometer, does this mean that its sides are 2 km and 2 km

am i rightt

A square with area 4 sq km is 2km by 2 km.

CB
• May 22nd 2011, 09:57 AM
moonnightingale
why u have written 3000000,
it should be 3000x 3000= 9000000

plz clarify
• May 22nd 2011, 11:23 AM
CaptainBlack
Quote:

Originally Posted by moonnightingale
why u have written 3000000,
it should be 3000x 3000= 9000000

plz clarify

3 sq km is 3 times a square km and a sq kn is one million square meters, so we want 3 million sq m.

3 sq km is not that same thing as a 3 km square.

CB