# WiMAX Transmitter

I was reading about WiMAX networks and how they can provide a 30mbit connection to a user 50km away!

Now, I don't have a great understanding of data transfer but I assume inverse power law applies??

Pf = Pi / 4*pi*r^2

At 50km

Pf = Pi / 10^10 * pi

For Pf = 30mbit/sec = 30*10^6
Pi must equal:

30*10^6 * 10^10 * pi = 10^18 bits/sec = 1 EXAbit/sec

Really?! Can they transmit an EXAbit of data per second? How the hell do these things work?!

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tech99
Gold Member
I was reading about WiMAX networks and how they can provide a 30mbit connection to a user 50km away!

Now, I don't have a great understanding of data transfer but I assume inverse power law applies??

Pf = Pi / 4*pi*r^2

At 50km

Pf = Pi / 10^10 * pi

For Pf = 30mbit/sec = 30*10^6
Pi must equal:

30*10^6 * 10^10 * pi = 10^18 bits/sec = 1 EXAbit/sec

Really?! Can they transmit an EXAbit of data per second? How the hell do these things work?!
The calculation is incorrect. You need to look up the Friis formula on the Internet as a starting point. This will give the received signal power, and then you need to work out if it will compete with the noise of the system.