0

Is there a way to (theoretically at least) calculate the decay on bandwith of a Wifi related to the streght signal? For example, I know that I can theoretically expect 54Mbps of a 802.11g at 100%, which will be the bandwith expected at a 30% of signal? is it lineal? is it the same?

I could not find any source for this, but considering the error replay involved, I guess it should be possible to calculate something like this. Anybody knows?

MadHatter
  • 78,442
  • 20
  • 178
  • 229
lithiium
  • 185
  • 9

1 Answers1

1

It's not nearly as simple as you probably think it is.

  1. Calculate the freespace loss:

    20 * (log(d) + log(f) + 1.62)
    

    Where d is the distance in meters, f is the frequency in kHz.

  2. Lookup the transmit strength of endpoint A, subtract the freespace loss, add the antenna gain at each end, add endpoint B's receive sensitivity, subtract a link budget (maybe 5 for small space WiFi, 10 for open environments, and 20+ for "dense" situations).

  3. Itterate the #2 calculation for various speeds and modulations. High end equipment will have the exact specs for a wide variety of configurations. Low end stuff publishes less information.

  4. For configurations where the final calculation comes out positive, it should work. Negative numbers should not work.

Chris S
  • 77,337
  • 11
  • 120
  • 212