Question

How can I calculate the expected range improvement for a given extra link budget?

Answer

The range improvement can be calculated based on the following formula:

where

- ΔR is the desired value of range improvement (ratio between the new and original range)

- n is the propagation factor (the typical outdoor value is between 2.8 and 4)

- ΔLB is the link budget improvement

The ΔLB link budget improvement can be achieved with higher conducted output power, better conducted sensitivity, or with higher antenna gain either on TX or RX side.

Let’s see an example:

Assuming a ΔLB = 3 dB additional link budget improvement (e.g. the TX power is increased or RX sensitivity is improved by 3 dB) and outdoor line of sight between the transmitter and the receiver (which results ~n = 3 propagation factor), the range improvement will be the following:

Thus, for example assuming 400m original range, 3 dB higher transmitter power or 3 dB better sensitivity would result ~500m range.