LoRa Calculator

Formula

The formula to calculate the link budget (LB) is:

\[ LB = P_{tx} - P_{rx} \]

Where:

\( LB \) is the link budget in dB.
\( P_{tx} \) is the transmit power in dBm.
\( P_{rx} \) is the receiver sensitivity in dBm.

The formula to calculate the free-space path loss (FSPL) is:

\[ FSPL = 20 \log_{10}(d \times 1000) + 20 \log_{10}(f) + 32.44 \]

Where:

\( FSPL \) is the free-space path loss in dB.
\( d \) is the distance in km.
\( f \) is the frequency in MHz.

Example

Let's say the transmit power is 14 dBm, the receiver sensitivity is -137 dBm, the frequency is 868 MHz, and the distance is 10 km. Using the formulas:

\[ LB = 14 - (-137) = 151 \text{ dB} \]

\[ FSPL = 20 \log_{10}(10 \times 1000) + 20 \log_{10}(868) + 32.44 \approx 123.44 \text{ dB} \]

So, the link budget is 151 dB and the free-space path loss is approximately 123.44 dB.

What is LoRa?

LoRa (Long Range) is a wireless communication technology that enables long-range transmissions with low power consumption. It is widely used in IoT applications for connecting devices over large distances.