Proxim Wireless - Calculations: System Operating Margin (SOM)

Calculations: System Operating Margin (SOM)

The System Operating Margin can be calculated by the formula listed below. SOM is the difference between the signal a radio is actually receiving vs. what it needs for good data recovery (i.e. receiver sensitivity). For further information on this formula, please review the figure below.

Note: This calculator is valid for frequencies below 6 GHz. The final values represent a first order approximation and should only be used as a guide. No guarantees or warranties are implied accordingly.

* denotes a required field
Calculation Input
Operating Frequency*	MHz	Distance Between Antennas*	Miles
Tx Antenna Gain*	dBi	Rx Antenna Gain*	dBi
Tx Cable Loss*	dB	Rx Cable Loss*	dB
Tx Power*	dBm	Rx Sensitivity	dBm

Calculation Results
Free Space Loss	dB
Rx Signal Level	dBm
Theoretical System Operating Margin	dB

System Operating Margin Example

Notes:

When calculation the system operating margin and you are using an amplifier on the receive side, do not add the amps RX gain to the SOM equation.

Calculations: System Operating Margin (SOM)

Calculation Input

Calculation Results