Calculating transmission distances

Calculating transmission distances
When determining the transmission for a given signal and fiber optic transmitter / receiver combination; the following rule of thumb is applied.
Please note that the numbers given are pessimistic and are offered a guide only

Calculate the maximum loss budget ( allowable loss between transmitter and reciver) ; ie:
Tx power = -7.5dBm – minimum level = -20dBm
Maximum loss = 12.5dBm

Calculate the losses of the path, including length and connectors
Use 0.3dBm loss per km for SDI or HD SDI add 0.5dBm for each connecter in the path ( including bulkheads)
Total loss = length in km x 0.3 + # of connectors x 0.5dBm
Total loss = 5dBm
Sutract path losses from the loss budget ( It that easy)