Microwave Link, Optical Fiber Communication, and Radio Frequency Link budget
The purpose of calculating the link budget is calculate the distance of communication. (link distance, cell range) between the broadcast device and the receiver at two different locations, depending on many factors such as transmission information requirements (service type, capacity…), Frequency, frequency deviation, broadcast power, receiver power, power loss (loss, attenuation), power gain (gain) that occur on the communication link due to many different factors, etc.
The Optic Fiber Communication Link, the link budget to calculate the Power budget, which is the ratio between the broadcast power from the transmitter and the sensitivity (threshold) of the receiver. This power budget needs to be greater than the total power loss that occurs on this link.
In the Microwave Link, a link budget to calculate the fade margin, which is the ratio between the calculated gain power and the sensitivity (threshold) of the receiver, a quantity of power reserved for energy loss due to rainfall. This fade margin needs to be greater than the energy loss caused by rainfall for a certain period, depending on a predetermined availability objective (for example, availability 99.99% per year).
In Radio Frequency Coverage Planning, a link budget to calculate the maximum allowable path loss MAPL (maximum allowable path loss) on the radio path between the base station and the mobile station, which is the payoff between Broadcast power of the transmitter and sensitivity (threshold) of the receiver. This MAPL energy loss to compare with the loss of path loss through radio propagation models such as Okumura-Hata, Cost231-Walfisch-Ikegami, Cost231-Ha, etc. to calculate the scope of radio cell (cell range).
In real work, they use planning tools (Pathloss4 / 5, Atoll, Planet, ASSET ...) to calculate Microwave link budget as well as Radio Coverage Prediction for Cell / Coverage Planning.