* '''SNR (Signal to Noise ratio) Method:''' The calculations using this method reveal what power of signal can we expect to receive at the antenna, and whether it is above the noise floor. It also reveals the difference in signal and noise power. Greater the signal to noise ratio, better is the signal received.

** Ex: ISS signals are received by everyone, but not everyone can receive the signals transmitted by a small satellite. This is because ISS has powerful transmission. Looking at the image below, you can clearly say, greater Tx power translates to better Rx power. That is if I shift Tx power upward by 1 dBm, the whole link shifts upward by 1 dBm,increasing the link margin.

* '''Eb/No Method:''' It is used in particular for digital modes of transmission. The exact meaning of Eb/No is better explained by [http://www.eletrica.ufpr.br/evelio/TE111/Eb_N0.pdf this document]. In a way, it signifies the signal to noise ratio of a digital communication protocol. The link margin helps determine the error in received bits i.e. If I receive with a bit error rate of 10^(-3) , 1 of every 1000 bits is likely to be faulty. Increasing data rate (bits/s) decreases the Eb/No margin and the bit error rate increases. Thus we would need to power the transmission more. There is always a data rate vs power trade off while deciding the design of a satellite.