In the simple version above, the signal and noise are fully uncorrelated, in which case S + N {\displaystyle S+N} is the total power of the received signal and noise together. A generalization of the above equation for the case where the additive noise is not white (or that the S / N {\displaystyle S/N} is not constant with frequency over the bandwidth) is obtained by treating the channel as many narrow, independent Gaussian channels in parallel: