Here we consider the case of a feedback control loop stabilized over an additive white noise (AWN) channel subject to a Signal-to-Noise Ratio (SNR) constraint. On that premise the initially known AWN channel may change its mean and/or variance due to changing transmission circumstances. Based on the channel input measurement we propose here the detection of such changes and the estimation of the new mean and/or variance values based on the channel SNR estimation, in particular for the AWN channel variance changes. We study the cases of the AWN channel when it is assumed to be located either over the direct path (between the controller and the plant model), or the feedback path (between the plant and the controller model).