Returning to Shannon's Original Meaning

Shannon theory is revisited to show that ergodicity is an indispensable element of channel capacity. The generalized channel capacity $C=\sup_{\bm{X}}\underline{I}(\bm{X}; \bm{Y})$ is checked with a negative conclusion and the popular assertion "the capacity of a slow fading channel is zero in strict Shannon sense" is found to be conceptually wrong.