Are the low temperature low frequency and high temperature high frequency ac conductivity of glasses the same phenomenon?

AC conductivity (sigma) of 61SiO(2) . 35Li(2)O . 3Al(2)O(3) . 1P(2)O(5) glass is obtained in the frequency (f) range from 10 Hz to 100 kHz and temperature (T) from 4 to 300 K, and also in the frequency range from 100 MHz to 3 GHz at room temperature. The conductivity behaviors with slope similar or equal to 1 of a log(sigma) versus log(f) plot in both low temperature-low frequency and high temperature-high frequency regions can be considered as the same phenomenon if one follows the empirical relationship sigma = B' exp(alpha T), where B' and alpha are experimentally determined constants. However, the asymmetric double-well potential (ADWP) model which has been successfully used for describing the low temperature-low frequency conductivity cannot explain the high temperature-high frequency conductivity satisfactorily without further modification.