A strong dependence of the rotational dynamics of the mesogenic units (beta- relaxation) on the order of the mesophase was found in sidechain liquid crystal polymers. The preexponential frequency factor, f (beta infinity)*, and the activation energy, E-alpha beta*, Of the p-relaxation rate both increase significantly (i.e., obeying a compensation law) with increasing order of the mesophase which is accompanied by a decrease of the mean lateral mesogenic distance. In this work, we show how these experimental results can be interpreted in a quantitative manner by using the general results of the coupling model for cooperative motions.