Coupled excitable elements in the presence of noise can exhibit oscillatory behavior with non-trivial frequency dependence as the coupling strength of the system increases. The phenomenon of frequency enhancement (FE) occurs in some coupling regime, in which the elements can oscillate with a frequency higher than their uncoupled frequencies. In this paper, details of the FE are investigated by simulations of the FitzHugh-Nagumo model with different network topologies. It is found that the characteristics of FE, such as the maximal enhancement coupling, enhancement level etc, are functions of the network topology and spatial dimensions. The effect of excitability and the spatio-temporal patterns during FE are investigated to provide an intuitive picture for the enhancement mechanism. Interestingly, some of these characteristics of FE can be described by scaling laws; suggesting the existence of universality in the FE phenomenon. The relevance of these results to biological rhythms are also discussed.