Undirected circulant graphs

A fundamental problem in designing massively parallel computer systems and fast communication networks is the maximization of the number of nodes given a diameter and degree of a network. This maximal number is bounded above by the Moore bound. For undirected circulant graphs, an upper bound is also given but no exact formula has been found yet for degree /spl ges/6. A refinement on this upper bound is given in this paper. It is determined also that this maximal number is odd.<
>