Radio Number for Special Family of Graphs with Diameter 2, 3 and 4

A radio labeling of a graph G is an injective function f: V (G) → Nbigcup{0}such that for every u, v (element of) V (G), |f(u) − f(v)| ≥ diam (G) – d(u, v)+1. The span of f is the difference of the largest and the smallest channels used, that is, max u, v (element of) V (G)^ {f(u) − f(v)} . The radio number of G is defined as the minimum span of a radio labeling of G and denoted as rn(G). In this paper, we present algorithms to get the radio labeling of special family of graphs like double cones, books and nC4 with a common vertex whose diameters are 2,3 and 4 respectively.