A broadcast is a function f that assigns an integer value to each vertex of a graph such that, for each v ∈ V , f (v) ≤ e (v), where e(v) is the eccentricity of v. The broadcast number of a graph is the minimum value of ∑ f(v) among all broadcasts f with the property that for each vertex u ∈ V, there exists some v ∈ V with f(v) > 0 such that d(υ,v) ≤ f(v). We present a new upper bound for the broadcast number of a graph in terms of its irredundance number and a new dual property of the broadcast number called the multipacking number of a graph. / Graduate