In this section our proposed protocol Event Segregation based Delay sensitive Routing is introduced and salient features of ESDR are explained. Directed Graph (digraph) theory is employed to serve as model for network topology in ESDR. Deployed nodes map to vertices and links between nodes represent edges of digraph. In digraph G=(N,A) vertices N are connected via edges or arcs A. Where N is the set of all deployed nodes. We denote the set of event sensing or data generating nodes by E, the set of broadcasting nodes by B and the set of courier nodes by C.