One of the unique aspects of ESDR is event segregation approach as it considers delay sensitivity associated with different types of events and assures efficient delivery to appropriate destination. We have devised a statistical model which considers different events occurring in sensing field. It is assumed that sensing node is able to determine the type of a particular sensed event and delay criticality associated with that event. In order to simplify the analysis occurring events are divided into three types: very critical, critical and normal/ordinary with the probability of occurrence pvc, pcr and pno respectively. Nodes with critical and very critical events are collectively termed as delay sensitive nodes and their data is termed as delay sensitive data. The nodes of each type of events are members of the sets defined as Evc, Ecr and Eno. Cardinality of these sets of node is given as:(17a)|Evc|=⌊pvc×|E|⌉ (17b)|Ecr|=⌊pcr×|E|⌉ (17c)|Eno|=⌊pno×|E|⌉ where sign ⌊⌉ represent the round off decimal value to nearest integer. The probability values are set as pvc=0.111, pcr=0.222 and pno=0.666 used in simulation section, which describe the number of nodes in each type of set. These values are assigned on the base of the assumption that more critical events are less likely to occur and vice versa. The values assigned to these probabilities ensure that; (i) the proportion of each type of nodes remain same throughout the network operation and (ii) the sum of all types of nodes is equal to the total number of data sensing nodes |E| as given by the following equation. (17d)|Evc|+|Ecr|+|Eno|=|E|