As described in the first part, we pay more attention to the
survival time of the sensor node in each sub-zone rather than
the entire area. Table 4 summarizes the rounds when 1%,
20%, 50% and 100% of the nodes died in those sub-zones.
The simulation results show that our proposed protocol
achieved approximately 50% and 10% increases in the number
of rounds compared with the direct transmission protocol
and LEACH when the first node died in a control area,respectively. Figure 5 shows the results when the node died in
those sub-zones with the initial energy of 0.25 J/node.