Fig. 3 shows the energy consumption versus the number of nodes. A tradeoff between the energy and the delay is obtained when both, the energy and the delay, are combined in a single objective function. The combined objective function allows both objectives to be minimized simultaneously. For the optimal solution the energy consumption is 15% of that of the HGR algorithm, while the energy consumption of MOGA is 50% of that of the HGR algorithm at N=50.
Fig. 4 depicts the delay versus the number of nodes. The results show that delay of MOGA is longer than that of the optimal one because the GA get trapped at local optimum solutions. Furthermore, the gap between MOGA and the HGR increases as the number of nodes increases because of the parallelism of GA in finding the solution.