# A Cache Placement Strategy with Energy Consumption Optimization in Information-Centric Networking
## 4 Simulation Results and Analysis
### Energy Savings
As the location of the cache in the ESCPS policy is selected from the user's point of view, the energy saving can still be kept at optimal when the number of users increases. Figure 3: (**a**) The effect of the number of users on energy savings (\(P_{c}\) = 0.1); (**b**) the effect of the number of users on energy saving (\(P_{c}\) = 1). The comparison results of the energy savings of each strategy are shown in Figure 4a,b, when the content size of the distribution changes (10 to 100). The analysis is performed under the parameter configurations of the best and worst case conditions. That is to say, \(P_{c}\) is 0.1 and 1, respectively. From Figure 4a, we can see that in the process of increasing the size of the distribution content, the order of saving energy consumption from high to low is: ESCPS > Random > LCD. The energy consumption saved by all three strategies is increased. This is because the cache space is small, and the cache is replaced frequently. As the space increases, the number of replacements is reduced, the hit rate is increased, and the energy saving effect of the cache nodes becomes more apparent. Among them, ESCPS has the largest increase. In ESCPS, the content of distribution is an important parameter in the income function. Therefore, when the content of distribution is increased, the benefit function of saving energy is increased. As the content of distribution increases, the energy saving is almost linearly increased. Compared with ESCPS, Random and LCD have less growth and less energy savings. Because cache placement nodes are randomly and singularly selected, they cannot guarantee the optimization of the selected placement node in terms of energy efficiency. Comparing Figure 4a with Figure 4b, the energy savings of all three strategies have been reduced when the size of the distribution content and the energy consumed by the node change are increased at the same time. Among them, the energy saving effect of ESCPS is still the best, showing good stability. Since the size of the distribution content is taken into account in the reward function, even if the distribution content size and the node replacement power consumption are increased at the same time, it is reduced to the smallest extent, and the energy that can be saved is still the largest. Among them, the change of LCD is the most obvious. Because the location of cache placement is too simplistic, the number of node changes cannot be chosen well. Therefore, when \(P_{c}\) is increased, the energy consumption of the consumed nodes is increased linearly, resulting in a sharp drop in energy savings. There is no effect of saving energy, but it consumes more energy. To some extent, Random is similar to LCD, as its method of selecting placement nodes is not targeted, the refinement of nodes is not considered, and the nodes in the network cannot be well utilized. Therefore, the energy saving effect of the selected placement node is not achieved, but the energy consumption is lost. In summary, among these three cache placement strategies, only ESCPS has strong adaptability to changes in the network environment, and the effect of saving energy consumption is always achieved. The comparison results of energy savings of each strategy at node distribution distance variation (1\(\sim\)20) are shown in Figure 5a,b. _Area_ refers to the distance between nodes in the network, which reflects the impact of network size on energy savings. The analysis is performed under the parameter configurations of the best and worst case conditions. That is to say, \(P_{c}\) is 0.1 and 1, respectively. Figure 4: (**a**) The effect of distribution content size on energy savings (\(P_{c}\) = 0.1); (**b**) the effect of distribution content size on energy savings (\(P_{c}\) = 1). From Figure 5a, we can see that as the _area_ is continuously increased, and three strategies show an upward trend. The order of growth and energy savings from high to low are: ESCPS > Random > LCD.