## 4 Cluster Sleep-Wake Scheduling Algorithm
### Cluster Sleep-Wake Scheduling Algorithm
#### 4.3.4 Description of the Algorithm
Both the cluster sleep-wake scheduling algorithm and the redundant node sleep algorithm adopt the redundant node sleep wake-up method. Therefore, only about 200 nodes are needed at the beginning of the network operation to achieve full coverage. The cluster sleep-wake scheduling algorithm uses a dense network topology model to ensure that there is one working node in each split unit, which can reduce node redundancy and increase node use. Therefore, there will be fewer working nodes in the cluster sleep-wake scheduling algorithm in the first 25 rounds. In the last 25 rounds, the number of working nodes in the cluster sleep-wake scheduling algorithm will be more. This is because the cluster sleep-wake scheduling algorithm divides the nodes in a cluster manner,

Figure 16: Relationship between network coverage and time. Figure 15: Relationship between the number of working nodes and coverage. uses the temporary control nodes to perform inter-cluster communication, reduces the number of data packet forwarding, and sets the sensing radius according to the node level to avoid unnecessary energy consumption, so the energy consumption in the network is There will be fewer, more nodes will work. Therefore, in the last 25 rounds, when the running time is the same, the cluster sleep-wake scheduling algorithm has more working nodes. As shown in Figure 18, shows how the number of working nodes required changes when network coverage changes. Compared with the redundant node sleep algorithm, with the increase of network coverage, the growth trend of the number of working nodes required by the cluster sleep-wake scheduling algorithm is more gradual. At the same time, in order to achieve 98% network coverage, the random deployment algorithm may require about 260 working nodes, the redundant node sleep algorithm may need about 220 working nodes, and the cluster sleep-wake scheduling algorithm only needs about 180 working nodes. This is because the cluster sleep-wake scheduling algorithm uses the division of the splitting unit to ensure that the working nodes can be more evenly distributed in the sensor network and improve the use of the nodes. At the same time, when the node is awakened, the partition units with coverage holes are also selected, which can reduce node redundancy and greatly improve network coverage. Therefore, when the coverage ratio is the same, the cluster sleep-wake scheduling algorithm has fewer working nodes. As shown in Figure 19, shows how the number of failed nodes changes over time. As you can see from the figure, the failed node starts to appear around 20 rounds. Compared with the random deployment algorithm and the redundant node dormancy algorithm, the cluster sleep-wake scheduling algorithm has a lower number of failed nodes and a slower growth trend. This is because the cluster sleep-wake scheduling algorithm uses a sleep-wake policy and a node rotation strategy to balance energy consumption and prevent a node from rapidly dying. At the same time, the method of dividing the cluster is used to reduce the number of times of forwarding of the data packet, and the method of dividing the node level is used to reduce the excess sensing energy consumption. The redundant node sleep algorithm only considers the sleep-wake strategy, and chooses to wake up the redundant node after the dead node appears. Therefore, in the case of the same runtime, the cluster sleep-wake scheduling algorithm has fewer failed nodes. As shown in Figure 20, shows how the remaining energy in the network changes as the network runs longer. It can be seen from the figure that the network residual energy of the cluster sleep-wake scheduling algorithm is always higher than the other two algorithms during the network operation. This is because compared with the redundant node sleep algorithm, the cluster sleep-wake scheduling algorithm adds node rotation strategy, cluster partition mode and node classification mode to save energy consumption to reduce energy consumption.