## 3 The Clustering Protocol
### Node Dormancy Mechanism
Compared to LEACH and SEP, the protocol in this paper has increased by approximately 40% and 90-103% in network lifetime and network throughput, respectively; Compared to DEEC, the protocol in this paper has increased by approximately 25% and 45-50% in network lifetime and network throughput, respectively. In heterogeneous networks, compared to LEACH, the advantages of SEP and DEEC are gradually reflected. In the stable period, SEP causes many nodes with high initial energy to act as CHs frequently, so the first node's death round in SEP is less than that in LEACH. Different from the former two, DEEC considers the residual energy of the nodes, so that the energy consumption of the nodes in the network is relatively more balanced. Compared with LEACH and SEP, its overall network performance is better. For the protocol in this paper, it takes into account the location and the remaining energy of the node, so that the total energy consumption in the network is smaller and the energy consumption is more balanced, and the network can survive more nodes after multiple iterations than the other three. Especially in terms of network throughput, it has increased by approximately 32% than DEEC. So, the protocol can achieve a certain improvement in terms of the round of the first node's death, network lifetime, network energy consumption, and network throughput. However, there are some shortcomings in our protocol:

First, the scenario considered by the protocol is too idealistic. In reality, even if the node energy is sufficient, transmission failure may occur due to the uncertainty of the natural environmental factors in the information transmission process. We can later consider adding a probability model to simulate the natural environment during the information transmission process. Second, the protocol is applicable only to 2D scenarios. Typical 3D scenarios, such as underground coal mines, underground pipe corridors, and indoor homes, in which, WSN must be arranged in three dimensions. Therefore, in the future we will consider proposing a clustering routing protocol suitable for 3D scenarios based on this protocol. Last, the protocol proposed in this paper does not optimize the information transmission path. Therefore, compared with some general low-latency protocols, its delay may be larger, which is not suitable for some projects with higher real-time requirements. Therefore, in the future we will consider optimizing the information transmission path through a relatively practical optimization algorithm. [PERSON], [PERSON] conducted the research, performed the simulations. [PERSON] led the research. [PERSON], [PERSON] supervised the work and proposed revised suggestions. All authors participated in the writing of the article. **Funding:** This research was supported by National Natural Science Foundation of China (Grant No. U1709212) and Zhejiang Province Public Welfare Technology Application Research Project (Grant No. GF18F030010) and Smart City Collaborative Innovation Center of Zhejiang Province. **Conflicts of Interest:** The authors declare no conflict of interest. ## References

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