### Related Work  
Inspired by the classical LEACH protocol, numerous hierarchical clustering protocols have evolved over the years that apply different factors to achieve better performances. Different clustering approaches in [30] analyze several clustering methodologies and categorizes current clustering into meta-heuristic, fuzzy logic, and hybrid based on network organization and clustering management strategies. Similarly, Ref. [31] compared the optimized clustering methods based on a few parameters and suggested the best approaches to a WSN application. An in-depth examination of LEACH-based protocols is discussed in [30], where it first focuses on cluster formation and CHs selection techniques and their benefits and drawbacks. As shown in Table 1, several reviews and surveys have focused on LEACH variants and successors. \begin{table}
\begin{tabular}{c c c} \hline \hline
**Reference** & **Description** & **Remarks** \\ \hline [PERSON] et al. [32], 2021 & Classified LEACH-based protocols based on CH selection, data transmission, and both CH selection and data transmission techniques & Discusses the strength and weaknesses of LEACH-based protocols but fails to study bio-inspired LEACH variants \\ \hline [PERSON] et al. [33], 2020 & Reviews LEACH successors based on single-hop and multi-hop models & Categorizes LEACH protocols based on the path of data transmission from CH to BS \\ \hline [PERSON] et al. [34], 2019 & Classification is conducted based on classical and swarm-intelligence approaches & Handling sink mobility, QoS requirement, and overhead due to dynamic topology in an energy constraint environment are still major issues \\ \hline [PERSON] et al. [35], 2018 & Analysis of different hierarchical routing protocols that are modified from LEACH based on energy efficiency only & Does not provide any information about the method or modification in detail \\ \hline [PERSON] et al. [36], 2017 & Classification of LEACH successors based on single-hop and multi-hop communication is conducted, and comprehensive studies have been provided & The survey presents a detailed summary but fails to inform about the simulation or testing tool, or software used in network analysis \\ \hline [PERSON] et al. [37], 2017 & Survey on classical-based and optimized-based routing protocols for mobile WSNs & Real-work implantations, overheads, and computational time have not been explored \\ \hline [PERSON] et al. [38], 2016 & LEACH and its extensions were discussed and compared that prolong network lifespan. The survey is not limited to proactive protocols and also focuses on reactive protocols such as TEEN [39], APTEEN [40], and TSEP [41] & The authors prove enhanced network lifetime with increased network area and distance to BS. However, the comparison conducted considered only a few protocols and variants of LEACH \\ \hline \hline \end{tabular}
\end{table} 
Table 1: Survey on LEACH-based Protocols. Nevertheless, it will be important to mention that all the reviews mentioned in Table 1 highlight the limited number of LEACH descendants compared to a few parameters. From the literature, it can be concluded that CH selection is the key parameter used by researchers to enhance the performance of any clustering algorithm. Throughout the process of CH selection, residual energy and the number of clusters in the network should be of paramount importance [48]. Other issues found in conventional clustering algorithms can be described as shown in Figure 3. Apart from these, network security is one of the key issues and various routing protocols have been suggested to make the network resilient against insider and outsider attackers [49]. Applications using wireless sensors need to be protected from packet insertion, modification, and eavesdropping. Data cryptography and encryption can avoid these security problems to protect against these issues.