Table 1.

Comparing different clustering protocols in Wireless Sensor Networks (WSNs) with our proposed method. LEACH: low-energy adaptive clustering hierarchy; TEEN: threshold-sensitive energy efficient sensor network protocol; PSO: Particle Swarm Optimization; HSA: Harmony Search Algorithm; CH: cluster head. TPSO-CR: Two-tier PSO protocol for Clustering and Routing. iCSHS: Integrated Clustering for Cuckoo Search and Harmony Search.

Reference	Clustering Schema	Converge	Energy-Efficient	Cluster Stability	Event Awareness	Routing	Clustering Objective
LEACH [22]	Random Distributed	No	Low	Low	No	single-hop	Changing CH based Prob./Random
TEEN [40]	Probability Centralized	No	Medium	Low	No	single-hop	Changing CH based Threshold
[23]	PSO-based Centralized	Low balanced	Moderate	High	No	single-hop	Energy Efficiency + Min Distance + Node Hop count
[41]	HSA-based Centralized	Low balanced	Medium	Low	No	single-hop	Energy Efficiency + Min Distance
TPSO-CR [27]	PSO-based Centralized	Moderate balanced	Moderate	High	No	multi-hop	Energy Efficiency + link Quality + Coverage
PSO-HSA [29]	PSO and HSA Centralized	Moderate balanced	High	High	No	single-hop	Energy Efficiency + Min Distance
iCSHS [42]	Cuckoo-based Distributed	Moderate balanced	Moderate	Low	No	multi-hop	Energy Efficiency + Node degree + Intra Distance + Coverage
This Paper	PSO and HSA Centralized	High balanced	very High	High	Yes	multi-hop	Energy Efficiency + Cluster Closeness + Coverage