In the era of IOT, importance of wireless sensor networks has increased. Energy consumption in communication is dependent on the cluster formation. Selection of optimal routes and nodes should be done in order to reduce energy consumption and latency. At present there are many techniques available for cluster formation.
Over the years numerous algorithms were introduced to optimize cluster routes. Routing algorithms can be classified into uniform and non-uniform clustering algorithms. Authors of  proposed non uniform cluster routing algorithm. The objective of this algorithm was to balance energy consumption in the nodes. In study  deployment scheme was proposed which reduced long hops in cluster into multiple small hops to reduce transmission time in the wireless sensor networks. Authors of  proposed a model based on fog layer computing. This model stores partial information of the nodes in advance in the fog layer, this reduces the interruptions between the communication and was helpful in moving sink node. A low-cost collaborative charging in wireless sensor networks technique was presented in study .
In  a data dissemination strategy which was based on ant colony optimization techniques was proposed. Authors named this strategy as transmission with multiple load balancing schemes (TMLBS). Load decentralization, load maintenance and load diversion schemes were used in this proposed model. Researchers of  proposed a relative low-cost filter-based framework FERA. This model adaptively used push/pull strategies and was able to handle data request in VANET effectively. Authors of  proposed DMOA which was motivated by morphological erosion and dilation on binary images. This algorithm was capable of extracting event backbone nodes and estimate the event region on their basis. A novel algorithm named as complex alliance strategy with multi-objective optimization of coverage (CASMOC) which improves the congestion in network was proposed in . Authors of this study also provided a proportional relation between working node and neighboring nodes for energy conversion.
Due to the uncertainty of data, there could be coverage blind area and redundant data. To deal with these authors of  proposed a novel model named as Coverage Control Algorithm for Moving Target Nodes based on Sensing Probability (CMTN-SP). Survivability aware connectivity restoration strategy was proposed in study. This strategy involves the design of load equilibrium mechanism and reliability enhancement measure. In study  a novel algorithm called energy-based k-coverage control algorithm (EBKCCA) was proposed. Based on the calculations by this algorithm authors concluded that multi transmission consumes less energy than single transmission.
In study  Energy efficient method for clustering is proposed. Firstly, a strong node is constructed in fog layer then data aggregation routing is constructed and at last particle swarm optimization is used to elect cluster head for effective routing.
Above discussed algorithms have shown promising results but there is still some room for advancement. Presently available algorithms are highly complex in nature. Apart from that energy efficiency is always a reason of concern.