A Survey on Classical and Optimized Hierarchical Routing Protocols for IoT and WSN

Static sensor network consisting of static sensor node with a fixed position of sink although served many purposes but still then it was not the best approach of deploying sensor nodes. Introduction of mobility in sensor networks helps in obtaining better energy consumption, increased coverage, uplifted the target tracking process and superior channel capacity. Beside several advantages of mobile sensor networks, it also possesses a challenge in order to build effective routing protocols. To facilitate mobility in wireless sensor networks, numerous routing protocols have been crafted. Based on their routing strategy, these routing protocols may be categorized as hierarchical based routing, flat-based routing, or location-based routing. In a mobile sensor network, the hierarchy-based routing approach has been found to outperform the other two procedures regarding power exhaustion, propagation delay, and cumulative network lifetime. This paper looks at some of the more traditional hierarchy-based routing protocols as well as some of the more advanced hierarchy-based routing protocols that have been developed in recent years. A comprehensive comparison is carried out on different routing protocols based on specific benchmarks like network delay, the lifetime of the network, scalability, fault-tolerance. Boon and bane of each routing protocols can be viewed in the comparison table. Finally, a quick summary followed with the conclusion and future direction ends the paper.