International Journal on Recent and Innovation Trends in Computing and Communication ISSN: 2321-8169 Volume: 5 Issue: 10 107 – 111 _______________________________________________________________________________________________ 107 IJRITCC | October 2017, Available @ http://www.ijritcc.org _______________________________________________________________________________________ Hierarchical Routing Protocols in Wireless Sensor Networks: A Survey and its Comparison S. Dhivya Department Of CSE Velalar College of Engineering and Technology Erode, India dhivyasakthi1994@gmail.com N. Jayanthi Department Of CSE Velalar College of Engineering and Technology Erode, India njayanthi1979@gmail.com Abstract— In Wireless Sensor Networks (WSN), profound research articles are presented to address the hierarchical routing protocols which reduce the energy consumption of sensor nodes and also prolong the life of the network. The state of art of this research article focus on the survey of different hierarchical routing protocols which is utilized to efficiently deliver the sensed data from source to sink node. This article presents a detailed survey on major clustering techniques LEACH, SEP, PEGASIS, and TEEN. Also, this article strongly examines about the advantages and limitations of each hierarchical routing protocol with its recent research issues. Finally, the paper concludes with some of the research issues in hierarchical routing protocols of wireless sensor networks. Keywords - Routing protocol; Wireless sensor network; Clustering; Energy consumption; Network lifetime __________________________________________________*****_________________________________________________ I. INTRODUCTION WSN consists of numerous battery powered Sensor node which normally operates in unattended mode. Since sensor nodes are limited with energy and, computational power, a lot of research is ongoing to design various routing algorithms that enhance the performance by considering single or multiple metrics. Designing a new routing protocol for wireless sensor networks are analyzed and presented the surveys [1-3], in various literature. This article presents the overview of hierarchical routing protocols with respect to the performance factors considered for selecting the cluster head and mobility support. Normally clustering techniques fall into two categories: Based on communication range and partitioning method to form clusters. Intra clustering and inter clustering falls in the first category. Based on method of Partitioning, it is classified as • Hierarchical • Density-based • Grid-based • Model-based Protocol operation and network structure are the two types of routing protocols. Hierarchical based routing protocols are examined in this paper. It is used to lower retransmission of data, strong scalability and high robustness [4]. To improve the system lifetime, hierarchical routing protocols support data collection, network scalability and also decreases data delay. In wireless sensor networks, several clusters are formed due to network partition. Each cluster has several nodes and that nodes send its information to the cluster head. Cluster head used to gather and aggregate the data from nodes and forward that data to sink node in clustering routing protocols [5]. The various hierarchical routing protocols based on clustering methods are LEACH, SEP, PEGASIS, and TEEN. II. RELATED WORKS A.LEACH [LOW ENERGY ADAPTIVE CLUSTERING HIERARCHY] PROTOCOL The LEACH algorithm is the most widely used clustering algorithm in wireless sensor networks. In order to reduce energy consumption of sensor nodes, the algorithm uses the random rotation method for cluster head selection in LEACH protocol. A number of variants for LEACH protocol have been proposed in the wireless sensor networks. The phases of LEACH protocol operation are the set-up phase and the steady-state phase. In set-up phase, the selection of cluster head and formation of cluster and also assignment of TDMA schedule are performed. The cluster formation is done based on centralized, distributed and hybrid. The cluster head selection is performed based on deterministic, random and probabilistic schemes. In steady- state phase, data transmission made based on inter or intra cluster communications. The cluster head transmits data to the sink using TDMA schedule [6]. The routing protocol in wireless sensor network for energy efficiency is multipath LEACH, which is used to reduce energy consumption and control overheads. The whole network is divided into clusters and each cluster will have a cluster head, which receives data from each nodes in the clusters and transmit that data to the sink. Multipath LEACH uses a number of paths to efficiently deliver data from source to destination [7]. LEACH (Low Energy Adaptive Clustering Hierarchy) protocol, which has been proposed in wireless