ATCEEC: A New Energy Efcient Routing Protocol for Wireless Sensor Networks N. Javaid 1,2 , M. Aslam 2 , K. Djouani 3 , Z. A. Khan 4 , T. A. Alghamdi 5 1 CAST, COMSATS Institute of Information Technology, Islamabad, Pakistan 2 EE Dept, COMSATS Institute of Information Technology, Islamabad, Pakistan 3 LISSI, UPEC, France and TUT, Pretoria, South Africa 4 Internetworking Program, FE, Dalhousie University, Halifax, Canada 5 CS Dept, College of CIS, Umm AlQura University, Makkah, Saudi Arabia AbstractIn this paper, we propose an Application- aware Threshold-based Centralized Energy Efcient Clustering (ATCEEC) protocol for routing in Wireless Sensor Networks (WSNs). The proposed protocol assumes that each wireless sensor (node) is capable of sensing two types of environmental dynamics; temperature and humidity. Operation of ATCEEC is based on an advanced central control algorithm, where, Base Station (BS) is responsible for the selection of Cluster Heads (CHs). This selection is carried out on the bases of nodes residual energy, average energy of the network, and relative distance between nodes and BS. ATCEEC achieves signicant stability, extended network lifetime and better control over the network operation. Our hybrid protocol is suitable for both proactive and reactive networks. Simulation results show that ATCEEC yields maximum network lifetime and stability period as compared to the selected protocols. Index TermsClustering, Energy Efcient, Routing Protocol, Centralized, Heterogeneous, Wireless Sensor Networks I. I NTRODUCTION Modern progression in Micro Electro Mechanical System (MEMS) based electronics technology empowered sensor de- signer (s) to develop low price, low power and small size sen- sors [1,2]. Such small devices (nodes) successfully integrate sensing, data processing and communication capabilities [3,4]. These nodes collectively cooperate with one another along with BS (s) to form a WSN. Some accustomed applications of WSNs are environmental monitoring, infrastructure protection, and temperature monitoring [5-7]. Usually battery of nodes can not be replaced and recharged due to the area of unattended deployment, so, network life- time depends upon the initial battery capacity of nodes. A careful energy resource management is needed to increase the lifetime of WSNs. In this regard, routing protocols play an important role. Existing complexity of routing protocols is due to dynamic nature of nodes, limited battery life, absence of conventional addressing scheme, self-organization [2,4], etc. Successful connectivity and energy efcient routing are the main challenges faced by routing protocols. In terms of initial energy levels of nodes, WSNs may be categorized into homogenous and heterogeneous networks. When all nodes are initially equipped with same energy level, the network is homogeneous, otherwise, heterogeneous. In heterogeneity-aware routing protocols, nodes are organized into clusters. One node in each cluster acts as CH, while others send sensed data to their respective CHs which forward the data to BS. Application based forwarding schemes are typi- cally employed in WSNs, where, the attribute based addresses are composed of a series of attribute-value pairs specifying certain physical parameters to be realized and transmitted. These protocols should be intelligent enough to adjust com- munication pattern in accordance with the variation in sensor network applications. When WSNs are supporting multiple critical and abrupt uctuating applications then routing should have dynamic functionality to cope these variations. We present ATCEEC, an advanced central control algorithm for application aware WSNs where each node senses temper- ature and humidity. The central control rests with BS which selects CHs on the bases of relative distance between nodes and BS, residual energy of nodes, and average energy of the network. Simulation results show improvement in terms of network lifetime. II. RELATED WORK In previous literature, cluster formation based routing pro- tocols have been proposed for both homogeneous and het- erogeneous sensor networks. LEACH [1] is one of the ear- liest homogeneous clustering routing protocols, however, its performance degrades in heterogeneous networks. LEACH- Centralized (LEACH-C) [2] use a centrally clustered algo- rithm which is not suitable for heterogeneous networks. SEP [3], E-SEP [4] and DEEC [5] perform well to some extent in heterogeneous sensor networks, however, these protocols use distributed algorithms which fail to select the required numbers of CHs. Unbalanced deployment is another important issue in conventional heterogeneous networks. In previous heterogeneity-aware clustering protocols, nodes with extra energy become CHs more frequently as compared to nor- mal ones. If the advanced nodes are not placed uniformly throughout the network eld then cluster formation will not be efcient which is the basic requirement.