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In the current scenario, the growth of IoT based solutions gives rise to the rapid utilisation of WSN. With energy constraint sensor nodes in WSN, the design of energy efficient MAC protocol along with timeliness requirement to handle collision is of paramount importance. Most of the MAC protocols designed for a sensor network follows either contention or scheduled based approach. Contention based approach adapts well to topology changes, whereas it is more costly in handling collision as compared to a schedule based approach. Hence, to reduce the collision along with timeliness, an effective TDMA based slot scheduling algorithm needs to be designed. In this paper, we propose a TDMA based algorithm named DYSS that meets both the timeliness and energy efficiency in handling the collision. This algorithm finds an effective way of preparing the initial schedule by using the average two-hop neighbors count. Finally, the remaining un-allotted nodes are dynamically assigned to slots using a novel approach. The efficiency of the algorithm is evaluated in terms of the number of slots allotted and time elapsed to construct the schedule using the Castalia simulator.

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A wireless sensor network is a collection of batterypowered sensor nodes distributed in a geographical area. Inmany applications, such networks are left unattended for along period of time. These networks suffer from the problemslike high energy consumption, high latency time, and end- to-end low packet delivery ratio. To design a protocol that findsa trade-off between these problems is a challenging task. Inorder to mitigate energy consumption issue, different existingMedia Access Control (MAC) protocols such as S-MAC, RMAC,HEMAC, and Congestion-less Single Token MAC protocols havebeen proposed which ensure better packet delivery but fail toensure energy efficiency due to high end-to-end latency. Theproblem of high end-to-end latency is resolved with the existingrouting protocols such as Fault Tolerant Multilevel Routingprotocol (FMS)and Enhanced Tree Routing (ETR) protocol.AS2-MAC and Multi Token based MAC protocol are able toimprove the end-to-end packet delivery ratio. However, thehierarchical network structure used in these protocols increasestime and energy consumption during network reconstruction.This problem was further resolved in Distributed HierarchicalStructure Routing protocol by constructing the network structurein a distributed manner. In all these existing protocols, efficienttoken management and reliable data delivery ratio was notproperly addressed, which in turn consume more energy. So,it is clear that MAC and routing protocols both together cangive better results related to data transmission in WSN. Inorder to achieve the same, in this paper, we propose a reliabledata transmission algorithm that satisfies both routing and MACprotocol to improve the end-to-end data delivery. The proposedprotocol uses different control message exchange that ensures datapacket delivery in each individual levels and it ultimately uses oftokens to ensure reliable data transmission along with reducedtraffic congestion during end-to-end data delivery. The algorithmconsiderably improves the packet delivery ratio along with reduceenergy consumption of each sensor node. Simulation studies ofthe proposed approach have been carried out and its performancehas been compared with the Multi Token based MAC protocol,AS-MAC protocol and ETR routing protocol. The experimentalresults based on simulation confirms that the proposed approachhas a higher data packet delivery ratio.

Wireless Sensor Network (WSN) consists of hundreds of sensor nodes, which are tiny, low cost, low power radio devices. These nodes are dedicated to perform certain functions such as sensing the environment, collecting the sensed data from the surrounding area, processing those data and send the information to the observer. One of the major challenges in WSN is to cover the desired area which is used to determine the quality of service(QoS) of the Network. Before the sensor nodes get deployed, one may want to know, among hundreds of nodes, which are the nodes that need to active so that every point in the deployment area is covered by at least one of the active sensor nodes and the total number of active nodes should be minimum. We call this requirement as complete area coverage. One of the important aspects of complete area coverage algorithm is to remove the redundant nodes and then check for the sensing coverage of the desired area. Various algorithms have already been proposed for the complete area coverage. In this paper, we use an incremental model using the 2-voronoi method to remove the redundant nodes and find the minimum number of nodes to cover the desired area. Extensive simulation studies of the proposed work have been carried out using Matlab simulator. The simulation studies clearly show that the number of active nodes to cover the whole intended area is quite less.