A Hybrid Sink Repositioning Technique for Data Gathering in Wireless Sensor Networks

Wireless sensor network (WSN) is a wireless network that consists of spatially distributed autonomous devices using sensors to cooperatively investigate physical or environmental conditions. WSN has a hundreds or thousands of nodes that can communicate with each other and pass data from one node to another. Energy can be supplied to sensor nodes by batteries only and they are configured in a harsh environment in which the batteries cannot be charged or recharged simply. Sensor nodes can be randomly installed and they autonomously organize themselves into a communication network. The main constraint in wireless sensor networks is limited energy supply at the sensor nodes so it is important to deploy the sink at a position with respect to the specific area which is the area of interest; which would result in minimization of energy consumption. Sink repositioning is very important in modern day wireless sensor network since repositioning the sink at regular interval of time can balance the traffic load thereby decreasing the failure rate of the real time packets. More attention needs to be given on the Sink repositioning methods in order to increase the efficiency of the network. Existing work on sink repositioning techniques in wireless sensor networks consider only static and mobile sink. Not much importance is given to the hybrid sink deployment techniques. Multiple sink deployment and sink mobility can be considered to perform sink repositioning. Precise information of the area being monitored is needed to offer an ideal solution by the sink deployment method but this method is not a realistic often. To reallocate the sink, its odd pattern of energy must be considered. In this chapter a hybrid sink repositioning technique is developed for wireless sensor network where static and mobile sinks are used to gather the data from the sensor nodes. The nodes with low residual energy and high data generation rate are categorized as urgent and the nodes with high residual energy and low data generation rate are categorized as non-urgent. Static sink located within the center of the network collects the data from the urgent nodes. A relay is selected for each urgent sensor based on their residual energy. The urgent sensor sends their data to the static sink through these relay. Mobile sink collects the data from the non-urgent sensors. The performance of the proposed technique is compared with mobile base station placement scheme mainly based on the performance according to the metrics such as average end-to-end delay, drop, average packet delivery ratio and average energy consumption. Through the simulation results it is observed that the proposed hybrid sink repositioning technique reduces the energy hold problem and minimizes the buffer overflow problem thereby elongating the sensor network lifetime

SINK REPOSITIONING OPTIMIZATION TECHNIQUE USING PARTICLE SWARM OPTIMIZATION IN WIRELESS SENSOR NETWORKS

In today’s wireless sensor networks mobile sinks plays an important role in data transmission and reception. Therefore it becomes very important to estimate the optimized position of the mobile sinks in order to improve the overall efficiency of the wireless sensor networks. In this paper, the particle swarm optimization technique has been used for the estimation of the position of the mobile sinks and its impact on the various performance factors of the wireless sensor network has been observed. The simulation result showed that finding the optimal location of the sink in the mobile environment improves the various performance parameters of the network thereby extending the overall lifetime of the network

Mobility based energy efficient and multi-sink algorithms for consumer home networks

With the fast development of the Internet, wireless communications and semiconductor devices, home networking has received significant attention. Consumer products can collect and transmit various types of data in the home environment. Typical consumer sensors are often equipped with tiny, irreplaceable batteries and it therefore of the utmost importance to design energy efficient algorithms to prolong the home network lifetime and reduce devices going to landfill. Sink mobility is an important technique to improve home network performance including energy consumption, lifetime and end-to-end delay. Also, it can largely mitigate the hot spots near the sink node. The selection of optimal moving trajectory for sink node(s) is an NP-hard problem jointly optimizing routing algorithms with the mobile sink moving strategy is a significant and challenging research issue. The influence of multiple static sink nodes on energy consumption under different scale networks is first studied and an Energy-efficient Multi-sink Clustering Algorithm (EMCA) is proposed and tested. Then, the influence of mobile sink velocity, position and number on network performance is studied and a Mobile-sink based Energy-efficient Clustering Algorithm (MECA) is proposed. Simulation results validate the performance of the proposed two algorithms which can be deployed in a consumer home network environment

Stratégie de Placement des Puits Mobiles dans les Réseaux de Capteurs sans Fil pour Bâtiments

National audienceLe besoin des réseaux de capteurs sans fil croit très rapidement dans un large éventail d'applications industrielles. Parmi celles-ci se trouve l'observation, le suivi des données physiques et l'automatisation des bâtiments. Dans ces réseaux, un grand nombre de capteurs transmettent via multi sauts les données collectées vers le puits le plus proche. Les capteurs qui sont proches des puits épuisent leurs réserves d'énergie beaucoup plus rapidement que les capteurs distants car ils ont une charge de trafic très importante. Ceci est dû au fait qu'ils transmettent leurs propres données ainsi que les données des capteurs éloignés provoquant ainsi prématurément la fin de la durée de vie du réseau. Le déplacement périodique des puits permet de résoudre ce problème en distribuant la charge du trafic entre les capteurs et améliorer ainsi la durée de vie du réseau. Dans ce travail, nous proposons un nouvel algorithme qui détermine le positionnement de plusieurs puits mobiles dans un réseau large échelle afin d'augmenter la durée de vie du réseau. Son principe se base sur le déplacement régulier des puits vers les capteurs distants qui ont le plus grand nombre de sauts à faire pour atteindre le puits le plus proche. Nous avons évalué les performances de notre solution par des simulations et comparé avec d'autres stratégies. Les résultats montrent que notre solution améliore considérablement la durée de vie du réseau et équilibre notablement la consommation d'énergie entre les nœuds. Ces résultats sont très utiles pour le déploiement réel de réseaux de capteurs sans fil au sein des bâtiments

Sinks Mobility Strategy in IPv6-based WSNs for Network Lifetime Improvement

International audienceThis paper investigates the sinks mobility in IPv6- based wireless sensors networks and specially in the new IETF proposed protocol RPL (Routing Protocol for Low power and Lossy Networks). We also show that even the mobility of sinks is not an explicit design criteria, the use of mobile sinks improves the network lifetime. In this work, we propose a new distributed and weighted moving strategy for sinks in RPL. We compared our proposed mobility approach with different others strategies. The results show that our proposed mobility approach notably balances the network load which leads to a significant network lifetime gain in large scale network

Coverage Protocols for Wireless Sensor Networks: Review and Future Directions

The coverage problem in wireless sensor networks (WSNs) can be generally defined as a measure of how effectively a network field is monitored by its sensor nodes. This problem has attracted a lot of interest over the years and as a result, many coverage protocols were proposed. In this survey, we first propose a taxonomy for classifying coverage protocols in WSNs. Then, we classify the coverage protocols into three categories (i.e. coverage aware deployment protocols, sleep scheduling protocols for flat networks, and cluster-based sleep scheduling protocols) based on the network stage where the coverage is optimized. For each category, relevant protocols are thoroughly reviewed and classified based on the adopted coverage techniques. Finally, we discuss open issues (and recommend future directions to resolve them) associated with the design of realistic coverage protocols. Issues such as realistic sensing models, realistic energy consumption models, realistic connectivity models and sensor localization are covered

Coordinated movement of multiple mobile sinks in a wireless sensor network for improved lifetime

Sink mobility is one of the most effective solutions for improving lifetime and has been widely investigated for the last decade. Algorithms for single-sink mobility are not directly applied to the multiple-sink case due to the latter’s specific challenges. Most of the approaches proposed in the literature use mathematical programming techniques to solve the multiple-sink mobility problem. However, doing so leads to higher complexities when traffic flow information for any possible sink-site combinations is included in the model. In this paper, we propose two algorithms that do not consider all possible sink-site combinations to determine migration points. We first present a centralized movement algorithm that uses an energy-cost matrix for a user-defined threshold number of combinations to coordinate multiple-sink movement. We also give a distributed algorithm that does not use any prior network information and has a low message exchange overhead. Our simulations show that the centralized algorithm gives better network lifetime performance compared to previously proposed MinDiff-RE, random movement, and static-sink algorithms. Our distributed algorithm has a lower network lifetime than centralized algorithms; sinks travel significantly less than in all the other schemes. © 2015, Koç and Korpeoglu

Energy efficiency mechanisms using mobile node in wireless sensor networks

A traditional network consists of gateway sensors which transmit data to the base stations. These nodes are considered bottlenecks in multihop-networks as they transmit their data as well as data from other nodes and hence they deplete faster in energy. One way to optimize energy efficiency in a WSN is to deploy a mobile base station which could collect data without a need for gateway nodes, and hence the multihop bottleneck would be minimized. We compare these two variations of WSN, one consisting of the multihop approach with gateway nodes, and we propose the other network structure, whereby a mobile base station collects data individually from each node using double Fermat’s spiral model