Forthcoming articles

International Journal of Sensor Networks

International Journal of Sensor Networks (IJSNet)

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International Journal of Sensor Networks (29 papers in press)

Regular Issues

  • Recent Advances in Wireless Sensor Networks with Environmental Energy Harvesting
    by Lei Shu, Wanjiun Liao, Jaime Lloret, Lei Wang 
    Keywords: .

  • Local Outlier Detection Based on Information Entropy Weighting   Order a copy of this article
    by Lina Wang 
    Abstract: As a key research area in data mining technologies, outlier detection can expose data inconsistent with the majority in the dataset and therefore is applicable in extensive areas. The addition of entropy weighting to the spatial local outlier measure (SLOM) and local distance-based outlier factor (LDOF) algorithms in outlier data mining, i.e. the adoption of entropy in the calculation of weighted distance is taken into consideration, leads to enhanced accuracy of outlier detection and produces more expense of time. The algorithm of entropy-weighted LDOF is more optimized than that of entropy-weighted SLOM in terms of detection accuracy. The superiority of the entropy-weighted algorithm is verified through experimental results.
    Keywords: Local outlier; detection; information entropy weighting; SLOM; LDOF.

  • Accurate Bus Occupancy Estimation for WLAN Probing Utilizing Probabilistic Models   Order a copy of this article
    by Lars Mikkelsen, Hans Peter Schwefel, Tatiana Madsen 
    Abstract: This paper obtains an improved estimator of number of people on the bus, based on probabilistic models. The improved estimator is based on a baseline estimator for number of WLAN enabled devices present on the bus. The estimated number of devices is subject to both false positives and false negatives. The false positives are caused by detecting devices on the roadside outside the bus and not being able to distinguish them from inside bus devices. The amount of false negatives depends on probe emission frequency, message losses due to collisions, MAC address randomization, WLAN channel selection and the time a person stays on a bus. The model proposed in the paper includes the influences of these factors assuming FP and FN being binomially distributed. Distribution parameters for false positives and false negatives are found from measurements.
    Keywords: WLAN probes; bus occupancy; device count; stochastic models; public transport; devices per person; maximum likelihood estimator; MAC randomization; probe frequency; probe signal strength.

  • Optimizing Rendezvous-based Data collection for Target Tracking in WSNs with Mobile Elements   Order a copy of this article
    by Jian Zhang, Tianbao Wang, Jian Tang 
    Abstract: Wireless sensor networks (WSNs) applications have referred to many fieldsrninvolving target tracking systems, however, energy efficiency issues in applications always suffer bottleneck and hence continuously receive significant attention for recent decades. In the literature, naturally, a mobility collector is utilized as an energy-efficient solution to prolong the network lifetime, meanwhile, data collection strategies are investigated due to the factors including the amount of contributed data and the range of transmittedrndistances. For contributed data, the quantization technology plays an important role in the sense of energy efficiency. Considering the uncertainty of sensing data for nodes, we proposed a distributed algorithm for selecting an contributed group from intra-cluster members to gather data with rigorously mathematical analysis. We formulate our design for target tracking as a selection optimization problem, maximizing the utilization of the quality of contributed data by using information matrix. As a result, we proposed an optimization algorithm named rendezvous-based data collection(RDC) which not only integrates positive factors mentioned above to track a target but also maintains WSNsrnfunctions more prior than traditional clustering. Furthermore, two stages of WSNs are analyzed for data collection, i.e., sensing data and transmitting data as far as intra-cluster and inter-cluster. Simulations verify that the proposed schemes achieve network energy saving as well as energy balance in the framework of target tracking.
    Keywords: Wireless sensor networks; Mobile collectors; Rendezvous nodes; Data collection; Fisher information matrix; Target tracking.

  • DVF-fog: Distributed Virtual Firewall in Fog Computing based on Risk analysis   Order a copy of this article
    by Ferdaous Kammoun-Abid, Amel Meddeb-makhlouf, Faouzi Zarai, Mohsen Guizani 
    Abstract: To eliminate network saturation during dada exchanges, Fog Computing is deployed as the technology that benefits from both Cloud computing and Internet of Things (IoT) paradigms. This new phenomena is called edge computing. In this study, we focus on network access control issues that are considered as grave challenges in a distributed environment such as fog/cloud computing. Therefore, we present an architecture for distributed fog with a divided topology into Zones and implement distributed firewall and distributed Controller. This way, we can combine user-based access control and distributed network-based access control based on risk analysis and estimation. The performance of our work is evaluated via simulations using Nessi
    Keywords: Fog computing; Access control; Distributed firewall; Risk analysis; Cooperative controller.

  • Online calibration of ultra-short baseline installation error in dynamic environment   Order a copy of this article
    by Liang Zhang, Tao Zhang, Jinwu Tong, Shaoen Wu 
    Abstract: Due to its advantages of small size and easy installation, the ultra-short base-line system is widely used in the navigation of ships and underwater vehicles. The installation error between the sensor and inertial measurement unit are the main sources of positioning inaccuracy. In high-precision navigation, the installation error is not negligible. A method based on Kalman filter is used to estimate the installation error of USBL in real time. The detailed derivation of Kalman filter for the calibration is presented in the paper. In order to show the validity of extending the installation error to the state of the filter, observability analysis is carried out. Simulation results show that the method proposed in this paper can calibrate the installation error between the ultra-short baseline and inertial measurement unit in real time and online. The positioning accuracy is improved five times by compensating the installation error. Therefore, the error calibration method proposed in this paper is effective and can greatly improve the positioning accuracy of USBL.
    Keywords: Error Calibration; Kalman filter; Ultra-short baseline; Observability analysis.

  • A Border Surveillance System using WSN under Various Environment Characteristics   Order a copy of this article
    by Imen Arfaoui, Noureddine Boudriga 
    Abstract: Surveillance has become one of the promising application areas of wireless sensor networks (WSNs) where detecting and tracking an intruder as it moves through a sensor network is becoming an increasingly important challenge. This motivate us to investigate the impact of some factors such as the area geography and the intruders behaviors that have influence on this application. For this, we present in this paper an efficient surveillance system that uses a WSN deployed inside a border area in order to detect an intruder at least N times from its entrance. The proposed surveillance system is examined under various environment characteristics, namely; obstacles free area, obstacles area and obstacles area with different intruders behaviors. To do this, we focus first on modeling the area into multi-thick lines architecture. Second, as a simple case study, we provide a deployment method that aims to detect the intruder from its entrance in an area without obstacles. Finally, we investigate the effect of the obstacles in the area to be monitored and we provide a general surveillance system for detection purpose that considers the intruders with different behaviors crossing an area with obstacles.
    Keywords: WSNs; border surveillance; intruder; detect; multi-thick lines; obstacles.

  • A Tumor Perception System Based on a Multi-layer Mass-spring Model   Order a copy of this article
    by Xiaorui Zhang, Jiali Duan, Wei Sun, Sunil Kumar Jha 
    Abstract: The virtual reality (VR) has been utilized in the preoperative planning of tumor surgery because it enables surgeons to touch and operate on tumor in a virtual environment. This paper proposes a virtual tumor perception system for preoperative tumor surgery planning. The system is based on a novel multi-layer mass-spring model, which consists of connected springs in series. The basic parameters of springs are equal ratio sequence. The core parameter shear modulus of springs can be dynamically adjusted according to the biological properties of soft tissue in clinical applications to simulate tissue heterogeneity. A palpation simulation algorithm is designed to help users to perceive the tumors. Two validation experiments are carried out: model accuracy experiment and practical perception experiment. Experiments indicate that the proposed model faithfully mimics actual clinical tumor, which is more accurate compared with models simulated by other systems.
    Keywords: tumor perception; virtual surgery; preoperative planning; mass-spring model; shear modulus adjusting; surgery planning; multi-layer springs; clinical application; palpation simulation; tissue heterogeneity.

  • Underwater acoustic localization by GMM fingerprinting with noise reduction   Order a copy of this article
    by Kun-Chou Lee 
    Abstract: In this paper, the underwater acoustic localization is given by GMM (Gaussian mixture model) fingerprinting with noise reduction. Underwater acoustic measurement always contains a lot of noises and fluctuates seriously. The fluctuating measurement will make the localization unreliable. To overcome this disadvantage, this paper gives two contributions. First, the SVD (singular value decomposition) technique is utilized to reduce the noise of underwater acoustic measurement. Second, the processed acoustic signal is statistically modelled by the GMM, which is a linear combination of multiple Gaussian functions, for fingerprinting and localization. By using the SVD technique, one can suppress the noise-related subspace and reconstruct clean signals from the signal subspace only. Experiments are conducted in a large indoor tank to examine the boundary reflection effect. Note that our underwater localization scheme is based on fingerprinting, which does not require any range or angle information. It can tolerate reflected, multi-path and random-noise components.
    Keywords: underwater acoustics; underwater localization; fingerprinting; noise reduction.

  • Smart Seismic Network for Shallow Subsurface Imaging and Infrastructure Security   Order a copy of this article
    by Maria Valero, Fangyu Li, WenZhan Song 
    Abstract: The use of seismic arrays as a tool for imaging subsurface infrastructures and monitoring the corresponding underground activities enables real-time subsurface security and surveillance applications. However, the existing approach relies on manual data collection and centralized computing, which may not work in communication-denied environments. These approaches may take a long time to get useful results. In this paper, we present a real-time smart seismic imaging system based on Ambient Noise Imaging on Networks (ANION) for a variety of subsurface infrastructure imaging applications. The proposed approach integrates in-situ signal processing techniques as well as inter-nodes communication and cooperation to obtain reliable velocity maps for subsurface characterization and monitoring. It generates real-time subsurface images by taking advantage of collective computation power in sensor networks while avoiding transferring all raw data to a central place or server. ANION system is autonomous, self-healing, scalable and independent of external interventions. Field tests demonstrate that such a system can detect underground pipelines and potentially its leakage that has important implications on infrastructure security. The uses can be extended to other applications like border security, building monitoring, underground water detection for agriculture, etc. An exhaustive evaluation regarding bandwidth utilization and communication cost were conducted to highlight the benefits of the proposed approach.
    Keywords: Smart Sensor Network; Subsurface security; infrastructure detection; activity monitoring; ambient noise.

  • Hierarchical and on-demand wireless energy transfer protocol in sensor networks with multiple chargers   Order a copy of this article
    by Vianney KENGNE TCHENDJI, Loïch KAMDOUM DEAMENI, Blaise PAHO NANA 
    Abstract: In this paper, we investigate the problem of efficient Wireless Power Transfer (WPT) in Wireless Rechargeable Sensor Networks (WRSNs). In our approach, special entities (called chargers) replenish the energy of sensor nodes wirelessly. One of the main point of our approach is the on-demand recharge request. We propose two protocols based on a clustered structure, and on a hierarchical structure of the chargers, for an efficient charging of sensor nodes. To significantly increase the efficiency of the charge and reduce the displacement of the chargers, we have introduced two important concepts: neighborhood and group of requests between the sensor nodes. Extensive simulations findings demonstrate significant performance gains, with respect to one of the best state of art charging methods of Madhja. In particular, our protocols improve several network properties and metrics, such as the network lifetime, coverage, routing and connectivity between the sensor nodes. A useful feature of our methods is that, they can be easily applied to 1-D, 2-D and 3-D networks.
    Keywords: Wireless Sensor Networks; Wireless Energy Transfer; On-demand charging; Wireless Charger.

  • A Case Study of CryptoBin Algorithm   Order a copy of this article
    by Ahmed Eltengy, Samaa Shohieb, Ali Takieldeen, Mohamed Ksasy 
    Abstract: The use of location-based solutions has improved significantly over the last few years. However, data encryption has become very important to maintain confidentiality and privacy, especially in the military and civil fields. This paper will present an application that encrypts data on the location and movements of military personnel or civilian researchers within an area on a specific mission. Using two transmission circuits and one receiver that is controlled by a microcontroller programmed by the encryption algorithm. This application is used and modified in several situations, and each case depends on the nature of the mission and the nature of the surrounding environment. The proposed system is tested in three different environments and achieves good results. This application can meet the confidentiality, authentication, simplicity, and practicality of security issues as a result of frequency and speed tests.
    Keywords: Cryptography; Location-Based Services; Location-Based Encryption; CryptoBin Algorithm; Location Security; Data Security.

  • Development of Range Free Three Dimensional Localization in Wireless Sensor Networks   Order a copy of this article
    by Shashi Bhushan Kotwal, Sandeep Singh Gill, Kuldeepak SinghSaini 
    Abstract: In the present work, a range free three dimensional localization technique using only crude RSSI information is presented. The range free localization algorithms have shown limited accuracy and to achieve high accuracy very large number of specialized anchor nodes is required; these anchor nodes also add to the cost of the system. If other nodes after their localization from anchor nodes act as pseudo anchors and help other nodes to find their coordinates, error propagation takes place and overall accuracy is suffered. In proposed solution distributed localization by the nodes within the communication range of few anchor nodes take place. The nodes use crude RSSI to approximate their minimum and maximum distance limits with respect to anchor nodes. The approximation involves a simple binary search algorithm. The crude distance limits help form the feasibility region of the node w.r.t anchor nodes. Then these nodes collaborate with each other and share their feasibility region to reduce error propagation. The feasibility region coordinates serve as initial particles in Particle Swarm Optimization (PSO) to solve the optimization problem of minimizing localization error. It was observed that based on simple calculations, nodes can be localized to a better accuracy compared to the existing algorithms and require fewer anchor nodes with limited communication range
    Keywords: Range free Localization; 3D WSN; and Three dimensional localization.

  • Network localization using Lagrangian optimization   Order a copy of this article
    by Ananya Saha, Buddhadeb Sau 
    Abstract: Abstract: The network localization problem with non-convex distance constraints may be modeled as a nonlinear optimization problem. The existing localization techniques either eliminate the non-convex distance constraints or relax these constraints into convex constraints to employ the traditional convex optimization methods like SDP, least square approximation, etc. for estimating positions of the nodes in a network. The validation and performance analysis of those methods were carried out through simulation studies. We propose a method to solve the original network localization problem with noisy distance measurements without any modification of constraints in the model. The proposed method is able to get rid of both the exclusion and relaxation of non-convex distance constraints which may change the original localization problem. Using the nonlinear Lagrangian technique for non-convex optimization, we convert the localization problem to a root finding problem of a single variable continuous function. This problem is then solved using bisection method. However, in each step of the bisection method, the computation of the functional values involves finite mini-max problem (FMX). We use sequential quadratic programming method (SQP) to fix the FMX problem. We observe through simulations that, the number of iterations in the bisection method is reasonable to achieve a desired label of accuracy in the solutions.
    Keywords: Keywords: Network localization technique; Localization with noisy distances; Mini-max optimization problem for localization; Application of Lagrange optimization in localization; Non-convex optimization for localization.

  • On-line Algorithm for Data Retrieval with Multiple Antennae in Wireless Communication   Order a copy of this article
    by Ping He, Weidong Li, Shufu Cao, Siyuan Ma, Kaihua Shi 
    Abstract: Given a set of requested data items and a set of multiple channels, on-line multi-antennae data retrieval problem (OMAP) is to download all requested data items from these channels when the clients are equipped with multiple antennae and donot know any a-prior knowledge of wireless data broadcast system, such that the total access latency is minimized and the access latency among all antennae keeps balance. So this paper proposes OMR and OMU that introduces the requested ratio and unretrieved ratio respectively when the length of data items is equal. In addition, when the length of data items is unequal, the paper proposes OML that introduces the length to compute the length ratio. Finally, we analyze the competitive rates of three algorithms. Through experiments, the proposed schemes can have currently better efficiency by comparing with some existing schemes and solve OMAP.
    Keywords: mobile computing; wireless communication; data retrieval; multiplernantennae; on-line algorithm.

  • Copula-based Reliability Modelling of Wireless Sensor Networks with Dependent Failures   Order a copy of this article
    by Ming Zhao, Jianfeng  
    Abstract: Wireless sensor networks (WSNs) have widely been applied in various industries and business fields covering large geographical regions, including the physical environment where it is difficult for human being to reach, for online information collection, processing and decision making. It is therefore important to be able to model, assess and predict the reliability of WSNs since the failures can have a great effect on the monitoring or control systems that are normally depending on the WSNs. The operational reliability of a WSN measures its ability to perform the required functions under the defined environment for a period of time. The reliability level of a WSN can be crucial on the performance and effectiveness of the whole monitoring or control system. In reliability engineering, there have been various reliability models that are used for characterizing the failure behaves of various devices or products. A common assumption that is not valid for WSNs in the existing reliability models is the independence of the failures between subsystems or components. In this paper, the general WSN reliability models are developed by deleting the independent assumption of component or subsystem failures and are consequently more reasonable to characterize the failure process of WSNs. The methodology in the proposed WSN reliability models is to consider that the failure times of subsystems are dependent variables and their joint distribution is obtained by binding their marginal failure distributions together through a copula function. When the copula function is given, the WSN reliability can be determined by using the derived joint distribution. For specific Frank copula functions, the Star-based WSN reliability models are derived and their properties are also discussed in this paper.
    Keywords: Reliability; Copula; Dependence; Wireless sensor network; Joint distribution.

  • A novel radio map construction method with reduced human efforts for Wi-Fi localization system   Order a copy of this article
    by Qiyue Li, Heng Xu, Wei Sun, Jie Li, Guojun Luo, Jianping Wang 
    Abstract: Fingerprint based Wi-Fi localization system often takes a lot of human efforts to measure the RSS of dense grid in a indoor environment. In this paper, we proposed two method to realized opimization length of RSS time series and grid division. We verity the chaotic characteristics of the RSS time series, and use phase space reconstruction algorithm to calculate the needed optimal length of RSS time series to be collected at each RP.Gaussian process regression(GPR) for fingerprinting based indoor localization is presented. The hyper-parameters of GPR is calculated by Conjugate gradient descent algorithm. The posterior means and variance of RSS is used in fingerprinting based localization. The performance of the proposed radio map construction framework is validated in real indoor environment, with using Bayesian positioning method, the localization error mean can be 1.5m and the construction time of radio map is greatly reduced with ensuring accuracy.
    Keywords: Wi-Fi localization; indoor; fingerprint; radio map construction; chaotic; GPR.

  • Multihop Multibranch Relaying with Energy Harvesting and Adaptive Transmit Power for Cognitive Radio Networks   Order a copy of this article
    by Nadhir Ben Halima, Hatem Boujemaa 
    Abstract: This article provides the Packet Error Probability (PEP) and throughput of Cognitive Radio Networks (CRN) with Energy Harvesting (EH) and Adaptive Transmit Power (ATP). Multihop multibranch relaying is considered and only the best Amplify and Forward (AF) branch is activated. Our analysis is valid for EH system using harvested energy from Radio Frequency (RF) signals. The powers of secondary nodes are adaptive so that interference to primary receiver $P_R$ is lower than interference threshold $I$. We also choose the harvesting duration to enhanced the end-to-end (e2e) throughput.
    Keywords: CRN; Energy harvesting; adaptive power; multihop multibranch relaying.

  • A Cloud Based Virtualization Protocol for Wireless Sensor Networks   Order a copy of this article
    by Marco Antonio Lopez Trinidad, Diego Fernandez Sumano, Eduardo Lopez, Horacio Tapia-McClung 
    Abstract: Virtual Sensor Networks (VSNs) allow to link physical sensor networks (WSNs) and specialized services that permit sensor data gathering, processing, and storing. In this manner VSNs provide concurrent, scalable and flexible access to a common pool of sensor nodes. Cloud computing technologies allow to deal with the WSNs heterogeneity (hardware footprint, communication protocols standards, etc.). This work proposes a real-time, centralized, cloud-based, service- oriented virtualization protocol under a publish-subscribe model, capable of masking WSNs errors and their limitations. Protocol implementation tests show, on a single virtual machine, its capability to subscribe to more than 100 WSN and continuously receive, store, filter and predict data from over 1,000 sensor nodes; also service reliably over 24,000 nodes from 500 requested VSN, using a stream of data from an original pool of 100 sensor nodes with an average VSN-publishing delay under 20 ms regardless of the WSN delays and errors.
    Keywords: Wireless Sensor Networks; Sensor Networks Virtualisation; Simulation of network performance; Communication Protocols Design.

  • Fixed Node Assisted Collection Tree Protocol for Mobile Wireless Sensor Networks   Order a copy of this article
    by Ramiro Liscano, Nadra Ben Otman, Shahram Shah Heydari, Dixit Sharma 
    Abstract: The Collection Tree Protocol (CTP) is widely used for data collection in static wireless sensor network applications. With the increasing deployment of mobile wireless sensor networks, the performance of this scheme in mobile scenarios becomes extremely important. The motivation in using collector style protocols in mobile sensor networks is that the sensors primarily send data to key collecting nodes, and often there is no need for more complex Mobile and Ad hoc routing protocols. We introduce the Fixed Node Assisted-CTP (FNA-CTP) which aims to enhance the performance of CTP in mobile scenarios by tuning the parameters of CTP for the mobile and fixed nodes in order to reduce the messaging overhead required to maintain the network in mobile scenarios. We provide a detailed evaluation of the performance of FNA-CTP in different mobile sensor network scenarios through a set of simulations which indicates the superior performance of FNA-CTP and discuss various design issues associated with this scheme.
    Keywords: Collection Tree Protocol (CTP); Mobile Wireless Sensor Networks; Wireless Sensor Networks (WSN).

  • A New Model and Algorithm for RSA Problem in Elastic Optical Networks   Order a copy of this article
    by Chunxia Ji, Yuping Wang, Xia Li 
    Abstract: Routing and Spectrum Allocation(RSA) is an important problem in elastic optical networks(EONs). With the increase of network scale and task requests, the imbalance of the network topology becomes more and more prominent, causing congestion of some links in the network and even paralyzation of the entire network. To tackle this issue, in this paper, we first set up an integer linear programming model for RSA problems in EONs, which minimizes the number of used slots, optimizes the balance of networks and the burden of KeyLinks (i.e., the links which are easy blocked when large requests comes). Then we design a new routing scheme called Dynamically Adjusted Shortest Hop Count and Minimum Rank Value First(DSHMRF) to select the candidate routes for each request. Moreover, we propose a new genetic algorithm called Direction and Distance- Based Genetic Algorithm(DDGA) to look for optimal routes for all requests among the candidate routes. To allocate the spectrum reasonably, we adopt First Fit (FF) scheme. Finally, the experiments are conducted on several network topologies of different scales with different request sets and the results indicate that the proposed model effective and the proposed genetic algorithm is efficient.
    Keywords: elastic optical network; routing and spectrum allocation; integer linear programming model; genetic algorithm.

  • SPRP: A SECURED ROUTING PROTOCOL FOR DELAY TOLERANT NETWORKS   Order a copy of this article
    by Swati Bansal, JAGTAR SINGH SIVIA, HARMINDER SINGH BINDRA 
    Abstract: A Delay Tolerant Network (DTN) depends on certain assumptions that nodes cooperate and coordinate towards message forwarding. However, this assumption can't be satisfied if there are malicious nodes in the network these malicious nodes intentionally attract and drop messages from other nodes of the network. In this paper we propose a scheme for preventing malicious nodes from launching the combination of Routing Misrepresentation and Sybil attacks. This scheme is based on identity based digital signature scheme. Each node in a network needs to verify its identity before taking an interest in the message exchange process. The proposed system is utilized to Secured Prophet Routing Protocol (SPRP) against the combination of Routing Misrepresentation and Sybil attacks. The resulting protocol is robust against these combinations of attacks.
    Keywords: Delay Tolerant Network; Routing Protocol; Prophet; Attacks; Delivery Probability; Overhead Ratio; Average Buffertime; Average Latency; Identity Based Digital Signature Technique.

  • Accelerometer based quantitative outcome measurement for hand function test   Order a copy of this article
    by Aneesha Acharya K, Somashekara Bhat, Kanthi M 
    Abstract: Hand Function test gives relationship between functional limitations in activities and performance components such as Range Of Motion and strength. Physicians assess the degree of impairment in the upper extremity based on the time taken to complete the tasks. This paper proposes a hand function test which incorporates sensor on the object. The quantitative parameters such as time and acceleration with which task is completed are measured. Accelerometer data is sensitive to the movement of the body and gives variety of movement patterns during task performance. Light Dependent Resistor (LDR) provides important movement queues, such as initialization and completion of the selected activity. As sensors are embedded on the object, there is a scope for free movement of upper extremity during performance of test. Auto-time calculation during test session certainly reduces the clinician intervention time. Clinician can give more emphasis on functional movement of hand rather than spending time in documentation. The field of application of this tool are in physiotherapy and occupational therapy.
    Keywords: Hand function test; upper extremity; outcome measurement; Light Dependent Resistor; accelerometer; ultrasonic sensor; Bluetooth.

  • Relay Node Deployment for Wireless Sensor Networks using Evolutionary Multi-objective Algorithm   Order a copy of this article
    by Qiang Wang, Hai-Lin Liu, Fangqing Gu 
    Abstract: In this paper, we study the relay node placement problem of, given a deployment of sensor nodes, finding the minimum number of relay nodes to increase the lifetime and reduce the deployment costs of WSNs simultaneously. In particular, we use the average remaining energy of the relay nodes to express the lifetimes of the WSNs. Due to the conflict of the average remaining time and deployment costs of relay nodes, we first formulate the relay node placement problem as a multi-objective optimization problem, which is difficult to address using traditional methods. Based on this, a novel evolutionary multi-objective algorithm is presented to solve the problem. Furthermore, a local search method is presented to improve the convergence of the algorithm. Simulation results show that the proposed relay node placement scheme can efficiently reduce the cost and increase the lifetime.
    Keywords: Cost; Relay node placement; Connectivity; lifetime; Wireless Sensor Networks; Evolutionary algorithm.

  • CITT - Construction of an Interference-Tolerant Tree Topology using Cross-Layer Information.   Order a copy of this article
    by Sergio Diaz, Diego Mendez 
    Abstract: WSNs operate on unlicensed frequency bands that are shared with other technologies, such as WiFi and Bluetooth. Under these circumstances, the wireless channels suffer from interference problems that result in unreliable communications. To cope with this problem, we propose a mechanism that builds and maintains a tree topology, which estimates the level of interference on the wireless channel and takes routing decisions accordingly. We call our mechanism Construction of an Interference-Tolerant Tree topology (CITT) and divide it into three steps: information collection, fault detection and fault recovery. In the first step, CITT gathers data related to the interference from the MAC layer. In the second step, CITT estimates the level of interference on the wireless channel by using a naive Bayes classifier. In the third step, CITT finds the routing paths with the lowest levels of interference. We implemented CITT on Contiki and evaluated it on a real testbed composed of 10 nodes. The results show that CITT outperforms RPL regarding end-to-end latency and packet reception rate, at the cost of a slight increase in power consumption.
    Keywords: Interference problem; Tree construction; Tree maintenance.

  • Clustered Heterogeneous Wireless Sensor Network Infrastructure for reliable and efficient Path Planning of Mobile nodes in Remote Area   Order a copy of this article
    by Pankaj Pal, Sachin Tripathi, Chiranjeev Kumar 
    Abstract: Remote area coverage by employing a mix of mobile and stationary sensors is a reliable and cost-effective approach. Path planning decision by mobile node deployed in a remote environment depends on information gathered from its surrounding. Since the decisions are made locally there is no global awareness of path trajectory among mobile nodes, resulting in path overlapping and uneven load balancing due to long distance traversals. This proposal presents a path planning approach that divides the target environment into clusters of equal coverage hole densities using $K-mean^{++}$ algorithm. Thereafter, mobile nodes are assigned to these clusters and are confined to detect and cover holes within their cluster. The effectiveness of cluster formation is measured using Multiple co-relational analysis, and then the variance of effectiveness is performed over different cluster formation to select the optimum cluster count. Restriction of the mobile node in different regions (cluster) of target area avoid overlapping of path trajectories and provide load balancing among nodes. Comparison with the previous state-of-the-art techniques demonstrates that the proposed work provide high coverage with limited movement.
    Keywords: Wireless sensor network; mobile sensor; path planning; clustering; coverage hole.

  • Virtual Backbone Construction for Large-Scale Ad Hoc UAV Networks   Order a copy of this article
    by Hai Yu, Qin Liu, Hejiao Huang, Xiaohua Jia 
    Abstract: Unmanned aerial vehicles (UAVs) technology has attracted great attention in recent years, and it has a wide range of applications. The communication among UAVs is a critical issue to support these applications. However, most of the existing routing algorithms are not suitable for UAV networks. In this paper, we propose a distributed virtual backbone construction algorithm for UAV networks. We also propose a distributed protocol to dynamically maintain this communication backbone. Our algorithm is purely distributed and scalable, as we only use the neighbour information of UAVs. We also utilize the over-heard messages broadcast by the neighbouring UAVs to construct the virtual backbone efficiently to interconnect all cluster heads (CHs). Our virtual backbone construction algorithm is efficient in terms of number of messages broadcast by each UAV and the completion time of the backbone construction. Simulation results also demonstrated that our proposed algorithm is efficient and effective.
    Keywords: Mobile ad hoc network; UAV; virtual backbone; clustering; routing.

  • Implementation of Compressive Sampling for Wireless Sensor Network Applications   Order a copy of this article
    by Nathan Ruprecht, Xinrong Li 
    Abstract: Since mid-20th century, we have accepted the Nyquist-Shannon Sampling Theorem in that we need to sample a signal at twice the max frequency component in order to reconstruct it. Compressive Sampling (CS) offers a possible solution of sampling sub-Nyquist and reconstructing using convex programming techniques. There has been significant advancements in CS research and development (more notably since mid-2000s), but still nothing to the advantage of everyday use. Not for lack of theoretical use and mathematical proof, but because of very limited implementation work. There has been little work on hardware in finding the realistic constraints of a working CS system used for digital signal processing (DSP) applications. Any parameters used in a system are usually assumed based on stochastic models, but not optimized towards a specific application. This paper aims to address a minimal viable platform to implement compressive sensing if applied to a wireless sensor network (WSN) system, as well as addressing a number of key parameters of CS algorithms to be determined depending on practical application requirements and constraints.
    Keywords: Compressive Sensing; Compressive Sampling; Wireless Sensor Network.

  • Design, Implementation and Analysis of Routing Based Attack Model for Delay Tolerant Networks with Prophet Routing Protocol   Order a copy of this article
    by Swati Bansal 
    Abstract: Delay tolerant network (DTN) is an evolution of Mobile Adhoc Network (MANET). It is an emerging area in the field of networking. As the technology of computer networks is developing rapidly, DTN require more security. In computing, network security is the main issue as the attacks by malicious and selfish nodes are increasing on the network day by day. This paper defines an attack model in which malicious nodes (in DTN with Prophet Routing Protocol) receive the data from genuine nodes. It is done by falsifying their routing information (delivery predictability). Later malicious nodes spoof their identity and receive message as destination nodes. Legitimate messages from the network are deleted by malicious nodes. The messages are also deleted from the source node buffer as the source node treats the message being delivered to the final destination. Delivery Probability, Overhead Ratio, Average Latency and Average Buffer time metrics are evaluated and analyzed using ONE simulator. In simulated network, 125 nodes are considered and by making only 3 % nodes (four) malicious, performance of the network is decreased by approximately 40 % to 50 %.
    Keywords: Delay Tolerant Network; routing Protocol; Prophet; Attacks; Delivery Probability; Overhead Ratio; Average Buffertime; Average Latency.