International Journal of Distributed Sensor Networks http://www.hindawi.com The latest articles from Hindawi Publishing Corporation © 2014 , Hindawi Publishing Corporation . All rights reserved. Evolutionary Optimization Algorithms for Sunlight-Based Positioning Sensor Networks Wed, 17 Dec 2014 06:34:28 +0000 http://www.hindawi.com/journals/ijdsn/2014/564072/ The sunlight intensity-based global positioning system (SGPS) is able to geolocate outdoor objects by means of the sunlight intensity detection. This paper presents the integration of SGPS into a sensor network in order to improve the overall accuracy using evolutionary algorithms. Another contribution of the paper is to theoretically solve both global and relative positioning of the sensors composing the network within the same framework without satellite-based GPS technology. Results show that this approach is promising and has potential to be improved further. Jose Pardeiro, Javier V. Gómez, Alberto Brunete, and Frode Eika Sandnes Copyright © 2014 Jose Pardeiro et al. All rights reserved. 5 G WiFi Signal-Based Indoor Localization System Using Cluster -Nearest Neighbor Algorithm Wed, 17 Dec 2014 00:10:51 +0000 http://www.hindawi.com/journals/ijdsn/2014/247525/ Indoor localization based on existent WiFi signal strength is becoming more and more prevalent and ubiquitous. Unfortunately, the WiFi received signal strength (RSS) is susceptible by multipath, signal attenuation, and environmental changes, which is the major challenge for accurate indoor localization. To overcome these limitations, we propose the cluster -nearest neighbor (KNN) algorithm with 5 G WiFi signal to reduce the environmental interference and improve the localization performance without additional equipment. In this paper, we propose three approaches to improve the performance of localization algorithm. For one thing, we reduce the computation effort based on the coarse localization algorithm. For another, according to the detailed analysis of the 2.4 G and 5 G signal fluctuation, we expand the real-time measurement RSS before matching the fingerprint map. More importantly, we select the optimal nearest neighbor points based on the proposed cluster KNN algorithm. We have implemented the proposed algorithm and evaluated the performance with existent popular algorithms. Experimental results demonstrate that the proposed algorithm can effectively improve localization accuracy and exhibit superior performance in terms of localization stabilization and computation effort. Feng Yu, Minghua Jiang, Jing Liang, Xiao Qin, Ming Hu, Tao Peng, and Xinrong Hu Copyright © 2014 Feng Yu et al. All rights reserved. A Middleware for the Integration of Smart Grid Elements with WSN Based Solutions Tue, 16 Dec 2014 13:57:22 +0000 http://www.hindawi.com/journals/ijdsn/2014/506203/ Currently, electricity distributors make use of various types of equipment divided into levels of automation. This automation enables the integration of elements such as Intelligent Electronic Devices (IEDs) to the supervision of the distribution electrical system, but there is not an appropriate environment to increase the scale of these elements. In this context, the smart grid comes with specifications that allow adding new elements to the intelligence of the power grid operation. However, the cost of communication is still an impediment to the scalability of the integration of these elements into the current structure. In this paper, we propose a middleware that optimizes the communication of this integration using wireless sensor networks (WSN). The goal is to ensure a gradual integration of new elements taking advantage of the increase in the number of sensor nodes in the network due to the scalability of the system itself. The conversion solutions have been used to allow easy communication between the WSN and the smart grid system, and we also have used data aggregation and compression techniques to increase the lifetime of the wireless sensor network. Paulo Régis C. de Araújo, Raimir Holanda, Antonio Wendell de Oliveira Rodrigues, André Luiz Carneiro de Araújo, José de Aguiar Moraes Filho, and João Paolo C. M. Oliveira Copyright © 2014 Paulo Régis C. de Araújo et al. All rights reserved. Hybrid Fingerprinting-EKF Based Tracking Schemes for Indoor Passive Localization Mon, 08 Dec 2014 12:13:20 +0000 http://www.hindawi.com/journals/ijdsn/2014/351523/ This paper investigates a combination of fingerprinting (FP) and extended Kalman filter (EKF) based tracking aiming to tackle conventional problems related to implementation of either tracking or fingerprinting separately. One of the common drawbacks of FP belongs to large data size and consequent large search space. By taking advantage of latest position estimate got from EKF, a virtual surveillance area (VSA) is defined around the estimate. The dimension of this defined surveillance area is much smaller than the size of indoor environment. Consequently, there will be a possibility for FP to be applied in larger areas maintaining the possibility of adding necessary grid points in order to achieve a desired localization performance. Additionally, in order to improve accuracy of ranging, we investigate the impact of a priori knowledge related to the clusters impulse responses and other features; the applied so called soft ranging algorithm for time of arrival (TOA) estimation is modified in order to take advantage of this a priori information and to make its decision variables more accurate. Simulation results show a promising performance improvement via using the proposed hybrid tracking technique and applying a priori information to soft ranging. The tradeoff is along a reasonable increased implementation complexity. Salar Bybordi and Luca Reggiani Copyright © 2014 Salar Bybordi and Luca Reggiani. All rights reserved. Node Replication Attacks in Mobile Wireless Sensor Network: A Survey Mon, 08 Dec 2014 07:45:34 +0000 http://www.hindawi.com/journals/ijdsn/2014/402541/ Mobile wireless sensor networks (MWSNs) comprise a collection of mobile sensor nodes with confined and finite resources. They commonly operate in hostile environments such as battle fields and surveillance zones. Owing to their operating nature, MWSNs are often unattended and generally are not equipped with tamper-resistant tools. With little effort, an adversary may capture the nodes, analyze and replicate them, and surreptitiously insert these replicas at strategic locations within the network. Keeping in view of the above, this paper places an emphasis on this aforementioned attack, known as node replication attack in MWSNs. Specifically, the current state-of-the-art of node replication attack in MWSNs is discussed, where this paper provides a detailed description of various existing detection and prevention mechanisms in literature with an aim to provide better understanding of the factors that need to be considered when designing defence mechanism of node replication attack. A detailed categorization of various detection techniques is provided in the paper with critical discussion on each categorization with respect to its advantages, disadvantages, and various constraints. To conclude the paper, a number of parameters are selected for comparison and analysis of all the existing detection schemes in the literature. Haafizah Rameeza Shaukat, Fazirulhisyam Hashim, Aduwati Sali, and M. Fadlee Abdul Rasid Copyright © 2014 Haafizah Rameeza Shaukat et al. All rights reserved. Container Security Device Chain Network for Safe Railway Transportation Sun, 30 Nov 2014 00:10:31 +0000 http://www.hindawi.com/journals/ijdsn/2014/767802/ The railway is one of the most important facilities for freight logistics. This paper suggests the use of the container security devices (CSDs), which has been adopted for the marine transportation so far, to enhance the security of railway freight transportation. The proposed protocol, CSD Chain Network Protocol (CCNP), was designed for a chain-form network of CSDs, each of which is attached to a container. In CCNP, unauthorized access to freight is reliably reported to the reader deployed at the locomotive. CCNP also cares about the fairness in energy consumption. In a usual chain network, a tag closer to the reader consumes more energy since it ought to forward packets coming from rear tags as well. However, in CCNP, the tag energy consumption for packet forwarding is always the same regardless of the position in a chain owing to an efficient data fusion scheme. In our simulation using QualNet, CCNP reduces the number of disconnections between tags by 59.5% as compared to general chain networks. The energy consumption also decreases by 91.3% of other networks not using an aggregation method. Sungryul Kim, Jeonghyun Kim, and Younghwan Yoo Copyright © 2014 Sungryul Kim et al. All rights reserved. Optimized Design of Relay Node Placement for Industrial Wireless Network Thu, 27 Nov 2014 00:10:11 +0000 http://www.hindawi.com/journals/ijdsn/2014/759826/ The industrial wireless network (IWN) is an important part of industrial CPS, which must address the key issue of reliable and real-time communication as well as the desired network lifetime. The nodes of IWN are usually fixed on the devices for better monitoring of the state information of the equipment and environment, while the relay node placement plays a significant role on network performance guarantee. This paper proposes an Integer Linear Program (ILP) placement strategy to meet the fault tolerance and survivability requirement. In addition, an edge coloring algorithm is proposed to solve the conflict of TDMA communication, which improves paralleled and real-time communication performance. Simulation results show that this placement strategy not only meets the requirements of robust communication and survivability, but also enhances real-time communication of IWN. Heng Zhang, Zeyu Zhang, Fengxiang Zhang, Li Li, and Ying Wang Copyright © 2014 Heng Zhang et al. All rights reserved. Coverage Capacity Optimization for Mobile Sensor Networks Based on Evolutionary Games Wed, 26 Nov 2014 00:10:12 +0000 http://www.hindawi.com/journals/ijdsn/2014/264307/ The optimal and distributed provisioning of high coverage capacity in mobile sensor networks is known as a fundamental but hard problem. The situation is exacerbated in a mobile wireless setting due to the dynamic coverage of a mobile sensor network resulting from continuous movement of sensors. In this paper, we propose an optimization framework for maximizing the coverage capacity in mobile sensor networks that comprise both stationary sensors (SSs) and mobile sensors (MSs). Both the intracoverage capacity and the intercoverage capacity are jointly optimized by considering the control of the power and distance between MSs and SSs and the interference among MSs. We propose a new noncooperative control algorithm that iteratively solves intracoverage capacity optimization between MSs and SSs. We also further formulate intercoverage capacity as evolutionary coalition game and present a new cooperative interference control algorithm that iteratively solves intercoverage capacity optimization among MSs. We prove the existence of a solution for iteration control equation of the power and distance and the interference to maximize the coverage capacity. Finally, we assess the performance of the proposed algorithm and show that proposed control scheme can effectively improve the average coveragecapacity in mobile sensor networks. Jianhua Liu, Guangxue Yue, Shigen Shen, Huiliang Shang, and Hongjie Li Copyright © 2014 Jianhua Liu et al. All rights reserved. Distributed Spectrum Sharing in Cognitive Radio Networks: A Pricing-Based Decomposition Approach Tue, 25 Nov 2014 09:28:51 +0000 http://www.hindawi.com/journals/ijdsn/2014/262137/ The limited radio spectrum has become a bottleneck for various wireless communications. To better utilize the scare radio spectrum, cognitive radios have recently attracted increasing attention, which makes spectrum sharing more viable. Sharing radio spectrum from primary users to secondary users is of great importance. A licensed primary user (PU) can lease its spectrum to secondary users (SUs) for wireless communications. This paper studies the problem of social welfare maximization of distributed spectrum sharing among a PU and SUs. We first formulate the problem of social welfare maximization which takes into account both the cost of the PU and the utility gained by each SU. The social welfare maximization is a convex optimization problem and thus can be solved by a centralized algorithm. However, the utility function of each SU may contain the private information. To avoid privacy leakage of SUs, we propose an iterative distributed algorithm based on a pricing-based decomposition framework. It is theoretically proved that our algorithm converges to the optimal solution. Simulation results are presented to show that our algorithm achieves the optimal social welfare and converges quickly in a practical setting. Yanmin Zhu, Wei Sun, Jiadi Yu, Tong Liu, and Bo Li Copyright © 2014 Yanmin Zhu et al. All rights reserved. A Novel Mesh Routing Using the Nodes with Identical Tree Level Mon, 24 Nov 2014 08:57:34 +0000 http://www.hindawi.com/journals/ijdsn/2014/647421/ Contemporary wireless sensor network (WSN) adopts IEEE 802.15.4 in its MAC and PHY layers. The mesh routing introduced in IEEE 802.15.5 standard, referred to as the basic mesh routing below, improves reliability and robustness of routing in WSNs since there are multiple routes from a node to the sink. In this paper, the mesh routing with identical level (MRIL) is proposed, which constructs the mesh using the tree generated per IEEE 802.15.5 standard, the two-hop neighbors of the nodes, and the nodes in the same level chains with each consisting of the nodes having identical tree level. The MRIL outperforms the basic mesh routing in terms of energy consumption, the average number of hops traversed per packet, the sizes of memory used to keep neighbor lists and connectivity matrices at nodes, and the number of packet transmissions in exchanging link state information. Li-yong Yuan, Lin Xu, Yi-hua Zhu, and Cong Sun Copyright © 2014 Li-yong Yuan et al. All rights reserved. TALK: Topology Aware LKH Key Management Tue, 18 Nov 2014 12:38:31 +0000 http://www.hindawi.com/journals/ijdsn/2014/762194/ Cryptographic key management for wireless sensor networks (WSNs) and mobile ad-hoc networks (MANETs) is a particularly challenging task, as they mostly consist of high counts of resource constrained nodes, especially when group communication and dynamic network membership capabilities are required. The logical key hierarchy (LKH) is a well-known class of protocols which aims to solve the key management problem and minimize rekeying overhead, using hierarchical structures and taking advantage of multicast communication. In this work we propose a method for obtaining LKH structures by taking into account the topology of the underlying network, leading to a further decrease in rekeying costs, in terms of packet transmissions. Dimitris Tsitsipis, Anthony Tzes, and Stavros Koubias Copyright © 2014 Dimitris Tsitsipis et al. All rights reserved. Online Authentication and Key Establishment Scheme for Heterogeneous Sensor Networks Tue, 18 Nov 2014 09:05:42 +0000 http://www.hindawi.com/journals/ijdsn/2014/718286/ In recent years, the adaptation of wireless sensor networks (WSNs) to application areas requiring mobility increased the security threats against confidentiality, integrity, and privacy of the information as well as against their connectivity. Since key management plays an important role in securing both information and connectivity, a proper authentication and key management scheme is required in mobility enabled applications where the authentication of a node with the network is a critical issue. In this paper, we present an authentication and key management scheme supporting node mobility in a heterogeneous WSN that consists of several mobile sensor nodes and a few fixed sensor nodes. We analyze our proposed solution by using the OMNET++ simulator to show that it requires less memory space and provides better connectivity and network resilience against node capture attacks compared to some existing schemes. We also propose two levels of secure authentication methods for the mobile sensor nodes for secure authentication and key establishment. Sarmad Ullah Khan, Luciano Lavagno, Claudio Pastrone, and Maurizio A. Spirito Copyright © 2014 Sarmad Ullah Khan et al. All rights reserved. DCEEMR: A Delay-Constrained Energy Efficient Multicast Routing Algorithm in Cognitive Radio Ad Hoc Networks Mon, 17 Nov 2014 11:55:44 +0000 http://www.hindawi.com/journals/ijdsn/2014/584197/ We discuss the delay-constrained energy efficient multicast routing problem in cognitive radio ad hoc networks. A cognitive radio ad hoc network is a wireless multihop network established by secondary users on varying available spectrum bands. The research on routing is a hot topic in the field of cognitive radio ad hoc networks. However, multicast routing algorithm study of cognitive radio ad hoc networks is still at its start stage. In this paper, we proposed a novel delay-constrained energy efficient multicast routing algorithm (DCEEMR) in cognitive radio ad hoc networks. The DCEEMR guarantees that the multicast tree can be found if it exists, and the multicast tree satisfies the delay bound and has low energy consumption. The algorithm uses delay-energy function to construct the multicast tree based on the spectrum selection. Through an example with random network topology, we demonstrate that our algorithm is better in terms of energy cost of multicast tree as compared to the existing algorithm QoS dependent multicast routing (QDMR). Moreover, the algorithm does not suffer from high complexity common to the algorithm QDMR. Experiment results by NS-2 show that the delay and cost of tree are lower than well-known multicast ad hoc on-demand distance vector (MAODV) protocol. Xuna Miao and Miaolei Deng Copyright © 2014 Xuna Miao and Miaolei Deng. All rights reserved. Downlink Traffic Scheduling with Contact Durations Awareness for Vehicular Infrastructures Mon, 17 Nov 2014 07:49:13 +0000 http://www.hindawi.com/journals/ijdsn/2014/451372/ The vehicular infrastructures or roadside units (RSUs) in vehicular delay tolerant networks (VDTNs) can be used as the gateways of the distributed sensor networks. The different classes of service (CoS) support are desired when more than one type of the sensed data are collected by the RSUs. In this paper, the CoS support traffic scheduling problem for the RSU in VDTNs is considered. By exploring the contact information between the vehicles and the RSU, the CoS traffic scheduling problem is formulated as a maximum weighted triple matching problem, where the traffic scheduling strategy is a timeslot-vehicle-traffic matched pair. A flow network based method is proposed to optimally solve the maximum weighted triple matching problem. Both the offline version and the online version of the traffic scheduling algorithm are developed. Extensive simulations are conducted and the simulation results show the effectiveness and efficiency of the proposed flow network based algorithms. Zhongjiang Yan and Bo Li Copyright © 2014 Zhongjiang Yan and Bo Li. All rights reserved. DSMC: A Novel Distributed Store-Retrieve Approach of Internet Data Using MapReduce Model and Community Detection in Big Data Sun, 16 Nov 2014 13:02:41 +0000 http://www.hindawi.com/journals/ijdsn/2014/430848/ The processing of big data is a hotspot in the scientific research. Data on the Internet is very large and also very important for the scientific researchers, so the capture and store of Internet data is a priority among priorities. The traditional single-host web spider and data store approaches have some problems such as low efficiency and large memory requirement, so this paper proposes a big data store-retrieve approach DSMC (distributed store-retrieve approach using MapReduce model and community detection) based on distributed processing. Firstly, the distributed capture method using MapReduce to deduplicate big data is presented. Secondly, the storage optimization method is put forward; it uses the hash functions with light-weight characteristics and the community detection to address the storage structure and solve the data retrieval problems. DSMC has achieved the high performance of large web data comparison and storage and gets the efficient data retrieval at the same time. The experimental results show that, in the Cloudsim platform, comparing with the traditional web spider, the proposed DSMC approach shows better efficiency and performance. Xu Xu, Jia Zhao, Gaochao Xu, Yan Ding, and Yunmeng Dong Copyright © 2014 Xu Xu et al. All rights reserved. Energy-Efficient Adaptive Routing and Context-Aware Lifetime Maximization in Wireless Sensor Networks Sun, 16 Nov 2014 06:26:24 +0000 http://www.hindawi.com/journals/ijdsn/2014/321964/ We design and implement a Bezier-based multipath routing algorithm that allows a given source node to send samples of data to a given sink node in large scale sensor networks. Multipath routing can distribute the energy load onto the multiple routes and thus increase the lifetime and quality of the network. It is important to stress the fact that evenly regulating the routing task among the more nodes of the network can also protect a node from failure considering that a node with heavy duty is likely to deplete its power quickly. On the contrary, all the traffic would be shipped along the shortest path routing, corresponding to the heavily congested path case, which in turn leads to overload of the nodes along the optimal routes between the sink and source pair and finally shortens the lifetime of the network. Also, multipath routing can increase end-to-end throughput and provide load balancing. Our view is that minimizing energy consumption while meeting acceptable latency for applications can lead to significant power savings. Our simulation results demonstrate that Bezier-based multipath routing approach significantly outperforms previous SWEEP, Tributaries and Deltas, and the shortest path approaches in terms of lifetime and latency. Shaohua Wan Copyright © 2014 Shaohua Wan. All rights reserved. Harnessing Vehicle-to-Vehicle Communications for 3G Downloads on the Move Thu, 13 Nov 2014 07:12:00 +0000 http://www.hindawi.com/journals/ijdsn/2014/657905/ This paper studies the problem of 3G downloads in vehicles on the move. Although the 3G brings larger coverage and instant access to data transfer, it may also incur high cost. We observe that many applications of vehicular 3G users can actually tolerate certain data access latency. In addition, vehicle-to-vehicle communications have been practical and can be exploited for intervehicle data delivery. Based on these observations, we propose to augment vehicular 3G users by data sharing through vehicle-to-vehicle communications. We formulate an optimization problem. The objective is to minimize the cost of 3G data communications, meanwhile maximizing the success probability of downloading all 3G user data. The two-hop transmission process and the bandwidth limitation in vehicular network are both modeled in the optimization problem. To lower the cost of 3G and meet the delivery ratio and delay constraints of data, one single-stage algorithm and one multistage algorithm are proposed for selection of seed vehicles (that download the data via 3G channel). We have evaluated our algorithm with simulations with real vehicular traces and the results show that our algorithms reduce the 3G cost and achieve good performance of data downloads. Yanmin Zhu, Qinghua Chen, and Chao Chen Copyright © 2014 Yanmin Zhu et al. All rights reserved. Research on Improvement of Spectrum Efficiency of Spread Spectrum OFDM Communication Scheme for Cruising Sensor Network Wed, 12 Nov 2014 12:32:09 +0000 http://www.hindawi.com/journals/ijdsn/2014/327540/ Cruising sensor nodes have an attractive application in monitoring liquid-based industrial environments. A cruising sensor node, equipped with various sensors, is self-propelled so that they can “cruise” to specified area to gather scientific data. The cruising sensor network consists of an array of such cruising nodes to perform collaborative monitoring task over a given area. A reliable and high-speed underwater acoustic (UWA) communication scheme is necessary for node-to-node communication. Most of the industrial liquid reservoirs are confined spaces, including large oil tanks and nuclear storage ponds. The communication in confined underwater space will suffer more severe multipath interference caused by numerous reflections from boundaries. Conventional orthogonal frequency-division multiplexing (OFDM) technique has poor performance in this channel. Instead, spread spectrum orthogonal frequency-division multiplexing (SS-OFDM), which applies spread spectrum technique into OFDM, has better performance in such severely multipath fading underwater channels. However, the spread spectrum process causes a huge waste in the spectrum efficiency. In order to enhance the transmission efficiency, a mapping sequence spread spectrum OFDM (MSSS-OFDM) method is proposed in this paper. The simulation and experimental results show that our scheme is a robust and spectrum efficient communication method for confined underwater space. Yuan Wang, Zhoumo Zeng, Yibo Li, Wen Zhang, Hao Feng, and Shijiu Jin Copyright © 2014 Yuan Wang et al. All rights reserved. Transient Fault Detection in Networked Control Systems Wed, 12 Nov 2014 11:18:14 +0000 http://www.hindawi.com/journals/ijdsn/2014/346269/ Transient faults appear unpredictablly and frequently in networked control systems (NCSs), which directly affect the safety of system. However, they can not be accurately identified due to various kinds of causes, so the detection of them needs more systematic and comprehensive system knowledge. Hence, a hierarchical and systematic detection approach based on function, behavior, and structure (FBS) models is proposed in this paper. The FBS models are established according to systematic knowledge of NCSs. And the transient faults are excavated in node level and system level, in which parameter match and model-based detections are employed. Moreover, the key implementation aspects of the proposed approach in NCSs are detailed on parameterization of FBS models, criteria, and feature parameters of faults, fault monitoring, fault detection, and real-time scheduling considering fault detection. At last, a simulation platform of a networked control liquid mixer system is described by Architecture Analysis and Design Language (AADL), and a transient fault is injected before the sample task in the node for fault detection. The simulation results show that the faults are exposed in the gradual detection hierarchies and the effectiveness of the detection scheme is quite promising. Xiong-Feng Huang, Chun-Jie Zhou, Shuang Huang, Kai-Xin Huang, and Xuan Li Copyright © 2014 Xiong-Feng Huang et al. All rights reserved. An Attribute-Based Encryption Scheme with Revocation for Fine-Grained Access Control in Wireless Body Area Networks Tue, 11 Nov 2014 06:51:49 +0000 http://www.hindawi.com/journals/ijdsn/2014/259798/ The wireless body area networks (WBANs) have emerged as a new method for e-healthcare. Without being measured face-to-face, the medical workers can give guidance to patients in a real-time way. WBANs can greatly improve the healthcare quality. The personal information and medical data are stored and processed in sensors. The security and privacy are two vital issues. In this paper, we design an attribute-based encryption scheme for fine-grained access control in WBANs. In our scheme, a user can decrypt a ciphertext if the attributes related with a ciphertext satisfy the user’s access structure. The users can be revoked if necessary. Therefore, the security and privacy of patients can be protected. Our scheme provides confidentiality, security, and resistance to collusion attack. We analyze the correctness, security, and energy consumption of the scheme. Ye Tian, Yanbin Peng, Xinguang Peng, and Hongbin Li Copyright © 2014 Ye Tian et al. All rights reserved. A Secure Online Key Establishment Scheme for Mobile Heterogeneous Sensor Networks Tue, 04 Nov 2014 09:11:36 +0000 http://www.hindawi.com/journals/ijdsn/2014/925479/ Advancement in wireless sensor network (WSN) technology makes it more attractive technology to be adopted in real world applications including home and industrial automation and e-health or infrastructure monitoring. However the mobility consideration in these applications makes the security requirements an essential and challenging task. To make the communication secure and the network robust against attacks, a proper key management scheme should be used. This paper presents a secure online key establishment and authentication scheme for mobility supported heterogeneous sensor networks. The performance evaluation of the proposed scheme is done using OMNET++ simulator while AVISPA tool is used to validate the security of the proposed scheme. It is clear from the obtained results that the proposed scheme provides better network connectivity at a low cost of memory occupation and communication overhead during the authentication and key establishment phases while improving its network resilience against attacks. Sarmad Ullah Khan, Claudio Pastrone, Luciano Lavagno, and Maurizio A. Spirito Copyright © 2014 Sarmad Ullah Khan et al. All rights reserved. Hybrid Transmission Power Control for Wireless Body Sensor Systems Thu, 30 Oct 2014 00:00:00 +0000 http://www.hindawi.com/journals/ijdsn/2014/259181/ In wireless body sensor network systems (WB-SNSs), the sensor nodes have very limited battery power because they are tiny, lightweight, and wearable or implantable. As a result, WB-SNSs require a very efficient transmission power control (TPC) algorithm for effectively reducing energy consumption and extending the lifetime of sensor nodes. To achieve this goal, we propose a novel TPC algorithm referred to as hybrid TPC. The hybrid TPC algorithm adaptively selects a conservative or an aggressive control mechanism depending on current channel conditions. The conservative control mechanism, which slowly changes transmission power level (TPL), is suitable in a dynamic environment. On the other hand, the aggressive control mechanism, which rapidly changes TPL, is ideal in a static environment. In order to evaluate the effectiveness of the hybrid TPC algorithm, we implemented various TPC algorithms and compared their performances against the hybrid TPC algorithm in different channel environments. The experimental results showed that the hybrid TPC algorithm outperformed other TPC algorithms in all channel environments. Woosik Lee, Byoung-Dai Lee, and Namgi Kim Copyright © 2014 Woosik Lee et al. All rights reserved. Erratum to “A Rendezvous Scheme for Self-Organizing Cognitive Radio Sensor Networks” Wed, 29 Oct 2014 11:44:02 +0000 http://www.hindawi.com/journals/ijdsn/2014/347191/ Junhyung Kim, Gisu Park, and Kijun Han Copyright © 2014 Junhyung Kim et al. All rights reserved. Design a Smart Control Strategy to Implement an Intelligent Energy Safety and Management System Tue, 28 Oct 2014 08:40:19 +0000 http://www.hindawi.com/journals/ijdsn/2014/312392/ The energy saving and electricity safety are today a cause for increasing concern for homes and buildings. Integrating the radio frequency identification (RFID) and ZigBee wireless sensor network (WSN) mature technologies, the paper designs a smart control strategy to implement an intelligent energy safety and management system (IESMS) which performs energy measuring, controlling, monitoring, and saving of the power outlet system. The presented RFID and billing module is used to identify user, activate smart power outlet (SPO) module, deduct payable for electricity, and cut off power supply to the outlets by taking away the RFID card. Further work on the SPO module, a control strategy based on the minimum effect and first-in first-out rule, is designed to autonomously shut down some of the power outlets instantly to prevent electrical circuit overload. In addition, the WSN transfers the power parameters of each SPO module to central energy monitoring platform, and the monitoring platform with graphical user interface (GUI) displays the real-time information and power charge of the electricity. Numerous tests validate the proposed IESMS and the effectiveness of the smart control strategy. The empirical findings may provide some valuable references for smart homes or smart buildings. Jing-Min Wang and Ming-Ta Yang Copyright © 2014 Jing-Min Wang and Ming-Ta Yang. All rights reserved. Secrecy Throughput in Inhomogeneous Wireless Networks with Nonuniform Traffic Mon, 27 Oct 2014 14:29:02 +0000 http://www.hindawi.com/journals/ijdsn/2014/460196/ We investigate the secrecy throughput of inhomogeneous wireless network, especially in cases of independent and uniform eavesdropper with single antenna and multiple antennas. Towards the inhomogeneous distribution of legitimate nodes, we novelly construct a circular percolation model under the idea of transforming “inhomogeneous” to “homogeneous.” Correspondingly, the information is transmitted by two ways: intracluster transmission and intercluster transmission. For intracluster transmission, a per-node secrecy throughput of is derived by circular percolation model, where and represent the number of nodes and clusters in the network, respectively. As for intercluster case, a connection called “information pipelines” is built. Then the per-node secrecy throughput of can be obtained, where denotes the minimum node density in the network. Moreover, when the eavesdropper is equipped with antennas, the per-node secrecy throughput of and is achieved for intracluster and intercluster transmission, respectively. Qiuming Liu, Li Yu, Peng Yang, and Zuhao Liu Copyright © 2014 Qiuming Liu et al. All rights reserved. Security Analysis in Wireless Sensor Networks Thu, 23 Oct 2014 06:18:02 +0000 http://www.hindawi.com/journals/ijdsn/2014/303501/ In recent years, wireless sensor network (WSN) is employed in many application areas such as monitoring, tracking, and controlling. For many applications of WSN, security is an important requirement. However, security solutions in WSN differ from traditional networks due to resource limitation and computational constraints. This paper analyzes security solutions: TinySec, IEEE 802.15.4, SPINS, MiniSEC, LSec, LLSP, LISA, and LISP in WSN. The paper also presents characteristics, security requirements, attacks, encryption algorithms, and operation modes. This paper is considered to be useful for security designers in WSNs. Murat Dener Copyright © 2014 Murat Dener. All rights reserved. Robust and Energy-Efficient Data Gathering in Wireless Sensor Network Wed, 22 Oct 2014 07:22:39 +0000 http://www.hindawi.com/journals/ijdsn/2014/960242/ Robustness and energy efficiency are critical for sensor information system, in which an abundance of wireless sensor nodes collects useful data from the deployed field. The chain-based protocols (like PEGASIS (Lindsey and Raghavendra, 2002)) are elegant solutions where sensor node has high energy efficiency. Unfortunately, if one node in the chain is failed due to some reasons such as energy exhaust, then the information cannot be forwarded to the sink. To improve system robustness and balance the energy consumption, this paper proposes a robust and energy-efficient data gathering (REEDG) approach, which is an improvement over the chain-based and grid-based network structures, in sensor information collecting system. In REEDG, data gathering is executed by a data transmitting chain which is composed by a series of virtual grids. Each grid communicates only with its neighbor grid and takes turns transmitting the information to the base station. Furthermore, an adaptive scheduling scheme is proposed to trade off energy consumption on each node and data forwarding delay. Experimental results show that, when compared with state-of-the-art approaches, REEDG achieves network lifetime extension of at least 13% as measured in terms of 20% dead nodes and improves the data transmission ratio at lowest 24% as 20% nodes fail. Juan Feng, Baowang Lian, and Hongwei Zhao Copyright © 2014 Juan Feng et al. All rights reserved. A Wi-Fi Cluster Based Wireless Sensor Network Application and Deployment for Wildfire Detection Mon, 20 Oct 2014 11:27:56 +0000 http://www.hindawi.com/journals/ijdsn/2014/651957/ We introduce the wireless sensor network (WSN) data harvesting application we developed for wildfire detection and the experiments we have performed. The sensor nodes are equipped with temperature and relative humidity sensors. They are organized into clusters and they communicate with the cluster heads using 802.15.4/ZigBee wireless links. The cluster heads report the harvested data to the control center using 802.11/Wi-Fi links. We introduce the hardware and the software architecture of our deployment near Rhodiapolis, an ancient city raising on the outskirts of Kumluca county of Antalya, Turkey. We detail our technical insights into the deployment based on the real-world data collected from the site. We also propose a temperature-based fire detection algorithm and we evaluate its performance by performing experiments in our deployment site and also in our university. We observed that our WSN application can reliably report temperature data to the center quickly and our algorithms can detect fire events in an acceptable time frame with no or very few false positives. Alper Rifat Ulucinar, Ibrahim Korpeoglu, and A. Enis Cetin Copyright © 2014 Alper Rifat Ulucinar et al. All rights reserved. A Statistical Analysis Based Probabilistic Routing for Resource-Constrained Delay Tolerant Networks Wed, 15 Oct 2014 07:03:00 +0000 http://www.hindawi.com/journals/ijdsn/2014/623193/ The nonexistence of end-to-end path between the sender and the receiver poses great challenges to the successful message transmission in delay tolerant networks. Probabilistic routing provides an efficient scheme to route messages, but most existing probabilistic routing protocols do not consider whether a message has enough time-to-live to reach its destination. In this paper, we propose an improved probabilistic routing algorithm that fully takes into account message’s time-to-live when predicting the delivery probability. Based on statistical analysis, we compute and update the expected intermeeting times between nodes. And then the probability for a message to be delivered within its time-to-live is computed based on the assumed exponential distribution. We further propose an optimal message schedule policy, by modeling the buffer management problem as 0-1 knapsack, of which the maximum delivery probability sum can be achieved by resorting to the back track technique. Extensive simulations are conducted and the results show that the proposed algorithm can greatly enhance routing performance in terms of message delivery probability, overhead ratio, and average hop count. Jixing Xu, Jianbo Li, Shan Jiang, Chenqu Dai, and Lei You Copyright © 2014 Jixing Xu et al. All rights reserved. Loop Assisted Synchronization-Free Localization for Underwater Acoustic Sensor Networks Tue, 14 Oct 2014 08:48:36 +0000 http://www.hindawi.com/journals/ijdsn/2014/829174/ Underwater acoustic sensor networks (UASNs) have attracted significant attention recently. Localization is one of the most important issues associated with UASNs. Most of the existing underwater localization algorithms require time synchronization. However, time synchronization is difficult to be achieved in the underwater networks. The beam width and three-dimensional direction of underwater acoustic sensor nodes are ignored by the existing underwater localization algorithms. This will increase the difficulty to avoid time synchronization. We develop a loop assisted synchronization-free localization to achieve synchronization-free localization algorithm when taking into account the beam width and direction of the underwater nodes. We propose link detection stage to get link state information (symmetry and length). In addition we introduce a loop-assisted localization method to solve the problem of asymmetric link ranging without time synchronization. Finally, we propose an intersections based location estimation mechanism for error problem in practical measurement and we improve the localization accuracy. The simulation results and experimental results verify the effectiveness and feasibility of the proposed work. Song Zhang, Deshi Li, Lei Li, and Zilong Liao Copyright © 2014 Song Zhang et al. All rights reserved.