International Journal of Distributed Sensor Networks http://www.hindawi.com The latest articles from Hindawi Publishing Corporation © 2015 , Hindawi Publishing Corporation . All rights reserved. Optimizing Unsatisfactory Handover Trigger in Heterogeneous Vehicular Networks Mon, 27 Apr 2015 13:58:09 +0000 http://www.hindawi.com/journals/ijdsn/2015/205879/ In heterogeneous vehicular networks, the communications among moving vehicles (MV) and between vehicles and the roadside infrastructures have posed a challenge for providing continuous mobility services. FMIPv6 looking toward the support of a timely and precise link layer (L2) trigger provides a fundamental mobility management approach. The time stamp of L2 trigger hence is crucial for guaranteeing the handover performance but is difficult to be obtained in the practical application scenarios. The unsatisfactory handover trigger includes the late L2 trigger and the premature L2 trigger. The former would cause a missed detection deteriorating the perceived quality of service, and the latter would cause a false alarm with serious performance loss and resources waste. To address this issue, we propose a solution to optimize the unsatisfactory handover trigger (O-UHT), including promptly determining the unsatisfactory handover trigger and elaborately developing the specific measures to reduce the performance loss caused by the above two cases. The simulations conducted on NS-2 platform have verified the efficiency. Ming Tao, Fagui Liu, and Chao Qu Copyright © 2015 Ming Tao et al. All rights reserved. RCTP: An Enhanced Routing Protocol Based on Collection Tree Protocol Thu, 23 Apr 2015 06:11:50 +0000 http://www.hindawi.com/journals/ijdsn/2015/363107/ Due to implementation of routing protocols in limited power supply devices in wireless sensor networks (WSNs), this paper presents and evaluates Rainbow Collection Tree Protocol (RCTP) as an enhanced version of Collection Tree Protocol (CTP). CTP is a lightweight, efficient, robust, and also reliable routing protocol for WSNs. CTP as a cross layer routing protocol is also a platform-independent protocol. It uses Trickle Algorithm to optimize the overhead cost and also makes it quickly adaptable to changes in topology. The basic foundation of CTP is on link quality identification and it uses expected transmission count (ETX). ETX is not stable during the time in real environments and ETX fluctuations cause the routing protocols to not work in optimum level. RCTP uses average expected transmission count (AETX) as link quality metric that has shown it is more stable than ETX. It also uses a new mechanism in parent selection to make it more accurate. Rainbow mechanism is used in RCTP to detect and route around connectivity nodes and avoid route through dead end paths. The Omnet++ has been used as a simulator and the results show RCTP performs more efficiently than CTP in dynamic and crowded environments. Fariborz Entezami, Martin Tunicliffe, and Christos Politis Copyright © 2015 Fariborz Entezami et al. All rights reserved. On the Use of Perfect Sequences and Genetic Algorithms for Estimating the Indoor Location of Wireless Sensors Tue, 21 Apr 2015 13:02:40 +0000 http://www.hindawi.com/journals/ijdsn/2015/720574/ Determining the indoor location is usually performed by using several sensors. Some of these sensors are fixed to a known location and either transmit or receive information that allows other sensors to estimate their own locations. The estimation of the location can use information such as the time-of-arrival of the transmitted signals, or the received signal strength, among others. Major problems of indoor location include the interferences caused by the many obstacles in such cases, causing among others the signal multipath problem and the variation of the signal strength due to the many transmission media in the path from the emitter to the receiver. In this paper, the creation and usage of perfect sequences that eliminate the signal multipath problem are presented. It also shows the influence of the positioning of the fixed sensors to the precision of the location estimation. Finally, genetic algorithms were used for searching the optimal location of these fixed sensors, therefore minimizing the location estimation error. M. Ferreira, J. Bagarić, Jose M. Lanza-Gutierrez, S. Priem-Mendes, J. S. Pereira, and Juan A. Gomez-Pulido Copyright © 2015 M. Ferreira et al. All rights reserved. Design of Unmanned Vehicle System for Disaster Detection Thu, 16 Apr 2015 15:48:09 +0000 http://www.hindawi.com/journals/ijdsn/2015/784298/ This work presents a novel unmanned vehicle system, capable of detecting risks in disaster areas. The rescuer can operate an unmanned vehicle to reach the disaster area via remote control. An android-based application program is used to control the remote vehicle via wireless network. The vehicle system is capable of detecting a variety of gases by the sensors deployed on it. The gas sensors can detect methane, ethane, and carbon dioxide. After detecting the gases, the vehicle passes the collected information to the rescuer for deciding which equipment can be used in the disaster. The gas detection sensors can reduce the injury risks of rescuers before they go into the disaster area. The vehicle is also equipped with a video surveillance camera to monitor the scene and find injured persons. A robotic arm is mounted on the head of the vehicle to grip objects and gather samples. Our unmanned system can effectively reduce casualties by gathering information about the disaster beforehand. Ming-Chih Chen, Chien-Hsing Chen, Ming-Sheng Huang, Jheng-Yu Ciou, and Guo-Tai Zhang Copyright © 2015 Ming-Chih Chen et al. All rights reserved. Self-Diagnosis and Self-Reconfiguration of Piezoelectric Actuator and Sensor Network for Large Structural Health Monitoring Thu, 16 Apr 2015 15:46:32 +0000 http://www.hindawi.com/journals/ijdsn/2015/207303/ For large structural health monitoring in practical applications, the sensor failure in large sensor network will generate the failure of the damage evaluation or the leaving of unmonitored area in a large structure. Hence, in order to realize a real-time and reliable evaluation for the large structural damage and satisfy the requirement of advanced maintenance of the structure, the paper introduces an efficient piezoelectric sensor failure monitoring approach integrated with self-diagnosis and self-reconfiguration reasoning method. Firstly, the developed method is introduced for large structural health monitoring. Then, the effects of piezoelectric actuator and sensor bonding defects on Lamb wave propagations are investigated in a real-world monitoring experiment for the large aviation aluminum plate. Lastly, the self-diagnosis and self-reconfiguration method of piezoelectric actuator and sensor network for large structural health monitoring based on Lamb wave for the passive and active damage monitoring is verified in the experiment. Based on the results shown in the experiment, a big potential in real-time application demonstrates that the method can accurately and rapidly identify the sensor failure by reasoning and analyzing Lamb wave propagations using proposed methods. Dong Liang, Liaoni Wu, Zhifeng Fan, and Yang Xu Copyright © 2015 Dong Liang et al. All rights reserved. Mining Potential Spammers from Mobile Call Logs Wed, 15 Apr 2015 11:46:47 +0000 http://www.hindawi.com/journals/ijdsn/2015/143745/ With the rapid development of mobile telecommunication, voice call spam has become a growing problem in China. Many mobile phone users have become the victim of spam calls and suffered heavy financial loss. Discovering of call spammers can benefit mobile network operators as well as users. Nowadays, the popular method for the task of mining call spammers has been performed by different applications on smartphones. These applications combine manual and automatic methods to detect spammers. Although the results of these client-based solutions are quite satisfying, it is extremely unfortunate that many people still use feature phones, which can not be equipped with third party applications. In this paper, we propose a server-based solution and take a call log file as an example, to analyze the characteristics of mobile call patterns. A time-based graph model and a simple and effective call log rank (CLRank) algorithm with ranking and classification were proposed to find potential call spammers. Compared with existing methods, our model just uses link information, and thus protects user privacy to the maximum extent. Experimental results show that our proposed model can find spammers from call logs automatically, dynamically, and effectively (with 84.5~91.8% of accuracy) without any manual interventions. Zhipeng Liu, Dechang Pi, and Yunfang Chen Copyright © 2015 Zhipeng Liu et al. All rights reserved. An Enhanced Communication Protocol for Location Privacy in WSN Wed, 15 Apr 2015 09:41:52 +0000 http://www.hindawi.com/journals/ijdsn/2015/697098/ Wireless sensor network (WSN) is built of many sensor nodes. The sensors can sense a phenomenon, which will be represented in a form of data and sent to an aggregator for further processing. WSN is used in many applications, such as object tracking and security monitoring. The objects in many situations need physical and location protection. In addition to the source location privacy, sink location privacy should be provided. Providing an efficient location privacy solution would be challenging due to the open nature of the WSN. Anonymity is a key solution for location privacy. We present a network model that is protected against local, multilocal, and global adversaries that can launch sophisticated passive and active attacks against the WSN. Abdel-Shakour Abuzneid, Tarek Sobh, and Miad Faezipour Copyright © 2015 Abdel-Shakour Abuzneid et al. All rights reserved. Low-Power and Reliable Communications for UWB-Based Wireless Monitoring Sensor Networks in Underground Mine Tunnels Tue, 14 Apr 2015 13:45:56 +0000 http://www.hindawi.com/journals/ijdsn/2015/456460/ This paper investigates the bit-error-rate (BER) and maximum allowable data throughput (MADTh) performance of a novel low-power mismatched Rake receiver structure for ultra wideband (UWB) wireless monitoring sensor networks in underground mine tunnels. This receive node structure provides a promising solution for low-power and reliable communications in underground mine tunnels with more than 90% reduction in power consumption. The BER and MADTh of the proposed receive nodes are investigated via Monte-Carlo simulations in UWB line-of-sight (LOS) and non-line-of-sight (NLOS) underground mine tunnels. The proposed mismatched receive nodes achieve a MADTh and BER performance approaching the corresponding optimal nodes with ≈1 dB and 1.5 dB BER performance degradation in LOS and NLOS scenarios, respectively. The mismatched PRake (M-PRake) receiver model with represents the best choice for low-power and reliable communications in sensor networks in underground mine tunnels with BER performance degradation of 1 dB and 3 dB in LOS and NLOS scenarios, respectively, as compared to the optimum detector. This minimal degradation in performance is traded for more than 90% reduction in power consumption. Mohamad Abou El-Nasr and Heba Shaban Copyright © 2015 Mohamad Abou El-Nasr and Heba Shaban. All rights reserved. Indoor Mobile Localization Based on Wi-Fi Fingerprint’s Important Access Point Thu, 09 Apr 2015 12:52:32 +0000 http://www.hindawi.com/journals/ijdsn/2015/429104/ With the development of the wireless communication technology and intelligent mobile phone, the positioning services based on Wi-Fi and mobile phone are increasingly demanded. In this paper, a Wi-Fi fingerprint localization method is proposed on the basis of important access points (IAP). For the Wi-Fi fingerprint, Wi-Fi access point with the highest received signal strength (RSS) is denoted as the important access point. At the localization stage, the fingerprints are chosen with the same IAP as the estimated fingerprint from the database. Then, the distance and the AP repetition of the fingerprints are used to calculate the similarity degree. The location of the fingerprint which matches the estimated fingerprint well can be regarded as the estimated location. Experimental results show that the proposed algorithm can achieve high accuracy in indoor environment. Pei Jiang, Yunzhou Zhang, Wenyan Fu, Huiyu Liu, and Xiaolin Su Copyright © 2015 Pei Jiang et al. All rights reserved. Adaptive Security in ODMAC for Multihop Energy Harvesting Wireless Sensor Networks Thu, 09 Apr 2015 09:58:10 +0000 http://www.hindawi.com/journals/ijdsn/2015/760302/ Energy Harvesting Wireless Sensor Networks (EH-WSNs) represent an interesting new paradigm where individual nodes forming a network are powered by energy sources scavenged from the surrounding environment. This technique provides numerous advantages, but also new design challenges. Securing the communications under energy constraints represents one of these key challenges. The amount of energy available is theoretically infinite in the long run but highly variable over short periods of time, and managing it is a crucial aspect. In this paper we present an adaptive approach for security in multihop EH-WSNs which allows different nodes to dynamically choose the most appropriate energy-affecting parameters such as encryption algorithm and key size, providing in this way energy savings. In order to provide evidence of the approach’s feasibility in a real-world network, we have designed and implemented it as extension of on-demand medium access control (ODMAC), a receiver-initiated (RI) MAC protocol specifically designed and developed to address the foundational energy-related needs of Energy Harvesting Wireless Sensor Networks. Alessio Di Mauro, Xenofon Fafoutis, and Nicola Dragoni Copyright © 2015 Alessio Di Mauro et al. All rights reserved. Co-UWSN: Cooperative Energy-Efficient Protocol for Underwater WSNs Tue, 07 Apr 2015 14:18:06 +0000 http://www.hindawi.com/journals/ijdsn/2015/891410/ Sensor networks feature low-cost sensor devices with wireless network capability, limited transmit power, resource constraints, and limited battery energy. Cooperative routing exploits the broadcast nature of wireless medium and transmits cooperatively using nearby sensor nodes as relays. It is a promising technique that utilizes cooperative communication to improve the communication quality of single-antenna sensor nodes. In this paper, we propose a cooperative transmission scheme for underwater sensor networks (UWSNs) to enhance the network performance. Cooperative diversity has been introduced to combat fading. Cooperative UWSN (Co-UWSN) is proposed, which is a reliable, energy-efficient, and high throughput routing protocol for UWSN. Destination and potential relays are selected that utilize distance and signal-to-noise ratio computation of the channel conditions as cost functions. This contributes to sufficient decrease in path losses occurring in the links and transferring of data with much reduced path loss. Simulation results show that Co-UWSN protocol performs better in terms of end-to-end delay, energy consumption, and network lifetime. Selected protocols for comparison are energy-efficient depth-based routing (EEDBR), improved adaptive mobility of courier nodes in threshold-optimized depth-based routing (iAMCTD), cooperative routing protocol for UWSN, and cooperative partner node selection criteria for cooperative routing Coop (Re and dth). S. Ahmed, N. Javaid, F. A. Khan, M. Y. Durrani, A. Ali, A. Shaukat, M. M. Sandhu, Z. A. Khan, and U. Qasim Copyright © 2015 S. Ahmed et al. All rights reserved. EAP-Swift: An Efficient Authentication and Key Generation Mechanism for Resource Constrained WSNs Tue, 07 Apr 2015 14:15:50 +0000 http://www.hindawi.com/journals/ijdsn/2015/460914/ Technological advances within the area of wireless sensor technology allow WSNs to be used in a increasing number of measurement scenarios. As new application areas are emerging, such as infrastructure monitoring and smart cities, the need for sensor mobility handling requires efficient and secure authentication protocols. This paper presents EAP-Swift, a novel EAP based authentication protocol with a focus on lightweight processing and faster response. It supports end-to-end session encryption key generation and mutual authentication. By utilizing lightweight hashing algorithms, the challenge-response authentication mechanism uses only two round trips to the AAA server for the complete authentication procedure leading to the reduction of latency by 33% compared to the baseline protocols. Further, using extensive experimentation, we validate that the authentication time can be kept below 250 ms and the power consumption can be kept below 15 mJ. Furthermore, we show that a battery lifetime of more than four years can be achieved when running the system on a regular button cell battery. Finally, the protocol was verified in terms of security using the AVISPA tool. Daniel Granlund, Christer Åhlund, and Patrik Holmlund Copyright © 2015 Daniel Granlund et al. All rights reserved. A Secure User Authentication Scheme against Smart-Card Loss Attack for Wireless Sensor Networks Using Symmetric Key Techniques Tue, 07 Apr 2015 13:59:05 +0000 http://www.hindawi.com/journals/ijdsn/2015/704502/ User authentication in wireless sensor networks (WSNs) is a critical security issue due to their unattended and hostile deployment in the field. In order to protect the security of real-time data query from an external user, many two-factor (password and smart-card) user authentication schemes are proposed. However, most of them are insecure against various attacks. This paper summarizes attacks and security requirements for two-factor user authentication in WSNs. Based on security requirements, a user authentication and session key establishment scheme is also proposed, and this scheme can resist smart-card loss attack merely by using symmetric key techniques. Security and performance analysis demonstrate that, compared to the existing schemes, the proposed approach is more secure and highly efficient. Lei Chen, Fushan Wei, and Chuangui Ma Copyright © 2015 Lei Chen et al. All rights reserved. On the Selection of Information Sources for Gossip Spreading Tue, 07 Apr 2015 13:28:01 +0000 http://www.hindawi.com/journals/ijdsn/2015/276014/ Information diffusion is efficient via gossip or rumor spreading in many of the next generation networks. It is of great importance to select some seed nodes as information sources in a network so as to maximize the gossip spreading. In this paper, we deal with the issue of the selection of information sources, which are initially informed nodes (i.e., seed nodes) in a network, for pull-based gossip protocol. We prove that the gossip spreading maximization problem (GSMP) is NP-hard. We establish a temporal mapping of the gossip spreading process using virtual coupon collectors by leveraging the concept of temporal network, further prove that the gossip spreading process has the property of submodularity, and consequently propose a greedy algorithm for selecting the information sources, which yields a suboptimal solution within of the optimal value for GSMP. Experiments are carried out to study the spreading performance, illustrating the significant superiority of the greedy algorithm over heuristic and random algorithms. Wenxiang Dong, Ying Yang, and Wenyi Zhang Copyright © 2015 Wenxiang Dong et al. All rights reserved. Weight-RSS: A Calibration-Free and Robust Method for WLAN-Based Indoor Positioning Tue, 07 Apr 2015 13:18:46 +0000 http://www.hindawi.com/journals/ijdsn/2015/573582/ Wi-Fi fingerprinting has become a promising solution for indoor positioning with the rapid deployment of WLAN and the growing popularity of mobile devices. In fingerprint-based positioning, the received signal strengths (RSS) from WLAN access points (APs) usually are regarded as positioning fingerprint to label physical location. However, the RSS variance caused by heterogeneous devices and dynamic environmental status will significantly degrade the positioning accuracy. In this paper, we first show the RSS variance based on a real dataset and analyze the relation existing in the RSS raw values. Then, we utilize both the raw RSS values and their relation to construct a new stable and robust fingerprint for indoor positioning. Experiment results indicate that our method can solve the RSS variance problem without any manual calibration. Zengwei Zheng, Yuanyi Chen, Tao He, Fei Li, and Dan Chen Copyright © 2015 Zengwei Zheng et al. All rights reserved. Flood Diversion Algorithm for Anticollision in RFID System Tue, 07 Apr 2015 13:08:14 +0000 http://www.hindawi.com/journals/ijdsn/2015/245914/ Radio frequency identification (RFID) provides a contactless approach for object identification. If there are multiple tags in the interrogation zone of a reader, tag collision occurs due to radio signal interference. To solve tags identification collision and improve identification efficiency in RFID system, a flood division anticollision (FDAC) algorithm has been presented. Firstly, the algorithm launches an estimation of the number of tags and according to the estimation result decides whether a flood diversion processing needs to be started or not. Secondly, when the flood diversion processing needs to be done, all tags are grouped and assigned to different models in which the tags are to be processed and identified in parallel. Thirdly, in the identification processing, for reducing data transmission, the reader needs only to send a three-dimensional-vector command to tags, tags respond to the command with part of collision-bit parameters, and stack and queue are adopted to store precious request command and tags’ ID to avoid repeatedly transmitting them between the reader and the tags. Simulation experiment results show that FDAC is superior to the dynamic frame slotted (DFS) Aloha algorithm, the binary-retreat tree algorithm (BRT) and the dynamic binary-search tree (DBST) algorithm, in the performances of data bits transmission, identification time delay, and energy consumption by the reader. Hua Huo, Jun Qiang Liu, and Yong Jie Wang Copyright © 2015 Hua Huo et al. All rights reserved. Design of a Wireless Sensor Network Monitoring System for Biological and Pharmaceutical Products Tue, 07 Apr 2015 11:34:46 +0000 http://www.hindawi.com/journals/ijdsn/2015/760242/ Biological and pharmaceutical (B&P) products are essential in modern life. Currently, the demand and requirements of these products are dramatically growing; product quality and integrity then become crucial. As a key factor for ensuring quality and integrity, the current product status monitoring system needs to be enhanced in a more sophisticated and comprehensive way. This research describes the design of a wireless sensor network (WSN) monitoring system for B&P products supply chain management. In this study, the system architecture is presented based on the proposed framework. The framework consists of three processes: the first one is to generate a WSN with full coverage, the second one is to determine the optimal position of the sink, and the last process is to add additional relay nodes for providing fault tolerance to the network. Finally, a feasibility test on B&P product storage in a hospital is conducted. The proposed system provides a systematic approach for the deployment of sensor nodes and relay nodes. It also provides a relatively simple and rapid method for industries in general to follow and implement when designing a WSN system. Chun Ho Wu, Chun Kit Ng, Lixing Wang, G. T. S. Ho, W. H. Ip, and J. Zhang Copyright © 2015 Chun Ho Wu et al. All rights reserved. 3D Self-Deployment Algorithm in Mobile Wireless Sensor Networks Mon, 06 Apr 2015 08:30:43 +0000 http://www.hindawi.com/journals/ijdsn/2015/721921/ The sensor deployment problem of wireless sensor networks (WSNs) is a key issue in the researches and the applications of WSNs. Fewer works focus on the 3D autonomous deployment. Aimed at the problem of sensor deployment in three-dimensional spaces, the 3D self-deployment (3DSD) algorithm in mobile sensor networks is proposed. A 3D virtual force model is utilized in the 3DSD method. A negotiation tactic is introduced to ensure network connectivity, and a density control strategy is used to balance the node distribution. The proposed algorithm can fulfill the nodes autonomous deployment in 3D space with obstacles. Simulation results indicate that the deployment process of 3DSD is relatively rapid and the nodes are well distributed. Furthermore, the coverage ratio of 3DSD approximates the theoretical maximum value. Chunyu Miao, Guoyong Dai, Xiaomin Zhao, Zhongze Tang, and Qingzhang Chen Copyright © 2015 Chunyu Miao et al. All rights reserved. Comprehensive Evaluation of Energy Efficiency Based on TOPSIS for Protocols of Collaborative Wireless Sensor Networks Sun, 05 Apr 2015 06:57:13 +0000 http://www.hindawi.com/journals/ijdsn/2015/640736/ Comprehensive evaluation of energy efficiency of protocols under certain cost conditions is a relatively new and ill-defined concept for collaborative wireless sensor networks (CWSN). In this paper, multicriteria decision making (MCDM) theory is introduced into comprehensive evaluation of energy efficiency of clustering protocols, which is the predecessor of collaborative protocols. Parameters about energy efficiency of total network, including cost and benefit parameters, are selected to construct a metrics system for the comprehensive evaluation. Technique for order preference by similarity to ideal solution (TOPSIS) without criterion weight is proposed as the method of MCDM, and it can be used to select most efficient scheme among many schemes. The experimental results show that the proposed method is effective and can be used in CWSN protocol selection and deployment of nodes. Ji’an Li, Jianzhong Zhou, and Yongchuan Zhang Copyright © 2015 Ji’an Li et al. All rights reserved. Distributed Sensor Fusion for Wire Fault Location Using Sensor Clustering Strategy Wed, 01 Apr 2015 11:04:05 +0000 http://www.hindawi.com/journals/ijdsn/2015/538643/ From reflectometry methods, this work aims at locating accurately electrical faults in complex wiring networks. Increasing demand for online diagnosis has imposed serious challenges on interference mitigation. In particular, diagnosis has to be carried out while the target system is operating. The interference becomes more even critical in the case of complex networks where distributed sensors inject their signals simultaneously. The objective of this paper is to develop a new embedded diagnosis strategy in complex wired networks that would resolve interference problems and eliminate ambiguities related to fault location. To do so, OMTDR (Orthogonal Multi-tone Time Domain Reflectometry) method is used. For better coverage of the network, communication between sensors is integrated using the transmitted part of the OMTDR signal. It enables data control and transmission for fusion to facilitate fault location. In order to overcome degradation of diagnosis reliability and communication quality, we propose a new sensor clustering strategy based on network topology in terms of distance and number of junctions. Based on CAN bus network, we prove that data fusion using sensor clustering strategy permits to improve the diagnosis performance. Wafa Ben Hassen, Fabrice Auzanneau, Luca Incarbone, François Pérès, and Ayeley P. Tchangani Copyright © 2015 Wafa Ben Hassen et al. All rights reserved. An Automatic Wi-Fi-Based Approach for Extraction of User Places and Their Context Tue, 31 Mar 2015 13:06:11 +0000 http://www.hindawi.com/journals/ijdsn/2015/154958/ With the analysis of various sensor data from the mobile devices, it is possible to extract user situations, so-called user context. This is needed for the development of modern, user-friendly services. Therefore, we developed a simple, nonintrusive, and automatic method based on the Wi-Fi fingerprints and GPS. The method finds user stay points, aggregates them into meaningful stay regions, and assigns them four general user contexts: home, work, transit, and free time. We evaluated its performance on the real traces of six different users who annotated their contexts over eight days. The method determined the stay mode of the users with accuracy, precision, and recall of above 96%. In combination with the novel approach for aggregation, all regions relevant to the users were determined. Among the tested aggregation schemes, the fingerprint similarity approach worked the best. The context of the determined stay regions was on average accurately inferred in 98% of the time. For the contexts home, work, and free time, the precision and recall exceeded 86%. The results indicate that the method is robust and can be deployed in various fields where context awareness is desired. Luka Vidmar, Mitja Štular, Andrej Kos, and Matevž Pogačnik Copyright © 2015 Luka Vidmar et al. All rights reserved. Source-Aware Redundant Packet Forwarding Scheme for Emergency Information Delivery in Chain-Typed Multihop Wireless Sensor Networks Tue, 31 Mar 2015 11:51:39 +0000 http://www.hindawi.com/journals/ijdsn/2015/405374/ For emergency information delivery of chain-typed multihop wireless sensor networks in closed long tunnel (CWSN-C), the scheme of sending the same packet multiple times is a good choice. In this paper, taking the application of rigid sliding guide obliquity monitoring in deep shaft as background, the source-aware redundant packet forwarding scheme for emergency information delivery in CWSN-C (SRPFEC) is proposed firstly. Secondly, more of comprehensive factors including application QoS and energy efficiency are considered for determining the number of redundant packets. Then, a method of solving for the number of redundant packets is proposed. Finally, Monte Carlo method and network simulation are employed to study the performances of proposed SRPFEC. The results show that (1) non-ACK scheme is highly suitable for the condition of large network size and hazardous wireless communication environment; (2) the non-source-aware solution is easy to use and is suitable for the occasion where the node could be replaced on demand expediently; (3) the source-aware solution has the better performance in energy efficiency and is suitable for the occasion where the network lifetime needs to be determined before deployment, and the node could not be replaced easily. Gongbo Zhou, Zhencai Zhu, Peng Zhang, and Wei Li Copyright © 2015 Gongbo Zhou et al. All rights reserved. A Deadline-Aware and Distance-Aware Packet Scheduling Algorithm for Wireless Multimedia Sensor Networks Tue, 31 Mar 2015 10:59:15 +0000 http://www.hindawi.com/journals/ijdsn/2015/803123/ We propose a wireless differentiated queuing service (WDQS) algorithm to meet the diverse delay requirements in wireless multimedia sensor networks (WMSNs). WDQS adopts novel latest departure time (LDT) scheduling criteria to differentiate forwarding emergency by considering the packets’ lifetime, the known delay it has already experienced, and the remaining delay it will experience. We also propose an effective approach to estimate the unknown delay for the remaining journey without any message overhead by exploiting the query mechanism of the sink. We further discuss analytically the packet’s lifetime setting to meet the end-to-end (e2e) delivery requirement. The simulation results verify our analytical discussion and show performance improvements in terms of e2e delay and packet drop rate. Lin Tang, Quansheng Guan, Shengming Jiang, and Bingyi Guo Copyright © 2015 Lin Tang et al. All rights reserved. Image-Based Object Identification for Efficient Event-Driven Sensing in Wireless Multimedia Sensor Networks Mon, 30 Mar 2015 12:21:45 +0000 http://www.hindawi.com/journals/ijdsn/2015/850869/ Applications based on video and image in wireless sensor network are highly attractive due to their wealth of information. In this context, application for object recognition and tracking using image and video information is one the attractive approaches that can be applied for event detection and localization, security processes, following of the rare animal species and control of road traffic, and so forth. However, the implementation of such approach with WMSN requires a specific image processing scheme and efficient transmission protocol. In fact, because of the limited energy of the batteries embedded in motes, the power consumption is the major constraint facing network life time and reliability in WMSN. The efficiency and the validity of these multimedia applications over wireless sensor networks are then dependent on the capabilities of the designer to provide low-power scheme for data processing and energy-aware transmission protocols. This paper presents a contribution to the design of low complexity scheme based on object identification for efficient sensing of multimedia information in wireless multimedia sensor networks. It proposes a new solution and explores the associated performances of this scheme. The presented results in this paper attest the high efficiency to achieve low-power objects identification when implemented in wireless motes. Mohsin S. Alhilal, Adel Soudani, and Abdullah Al-Dhelaan Copyright © 2015 Mohsin S. Alhilal et al. All rights reserved. Heuristic Algorithms for One-Slot Link Scheduling in Wireless Sensor Networks under SINR Mon, 30 Mar 2015 08:25:49 +0000 http://www.hindawi.com/journals/ijdsn/2015/806520/ One-slot link scheduling is important for enhancing the throughput capacity of wireless sensor networks. It includes two aspects: maximum links scheduling (MLS) and maximum weighted links scheduling (MWLS). In this paper we propose two heuristic algorithms for the two NP-hard problems with obvious power assignments under the SINR (signal-to-interference-plus-noise-ratio) model. For MLS, we propose an algorithm MTMA (maximum tolerance and minimum affectance), which improves the currently best approximation algorithm by 28%–62% on average. For MWLS, we give an effective heuristic algorithm MWMA (maximum weighted and minimum affectance), which performs better on improving the throughput and reducing the running time. The correctness and performance of our algorithms are confirmed through theoretical analysis and comprehensive simulations. Hui Deng, Jiguo Yu, Dongxiao Yu, Guangshun Li, and Baogui Huang Copyright © 2015 Hui Deng et al. All rights reserved. Self-Organizing Architecture for Information Fusion in Distributed Sensor Networks Sun, 29 Mar 2015 08:21:42 +0000 http://www.hindawi.com/journals/ijdsn/2015/231073/ The management of heterogeneous distributed sensor networks requires new solutions that can address the problem of automatically fusing the information coming from different sources in an efficient and effective manner. In the literature it is possible to find different types of data fusion and information fusion techniques in use today, but it is still a challenge to obtain systems that allow the automation or semiautomation of information processing and fusion. In this paper, we present a multiagent system that based on the organizational theory proposes a new model to automatically process and fuse information in heterogeneous distributed sensor networks. The proposed architecture is applied to a case study for indoor location where information is taken from different heterogeneous sensors. Javier Bajo, Juan F. De Paz, Gabriel Villarrubia, and Juan M. Corchado Copyright © 2015 Javier Bajo et al. All rights reserved. A Breakthrough in Multihop Wireless Multimedia Sensor Networking Protocols Thu, 26 Mar 2015 09:34:26 +0000 http://www.hindawi.com/journals/ijdsn/2015/921040/ Byung-Seo Kim, Sung Won Kim, Chi Zhang, and Miao Pan Copyright © 2015 Byung-Seo Kim et al. All rights reserved. Verification and Validation of the Performance of WSN Thu, 26 Mar 2015 07:46:33 +0000 http://www.hindawi.com/journals/ijdsn/2015/960170/ Seong-eun Yoo, Poh Kit Chong, Seong Hoon Kim, and Minh-Long Pham Copyright © 2015 Seong-eun Yoo et al. All rights reserved. Balance Transmission Mechanism in Underwater Acoustic Sensor Networks Wed, 25 Mar 2015 14:11:31 +0000 http://www.hindawi.com/journals/ijdsn/2015/429340/ With the rapid development of underwater acoustic modem technology, underwater acoustic sensor networks (UWASNs) have more applications in long-term monitoring of the deployment area. In the underwater environment, the sensors are costly with limited energy. And acoustic communication medium poses new challenges, including high path loss, low bandwidth, and high energy consumption. Therefore, designing transmission mechanism to decrease energy consumption and to optimize the lifetime of UWASN becomes a significant task. This paper proposes a balance transmission mechanism, and divides the data transmission process into two phases. In the routing set-up phase, an efficient routing algorithm based on the optimum transmission distance is present to optimize the energy consumption of the UWASN. And then, a data balance transmission algorithm is introduced in the stable data transmission phase. The algorithm determines one-hop or multihop data transmission of the node to underwater sink according to the current energy level of adjacent nodes. Furthermore, detailed theoretical analysis evaluates the optimum energy levels in the UWASNs with different scales. The simulation results prove the efficiency of the BTM. Jiabao Cao, Jinfeng Dou, and Shunle Dong Copyright © 2015 Jiabao Cao et al. All rights reserved. Delay-Sensitive Routing Schemes for Underwater Acoustic Sensor Networks Wed, 25 Mar 2015 06:37:46 +0000 http://www.hindawi.com/journals/ijdsn/2015/532676/ Underwater Acoustic Sensor Networks (UASNs) offer their practicable applications in seismic monitoring, sea mine detection, and disaster prevention. In these networks, fundamental difference between operational methodologies of routing schemes arises due to the requirement of time-critical applications; therefore, there is a need for the design of delay-sensitive techniques. In this paper, Delay-Sensitive Depth-Based Routing (DSDBR), Delay-Sensitive Energy Efficient Depth-Based Routing (DSEEDBR), and Delay-Sensitive Adaptive Mobility of Courier nodes in Threshold-optimized Depth-based routing (DSAMCTD) protocols are proposed to empower the depth-based routing schemes. The performance of the proposed schemes is validated in UASNs. All of the three schemes formulate delay-efficient Priority Factors (PF) and Delay-Sensitive Holding time () to minimize end-to-end delay with a small decrease in network throughput. These schemes also employ an optimal weight function () for the computation of transmission loss and speed of received signal. Furthermore, solution for delay lies in efficient data forwarding, minimal relative transmissions in low-depth region, and better forwarder selection. Simulations are performed to assess the proposed protocols and the results indicate that the three schemes largely minimize end-to-end delay along with improving the transmission loss of network. N. Javaid, M. R. Jafri, S. Ahmed, M. Jamil, Z. A. Khan, U. Qasim, and S. S. Al-Saleh Copyright © 2015 N. Javaid et al. All rights reserved.