International Journal of Distributed Sensor Networks The latest articles from Hindawi Publishing Corporation © 2014 , Hindawi Publishing Corporation . All rights reserved. A Novel Mesh Routing Using the Nodes with Identical Tree Level Mon, 24 Nov 2014 08:57:34 +0000 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 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 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 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 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 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 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 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 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 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 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 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 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 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 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 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 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 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 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 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 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. Distributed Vector Quantization over Sensor Network Mon, 13 Oct 2014 07:25:17 +0000 A vector quantizer is a system for encoding the original data to reduce the bits needed for communication and storage saving while maintaining the necessary fidelity of the data. Signal processing over distributed network has received a lot of attention in recent years, due to the rapid development of sensor network. Gathering data to a central processing node is usually infeasible for sensor network due to limited communication resource and power. As a kind of data compression methods, vector quantization is an appealing technique for distributed network signal processing. In this paper, we develop two distributed vector quantization algorithms based on the Linde-Buzo-Gray (LBG) algorithm and the self-organization map (SOM). In our algorithms, each node processes the local data and transmits the local processing results to its neighbors. Each node then fuses the information from the neighbors. Our algorithms remarkably reduce the communication complexity compared with traditional algorithms processing all the distributed data in one central fusion node. Simulation results show that both of the proposed distributed algorithms have good performance. Chunguang Li and Yiliang Luo Copyright © 2014 Chunguang Li and Yiliang Luo. All rights reserved. Reliability Aware Routing for Intra-Wireless Body Sensor Networks Sun, 12 Oct 2014 11:29:49 +0000 With the promise of cost effective, unobtrusive, and unsupervised continuous monitoring, wireless body sensor networks (WBSNs) have attracted a wide range of monitoring applications such as medical and healthcare, sport activity, and rehabilitation systems. Most WBSN’s medical and healthcare applications are real-time and life-critical, which require strict guarantee of quality of service (QoS), in terms of latency, and reliability. Reliability in routing plays key role in providing the overall reliability in WBSNs. This paper presents reliability aware routing (RAR) for intra-WBSNs that aims to provide high reliability for reliability constraint data packets. It considers the high and dynamic path loss due to body postural movements and temperature rise of the implanted biomedical sensor nodes. We have used two network models in this paper: RAR without Relays (RAR) and RAR with Relays (RARR). The simulation results reveal that RARR outperforms the other state-of-the-art schemes while RAR has slightly low reliability at low data rates as compared to RARR but significantly higher than other state-of-the-art schemes. Javed Iqbal Bangash, Abdul Hanan Abdullah, Mohammad Abdur Razzaque, and Abdul Waheed Khan Copyright © 2014 Javed Iqbal Bangash et al. All rights reserved. Performance Analysis of Resource-Aware Task Scheduling Methods in Wireless Sensor Networks Mon, 22 Sep 2014 07:51:27 +0000 Wireless sensor networks (WSNs) are an attractive platform for monitoring and measuring physical phenomena. WSNs typically consist of hundreds or thousands of battery-operated tiny sensor nodes which are connected via a low data rate wireless network. A WSN application, such as object tracking or environmental monitoring, is composed of individual tasks which must be scheduled on each node. Naturally the order of task execution influences the performance of the WSN application. Scheduling the tasks such that the performance is increased while the energy consumption remains low is a key challenge. In this paper we apply online learning to task scheduling in order to explore the tradeoff between performance and energy consumption. This helps to dynamically identify effective scheduling policies for the sensor nodes. The energy consumption for computation and communication is represented by a parameter for each application task. We compare resource-aware task scheduling based on three online learning methods: independent reinforcement learning (RL), cooperative reinforcement learning (CRL), and exponential weight for exploration and exploitation (Exp3). Our evaluation is based on the performance and energy consumption of a prototypical target tracking application. We further determine the communication overhead and computational effort of these methods. Muhidul Islam Khan and Bernhard Rinner Copyright © 2014 Muhidul Islam Khan and Bernhard Rinner. All rights reserved. Advanced Sensor Technology and Applications in Industrial Control System 2014 Thu, 18 Sep 2014 06:14:26 +0000 Tai-hoon Kim, Sabah Mohammed, Ruay-Shiung Chang, and Carlos Ramos Copyright © 2014 Tai-hoon Kim et al. All rights reserved. P-LEACH: An Efficient Cluster-Based Technique to Track Mobile Sinks in Wireless Sensor Networks Wed, 17 Sep 2014 06:04:51 +0000 For a wireless sensor network (WSN) with a large number of inexpensive sensor nodes, energy efficiency is the major concern in designing network structure and related algorithms. If network collects sensor data using mobile sinks, object tracking mechanism must consider the energy efficiency of sensor nodes in the networks as a whole. Recently research works on WSNs with mobile sinks apply prediction techniques for sink tracking in order to improve tracking precision while keeping the number of active nodes to the minimum. In this paper, we analyze existing works for sink tracking in WSN and propose P-LEACH that is cluster-based prediction technique for WSN with mobile sinks. Simulation results show that P-LEACH performs better than previous techniques in terms of energy saving of sensor nodes and data transmission performance. Sungchol Cho, Li Han, Bokgyu Joo, and Sunyoung Han Copyright © 2014 Sungchol Cho et al. All rights reserved. A Lightweight Classification Algorithm for External Sources of Interference in IEEE 802.15.4-Based Wireless Sensor Networks Operating at the 2.4 GHz Tue, 16 Sep 2014 09:23:02 +0000 IEEE 802.15.4 is the technology behind wireless sensor networks (WSNs) and ZigBee. Most of the IEEE 802.15.4 radios operate in the crowded 2.4 GHz frequency band, which is used by many technologies. Since IEEE 802.15.4 is a low power technology, the avoidance of interference is vital to conserve energy and to extend the lifetime of devices. A lightweight classification algorithm is presented to detect the common external sources of interference in the 2.4 GHz frequency band, namely, IEEE 802.11-based wireless local area networks (WLANs), Bluetooth, and microwave ovens. This lightweight algorithm uses the energy detection (ED) feature (the feature behind received signal strength indication (RSSI)) of an IEEE 802.15.4-compliant radio. Therefore, it classifies the interferers without demodulation of their signals. As it relies on time patterns instead of spectral features, the algorithm has no need to change the channel. Thus, it allows the radio both to stay connected to the channel and to receive while scanning. Furthermore, it has a maximum runtime of merely one second. The algorithm is extensively tested in a radio frequency anechoic chamber and in real world scenarios. These results are presented here. Sven Zacharias, Thomas Newe, Sinead O’Keeffe, and Elfed Lewis Copyright © 2014 Sven Zacharias et al. All rights reserved. Multi-Channel Packet-Analysis System Based on IEEE 802.15.4 Packet-Capturing Modules Tue, 16 Sep 2014 07:42:06 +0000 There have been increasing demands for research into multi-channel-based wireless sensor network protocols and applications to support requirements such as increased throughput and real-time or reliable transmission. Researchers or developers of these protocols and applications have to simultaneously analyze the exchanged packets for correctness of both their contents and message exchange timelines. However, if developers were to use multiple conventional single-channel packet sniffers for this purpose, debugging during development and the verification process becomes extremely tedious and difficult because of the need to check the correctness of the protocols over multiple channels individually. Therefore, we present a multi-channel packet-analysis system (MPAS) that helps in debugging and verification for multi-channel protocols or applications. Wireless packets are detected and timestamped by each sniffer module in the MPAS for each channel, and packets are preprocessed and transmitted to a GUI-based analyzer, which then parses the received packets and shows them in order. We present the design and implementation results of the MPAS and evaluate its performance by comparing it against a widely used packet sniffer. Seong-eun Yoo, Poh Kit Chong, Jeonghwan Bae, Tae-Soo Kim, Hiecheol Kim, and Joonhyuk Yoo Copyright © 2014 Seong-eun Yoo et al. All rights reserved. QoS-Based Path Switching Mechanism in Mobile SCTP Mon, 15 Sep 2014 08:15:43 +0000 In mobile SCTP, a mobile terminal has two or more network interfaces and vertical handover occurs when it moves from one network to another. The delay due to the handover process and the slow-start phase of SCTP’s congestion control after handover cause substantial performance degradation. If the mobile node goes back and forth frequently, excessive handovers occur and data transmission quality deteriorates. In order to provide the required level of QoS for on-going application, the frequency of handovers should be kept minimized. In this paper, we propose a transport layer handover mechanism using the mobile SCTP. We take the QoS requirements of application as the major criterion in deciding path switching. In our mechanism, the mobile node in overlapping area does not perform handover if the current network metrics satisfy the QoS requirements of on-going application. Both analytic evaluation and simulation results show that the proposed mechanism significantly improves the throughput by suppressing unnecessary handovers. Our research results can also be applied to distributed mobile sensor networks. Li Han, Shimin Sun, Bokgyu Joo, and Sunyoung Han Copyright © 2014 Li Han et al. All rights reserved. Theoretical and Linearity Analysis for Pressure Sensors and Communication System Development Sun, 14 Sep 2014 00:00:00 +0000 For the safety, reliability, and fuel economy, new road vehicles and automotive pressure sensor are being equipped with tire pressure measurement system (TPMS) in the vehicle. This paper describes the theoretical analysis and linear behavior of direct-type tire pressure sensor while the vehicle is operating. A rugged pressure sensor, thin-film piezoresistive pressure sensor, design is presented as a modular design approach for TPMS, where all the main parts of the TPMS can be connected together for easiness in integration, maintenance, and replaceability. This can also result in reducing replacement cost as well as maintaining linearity behavior of pressure sensor’s property. Three-dimensional model was analyzed with material properties; the resonance frequency of the model calculated is 24 kHz and sensitivity is calculated to be 1.2 µV/V·kPa. Our result shows that a thin-film technology of sensor design is still a viable solution for vehicular sensor and system measurement development. Taikyeong Jeong Copyright © 2014 Taikyeong Jeong. All rights reserved.