Forthcoming articles


International Journal of Ad Hoc and Ubiquitous Computing


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International Journal of Ad Hoc and Ubiquitous Computing (130 papers in press)


Regular Issues


  • Privacy and Technology Challenges for Ubiquitous Social Networking   Order a copy of this article
    by Antonio Sapuppo, Boon-Chong Seet 
    Abstract: Ubiquitous social networking can be seen as an evolution of ubiquitous computing supporting the social well-being of people in their everyday lives. The vision of ubiquitous social networking focuses on enhancing social interactions among its participants during users physical meetings. This target is leading towards important challenges such as social sensing, enabling social networking and privacy protection. In this paper we firstly investigate the methods and technologies for acquisition of the relevant context for promotion of sociability among inhabitants of ubiquitous social networking environments. Afterwards, we review architectures and techniques for enabling social interactions between participants. Finally, we identify privacy as the major challenge for networking in ubiquitous social networking environments. Consequently, we depict design guidelines and review privacy protection models for facilitating personal information disclosure.
    Keywords: Privacy; Ubiquitous Computing; Information Disclosure; Context awareness; Social Networking; Design Guidelines.
  • Cross-Layer-based Reliable Robust Transmission for Emergency Messages in High Mobility Unreliable VANET Networks   Order a copy of this article
    by Ben-Jye Chang 
    Abstract: To achieve active safe driving and autonomous driverless vehicle have become a key trend in Intelligent Transport Systems (ITS) recently. However, in the high-mobility unreliable Vehicular Ad-hoc NETworks (VANETs), the emergency messages are difficult to disseminate to receivers in time. The efficiency of the active safe driving is thus degraded significantly. The reliable end-to-end transmission protocol suffers from extremely reliable links and high mobility, and hardly provides an accurate congestion window (cwnd) for transmissions. This paper thus proposes a Cross-Layer-based reliable robust Transmission Control Protocol, namely CL-TCP, to forward real-time emergency messages in VANET. To overcome the unstable network topology in VANET, CL-TCP proposes several TCP states: normal, congestion, loss, unstable, frozen and disconnecting, to control TCP cwnd according to the underlying network status of the layer 2 (L2) and the layer 3 (L3) protocols. Additionally, in L2 we propose the Enhanced AODV (EAODV) algorithm to determine the path with the longest path lifetime as the optimal path in L2, and thus increase the path reliability and maximize the throughput. The designed cross-layer messages include: CL_EAODV, CL_ICMP_FB, CL_ICMP_DU, etc. Numerical results demonstrate that CL-TCP outperforms others in goodput, the number of link-breaks, average packet delivery ratio, etc. Furthermore, CL-TCP yields a higher fairness among TCP connections.
    Keywords: Cross-layer, active safe driving, Enhanced AODV, Frozen state, reliable robust transmission, VANET
  • Efficient Traffic Load Reduction Algorithms for Mitigating Query Hotspots for Wireless Sensor Networks   Order a copy of this article
    by Chia-Hsu Kuo, Tzung-Shi Chen, Ying-Hung Lo 
    Abstract: In query-based wireless sensor networks, a hotspot of the designated node may cause the heavy power consumption due to the frequent query request among sensor nodes for specific events. A hotspot also leads to the fluctuation of traffic flow among its neighboring nodes and the unbalanced energy among those neighboring sensor nodes. To mitigate the hotspot phenomenon, a target region with the fluctuation of traffic flow around the hotspot in order to handle the unbalance traffic load is first constructed. In this paper, we propose two efficient traffic load reduction algorithms for mitigating query hotspots for wireless sensor networks. The algorithms solve the hotspot problem with frequent query requests. One is Distance-based Mobile Agent Selection (DMAS). The other is Greedy-based Mobile Agent Selection (GMAS). A sensor node connected to the boundary nodes in the target region, called limb node, shares the heavy traffic load of the hotspot by through of gathering the events to the hotspot and responding the request data to the targeted nodes. In other words, the boundary node equipped with mobile agent is called limb node that moves around the hotspot. By setting up mobile agents (boundary nodes) within a target region around the hotspot, we use DMAS and GMAS to mitigate the hotspot phenomenon. In this paper, we investigate the mobile agent selection problem and conduct the experiment in different environment condition. Experiment results include the comparisons of hotspot rate, the comparisons of total energy consumption, hotspot traffic rate with different RT value, hotspot traffic rate with different query frequency, and the effect of the hotspot overlay avoidance. The results show that both DMAS and GMAS can mitigate the traffic rate of hotspot around 50%, effectively.
    Keywords: Wireless Sensor Network; Hotspot; Mobile Agent; DMAS, GMAS.
  • Performance Evaluation of Beacon Enabled IEEE 802.15.4 Network with Downlink and Uplink Traffic and Limited Retransmission   Order a copy of this article
    by mahshad parsa, Seyed Ahmad Motamedi, Hadi Safdarkhani, Mohsen Maadani 
    Abstract: Nowadays, wireless communication is a developing technology. IEEE 802.15.4 is the commonly used standard in low-data-rate and low-power applications. In real-time communications, quality of service is an important issue where delay parameter plays a crucial role. In this paper, at first a novel Markov model has been proposed for the IEEE 802.15.4 standard considering limited retransmission and both uplink and downlink traffics at the same time. Then based on the developed model and using queuing theory the average transmission delay of a packet is derived. It is shown, using numerical simulations, that the behavior of the proposed model is close to the IEEE 802.15.4 protocol and the average delay derived from mathematical expressions and markov simulations are really close to each other.
    Keywords: IEEE 802.15.4 standard; Markov chain; Mac layer service time; Uplink and Downlink transmission; Packet delay
  • Crowd Location Forecasting at Points of Interest   Order a copy of this article
    by Jorge Alvarez-Lozano, J. Antonio García-Macías, Edgar Chávez 
    Abstract: Predicting the location of a mobile user in the near future can be used for a large number of user-centered ubiquitous applications. This can be extended to crowd-centered applications if a large number of users is included. In this paper we present a spatio-temporal prediction approach to forecast user location in a medium-term period. Our approach is based on the hypothesis that users exhibit a different mobility pattern for each day of the week. Once factored out this weekly pattern, user mobility among points of interest is postulated to be markovian. We trained a hidden Markov model to forecast user mobility and evaluated our approach using a public dataset. The experimental results show that our approach is effective considering a time period of up to seven hours. We obtained an accuracy of up to 81.75 % for a period of 30 minutes, and 66.25 % considering 7 hours.
    Keywords: Data mining; Data sharing; Spatio-temporal crowd location forecasting; User location predictability; User mobility similarity.
  • Selectable Sensing Period Optimization for Energy-Constrained Cognitive Radio Networks   Order a copy of this article
    by Long Zhang, Liusheng Huang, Hongli Xu 
    Abstract: Recently, cognitive radio has been proposed to improve the spectrum resource utilization. In cognitive radio networks, the secondary (or unauthorized) users (SUs) are allowed to sense, detect and utilize the frequency bands that are not currently being used. Once the primary user (PU) is active, the secondary users have to vacate the channel within certain amount of time. Thus, it is a challenging task to find the suitable sensing period for better spectrum utilization. In this paper, we propose a selectable sensing period optimization (SSPO) mechanism. In the algorithm, each secondary user use the different periods for channel detection according to the different channel states. so that we can deal with the tradeoff between spectrum utilization and energy consumption more flexibly. We consider the constraint of interference to PU and the energy consumption to compute the optimal sensing periods. Our simulation results demonstrate that, with the constraint of energy consumption, the SSPO algorithm can gain the spectrum utilization 22.8% more than the previous algorithm. Moreover, with the constraint of spectrum utilization, the SSPO algorithm can save the energy consumption 20.6% more than the previous algorithm.
    Keywords: Cognitive radio networks, Spectrum sensing, Energy constraint, Selectable sensing period
  • Performance Analyses of Minimizing Emergency Message Collisions and Maximizing Network Throughput in IEEE 802.11p VANET Network   Order a copy of this article
    by Ben-Jye Chang, Ying-Hsin Liang, Jiun-Ting Lai 
    Abstract: IEEE 802.11p is proposed as the VANET wireless MAC interface for the transmissions of emergency messages in V2V and V2I Communications. However, in a high mobility VANET, QoS of both the emergency message (EM) and handoff transmissions suffer from high collision probability of the contention-based media access mechanism and high interference exhibiting near the cell-edge that encodes a low coding rate of the Adaptive Modulation and Coding (AMC) scheme. Thus, this paper proposes an efficiency MAC for IEEE 802.11p to solve above critical issues, in which the approach consists of three main mechanisms: 1) the Sigmoid-based CW Decrease (SWD) algorithm,2) the Dynamic Initial CW (DIW) algorithm, and 3) Relay-based partition Collision Domain for Handoffs (RCDH). Note that the CW decrease formulation is determined based on the Sigmoid function. Numerical results demonstate that the analysis results are close to the simulation results, and thus justify the correctness of the mathematical analytical model. In addition, the proposed approach outperforms the compared approaches (including the IEEE 802.11p std.) in EM transmission delay, collision probability, throughput, and MAC frame dropping probability.
    Keywords: IEEE 802.11p, Markov chain model, Contention window, Sigmoid function, VANET
  • Link-Preserving Interference-Minimization Channel Assignment in Multi-Radio Wireless Mesh Networks   Order a copy of this article
    by Li-Hsing Yen, Kuo-Wei Huang 
    Abstract: Using multiple channels with multiple radios per node in a wireless mesh network can potentially improve system capacity. This design requires the appropriate assignments of channels/radios to wireless backhaul links and creates a tradeoff between conflicting constraints and requirements. This study attempts to maximize the number of operative links, where a link is operative if radios at both ends of the link share a common channel (i.e., are link-preserving) and experience sufficiently low co-channel interference. These two criteria are conflicting in nature. A link-centric, channel-first radio resource assignment scheme that considers physical interference model and tight radio constraint is proposed. The proposed approach ensures link preservation and assigns channels to links based on the predicted upper bound and lower bound of the accumulated co-channel interference associated with particular assignments. Simulation results indicate that the proposed algorithm outperformsrnexisting approaches in the number of operative links, particularly when only a few channels, or many radios, are available.
    Keywords: channel allocation; wireless mesh network; interference; multi-radio
  • An Efficient Indexing and Query Mechanism for Ubiquitous IoT Services   Order a copy of this article
    by Chu Du 
    Abstract: Nowadays mobile equipments are used widely and connected to the Internet ubiquitously. Billions of sensing devices are deployed for collecting context information in order to support intelligent and realtime decision support. Besides functionality specification, most devices have spatial and temporal constraints. In this setting, how to organize sensing devices properly and thus to achieve the discovery of devices efficiently with respect to the requirement of certain applications is a challenge. To remedy this issue, this paper proposes a multiple index method to organize sensing devices considering their functionality specifications, spatial and temporal attributes, and develops a query mechanism leveraging this multiple indexes. Experiment results show that this technique is effective and efficient.
    Keywords: Ubiquitous IoT Services; Sensing Devices; Functionality Clustering; Spatial and Temporal Indexes
  • BEST: A Bidirectional Efficiency-Privacy Transferable Authentication Protocol for RFID-Enabled Supply Chain   Order a copy of this article
    by Saiyu Qi, Li Lu, Zhenjiang Li, Mo Li 
    Abstract: Radio Frequency Identification (RFID) technique is gaining increasing popularity in supply chain for product management. By attaching a tag to each product, a reader can employ an authentication protocol to interrogate the tag's information for verification, which facilitates the automatic processing and monitoring of products in many applications. However, most current solutions cannot be directly used as they cannot balance the tradeoff between the privacy and efficiency for individual parties. In this paper, we design a bidirectional efficiency-privacy transferable (BEST) authentication protocol to address this issue. In a relatively secure domain, BEST works in an efficient manner to authenticate batches of tags with less privacy guarantee. Once the tags flow into open environment, BEST can migrate to provide stronger privacy protection to the tags with moderate efficiency degradation. The analytic result shows that BEST can well adapt to the RFID-enabled supply chain.
    Keywords: RFID; tag; product management; supply chain; authentication; privacy; communication efficiency; wireless device; secure protocol; dynamic requirements.
  • An Efficient Mutual Distance Bounding Protocol over a Binary Symmetric Noisy Communication Channel   Order a copy of this article
    by Hoda Jannati, Abolfazl Falahati 
    Abstract: Distance bounding protocols have been suggested to protect an RFID communication system against relay attack. In such protocols, a verifier establishes an upper bound for the physical distance between a user and itself as well as authenticating the user. Recently, mutual distance bounding protocols in which both communication parties play not only as a user but also as a verifier have been proposed to be deployed for secure positioning protocols. In this paper, the performance of the existing mutual distance bounding protocols is analyzed over a noisy communication channel. The analytic results show that these protocols provide a much higher rejection probability of a valid user due to channel errors than distance bounding protocols. Furthermore, a novel method is proposed to convert every distance bounding protocol into a mutual distance bounding protocol. Within this method, for each one of the two communication parties, the produced mutual distance bounding protocol provides the performance and security level exactly equal to those of its own associated distance bounding protocol at the same noisy environment, without transmitting any extra messages at the end of the protocol.
    Keywords: Mutual distance bounding protocol; Distance fraud attack; Mafia fraud attack; Relay attack; False-accept probability; False-reject probability; Rapid bit exchange.
  • An Energy-Efficient Two Phases Cluster Head Selection in Corona-Based Wireless Sensor Networks   Order a copy of this article
    by Chung-Shuo Fan 
    Abstract: Due to unbalanced traffic pattern of wireless sensor networks (WSNs), larger load may be imposed to CHs (cluster heads) around the sink. Under this situation, CHs closer to the BS drain their energy earlier than those farther away from the sink. This paper first calculates cluster density of each corona according to the energy consumption of each CH. Then, this paper defines the range of CH candidates in phase 1 and phase 2 in order to choose the suitable CH so that sensor nodes forward data toward the BS and reduce the energy consumption. This paper further adopts cluster maintenance, which implement the cross-level data transmissions when specific conditions happen. Simulation results show that the proposed TPS (Two Phases cluster head Selection in WSNs) effectively prolongs the network lifetime and reduces the energy consumption over LEACH (Low Energy Adaptive Clustering Hierarchy), and MR-LEACH (multi-hop routing with LEACH).
    Keywords: WSNs; wireless sensor networks; energy efficiency; clustering; cluster head.
  • Modeling Software Fault Management with Runtime Verification   Order a copy of this article
    by Xingjun Zhang, Yan Yang, Endong Wang, Ilsun YOU, Xiaoshe Dong 
    Abstract: To achieve the software fault tolerance at runtime, base on runtime verification techniques, this paper proposes a runtime model of running program, which is used to define the actions and constrains for runtime software fault management. This model contains the descriptions of event, path, scope and adjustment. A runtime fault management system prototype, which mainly includes the rule description, event acquisition, fault diagnosis and handling, is implemented to verify the model. Two test cases are used to estimate the effect of the prototype, and the results show that this method can handle faults successfully at runtime.
    Keywords: software fault tolerance, runtime verification,runtime model
  • Optimizing Sink-Connected Barrier Coverage in Wireless Sensor Networks   Order a copy of this article
    by Yung-Liang Lai, Jehn-Ruey Jiang 
    Abstract: This paper proposes an algorithm to solve the sink-connected barrier coverage optimization problem, which is concerned with how to select randomly deployed sensor nodes of a wireless sensor network (WSN) to reach two optimization goals: (1) to maximize the degree of barrier coverage with the minimum number of detecting nodes, and (2) to make the detecting nodes sink-connected with the minimum number of forwarding nodes. The detecting nodes are those for detecting intruders crossing a belt-shaped area of interest. On detecting intruders, they send intruding event notifications to one of the sink nodes with the help of the forwarding nodes to relay the notifications. We prove the optimality of ONSA, perform simulations for ONSA, and compare the simulation results with those of a related algorithm to show ONSAs advantages.
    Keywords: Wireless sensor networks; Barrier coverage; Maximum flow minimum cost algorithm; Sink connectivity; Energy efficiency
  • A SMART SAFETY CANE FOR HUMAN FALL DETECTION   Order a copy of this article
    by Ping Hsu Chen, Yung-Hui Li, Che Wun Chiou, Chiou-Yng Lee, Jim-Min Lin 
    Abstract: Lots of countries have gradually become an aging society, therefore, the safety issues of the elderly attract more and more attentions. Falling is one of the major reasons for the accidental injuries of the elderly, and many times such accidents have become irreparable regrets because of the delayed arrival of the ambulances. Therefore, how to detect the instances of fall of the elderly, and how to provide medical care to them immediately after such accident happens are extremely important. Many old people choose to use a cane to assist walking. In this study, we propose to attach to the cane with intelligent embedded system with acceleration detection ability. Such system is able to collect the characteristics of the position of the cane when it is used by the elderly in real time. We analyze the data with finite state machine in order to detect the fall accidents of the elderly. The smart cane is able to send alarm and location of the elderly to the hospital as soon as such accidents are detected, so that the ambulance can be dispatched immediately after the accident happened.
    Keywords: Embedded System, Android Smart Phone, Smart Safety Cane, Human Fall Detection, Finite-State Machine (FSM)
  • Performance Analysis on Network Connectivity for Vehicular Ad Hoc Networks   Order a copy of this article
    by Ruifeng Chen 
    Abstract: This paper proposes a simplified but reasonable uninterrupted highway model to evaluate the network connectivity performance for vehicular ad hoc networks (VANETs) from the view of both individual vehicle and global network. Three parameters: conditional connectivity of the communication pair of individual vehicles, global network connectivity probability, and the vehicle isolation probability are investigated. By combining the probability density function of inter-vehicle initial distance and the distribution of vehicles' relative speed, which are both derived in this paper, the closed-form of conditional connectivity is obtained. To derive the closed-forms of network connectivity and vehicle isolation probabilities, the analytical model takes into consideration the key factors such as communication range, vehicle speed, and enter intensity. The analytical results are validated by extensive simulations. Our derived highway network connectivity model could be applied in the study of a number of metrics related to connectivity in vehicular ad hoc networks.
    Keywords: Vehicular Ad Hoc Networks; connectivity performance; isolation probability; vehicular communications.
  • Cooperative Opportunistic Network-coded Transmission Strategy for Wireless Mesh Networks   Order a copy of this article
    by Ke Xiong, Pingyi Fan, Su Yi, Ming Lei, Zhangdui Zhong 
    Abstract: Opportunistic Network Coding (ONC) is a promising technology to implementrnnetwork coding in practical systems. Compared with traditional network coding, the main advantage of ONC is that it allows the encoding node to decide whether it employs network coding or not based on the status of all its input streams. However, due to the nature of fading, wireless links may not always be with high quality. So, the performance gain of ONC over traditional methods may be decreased due to wireless links in deep fading. Fortunately, some techniques, such as cooperative diversity and ARQ (Automatic Repeat reQuest) can be used to mitigate it. In this paper, we consider a wireless mesh network model, where two sources want to transmit their information to their own destination, respectively, via the help of a common relay node. In order to improve the network performance by taking the advantage of ONC, ARQ and cooperative diversity, we propose a new cooperative opportunistic network-coded transmission strategy. The advantage of our proposed CP-ONC over ONC is that it employs truncated ARQ and cooperative diversity to enhance the reliability of the wireless links so that more network coding opportunities can be obtained in CP-ONC. We analyze the system performance in terms of network throughput and delay, where we derive some explicit expressions for them. Extensive simulations are presented, which show that our proposed CP-ONC achieves higher system performance gain over ONC in terms of network throughput and average delay, especially in low signal to noise ratio (SNR) region. Besides, we also discuss the impact of the maximum limit of the number of time slots for truncated ARQ and the impact of network topology on the system performances.
    Keywords: Cooperative Communications; Network Coding; Opportunistic NetworkrnCoding; Cooperation diversity; Automatic Repeat reQuest.
  • Localized Sensor Direction Adjustments with Geometric Structures of Voronoi Diagram and Delaunay Triangulation for Directional Sensor Networks   Order a copy of this article
    by Tien-Wen Sung, Chu-Sing Yang 
    Abstract: A directional sensor network consists of directional sensors instead of the omnidirectional ones in the conventional wireless sensor networks. The sensing coverage of a directional sensor network depends on the directionality and size-specific sensing angle of the sensors. The conditions are dissimilar from those of omnidirectional sensor networks for researches, especially on the sensing coverage. There exists a great number of researches aimed at coverage issues of omnidirectional sensor networks. Some of these researches utilized the geometric structure such as Voronoi Diagram or Delaunay Triangulation for solving the coverage problems. For field coverage problem in directional sensor networks, the geometric structures of Voronoi Diagram and Delaunay Triangulation have not drawn the attention of researchers. This study utilized Voronoi Diagram and Delaunay Triangulation and proposed four basic distributed and localized sensor direction adjustment algorithms with the characteristics of these two geometric structures to explore the field coverage improvement in directional sensor networks. The simulation results and comparisons of coverage performance of the proposed four basic algorithms are provided. They can give the clarity of the performance results and have a reference value for future advanced studies on various coverage issues in directional sensor networks.
    Keywords: Directional sensor network; Geometric structure; Voronoi Diagram; Delaunay Triangulation; Sensor field coverage
  • A One-Hop Information Based Geographic Routing Protocol for Delay Tolerant MANETs   Order a copy of this article
    by Lei You, Jianbo Li, Changjiang Wei, Chenqu Dai 
    Abstract: Delay and Disruption Tolerant Networks (DTNs) may lack continuous network connectivity. Routing in DTNs is thus a challenge since it must handle network partitioning, long delays, and dynamic topology. Meanwhile, routing protocols of the traditional Mobile Ad hoc NETworks (MANETs) cannot work well due to the failure of its assumption that most network connections are available. In this article, a geographic routing protocol is proposed for MANETs in delay tolerant situations, by using no more than one-hop information. A utility function is designed for implementing the under-controlled replication strategy. To reduce the overheads caused by message flooding, we employ a criterion so as to evaluate the degree of message redundancy. Consequently a message redundancy coping mechanism is added to our routing protocol. Extensive simulations have been conducted and the results show that when node moving speed is relatively low, our routing protocol outperforms the other schemes such as Epidemic, Spray and Wait, FirstContact in delivery ratio and average hop count, while introducing an acceptable overhead ratio into the network.
    Keywords: Geographic Routing; Protocol; Delay Tolerant Networks; Mobile Ad-Hoc Networks; One-hop Information.
  • Joint Relay Assignment and Bandwidth Allocation for All-to-One Communication in Cooperative Networks   Order a copy of this article
    by Hongli Xu 
    Abstract: Bandwidth allocation is an efficient way for throughput optimization in wireless mesh networks (WMNs). Recently, cooperative communication is regarded as a promising technology to improve the transmission capacity of wireless links. Accordingly, this paper pursues the objective of network throughput maximization through cooperative communication and bandwidth allocation while achieving the max-min fairness. As relay assignment plays an important role for cooperative communication, we first define the joint relay assignment and bandwidth allocation (JRB) problem for WMNs. The problem is formulated into the integer programming, and shown to be NP-hard by reduction from the max-min association control problem. Then, this paper presents a distributed algorithm TRBA to solve the JRB problem. In the algorithm, relay assignment and bandwidth allocation are jointly implemented with local decision, so that the network throughput can be enhanced greatly. The theoretical analyses show that the proposed algorithm can reach the approximate performance of O(1) for the JRB problem. Moreover, another algorithm, called ITRBA, is presented to improve the average bandwidth of all mesh nodes while still preserving the max-min fairness compared with the TRBA algorithm. Our simulation results demonstrate that the proposed algorithms can almost reach the same network throughput as the optimal method, and improves the network throughputs about 20.0% more than that of the pervious bandwidth allocation method.
    Keywords: Cooperative Communication, Relay Assignment, Bandwidth Allocation, Network Throughput, Max-Min Fairness
  • Polling in the Frequency Domain: A New MAC Protocol for Industrial Wireless Network for Factory Automation   Order a copy of this article
    by Yang Xiao, Junru Lin, Wei Liang, Haibin Yu 
    Abstract: Wireless technologies are becoming more and more attractive for industrial communication. In the field of factory automation, the high communication requirements in terms of predictability, reliability and real-time make the adoption of wireless technologies challenging, due to the inefficiency of the wireless physical layer and nondeterministic media access control (MAC) protocols. In this paper, a Frequency Domain Polling MAC protocol (FDP-MAC) is proposed, which takes advantage of the Orthogonal frequency-division multiplexing (OFDM) technology to achieve simultaneously polling. In the FDP-MAC, a dynamic Time division multiple access (TDMA) scheduling and a downlink acknowledgements aggregation method are also presented to improve the communication efficiency further. We validate the effectiveness of FDP-MAC through simulations, and results indicate that FDP-MAC can meet typical factory automation applications communication requirements.
    Keywords: Polling , Frequency Domain, MAC , Industrial Wireless Network, Factory Automation
  • Adaptive Filtering Based Collaborative Actuation for Wireless Sensor and Actuator Networks   Order a copy of this article
    by Lei Mo, Bugong Xu 
    Abstract: Wireless sensor and actuator networks are emerging as a new generation of sensor networks. To accomplish effective sensing and acting tasks, efficient coordinate mechanisms among the nodes are desirable. As an attempt in this direction, this paper develops a collaborative estimation and control mechanism, which addresses the nodes coordination in a distributed manner. First, we discuss the system model and system partition that are used to construct the distributed architecture. Then, a collaborative estimation and control scheme is proposed to coordinate sensor and actuator nodes. This scheme includes two components, namely recursive least squares based federated Kalman filter (RLS-FKF) and PID neural network (PIDNN). It schedules the corresponding nodes based on the characteristics of current events, deals with data fusion and system estimation problems through RLS-FKF, and utilizes PIDNN controller to improve system transient and steady-state responses. Simulations demonstrate the effectiveness of proposed methods.
    Keywords: Wireless sensor and actuator networks; Recursive least squares; Federated Kalman filter; PID neural network.
  • MMS-MVN: A Multimedia Multicast Scheduling method for Multi-hop Vehicular Networks   Order a copy of this article
    by Miao Hu, Zhangdui Zhong, Chih-Yung Chang 
    Abstract: Emerging technologies for vehicular Ad Hoc networks (VANETs) have aroused tremendous attentions in both the safety and entertainment related applications. In this paper, the multimedia multicast scheduling design problem for multi-hop vehicular networks is studied. Many previous works on multimedia scheduling problem focused on the design for one-hop networks or multi-hop networks with fixed relay stations. However, for multi-hop vehicular networks, with the possibility that each vehicle can be selected as relay and various channel conditions etc., the optimal scheduling scheme is hard to obtain. We develop a heuristic scheduling algorithm to approach the performance of the intractable optimal scheduling scheme. Simulation results show that performance of the proposed heuristic algorithm approaches the optimal results and shows some good properties against other algorithms, which verifies the contribution of our work.
    Keywords: layered multimedia, multicast schedule, multi-hop transmission, VANETs
  • TIE-MAC: Tolerable Interference Estimation based Concurrent Medium Access Control for WLAN Mesh Networks   Order a copy of this article
    by Lei Lei, Shengsuo Cai, Liang Zhou, Xiaoming Chen 
    Abstract: This paper presents TIE-MAC, tolerable interference estimation based concurrent medium access control protocol for WLAN mesh networks. The goal is to increase spatial reuse, achieve high throughput and reduce average energy consumption through exploiting concurrent transmissions among neighboring nodes. TIE-MAC confirms that the tolerable interference of the receiver plays a key role in determining the efficiency of concurrent transmission scheduling, and puts forward a novel tolerable interference estimation mechanism, enabling the receivers to precisely estimate their tolerable interference. Meanwhile, a Concurrent Transmission Gap (CTG) is inserted between the transmission of the RTS/CTS and data packets to offer the nodes in the vicinity of the receiver the chance to schedule possible overlapping transmissions. The size of the CTG is optimized using an exponential smoothing model based adjustment algorithm. Moreover, sequenced ACKs are introduced in TIE-MAC and used in combination with the tolerable interference estimation mechanism to avoid possible collisions among different concurrent transmissions. Simulation results show that TIE-MAC gains better throughput and energy consumption performance in comparison with existing concurrent transmission protocols as well as the active WLAN mesh standard.
    Keywords: WLAN mesh networks; concurrent medium access control; tolerable interference estimation; throughput enhancement; energy saving
  • Matrix-based Key Pre-distribution Schemes in WMNs Using Pre and Post Deployment Knowledge   Order a copy of this article
    by Yuexin Zhang, Li Xu, Xinyi Huang, Jie Li 
    Abstract: Like other types of wireless networks, wireless communication in wireless mesh networks (WMNs) is vulnerable to many malicious activities. Thus it is a must to protect wireless transmission by proper security measures. As a fundamental security technology, symmetric key pre-distribution has been widely studied to ensure the security of wireless communication. This paper presents two matrix-based pairwise key establishment schemes for mesh clients. In our schemes, a mesh client only needs to pre-load an independent key seed which can be used to generate a column of secret matrix. It can establish pairwise keys with neighbor clients after mesh routers broadcast public matrices. Motivated by this heterogeneity (mesh routers are much more powerful than mesh clients, both in communication and storage), energy-consuming operations can be delegated to mesh routers to alleviate the overhead of mesh clients when they establish pairwise keys. By using pre and post deployment knowledge, neighbor mesh clients in our scheme can directly establish pairwise keys with a very light communication and storage cost.
    Keywords: Pairwise Key; Matrix; Pre and Post Deployment Knowledge; Wireless Mesh Networks; Wireless Sensor Networks.
  • Introducing Extreme Data Storage Middleware of Schema-free Document Stores using MapReduce   Order a copy of this article
    by Kun Ma, Bo Yang 
    Abstract: Referred to NoSQL, schema-free databases feature elasticity and scalability in combination with a capability to store big data and work with Cloud computing systems, all of which make them extremely popular. In particular, the creation of the data warehouse is gaining a significant momentum. Although large corporate early adopters paved the way, since then, data warehousing has been embraced by organizations of all sizes. However, there are few publications on data warehouse of NoSQL. In this paper, an extreme data storage middleware (EDSM) of schema-free document stores using MapReduce is presented to address the issue of formulating no redundant data warehouse with small amount of storage space for the purpose of their composition in a way that utilizes the MapReduce framework. First, the definition of cell with an effective lifecycle tag is given. Second, the architecture and extreme data storage principles are presented. At last, the capture-map-reduce procedures are discussed to create the NoSQL data warehouse. The experiment is shown to successfully build the NoSQL data warehouse reducing data redundancy compared with document with timestamp and lifecycle tag solutions. Our experiment also provides insight into some of the key challenges and shortcomings that researchers and engineers face when designing the data warehouse middleware.
    Keywords: extreme data storage; historical data; change data capture; MapReduce; NoSQL; lifecycle tag; data warehouse; data redundancy
  • Experimental Analysis of CCA Threshold Adjusting for Vehicle EWM transmission in V-CPS   Order a copy of this article
    by qingwen han, Lingqiu zeng, Le Yang, Yuebo Liu 
    Abstract: Vehicular Cyber-physical System (V-CPS) offers the potential to significantly improve the safety, comfort and entertainment to motorists. The topic of emergency warning message (EWM) transmission is still most important for V-CPS because of the thousands of lives taken by traffic accident. The EWM dissemination is expected to inform the related vehicles in time, and in this paper, we proposed a new EWM dissemination mechanism based on an improved CCA method to reduce the transmission delay by shorten the sensing time for idle channel. Experimental results obtained from the testbedEyeNetshowed that for 3-hop manner, the proposed mechanism employing an appropriate CCA threshold setting can shorten the transmission delay with 12ms, while under one hop condition, it should guarantee a relative high successful dissemination rate about 60%.
    Keywords: V-CPS; information dissemination; emergency warning message; regional flooding; CCA
  • Tour and Path Planning Methods for Efficient Data Gathering using Mobile Elements   Order a copy of this article
    by Khaled Almi'ani, Anastasios Viglas, Lavy Libman 
    Abstract: Several studies in recent years have considered the use of mobile elements for data gathering in wireless sensor networks, so as to reduce the need for multi-hop forwarding among the sensor nodes and thereby prolong the network lifetime. Since, typically, practical constraints preclude a mobile element from visiting all nodes in the sensor network, the solution must involve a combination of a mobile element visiting a subset of the nodes (cache points), while other nodes communicate their data to the cache points wirelessly. This leads to the optimization problem of minimizing the communication distance of the sensor nodes, while keeping the tour length of the mobile element below a given constraint. Based on the structure of the tour we investigate two variations of this problem. We start by considering the case where the mobile element tour should starts and ends at a predefined sink. Then we consider the unrestricted case, where the mobile element tour is not required to include the predefined sink node. Several algorithms in existing literature have tackled these problems by separating the construction of the mobile element tour from the computation of the multi-hop forwarding routes to the cache points. In this paper, we propose new algorithms that alternate between these phases and iteratively improve the outcome of each phase, based on the result of the other. We compare the resulting performance of our algorithm with the best known comparable schemes in the literature.
    Keywords: Data gathering, mobile elements, path planning algorithms
  • A Cross-Layer Approach for Multi-Layer Multicast Routing in Multi-Channel Multi-Radio Wireless Mesh Networks   Order a copy of this article
    by Leili Farzinvash, Mehdi Dehghan 
    Abstract: In this paper we consider multicast applications with bandwidth heterogeneous receivers in Multi-Channel Multi-Radio Wireless Mesh Networks (MC-MR WMNs). Multi-layering is a well-established approach to handle bandwidth heterogeneity of the receivers. Existing multi-layering schemes are proposed to address only single-channel settings. In the context of MC-MR WMNs, the channel assignment problem will be coupled with multicast routing, thus necessitating a cross-layer solution. In this paper, we propose an optimal cross-layer model, which aims at maximizing the total number of obtained layers by the receivers. We include network coding in our design to take advantage of its capacity boosting in multicast routing. To alleviate time complexity of the optimal model, we propose Grouping-based Multi-Layer Multicast (GMLMC) algorithm, which yields close to optimal throughput in polynomial time. GMLMC performs channel assignment firstly. Then, the layers are processed consecutively to determine the obtained layers by the receivers, with respect to their available bandwidths. To process a layer in polynomial time, the receivers are partitioned into constant-size groups. Next, subscribing the receivers to the layer is investigated in each group independently. Our extensive simulations show that the throughput of GMLMC is no less than 96% of the optimum. In addition, we study the pattern of layer reception to the receivers in GMLMC. It turns out that the generated results of GMLMC resembles very much to the optimal solutions in this respect.
    Keywords: wireless mesh networks; multicast; multi-layer; network coding; channel assignment; multi-channel multi-radio systems; cross-layer optimization.
  • Verifying Vehicle Control Systems by Using Process Calculi   Order a copy of this article
    by Gabriel Ciobanu, Armand Rotaru 
    Abstract: The paper deals with the safety of car control systems in which vehicle-to-vehicle interactions are described in a modular and compositional manner. Such a description simpli fies a complex veri fication process, which involves control decisions regarding acceleration, deceleration, lane switching and breaking distance. We focus on the problem of adjusting vehicle speed in order to maintain a proper distance between vehicles on the same lane. The components of the control system are represented as processes in the process algebra Communicating Sequential Processes, and the compositional parallel operator is used to describe the whole system. Safety properties are formally verifi ed by employing the Concurrency Workbench of the New Century tool.
    Keywords: Adaptive Cruise Control; Communicating Sequential Processes; Model Checking; Concurency Workbench of the New Century.
  • A Linear Regression-Based Delay-Bounded Multicast Protocol for Vehicular Ad Hoc Networks   Order a copy of this article
    by Tong-Ying Juang 
    Abstract: Vehicles inform emergent events and car accidents by using a routing protocol in vehicular ad hoc networks (VANETs), which is a wireless ad hoc network that operate in a vehicular environment to provide communication between vehicles. This study focuses on a linear regression-based delay-bounded multicast protocol that delivers messages to numerous destination regions within a user-defined delay time for each region by minimizing radio usage. In our protocol, a message can be delivered to destination regions by using a hybrid of data muling (carried by a vehicle) and forwarding (delivered through a radio). Thus, if the available time is sufficient, then the message is delivered through muling; otherwise, the message is delivered by forwarding. The proposed protocol comprises two schemes: the greedy and centralized schemes. The simulation results indicated that the proposed multicast protocol performed more favorably than existing protocols did regarding total transmitted bytes.
    Keywords: vehicular ad hoc networks (VANETs); multicast; routing protocol; delay-bounded; linear regression.
  • Design and Implementation of an IoT Multi-Interface Gateway for Establishing a Digital Art Interactive System   Order a copy of this article
    by Zhi-yong Bai, Chin-Hwa Kuo, Tzu-Chia Wang 
    Abstract: The Internet of Things (IoT) can be established by connecting smart objects in a wireless manner. However, a variety of technologies of wireless networks, including Bluetooth, ZigBee, WiFi and infrared, which have been embedded into smart objects or controllers, cannot exchange information since they apply different standards or even work on different frequencies. To provide information exchange in heterogeneous networks, this paper proposes the design and implementation an IoT multi-interface gateway, which can transform the information into a data which can be recognized by various smart objects. In the interactive system, the IoT multi-interface gateway can be used for digital arts or some smart spaces that can automatically control traditional TV, air condition, smart meter, sphygmomanometer, smart phone, etc. The implementation shows that the IoT gateway can exchange data among various smart objects that use different wireless technologies and also guarantee the stability of data conversion time.
    Keywords: digital arts; gateways; heterogeneous networks; identification; interactive systems; IoT; internet of things; smart objects
  • A Reverse Auction Algorithm for Carrier Allocation in Femtocells for Multimedia Applications   Order a copy of this article
    by Zhibin Gao, Hua-Pei Chiang, Lianfen Huang, Yannan Yuan, Huaiyu Dai, Yueh-Min Huang 
    Abstract: An efficient carrier allocation algorithm is important for Self-Organized Networks (SON). SON can significantly improve network performance and user experience which greatly help relieve the heavy loading of the current multimedia applications for mobile environments. This paper proposes a distributed algorithm for carrier allocation using a reverse auction algorithm, wherein the original cells affected by newly added cells self-organize into auction groups to facilitate new carrier allocation. The computational overhead required to adapt to topology changes can be significantly reduced compared with the conventional topology-based approaches that ignore prior assignments. The number of original cells affected by the reallocation is as small as possible in the reverse auction algorithm while optimizing carrier allocation. We investigate the algorithm performance in various scenarios. Our results indicate that the reverse auction algorithm exhibits significant advantages compared to traditional approaches, especially in highly dynamic networks where frequent resource re-allocation is needed.
    Keywords: carrier allocation; small-scale network; reverse auction algorithm; network capacity
  • An Overview of Centralised Middleware Components for Sensor Networks   Order a copy of this article
    by Martijn Onderwater 
    Abstract: Sensors are increasingly becoming part of our daily lives: motion detection, lighting control, environmental monitoring, and keeping track of energy consumption all rely on sensors. Combining data from this wide variety of sensors will result in new and innovative applications. However, access to these sensors - or the networks formed by them - is often provided via proprietary protocols and data formats, thereby obstructing the development of applications. To overcome such issues, middleware components have been employed to provide a universal interface to the sensor networks, hiding vendor-specific details from application developers. The scientific literature contains many descriptions of middleware components for sensor networks, with ideas from various fields of research. Recently, much attention in literature is aimed at what we, in this paper, define as 'centralised' middleware components. These components consider sensor networks that have no capacity -- in terms of memory, data storage, and cpu power -- to run middleware components (partially) on the sensor nodes. Often, viewed from the position of the middleware component, these sensor networks function as simple data providers for applications. In this paper we introduce the term 'centralised' for such middleware components, guided by a literature review of existing middleware components for sensor networks. We describe their general architecture, give a description of a representative set of four centralised middleware components, and discuss advantages and disadvantages of these components. Finally, we identify directions of further research that will impact centralised middleware systems in the near future.
    Keywords: Sensor network middleware, Centralised middleware components, Sensor web enablement, Middleware categorisation, Sensor web, Web services, Sensor networks.
  • Scalable Cross-Layer Multipath Routing under Interference Constraints in Wireless Mesh Networks   Order a copy of this article
    by Wei Feng, Suili Feng, Yuehua Ding, Yun Liu 
    Abstract: This paper investigates the problem of flow routing under interference constraints for wireless mesh networks. A new routing metric called Cross-Layer Weight Function (CLWF), which is proved to be isotonic using virtual network decomposition, is initially developed by considering the traffic load and interference. Based on CLWF, a new routing algorithm called Weighted Hybrid Multipath Routing Algorithm (WHMRA) is proposed in which the joint design of CLWF-based multi-point relay selection algorithm and fuzzy-slighted routing algorithm is introduced to improve the routing scalability. In addition, a cross-layer design framework is also developed in WHMRA in order to exchange information and enable interaction between layers where is enforced strict boundaries in original OSI networking model. Finally, through the system simulation and performance comparison, the proposed algorithms are demonstrated to succeed in improving network performance in terms of delay, packet loss ratio, throughput and overhead.
    Keywords: Routing protocol; Routing metric; Cross-layer design; Interference constraints; Routing scalability
  • Dynamic IEEE 802.21 Information Server Mesh Architecture for Heterogeneous Networks   Order a copy of this article
    by Luis Javier García Villalba 
    Abstract: The future wireless communications is expected to integrate different link layerrntechnologies and to allow the most appropriate network to be selected depending on different criteria. Mobile nodes (MN) may want to discover neighboring networks and detailed parameters before it moves into the coverage areas of the candidate networks, focusing on the optimization of handover processes. In the IEEE 802.21 standard, a media independent information service (MIIS) is developed providing network information within a geographical area. However, the MIIS focuses on the static information (channel information, servicernprovider name, network type supported, etc.). Dynamic information includes link-layer parameters such as available network resources, throughput, data rate, etc. This paper proposes a DISMA (Dynamic Information Server Mesh Architecture) for real-time collection, discovery and sharing of dynamic network information. With DISMA, the MN is able to retrieve realtimerndynamic information using a decentralized MIIS framework. Finally, this distributed approach generates an important advantage regarding the scalability and robustness if compared with the traditional centralized scheme. This paper also provides NS-2 simulation results and analytical models to prove the feasibility and performance of DISMA scheme.
    Keywords: Architecture; DISMA; Dynamic Information; Handover; Heterogeneous Networks; IEEE 802.21; Media Independent Information Service; Mesh; MIIS; Mobility; Server.
  • A Non-Interactive Certificateless Two-Party Authenticated Key Agreement Protocol for Wireless Sensor Networks   Order a copy of this article
    by Suman Bala, Anil Verma 
    Abstract: Security plays a vital role in wireless sensor networks (WSN) but due to hardware constraints it becomes very challenging. Key exchange protocol(s) is one of the important factors for establishing communication between two parties. Recent works support the use of pairing free certificateless authenticated key exchange protocol(s) and becomes a promising base in a energy-famished WSN. Certificateless concept provides an authentication by eliminating the need of certificates of traditional public based cryptography and key escrow problem of identity based cryptography. This paper presents a Non-Interactive Certificateless Two-party Authenticated Key Agreement (NI-CTAKA) protocol for WSN. The proposed protocol is pairing-free as well as reduces number of scalar point multiplications. This protocol has been implemented on MICAz platform using TinyOS-2.1.2 and RELIC-0.3.3 cryptographic library and the results has been analysed for storage-cost, running time and energy consumption. Further, the proposed protocol for WSN is proven to be secure in the security model presented by Lipold et al., which is an extended version of Swanson and Jaos model, which is based on LaMacchia et al.s extended Canetti- Krawczyk (eCK) model. NI-CTAKA protocol is secure even if the Key Generation Centre (KGC) actively tries to break the scheme: it may either reveal ephemeral-secret-key or reveal secret-valuer or replace public-keys but not both. The comparative analysis proves that the proposed protocol is more efficient than the existing protocols.
    Keywords: CertificateLess Public Key Cryptography; Key Agreement; Pairing-free; Wireless Sensor Network.
  • Imprecise-Query Processing in Wireless Sensor Networks: A Fuzzy-based Approach   Order a copy of this article
    by Mehdi Dehghan, Parand Akhlaghi, Mohammad Mehdi Ebadzadeh 
    Abstract: Traditional query processing systems in sensor networks require precise and explicit definition of predicative thresholds to extract data. The acquired data can be imprecise and uncertain due to different reasons like measurement errors or environmental noise. In this paper, we take on a fuzzy based approach to design a flexible query structure with linguistic and semantic predicates in sensor networks. In addition, we introduce a Fuzzy-based Query Correlation Index (FQCI), which quantifies the correlation between a sensor node and a query, based on a priori defined fuzzy membership functions, which are individual to each node. Also, our proposed fuzzy query structure can support queries with multiple predicates. This approach can reduce the rigidity in the declarative structure of query and minimize energy consumption, while providing a flexible service for event monitoring applications. Simulation results demonstrate that our method can achieve high fidelity with reasonable energy efficiency.
    Keywords: Fuzzy query processing . Wireless sensor networks . Data acquisition . Correlation
  • An Anonymous Authentication Scheme in Data-Link Layer for VANETs   Order a copy of this article
    by Lin Yao, Chi Lin, Guowei Wu, Taeyoung Jeong, Kangbin Yim 
    Abstract: In Vehicular Ad-hoc Networks (VANETS), security and privacy are indispensable issues for guaranteeing the soundness of such a technology. In this paper, we focus on designing an efficient and lightweight anonymous authentication scheme. We propose a novel biometrics-based mutual authentication scheme in the data-link layer to protect a vehicles privacy during its authentication phase. Our authentication scheme includes two phases, initialization and anonymous authentication. During the initialization phase, biometric encryption technique is applied to generate Bioscript. During the anonymous authentication phase, a new session key is generated to achieve the traffic confidentiality. Meanwhile, a newly temporary MAC address is negotiated to conceal the real MAC address. Security and privacy analysis show that our scheme can resist various attacks in the data-link layer. Furthermore, simulation results demonstrate that our scheme is a lightweight protocol.
    Keywords: Anonymous Authentication, Link Layer, VANET
  • Link Connectivity under More Realistic Channel Model for Vehicle-to-Vehicle Communications   Order a copy of this article
    by Ruifeng Chen, Zhangdui Zhong, Victor Leung, David G. Michelson 
    Abstract: Vehicle-to-Vehicle (V2V) communication is commonly used to improve traffic safety. Since the antennas are very low in V2V scenarios, the V2V communication link is easily blocked by other vehicles. This might affect the communication range and system performance significantly. The shadowing effect caused by other vehicles has been ignored in most of the existing V2V channel models, and it is thus neglected in the system performance evaluation. By incorporating channel state transition with a measurement-based dual-slope path loss model, an obstacle-based model is presented in this paper for the V2V highway scenarios to capture the dynamic characteristics of radio channels, in the presence of other vehicles as moving obstacles. The joint effects of the radio environment and traffic flow on link connectivity are mainly investigated. The obstruction probability is represented, and the connectivity-related metrics are evaluated: inter-vehicle connectivity probability and link duration. All the analytical results are validated by extensive simulations under the measurement-based path loss model, and are also compared to the existing models. The results can be used for the system design and development of a channel simulator for vehicular communications.
    Keywords: Vehicle-to-Vehicle; connectivity performance; realistic channel model; moving obstacles.
  • Localized Querying and Location Update Service in Wireless Sensor and Robot Networks with Arbitrary Topology   Order a copy of this article
    by Milan Lukic, Ivan Mezei 
    Abstract: In a typical Wireless Sensor and Robot Networks setup, sensor nodes detect events which require response from mobile robots. First, a static information structure is established in the network, allowing an event-detecting node to send a request to a nearby robot, to visit its location. The movement of the robots imposes changes in the network structure, which are handled in location update process. These protocols should perform in a localized, distance-sensitive, energy ecient manner. Here we present a new protocol based on localized formation of Voronoi cells (vCell), and compare it with existing protocols (Quorum and iMesh) in dense networks, sparse networks, and networks with holes in topology. We also present location update algorithms which deal with robot mobility. Our simulations show that vCell achieves nearly 100% success rate in nding the nearest robot in dense networks. In sparse networks, it outperforms the other existing solutions by up to 40%.
    Keywords: Wireless Sensor and Robot Networks; localized querying; location update; iMesh; Voronoi diagram
  • Distance Bounding-based RFID Binding Proof Protocol to Protect Inpatient Medication Safety against Relay Attack   Order a copy of this article
    by Abolfazl Falahati, Hoda Jannati 
    Abstract: RFID binding proof protocols are suggested for the past decade to guard inpatient medication safety and to prevent medication errors in hospitals. In such protocols, the main goal is to authenticate two RFID tags (one for the patient and one for the patients drug) simultaneously using an RFID reader by a nurse. This paper reveals that the existing RFID binding proof protocols are vulnerable to a relay attack. In the relay attack, an attacker is able to change the patients drug without the nurse and the patient noticing the change. Furthermore, to overcome this weakness a paired distance bounding protocol is proposed with two security parameters (N and t) to be deployed for RFID binding proof protocols. In a paired distance bounding protocol, two tags are authenticated simultaneously, and furthermore, an upper bound for the physical distance between these two tags and the reader is established. This implies the presence of both tags in the readers area. The analytic results for the proposed protocol show that, with the appropriate selection of N and t parameters, the proposed protocol achieves a desirable security level against the relay attack.
    Keywords: Distance bounding protocol; Mafia fraud attack; Medication errors; Relay attack; RFID binding proof protocol.
  • Adaptive RSU Re-routing under Delay Constraint in Multi-hop Vehicular Networks   Order a copy of this article
    by Tsan-Pin Wang, Chien-Chao Tseng, Kuo-Lung Wang 
    Abstract: Vehicular Wireless Networks (VWNs) offer wireless multi-hop communications between vehicles and Roadside Units (RSUs). A multi-hop wireless network with carry-and-forward routing may suffer from longer delay in packet delivery. However, the applications may demand stringent delay requirement in multi-hop VWNs. Therefore, this paper proposes an adaptive RSU re-routing strategy to alter the current associated RSU to the best RSU under delay or throughput constrains for applications in multi-hop VWNs. Performance results show that the proposed strategy is able to adaptively select a suitable packet size for the trade-off between delay and through put to satisfy the diverse requirements of applications in multi-hop VWNs.
    Keywords: IEEE 802.11p, vehicular networks, multi-hop, carry-and-forward routing
  • Inter-node Relationships in Short-Range Mobile Social Networks   Order a copy of this article
    by Zhiting Lin, Xiufang Jiang 
    Abstract: Empirical studies have provided evidence suggesting that human mobility and the resulting contact opportunities of short-range mobile social networks are not entirely random. Most of these studies claim that power-law characterizes diverse aspects of human mobility patterns. However, is the power-law distribution assumption really reliable? Furthermore, these studies typically focus on aggregated statistics or on models for individual users, and do not capture the inter-node relationships. We empirically studied some statistical properties of inter-node relationships, and proposed a universal scheme, named A-Scheme, to improve existing probabilistic routing approaches. In most of those approaches, decision is made using a static method. However, we claim that judging threshold varies according to activity is more suitable. Simulation results show that A-Scheme improves the performance of existing probabilistic routing approaches in terms of cost, success rate, and delay.
    Keywords: inter-node relationships; disconnected networks; short-range mobile social networks; routing approach
  • Optimal and Heuristic Algorithms for Constructing Interference-free Multicast trees subject to delay and energy constraints on Wireless Mesh Networks   Order a copy of this article
    by Wen-Lin Yang 
    Abstract: Due to the great concerns of on environmental protection and the high rising of prices in oil,\r\n the energy efficiency has become an important factor for designing network applications.\r\n In this paper, we study an optimization problem which is concerned about how to construct an\r\ninterference-free multicast tree subject to delay and energy constraints on a multi-channel multi-radio \r\nwireless mesh network. The objective of this problem is to maximize the number of mesh clients that \r\ncan be included in the multicast tree. This problem is then referred as the\r\nenergy-delay-constrained and maximum-revenue-based multicast (EDMRM) problem.\r\nIn this article, we first propose an optimal algorithm on the basis of integer linear programming for \r\nthe EDMRM problem. The most important feature of this ILP-based optimal algorithm is that \r\n the following four factors: routing, interference, delay and energy, \r\n can be taken into account simultaneously when a multicast tree is determined.\r\n Since the EDMRM problem is NP-hard, the ILP-based algorithm is only feasible for small-scale networks.\r\n Hence, we also provide a tabu-based heuristic algorithm which can be used to improve the \r\n solution quality of a given channel-allocated multicast tree.\r\nThe experimental results show that the tabu-based algorithm can outperform the other approaches\r\nwhich have been presented in the literature.
    Keywords: wireless mesh networks; delay and energy constraints; tabu; integer linear programming; maximum-revenue multicast trees
  • Pseudonym-based Privacy-preserving Scheme for Data Collection In Smart Grid   Order a copy of this article
    by Xiaobin Tan, Jiangyu Zheng, Cliff Zou, Yukun Niu 
    Abstract: Smart Grid provides significant enhancement to the reliability and efficiency of the electricity systems, but it also brings up new challenges on consumer's privacy issue. On one hand, for better operation, the Energy Supplier (ES) should know the correct total consumption of all SMs. On the other hand, from the consumers' perspective, ES should not know the consumption of every SM, which exposes consumer's privacy. To tackle this challenging issue, in this paper we present a novel privacy-preserving scheme based on pseudonym. Before SMs join in a network, we require Diffie-Hellman key exchange and SM registration to authenticate SMs. A function of the group key, time and the number of SMs is introduced to generate pseudo IDs for SMs. Then each SM sends data packet with its pseudo ID to ES rather than its original ID. A simple message authentication is designed to defend against false data attack. Security analysis is provided to justify the efficiency of our scheme. We evaluate the privacy-preserving level by introducing an information theoretic metric -- degree of anonymity. Simulations are carried out and results show that our scheme is lightweight comparing to related works.
    Keywords: Smart Grid; Smart Meter; Data Collection; Pseudonym; Privacy Preserving; Message Authentication.
  • Simulation-Based Performance Comparison of Two Routing Protocols for Aircraft Ad-Hoc Networks   Order a copy of this article
    by Ki-Il Kim, Saifullah Khan 
    Abstract: As a large amount of research for mobile ad-hoc networks has been conducted in recent years, new emerging research challenge, aircraft ad-hoc networks, has attracted considerable attention from the research community. These networks aim to construct self-organizing networks with ying aircrafts in the sky instead of typical aircraft-ground- aircraft communications. However, due to unique properties of aircraft ad-hoc networks, it is infeasible to employ current routing protocols that were developed for pure mobile ad-hoc networks or vehicular ad-hoc networks. To solve above fundamental problem, a few research including GRHAA and AeroRP have been proposed and analyzed through simulation. However, since these protocols were compared with typical routing protocols for ad-hoc networks with simulation scenarios that were con_gured with unrealistic parameters for aircraft ad-hoc networks, more reliable and credible simulation studies are essentially needed. Based on this demand, in this paper, we conduct simulation-based performance evaluation for two mentioned protocols with new relevant parameters. They include mobility model, medium access control protocol and density of nodes. And then, we analyze the impact of each parameter on corresponding protocols in several ways and present the discussion. Based on simulation results, we can identify that two routing protocols are suitable for aircraft ad-hoc networks. Furthermore, GRHAA shows better performance than AeroRP in the aspects of packet delivery ratio and similar delay by the help of hierarchical architecture as well as more accurate position prediction scheme in heterogeneous environments. On the other hand, small performance gap between two protocols is observed where homogenous networks are assumed.
    Keywords: Aircraft ad-hoc networks; Performance Evaluation; Routing Protocol; Simulation
  • Integrating DSRC and Dead-Reckoning for Cooperative Vehicle Positioning under GNSS-Challenged Vehicular Environments   Order a copy of this article
    by Jiang Liu 
    Abstract: As the fundamental information for describing the dynamic state of vehicles, vehicle position is a significant element for the cooperative vehicle infrastructure systems. Global Navigation Satellite System (GNSS) is considered as an effective approach for realizing accurate and reliable vehicle positioning. In order to overcome the GNSS-challenged environments in urban areas, a low-cost cooperative vehicle positioning solution is proposed in this paper by exploring the capability of Dedicated Short Range Communication (DSRC) and Dead Reckoning (DR). The mechanism of DSRC-based cooperative positioning using the Carrier Frequency Offset (CFO) observation is analyzed. The Bayesian filtering scheme is employed for realizing the information fusion of DSRC and DR, which promotes a DSRC/DR integration-based solution to compensate GNSS and achieve the desirable accuracy and availability. Results from a cooperative simulation platform show an encouraging performance stage of the proposed solution. Under the GNSS-challenged conditions, the accuracy and service availability are assured for supporting the cooperative vehicular applications.
    Keywords: dedicated short range communication; dead reckoning; vehicular ad hoc network; cooperative positioning; sensor information fusion
  • HMMCCN:A Hierarchical Mobility Management Scheme for Content-Centric Networking   Order a copy of this article
    by Fei Ren, Huachun Zhou, Li Yi, Yajuan Qin, Zhang Hongke 
    Abstract: Content-Centric Networking (CCN) has emerged as a promising paradigm in current Internet. Due to the interest-driven, we concern more about the content itself rather than the place it located, and therefore, CCN supports subscriber mobility natively, however, it remains a major challenge in publisher mobility. In this paper, we propose a hierarchical mobility management scheme for CCN (HMMCCN) which contains an overlay mapping structure to store the old-to-new name binding relationship and perform the mobility management for mobile devices. This allows for efficient simultaneous mobility and supports seamless handoff for interactive communication. The main goals of this paper are: (a) to propose a mobility scheme suitable for all mobile nodes in CCN, both the publishers and subscribers; (b) to describe the hierarchical mobility management procedure during intra-domain and inter-domain handoff; (c) to establish an analytical model and formulate the location update signaling cost, handoff delay and (d) to calculate kopt in the Content Router (CR) for decreasing the total overhead during handoff.
    Keywords: Content-Centric Networking; hierarchical mobilty management; inter-domain mobility; intra-domain mobility;
  • Lifetime optimization for linear wireless sensor networks under retransmission   Order a copy of this article
    by Ruiying Li, Haitao Liao, Xiaoxi Liu, Ning Huang 
    Abstract: The lifetime of wireless sensor networks (WSN) is strongly affected by the energy consumption, which is partly attributed to retransmission. In this paper, the energy consumption of a linear WSN is analyzed based on basic energy consumption models and a retransmission model. Optimization models are proposed with the objective of maximizing WSN lifetime under the coverage and success transmission rate constraints. In particular, for traditional uniform and non-uniform sensor deployment problems without considering the sleep/wakeup mechanism, the number of sensors and their distances are optimized. Moreover, for a linear WSN with a sleep/wakeup mechanism, a sensor deployment scheme is developed by optimally assigning sensors to fixed locations. The genetic algorithm and the generalized reduced gradient method are applied to solve these problems. Our case studies illustrate that the lifetime of WSN with and without retransmission are different, and it is important to consider retransmission in WSN lifetime optimization.
    Keywords: wireless sensor networks; retransmission; lifetime; energy consumption; node deployment.
  • Extremal Optimization Approach to Joint Routing and Scheduling for Industrial Wireless Networks   Order a copy of this article
    by Zhidong HE 
    Abstract: Industrial Wireless Networks (IWNs), such as WirelessHART and ISA1001.11A, differ significantly from ad hoc and traditional mesh networks in their use of centralized management architecture and battery powered devices. As the critical problems of network management, routing and link scheduling for IWNs have been studied separately in previous research but may result in optimization performance loss since the synergies of joint optimization cannot be exploited. In this paper, we propose a technique based on the Extremal Optimization (EO) approach to solve the joint routing and link scheduling problem in IWNs. After analyzing the feasibility of cross-layer optimization in IWNs, an integer linear programming (ILP) model, which is in accordance with the characteristics of IWNs, is presented to optimize the real-time performance and the network lifetime. Then, Extremal Optimization is investigated to solve the joint optimization problem. To the best of our knowledge, it is the first time that EO is used for working out optimization problems in wireless environments. The fitness assignment strategy, mutation rules and the operating process of EO method are designed to solve the ILP model. Extensive numerical results show that our algorithm can achieve real-time communication with improved latency and optimal network lifetime with balanced energy consumption among nodes at a fast computation rate. Through analyzing, it is demonstrated that there is a tradeoff between energy consumption and path delay, thus making our optimization model flexibly configurable for different application needs.
    Keywords: Extremal Optimization Method; Routing; Link Scheduling; Joint Optimization; Industrial Wireless Networks
  • Energy-Efficient and Low-Delay scheduling scheme for low power wireless sensor network with real time data flows   Order a copy of this article
    by Zheng Zhang, Zhenbo Li, Jiapin Chen 
    Abstract: In this paper, we propose an energy-efficient and low-delay scheduling scheme for interruptible preamble sampling based MAC protocols (e.g., BoX-MAC-2 and X-MAC) in IEEE 802.15.4 wireless sensor network (WSN), which considers energy efficiency while reducing delay and contention in the context of real time data gathering and remote monitoring applications. Its built on MAC layer and exploits local information to coordinate the MAC schedules of nodes in a slowly-changing topology, just with light overhead. The scheme also considers the adaptation to data aggregation with real time data flows. Therefore, our scheme allows for much longer network lifetime while satisfying the delay constraints. The implementation and simulation results show the performance of the proposed scheme.
    Keywords: Energy-Efficient; Low-Delay; Scheduling; MAC; Wireless Sensor Network;
  • A Distributed Joint Topology Control and Forwarding Protocol in MANETs Using Game Theory   Order a copy of this article
    by Yaghoub Alizadeh Govarchinghaleh, Masoud Sabaei, Omid Tavallaie 
    Abstract: In MANETs, each node tries to maximize its utility in the network and saves its limited resources including energy and bandwidth due to different ownerships and selfish behavior which can cause nodes not to cooperate in network tasks such as topology control and packet forwarding and it affects performance of all tasks of the network. Thus, the induced topology lacks favorable specifications including connectivity, optimized energy consumption. Topology control and packet forwarding mutually affect each other. In addition, retrieving complete information about MANETs is challenging because of mobility and high signaling cost. In this paper, the issue of nodes selfishness in topology control and packet forwarding has been addressed by game theory. It is assumed that nodes have local information. Simulation results show that the proposed model decreases the signaling cost of the topology control, increases the network life and dramatically decreases the transmission power variance.
    Keywords: Mobile ad-hoc network; MANET; Game theory; Topology control; Packet forwarding; Cooperation; Non-cooperative game; local information; network life time; energy consumption.
  • Energy optimized resource scheduling algorithm for private cloud computing   Order a copy of this article
    by sudhir goyal, seema bawa, Bhupinder Singh 
    Abstract: In Universities, IT infrastructure is usually non-centralized. Setting up a private cloud setup in academic institutes has an edge over the traditional approach of IT infrastructure distribution to its various departments, schools and centres etc. This work proposes an energy efficient resource management solution specially designed for small and medium sized Infrastructure as a Service (IaaS) cloud in Universities. The proposed algorithm optimizes the energy consumption through efficient resource scheduling, Virtual Machine (VM) consolidation and VM admission control policies. Proposed algorithm has been evaluated by keeping in consideration the number of accepted incoming VM requests and energy consumption of cloud infrastructure. Experimental results reveal that proposed algorithm enhances the acceptance rate of VM requests with the reduction of overall energy consumption of cloud infrastructure.
    Keywords: private cloud, energy efficient, resource management, virtual machine.
  • An Energy-Efficient Mobile Target Detection Scheme with Adjustable Duty Cycles in Wireless Sensor Networks   Order a copy of this article
    by Anfeng Liu, Yanling Hu, Zhigang Chen 
    Abstract: In this paper, an energy-efficient mobile target detection scheme with adjustable duty cycles (TDADC) is proposed. TDADC has three advantages. Firstly, it takes full advantage of the residual energy and improves the effective energy utilization by increasing the sensing duty cycle of non-hotspot nodes. Secondly, the new scheme can significantly improve the overall probability of target detection. Thirdly, the notification transmission latency can be reduced by increasing the communication duty cycles of non-hotspot area. The problem of target detection can be addressed as an optimal problem tradeoff between the target detection quality and network lifetime. A novel measurement framework called Weighted Quality of Target Detection (WQTD) is also proposed to measure the quality of target detection. Both theoretical and simulation results show that the proposed scheme significantly improved the probability of target detection, decreased the notification transmission latency and detection delay without reducing the network lifetime.
    Keywords: wireless sensor networks, target detection, duty cycles, energy-efficient, delay
  • A secure and efficient time-bound hierarchical access control scheme for secure broadcasting   Order a copy of this article
    by Vanga Odelu, Ashok Kumar Das, Adrijit Goswami 
    Abstract: In a time-bound cryptographic key assignment scheme, distinct temporal keys for distinct time periods are assigned to the channels in order to encrypt and decrypt the channels for secure broadcasting. It has numerous applications including the Pay-TV systems. Several time-bound key management schemes for hierarchical access control have been proposed in the literature. The novel schemes proposed by Tzeng, Chien and Bertino et al. are insecure against collusion attacks. Moreover, these time-bound key management schemes do not support the dynamic property \individual channels subscription" to a user associated to a channel group as all the users associated to that channel group use the same user secret key (group secret key). In this paper, we aim to propose a novel time-bound hierarchical access control scheme for secure broadcasting, in which each user needs to store a distinct and unique user's private key, and hence each user in a channel group can subscribe for an individual channel. Our scheme reduces significantly the implementation cost and also improves the computational performance along with extra features. Through the informal and formal security analysis, it is shown that our scheme is secure against various known attacks including the collusion attack. As a result, our scheme is more secure and efficient as compared to other related schemes in the literature.
    Keywords: Time-Bound hierarchical access control;Symmetric-key cryptosystem;Hash function; Key management;Secure broadcasting.
  • Effective Self-Adjustment Places of Interest Discovery in Public Places   Order a copy of this article
    by Chow-Sing Lin, Shang-Hsuan Hsu 
    Abstract: Existing fingerprint-based places of interest (POIs) finding approaches mainly rely on WiFi signal fingerprints of fixed/static access points. Due to the prevalence of smartphones and 3G networks, the increasing number of smartphones acting as mobile access points in public places have hindered the ability to effectively learn and identify POIs. The effective removal of these casually appearing WiFi beacons generated by mobile access points, which would improve the accuracy of place discovery, has recently become the centre of attention for a lot of research. In this paper, we propose the self-adjustment places of interest discovery system (SAPID) to deal with the aforementioned problem. In addition to entrance and departure detection of POIs, we further classified POIs into hierarchical classes based on their semantic meanings to accelerate POI matching in a POI database with the proposed hierarchical matching as opposed to traditional linear matching. With the proposed weighted merging of the fingerprints of entrance and matched POI, the SAPID is more robust than the state-of-art place discovery algorithms such as BeaconPrint, PlaceSence, and SensLoc, in detecting POIs located in public places where mobile access points are very likely to be present. The experiment results show that compared to state-of-art place discovery algorithms, the SAPID has better precision, recall, and F1 score in POI discovery.
    Keywords: Location-Based Service, Place of interest, Place Finding, WiFi Beacon, Fingerprint.
  • Service Composition with Quality of Service Management in Environmental Sensor Networks   Order a copy of this article
    by Nguyen Cuong, Federico Domínguez, Long Nguyen, Abdellah Touhafi, Kris Steenhaut 
    Abstract: Environmental sensor networks consist of geographically distributed resource-constrained computers that use sensors to measure environmental parameters. They typically collect and distribute environmental data in near real-time using different types of web services. These services are consumed by users and applications that expect appropriate Quality of Service (QoS) levels. However, acceptable and stable QoS levels are difficult to maintain in environmental sensor networks due to limited computing resources and hostile deployment conditions. We developed a new approach to efficiently manage QoS levels in these networks using two separate tasks: online QoS estimation and QoS-aware service composition. This paper presents our first prototype of a web service composition system that leverages Bayesian classification techniques to perform online QoS estimation by constantly monitoring key environmental and network performance parameters. This system has been tested in a live noise pollution environmental sensor network deployed in the Flanders region in Belgium.
    Keywords: environmental assessment, service composition, sensor networks, QoS management, sensor-based systems, service performance, estimation model, Naive Bayesian Networks.
  • A reliable and energy-efficient outdoor localization method for smartphones   Order a copy of this article
    by Anhua lin 
    Abstract: Location has become a key service for smartphone applications. Nowadays, GPS and network-based technology have been widely used to provide location service. However, the former suffers its high power consumption and "urban canyons", and the latter has some imperfections in location accuracy. In order to circumvent these problems, we present a reliable and energy-efficient localization system using inertial sensors commonly found on today's smartphone, which make up for the existing technologies. In this paper, we first give an overall view of the localization system, and then describe the key components separately. Further more, reliable algorithms for displacement determination and heading direction have been developed, and Vincenty's formulae are employed to calculate the latitude and longitude of the endpoint. In order to prevent accumulated error, location error correction mechanism based on local map information and A-GPS are introduced. Measurements on Samsung I9100 and evaluation in the real condition confirm anticipated benefits. Results show that ACMG uses 24:7% less power consumption than GPS, and get a mean location accuracy of less than 6:7m in the playground of Nankai University.
    Keywords: step detection;step length;heading direction;corner signature; outdoor localization; map tiles
  • A Context-Aware Service Framework for Mobile Ad Hoc Networks   Order a copy of this article
    by Tzung-Shi Chen, Neng-Chung Wang, Gwo-Jong Yu, Hsin-Ju Chen 
    Abstract: Following the development of wireless technology, a variety of mobile devices are now capable of communicating with each other. To do so, a mobile ad hoc networks (MANET) is established by mobile devices without relying on a fixed infrastructure. Due to the characteristics of rapid deployment and flexible construction, MANETs usually have attractive applications with regard to intelligent transportation systems and digital life. In this paper, we propose a service framework for supporting context-aware environments in MANETs. A virtual overlay network and two novel approaches within this framework have been addressed to significantly improve the efficiency of the data delivery. The surrounding context of mobile nodes is used to determine our strategy adopting push-based or pull-based approaches. When a real-time event occurs in a node, a push-based approach is adopted to disseminate urgent messages to neighboring nodes. On the contrary, a pull-based approach is adopted and a virtual backbone, namely a segment-tree virtual network (STVN), is constructed to conduct contextual information. Simulation results show that our proposed approach outperforms the existing publish/subscribe approach.
    Keywords: context-aware; mobile ad hoc networks; overlay networks; publish/subscribe; service framework
  • EstQoS: establishing QoS in multirate multihop Wireless Mesh Networks through available bandwidth computation and efficient admission control   Order a copy of this article
    by Dibakar Chakraborty 
    Abstract: Establishing QoS provisions in multirate multihop Wireless Mesh Networks is a challenging task. Locating effective admission control is the foremost need to efficiently utilize the scarce network resources and provide QoS guarantees. In this paper, we propose an EstQoS methodology comprising two phases. Phase 1 (EstAB) computes the available bandwidth of a node considering the hidden terminals' presence. We build an analytical model for EstAB phase. Phase 2 (AdmissionControl) consists of an effective admission control algorithm which defines a data rate adaptive scheme for non realtime ows to ensure efficient use of the channel bandwidth. On the other hand in case of realtime ows, the admission control algorithm ensures that the channel is not overloaded and the delay constraint is satisfied.
    Keywords: QoS, admission control, available bandwidth, multirate, Wireless Mesh Network.
  • Minimum Chunk-Transmission Delay for Active Safe Driving in Vehicular Ad-Hoc Networks   Order a copy of this article
    by Ben-Jye Chang, Ying-Hsin Liang, Cheng-Hsin Liu 
    Abstract: The active safe driving application, one of the important trends in future wireless mobile applications, offers real-time video streaming services and real-time emergency messages (EMs) to improve the driving safety in the intelligent transportation system (ITS). As the required (or shared) video and EM quality increasing, the constraints of packet delay, packet loss rate and the required bandwidth of packet transmissions become critically in Vehicular Ad-hoc NETwork (VANET). Multicasting is thus adopted to reduce the bandwidth waste rate while a sender wants to send real-time videos to a group of receivers. Although the multicasting VANET can adopt the retransmissions of lost chunks, it yields a long multicasting delay and wastes bandwidth for re-sending video chunks to the receivers that have successfully received chunks. This paper thus proposes a Peer-to-Peer (P2P) overlay network to cooperate with the multicast VANET, namely the minimum Delay-Guarantee chunk Reloading approach (DGR), to reload the lost or unconfirmed chunks timely. In DGR, a chunk with the least delay to the lost-chunk node is selected as the optimal compensating chunk. Numerical results demonstrate that DGR outperforms the compared approaches in successful chunk reload rate, average chunk delay, and chunk delivery ratio. Clearly, the retransmission-based multicasting and the random chunk-selection mechanism lead to obvious long delay and large bandwidth waste rate. DGR minimizes the chunk compensation delay and bandwidth waste rate.
    Keywords: Multicast VANET networks, P2P-based chunk reloading, real-time video streaming, the least-delay guarantee
  • Implementation of a Virtual Switch Monitor System Using OpenFlow on Cloud   Order a copy of this article
    by Chao-Tung Yang 
    Abstract: As a next generation networking protocol, the OpenFlow mechanism speeds up network performance by separating the control plane from the data plane. It can be implemented for QoS functions: users in need of network resources or with higher priorities defined by the system are allocated with adequate resources. In addition to the communication protocol, another two elements are needed to implement a complete OpenFlow system: the switch, either physical or virtual, which supports OpenFlow, and the controller, which sends setting packets of flows to control the switch flow table. With OpenFlow, users are not restricted to functions provided by the specific switch or router, such as RIP, OSPF, EGP routing protocols, firewalls, QoS, Anti-Virus, and NAT, since it provides a standard Application Programming Interface to let users have the freedom to define their wanted functions instead of predefined functions bundled in the manufacturers proprietary operating system. The main goal of this paper is to create an OpenFlow switch monitoring system, which oversees all hosts and traffic pass through switches under the controller, and provides a simple web page by which the network administrator can modify the priority of each flow and manage the whole network with great ease.
    Keywords: OpenFlow; Software Defined Network; Cloud Computing; Open vSwitch;
  • Dynamic Transmission Power Switch for Fast Data Collection in Duty-cycled Sensor Networks   Order a copy of this article
    by Zuzhi Fan 
    Abstract: Battery-powered sensor networks are often duty-cycled to conserve nodes energy and prolong network lifetime. In such intermittently-connected networks, the waiting time over multi-hop data forwarding dominates delivery latency, which is the main challenge and unacceptable for delay-sensitive applications. In this work, we address the optimization problem for duty-cycled sensor network with transmission power control. In particular, we propose Dynamic Transmission Power Switch (DTPS), a cross-layer approach which jointly considers power control with multi-parent forwarding for the fast data collection. In DTPS, each node dynamically selects a sequence of transmission pairs to deliver data packets. Extensive simulation results show that our scheme can reduce both delivery delay and energy consumption for data collection applications.
    Keywords: Wireless Sensor Network; Data Collection; Transmission Dower Switch; Delay Optimization
  • Efficient Active Rule Processing in Wireless Multimedia Sensor Networks   Order a copy of this article
    by Pinar Sarisaray-Boluk 
    Abstract: Wireless Multimedia Sensor Networks (WMSN) can provide surveillance convenience, provided that there is appropriate personnel to check the received data for possible intrusions. To reduce the human involvement, one of the e_ective techniques is to implement a reactive system at the sink for taking certain actions. For such a purpose, all the multimedia data should be available at the sink for processing. However, due to limited energy resources in Wireless Multimedia Sensor Networks (WMSN), there is a need to perform data reduction and elimination over raw video data at the camera sensors before they are sent to the sink. Nonetheless, this data reduction and elimination may create imprecision and uncertainty in the data received by the sink, reducing the quality of decision making. In this paper, we propose a reactive mechanism for not only fusing uncertain data at the sink but also for automated processing of data using active rules, extending the classical Event-Condition-Action (ECA) structure. In this mechanism, data fusion is performed using fuzzy logic to handle impreciseness and uncertainty in the received data. The fused data is then processed to infer certain prede_ned actions. These actions are triggered based on both the prede_ned event de_nitions in the system and the collected temporal and spatial data about the detected objects. A proof-of-concept is provided for the feasibility of the proposed approach on a power-plant surveillance application. Through experimentation, the proposed mechanism has also been shown to provide good accuracies while making signi_cant energy savings at the cameras.
    Keywords: Wireless Multimedia Sensor Networks; Active Rule; Complex Event Processing; Event Condition Action
  • Protected pointers in wireless sensor networks   Order a copy of this article
    by Lanfranco Lopriore, Gianluca Dini 
    Abstract: With reference to a distributed architecture consisting of sensor nodes connected by wireless links in an arbitrary network topology, we consider a segment-oriented implementation of the single address space paradigm of memory reference. In our approach, applications consist of active entities called components, which are distributed in the network nodes. A component accesses a given segment by presenting a handle for this segment. A handle is a form of pointer protected cryptographically. Handles allow an effective implementation of communications between components, and key replacement. The number of messages generated by the execution of the communication primitives is independent of the network size. The key replacement mechanism is well suited to reliable application rekeying over an unreliable network.
    Keywords: cryptographic key, key replacement, sensor node, single address space, symmetric- key cryptography.
  • Security and Performance Analysis of the SEAP Authentication Protocol in MANETs   Order a copy of this article
    by Soumyadev Maity, R. C. Hansdah 
    Abstract: Authentication protocols are essential for ensuring the security of communications in MANETs. However, efficiency is equally important for a MANET authentication protocol. This paper describes and analyzes a secure and efficient authentication protocol (SEAP) designed for MANETs. The SEAP protocol is a server coordination based pairwise symmetric key management protocol which works on a hierarchical network architecture and supports dynamic membership. Besides, the protocol uses a passive external membership granting server (MGS) to provide stronger security. To ensure efficiency, the protocol uses only symmetric key cryptography, and to achieve storage scalability, it makes use of a pseudo random function (PRF). The protocol is also robust against authentication server compromise. We have formally proved the correctness of the security grantees provided by the SEAP protocol using the strand space verification model. The paper includes a qualitative comparison with the other recently proposed protocols and also a comprehensive comparison with other existing protocols based on the results obtained from simulations. To demonstrate the applicability of the protocol in practical scenarios, its performance is also evaluated on a MANET testbed. Both simulation and experimental study demonstrate the effectiveness of the proposed protocol.
    Keywords: Authentication Protocol, MANET, Pseudo Random Function, Strand Space Model
  • Cooperative Topology Control for Low Interference in Wireless Ad Hoc Networks   Order a copy of this article
    by Xinglong Wang, Liusheng Huang 
    Abstract: Cooperative communication (CC) can exploit spatial diversity via neighbors antennas, which may cause serious interference as well. The previous works on the cooperative topology control problem mainly constructed the energy-efficient topologies for wireless ad-hoc networks, but could not guarantee the interference performance. Thus, this paper studies the interference-aware cooperative topology control problem. We first introduce a nodal interference model for the CC scheme. Based on this model, two problems are defined according to different criteria. One is to obtain a strongly connected topology with min-max interference (hereafter called CTCMMI), and the other is to construct a strongly connected topology with min-average interference (hereafter called CTC-MAI). Then, we design a binary-search-based algorithm, called DBS, to optimally solve the CTC-MMI problem. As the CTC-MAI problem is shown to be NP-hard, we propose a distributed algorithm DBCT and prove that DBCT can reach the approximate factor of 4 for CTC-MAI. Finally, extensive simulations show the high efficiency of the proposed algorithms compared with previous methods. For example, DBCT can construct the cooperative topology with low-average interference, and reduce the energy consumptions by about 30% compared with traditional methods.
    Keywords: Topology Control; Cooperative Communication; Low-Interference; Energy Efficiency;
  • A hidden Markov model combined with RFID-based sensors for accurate vehicle route prediction   Order a copy of this article
    by Ye Ning, Zhong-qin Wang, Reza Malekian, Ru-chuan Wang, Ting-ting Zhao, Darius Andriukaitis, Algimantas Valinevicius, Dangirutis Navikas, Vytautas Markevicius 
    Abstract: The road transport of dangerous goods (RTDG) arouses more and more attentions in recent years. Vehicle location devices only based on GPS technology have played an important role on the current market. However, there are obvious shortcomings by using a simple GPS method in the aspect of positioning accuracy and coverage. In the blind area of GPS, a vehicle's route could not be detached in real time, which will lead to manage and follow the tracks of vehicle difficultly. In this paper, we propose an approach based on Hidden Markov Model (HMM) to provide static predictions on driver routes. Our approach is based on building the probabilistic model through observation of the driver's habits from a map database involving RFID information. Before we predict a vehicle's route, we firstly compute the shortest path from starting point to destination point. Then through this path we could filter some redundant data. Finally, experiments demonstrate that we acquire high prediction accuracy under different periods of traffic conditions by training the HMM.
    Keywords: Hidden Markov Model; Vehicle Route Prediction; Route Filtering; RFID
  • Threshold-Based Cooperative Communication of Energy Harvesting Active Networked Tags   Order a copy of this article
    by Mengistu A. Mulatu, Li-Chung Chang, Yunghsiang S. Han, Fikreselam Gared Mengistu, Der-Feng Tseng 
    Abstract: Using cooperative transmission allows energy-harvesting active networked tags (EnHANTs) to cooperate regarding information transmission and reception, achieving higher throughput compared with non-cooperative counterparts. In this paper, a battery-threshold-based optimal cooperative transmission strategy is proposed for EnHANTs, allowing EnHANT-equipped objects to communicate with the destination (i.e. the reader) either directly or by cooperating with neighboring objects. A strategy adapted to request states and available energy resources is considered, and an optimal transmission policy for EnHANTs is developed to maximize the long-term average throughput by formulating a Markov decision process (MDP) model. The simulated results indicate that the proposed strategy yields superior performance compared with single-link transmission.
    Keywords: Cooperative transmission strategy; energy harvesting tags; Markov decision process; value iteration
  • A Context-Sensitive Service Composition Framework for Dependable Service Provision in Cyber-Physical Systems   Order a copy of this article
    by Tao Wang 
    Abstract: Most of the SOA-based mechanisms for web services are insufficient to support dependable service composition with the heterogeneous, dynamic, and numerous physical entities in CPS. Taking into account the contexts of physical entities, this paper presents a context-sensitive service composition framework in CPS with dependability requirements. Firstly, an ontology model for context-sensitive service specification of physical entities is proposed. Then, with a service spanning tree (SST) based hierarchical service management scheme., a service workflow spanning graph (SWSG) is used to map the workflow-based abstract process model of a given task to multiple sets of atomic service instances. Finally, we present a two-phase context-sensitive service composition optimization mechanism, which is able to select out the optimal service providers to implement the task effectively and dependably. The experiment results show that the precision and efficiency of service discovery, the success ratio of workflow execution, as well as the performance of service combination optimization have been greatly improved with our proposed method.
    Keywords: Cyber-physical system; service composition; context-sensitive; service spanning tree; service workflow spanning graph; service combination optimization
  • The Internet of Things Communication Protocol for Devices with Low Memory Footprint   Order a copy of this article
    by Sašo Vinkovič, Milan Ojsteršek 
    Abstract: This paper describes a new communication protocol, named XMC which is designed for the transmission of messages between an embedded device and a remote system. A new markup language called XMDD has also been developed and is used to describe the functional profile of the embedded device. The main advantage of XMC communication protocol is its flexibility and independence from the device type. It is suitable for communication with devices that have a curtailed amount of working memory (a few kB) and limited computing power, i.e. 8-bit or 16-bit microcontrollers. Messaging between embedded device and remote systems is done without any interference with the basic source code of the embedded device, thus allowing access to all functionalities and features of the connectable embedded device and is based on the functionality dictionary and built-in features of an embedded device. It also maintains a low production price for the embedded device and from the programming point of view provides a transparent and flexible upgrade of the hardware and software without any redundancy input.
    Keywords: communication protocol, internet of things, home automation, functional profile, smart appliance, code generation, embedded system, framework
  • Sampling Design Schemes for Distributed Parameter Estimation Networks   Order a copy of this article
    by Ming-Fong Hsu, Chao-Tang Yu, Tsang-Yi Wang, Tsai-Cheng Wu 
    Abstract: The present study proposes two sampling schemes for distributed parameter estimation networks. In both cases, the estimation network is assumed to comprise a number of remotely located sensors which process the observed signal locally and then convey the processed data to a data fusion center to make the final estimate of the parameter of interest. In the first sampling scheme, all of the sensors in the estimation network utilize the same number of sampling points, and the aim is to determine the distribution of the sampling points at each sensor which maximizes the estimation accuracy. By contrast, in the second sampling scheme, the sensors are assigned a different number of sampling points, and the objective is to determine the sampling point assignment which maximizes the overall estimation performance given a constraint on the total number of sampling points available. The two sampling design problems are solved by maximizing the Fisher information (or minimizing the Fisher information loss). The validity of the proposed sampling design schemes is demonstrated by means of two numerical examples.
    Keywords: distributed estimation; sampling design; optimal allocation; sensor networks; maximum likelihood estimation; person by person optimization.
  • Practical and Self-Con gurable Multihop Wireless Infrastructure: A Functional Perspective   Order a copy of this article
    by Muhammad Hamad Alizai 
    Abstract: Multihop wireless networks require self-configurable and reliable communication infrastructure that can quickly adapt itself to the rapidly changing network conditions without manual reconfiguration. The key to developing such a communication infrastructure requires (i) efficient link estimation mechanisms, (ii) reliable routing algorithms, and (iii) stable addressing schemes.In the past decade, a number of practical solutions have been developed for these three main components of multihop wireless infrastructure in inherently similar sensor networks, mesh networks and MANETs. However, we lack a comprehensive review that classifies these solutions and compares them on the basis of a set of properties desired in wireless networks.In this review, we classify different techniques implemented and evaluated by the research community, define a set of properties, and functionally compare representative techniques from each class.Our main departure from the existing literature is that (i) we focus on practical and self-configurable solutions that have widely been used in deployments and contributed to the open-source community, and (ii) we present a funcitonal comparison to elaborate the design philosophy and usability of these protocols and not just their performance.
    Keywords: link estimation, routing, addressing, wireless protocols, sensor networks, mesh networks, multihop wireless
  • QoS-Aware Virtual Machine Provisioning and Scheduling in Green Cloud Computing   Order a copy of this article
    by Md. Abdur Razzaque, Amit Kumar Das, Tamal Adhikary, Mohmmad Mehedi Hassan, Biao Song, Sana Ullah 
    Abstract: The aim of Green Cloud Computing (GCC) is to seamlessly integrate management of computing and communication resources to provide QoS, robustness, and energy-efficiency. The key challenge in GCC is to achieve multiple contradictory objectives, i.e. meeting the level of service defined in service level agreement (SLA) while minimizing energy consumption. In the literature, many existing works have been proposed to improve the estimation accuracy of the capacity required for static/dynamic virtual machine (VM) creation and scheduling. However, these approaches overlook the energy consumption cost for communication devices and network appliances and VMs scheduling. In GCC, it is approved that significant amount of energy is consumed in order to render the high level of computation facility. In this paper, a framework for QoS-aware adaptive VM scheduling and provisioning, named VSA, has been developed to provide automated, exible and energy-efficient management of the resources in a multi-cluster cloud data centre. To do so, the VMs for similar type of requests have been recycled so that the creation time of VM can be minimized and used to serve more user requests. Additionally, a cluster formation mechanism based on network vicinity among the data centres has been proposed. Also, intra-cluster and inter-cluster algorithms have been developed to handle energy conservation and resources availability and requirements. Simulation results show that the VSA system is able to conserve significant amount of energy while maintaining the QoS.
    Keywords: Cloud Computing; Green Cloud Computing; VM Provisioning; VM Scheduling, Quality of Service
  • A framework of cloud service selection based on trust mechanism   Order a copy of this article
    by Yuli Yang, Xinguang Peng, Donglai Fu 
    Abstract: Although cloud computing can provide the convenience for customers, customers still face the challenge to choose the appropriate cloud service, which can satisfy their different QoS requirements. Because traditional methods could not quantify the security of cloud services effectively, a novel method was proposed to quantify their security in the paper. In the proposed method, the definition of trust was given in the context of cloud service selection, and the trust mechanism based on cloud model theory was adopted to quantify the security of cloud services. Taking three QoS requirements of trust, cost and time into account, we put forward a multi-QoS-aware cloud service selection strategy, and employed the analytic hierarchy process (AHP) method to compute the utility value of each cloud service, which can help the cloud customer to select the appropriate cloud service according to his QoS requirements. Compared with traditional methods, the proposed method is sensitive to the change of the security. The multi-QoSaware cloud service selection strategy can provide a simple and effective decision-making method for cloud customers.
    Keywords: cloud computing; cloud service selection; Quality of Service (QoS); cloud model; Analytic Hierarchy Process (AHP).
  • Context-aware Framework to Support Situation-awareness for Disaster Management   Order a copy of this article
    by Aicha Aid, Idir Rassoul 
    Abstract: When a crisis event occurs, there is a strong need for any involved decision maker to gather in short time frames relevant situational information from different available data sources, to better understand the caused disruptions. Technological devices proliferation and ICT efficiency in timely information sharing didnt leave a choice to responders only to adopt them, supporting their operations. This article proposes a framework that aims to solve challenges brought by this new paradigm of information sharing. Based on service oriented architecture, our framework relies on Web Service standard for Devices to make pervasive situation-awareness environment that allows seamless integration of heterogeneous devices. It also provides solutions to filter in real time received information by taking into account the decision makers context. This context-aware mechanism plays an important role in making the data source intelligent that delivers personalized and actionable view of the situation, relevant to decision maker current needs.
    Keywords: pervasive computing; context-awareness; situation-awareness; disaster management; DPWS; ubiquitous environment; semantic web; information filtering; event extraction; emergency response.
  • Can wireless sensor networks be emotional? A survey of computational models of emotions and their applications for wireless sensor networks   Order a copy of this article
    by Tahir Emre KALAYCI, Majid Bahrepour, Nirvana Meratnia, Paul J. M. Havinga 
    Abstract: Advances in psychology have revealed that emotions and rationality are inter- linked and emotions are essential for rational behaviour and decision making. Therefore, integration of emotions with intelligent systems has become an important topic in engineering. The integration of emotions into intelligent systems requires computational models to generate emotions from external and internal sources. This paper first provides a survey of current computational models of emotion and their applications in engineering. Finally, it assesses potential of integrating emotions in wireless sensor networks by listing some use scenarios and by giving one model application. In this model application performance of a neural network for event detection has been improved using Brain Emotional Learning Based Intelligent Controller (BELBIC).
    Keywords: artificial intelligence; BELBIC; emotions; emotional learning; wireless sensor networks.
  • Cooperative Routing In Mobile Ad Hoc Networks Using Fuzzy Logic   Order a copy of this article
    by Venkanna Udutalapally, Leela Velusamy R 
    Abstract: Mobile Ad hoc Network, needs an unconditional cooperation among the nodes to communicate. Presence of malicious or selfish nodes in the routing path will affect the routing performance. In this paper, Fuzzy Logic Based Trust-AODV is proposed, which is an enhancement to the existing AODV protocol. The algorithm uses decision factors such as Packet forwarding trust, Energy level, and Time of Availability to decide the dynamic changing behavior of a mobile node. Further, the decision factors are incorporated into Fuzzy logic model to calculate the Final Trust value of a mobile node which is used to establish a cooperative routing path. The simulated results are compared with AODV, DSR, TDSR and AOTDV algorithms with respect to routing parameters such as Packet delivery ratio, Average delay, Routing packet overhead, and Energy consumption. The simulation results indicate that the proposed routing algorithm improves the routing performance.
    Keywords: Trust Management, Cooperative routing, Fuzzy Logic, MANET, AODV, DSR, AOTDV, FLBT-AODV.
  • Coherent, Automatic Address Resolution for Vehicular Ad Hoc Networks
    by Luis Urquiza-Aguiar, Carolina Tripp-Barba, David Rebollo-Monedero, Ahmad Mohamad Mezher, Mónica Aguilar, Jordi Forné 
    Abstract: The interest in vehicular communications has increased notably. In this paper, the use of the Address Resolution (AR) procedures is studied for vehicular ad hoc networks (VANETs). We analyse the poor performance of AR transactions in such networks and we present a new proposal called Coherent, Automatic Address Resolution (CAAR). Our approach inhibits the use of AR transactions and instead increases the usefulness of routing signalling to automatically match the IP and MAC addresses. Through extensive simulations in realistic VANET scenarios using the Estinet simulator, we compare our proposal CAAR to classical AR and to another of our proposals that enhances AR for mobile wireless networks, called AR+. In addition, we present a performance evaluation of the behaviour of CAAR, AR and AR+ with unicast traffic of a reporting service for VANETs. Results show that CAAR outperforms the other two solutions in terms of packet losses and furthermore, it does not introduce additional overhead.
    Keywords: vehicular ad hoc networks (VANETs); address resolution (AR); address resolution protocol (ARP); neighbour discovery (ND) routing protocols; wireless ad hoc networks.

Special Issue on: "Security Aspects in Pervasive and Ubiquitous Computing,"

  • Key revocation in wireless sensor networks: a survey on a less-addressed yet vital issue   Order a copy of this article
    by Dieynaba Mall, Karim Konaté, Al-Sakib Khan Pathan 
    Abstract: Key management in wireless sensor network (WSN) includes two important aspects namely key distribution, which constitutes the task of distributing secret keys to nodes in the network, and key revocation, which refers to the task of securely withdrawing the key information relating to any compromised node or because of tactical reasons. While in the existing literature, key distribution has been extensively studied, key revocation has received relatively little attention. A vital security issue like this needs proper recognition to be considered as a critical research area, not just as a partial segment of key management. With this motivation, in this paper, we present our rationale behind recognising the area and analyse the state-of-the-art key revocation techniques. Alongside our survey on the prominent schemes, we also present an analysis of security and performance that highlights the advantages and disadvantages of each scheme that explicitly mentions the method of key revocation.
    Keywords: key revocation; key management; network security; wireless sensor networks; WSNs; key management.
  • Reconfigurable content-based image retrieval on peer-to-peer networks   Order a copy of this article
    by Chun-Rong Su, Jiann-Jone Chen 
    Abstract: Performing content-based image retrieval (CBIR) from Internet scale databases connected through peer-to-peer (P2P) networks, abbreviated as P2P-CBIR, helps to explore the large-scale image database distributed over connected peers. For P2P topology, the flexible decentralised unstructured P2P network topology is adopted, based on which informed-like searching approach enables flexible routing control when peers join/leave. The scalable retrieval control can be developed based on the P2P-CBIR framework, which can adapt the query scope and progressively refine the accuracy during the retrieval process. By reconfiguring system at each regular interval times, we can effectively reduce trivial peer routing and retrieval operations due to imprecise configurations. Experiments demonstrated that the average recall rate of the proposed P2P-CBIR method with reconfiguration is higher than that without about 10.73%, while the latter outperforms previous methods, i.e., firework query model (FQM) and breadth-first search (BFS), about 27% and 57%, respectively, under the same time-to-live (TTL) setting.
    Keywords: P2P networks; peer-to-peer networks; multi-instance query; reconfigurable CBIR; content-based image retrieval; scalable retrieval; peer linking reconfiguration; ubiquitous computing; flexible routing control; average recall rate.
  • Security analysis and improvement of a mutual authentication scheme under trusted computing   Order a copy of this article
    by Fahad T. Bin Muhaya 
    Abstract: Recently, Yang et al. proposed a smart card and password-based mutual authentication scheme under trusted computing, and they claimed that their scheme can resist kinds of attacks. But they did not consider the stolen smart card attack which is an important attack in smart card-based authentication scheme. In this paper, we first analyse the stolen smart card attack to Yang et al.'s scheme, and then propose an enhanced mutual authentication scheme for trusted computing. Our scheme can resist the stolen smart card attack and other attacks, and can quickly detect the unauthorised login at the beginning when the user input the wrong identity or wrong password.
    Keywords: user authentication; passwords; stolen smart cards; cryptanalysis; trusted computing; trust; cryptography; security analysis; mutual authentication; unauthorised login; wrong identity; wrong password.
  • A quantitative and knowledge-based approach to choosing security architectural tactics   Order a copy of this article
    by Suntae Kim 
    Abstract: This paper presents a quantitative approach to choosing security architectural tactics using architectural tactic knowledge base. An architectural tactic is an architectural design building block pertaining to a software quality. The tactic knowledge base is a tactic repository composing of architectural tactic specifications defined in role based metamodelling language (RBML) and their relationships expressed in a feature model. In this paper, a cost of an architectural tactic is estimated by using the use case points method, and a level of tactic contribution for non-functional requirements (NFRs) is predicted by the analytic hierarchy process (AHP) and sensitivity analysis. Then, the proposed approach suggests the best possible fit which is likely to satisfy NFRs. We applied the approach to choosing security architectural tactics for building software architecture of an online trading system.
    Keywords: security architectural tactics; secure software architecture; quantitative tactic selection; architectural tactic knowledge base; software quality; metamodelling; RBML; feature modelling; non-functional requirements; NFRs; analytical hierarchy process; AHP; sensitivity analysis; online trading systems.
  • Anti-forensic steganography using multi-bit MER with flexible bit location   Order a copy of this article
    by Rong-Jian Chen, Shi-Jinn Horng, Po-Hsian Huang 
    Abstract: This work develops an anti-forensic steganography system using the proposed multi-bit MERs with flexible bit location embedding method (multi-bit MER_FBL embedding method) to overcome the problem of forensics and to achieve high performance including both large embedding capacity and high image quality. The proposed multi-bit MER_FBL embedding method hides multi-bit (k-bit, k ≥ 1) logo/secret data into any adjoining (starting with the ith location) k-bit bibi−1…bi−k+ of cover data only introduces MEE in the range of 0 to ±(2k - 1)2i−k; moreover, its flexible bit location enhances the embedded security as security increases as the embedding location closing to the MSBs of cover data. We thus develop a thresholding mechanic to evaluate the anti-forensics degree of the proposed method. Finally, antiforensics of the proposed steganography systems are demonstrated using the visual attack and the statistical attack of Chi-square analysis.
    Keywords: steganographgy; anti-forensics; multi-bit embedding; minimum error replacement; flexible bit location; multi-bit MER; embedding capacity; image quality; embedded security; thresholding mechanic; visual attack; statistical attack; Chi-square analysis.
  • A new handover authentication protocol based on bilinear pairing functions for wireless networks   Order a copy of this article
    by Debiao He, Muhammad Khurram Khan, Neeraj Kumar 
    Abstract: Seamless handover over multiple access points is highly desirable to mobile nodes, but ensuring security and efficiency of this process is challenging. Many such protocols have been proposed but most of them are either insecure or inefficient. Very recently, He et al. proposed an improved protocol to overcome the weakness of a novel handover authentication protocol, namely PairHand. Later, they pointed out that their protocol is vulnerable to a private key compromised problem under certain circumstances and proposed an improved protocol to overcome the weakness. In this paper, we examine the security of He et al.'s improved protocol and show it is vulnerable to a private key compromised problem. To improve security, we propose a new ID-based signature protocol and construct a new handover authentication protocol based on the proposed signature protocol.
    Keywords: wireless networks; network security; privacy protection; efficiency; handover authentication; bilinear pairing; seamless handover; mobile nodes; compromised private key; ID-based signature protocol.
  • An improved biometric-based remote user authentication scheme for connected healthcare   Order a copy of this article
    by Dheerendra Mishra, Ankita Chaturvedi, Sourav Mukhopadhyay 
    Abstract: The advancements in technology have made the internet an efficient and scalable tool to utilise for various online services; one of them is connected healthcare. The connected healthcare system presents the platform to deliver clinical service door to door. In these online services, it is required to ensure the authenticity of patients to protect medical resources/services. In 2013, Chang et al. presented biometric-based remote user authentication scheme with user anonymity for connected healthcare. They claimed that their biometrics based scheme is secure and efficient to validate the legality of the patient. Recently, Das and Goswami demonstrated that Chang et al.'s scheme is vulnerable to insider attack and man-in-the middle attack. They also showed some flaws in login and password change phases of Chang et al.'s scheme. Furthermore, they presented an improved scheme. However, we observe that Das and Goswami's scheme does not provide three factor authentication and is vulnerable to offline identity guessing attack. Further, we propose an improved biometric-based remote user authentication scheme for connected healthcare, which provides efficient login and password change phases where smart card quickly identifies the incorrect input. Moreover, the proposed scheme satisfies all desirable security attributes and achieves three factor authentication.
    Keywords: e-medicine; connected healthcare; network security; smart cards; passwords; login; biometrics; cryptanalysis; cryptography; remote user authentication; patient authentication; user anonymity; three factor authentication; e-healthcare; electronic healthcare; healthcare technology.

Special Issue on: "Dynamism and Mobility Handling in Mobile and Wireless Networking,"

  • A Resource Management Scheme and Its Performance Analysis for Integrated Wireless and Mobile Networks with Multiple Traffics   Order a copy of this article
    by Zhen-Jiang Zhang, Qing-An Zeng, Wei Shen, Hua-Pei Chiang, Yueh-Min Huang 
    Abstract: Wireless and mobile networks have experienced a great success in the past few years. However, any single type of wireless and mobile network cannot provide all types of services. An integrated wireless and mobile network is introduced by combining these different types of wireless and mobile networks to provide more comprehensive services. Although an integrated wireless and mobile network provides more connection options for mobile users than a single type of wireless and mobile network, it imposes great challenges in many perspectives. One of such challenges is to efficiently manage resource for supporting multiple services. Although a lot of resource management schemes have been proposed to support multiple traffics in wireless and mobile networks, most of them focus on multiple traffics in a single type of wireless and mobile network or a single type of traffic in an integrated wireless and mobile network. Therefore, they may not be suitable to support multiple traffics in an integrated wireless and mobile network. In this paper, we propose a resource management scheme to support multiple traffics in an integrated wireless and mobile network. An algorithm is also designed to solve the unfairness problem of resource management between the real-time and non-real-time traffic.
    Keywords: Integrated wireless mobile networks, resource management, multiple traffics
  • An Energy-Efficient and Client-Centric Data Streaming Technique on Smartphones   Order a copy of this article
    by Abdulhakim Abogharaf, Veluppillai Mahinthan, Kshirasagar Naik 
    Abstract: Today's users extensively download video files on their wireless handheld devices, namely, smartphones and tablet computers, which are inherently power constrained. The batteries on those devices barely last for 2-3 hours while downloading and playing video files. Experiments have shown that video downloading accounts for a large portion of the total energy cost of downloading and playing video files. In this paper, we present a novel, energy-efficient and purely client-centric video downloading algorithm with three tunable parameters namely, buffer size, low water mark and socket- reading size. By implementing the algorithm on a smartphone and measuring the actual energy cost of downloading video files, we show the impacts of the three parameters on the energy cost of video downloads. By tuning the buffer size, low water mark, and socket- reading, we observed energy savings to the extent of 60%, 64%, and 63%, respectively. By incorporating our algorithmic approach into the process of video downloading, mobile application (app) developers will be better positioned to fine tune their apps to reduce the total energy cost of downloading large files in general.
    Keywords: Smartphones; data streaming; energy consumption.
  • Efficient Authentication Approach for Highly Dynamic Vehicular Ad Hoc Networks   Order a copy of this article
    by Kanika Grover, Alvin Lim 
    Abstract: Vehicular Ad hoc Networks (VANETs) possess an extremely dynamic nature accompanying the high mobility feature. In VANETs, each vehicle sends out safety messages at regular intervals. IEEE 1609.2 security standard for VANETs recommend the use of secure Elliptic Curve Digital Signature Algorithm (ECDSA) signatures for authenticating broadcast messages. ECDSA provides source authentication, message integrity and non-repudiation; with the drawback of signature verification overhead. Due to this, a large number of messages expire in the verification queue. Considering time-bound VANET broadcast messages authenticated using complex ECDSA verification, we propose a probabilistic verification for highly dynamic and mobile vehicles to reduce packet loss ratio. Along with our intelligent authentication strategy, we maintain conditional privacy of the vehicles through a lightweight vehicle registration process. We implement the complete solution in a realistic VANET scenario. With ns-2 simulations, we show that our algorithm decreases message loss by an overall average of $68\%$ compared to other broadcast authentication algorithms.
    Keywords: VANET; Broadcast; Authentication; Privacy; ECDSA; Wireless
  • Developing a Wireless Based Dynamic Management Mechanism for Intravenous Drip Scheduling   Order a copy of this article
    by Chien-Liang Chen, Nan-Chen Hsieh, Lun-Ping Hung 
    Abstract: In this rapidly developing high-tech environment, building a nursing information system is essential. When an emergency occurs, nurses must immediately remove obstacle interrupting medical care to assist medical treatment successfully. In this paper, a system built in a mobile nursing station accompanied by a high-tech device installed in the infusion drip equipment transmitting signals through a ZigBee wireless network is proposed. This system uses a dynamic wireless infusion monitoring mechanism. When an emergency occurs, the intravenous drip sends out an alert message through the wireless environment to the system in the mobile nursing station. The system will reschedule previous processing ranks to assist nurses in taking care of routine medical operations efficiently. By applying this system, nurses can devote themselves to providing better quality medical care and claims for medical negligence or medical malpractice can be reduced.
    Keywords: mobile nursing station; infusion monitoring; ZigBee; Nursing Information Systems
  • SocioCar: A Transient Social Vehicular Network   Order a copy of this article
    by Rasool Esmaeilyfard, Faramarz Hendessi 
    Abstract: The increasing use of vehicles and the heavy traffic emerged in metropolises have both turn to an important part of people's daily routine. This situation could provide a unique opportunity for some kind of social communication among people. However, this social communication has its requirements and constraints. In this paper, we introduce the notion of SocioCar in order to develop a transient social vehicular network service. This service inspires the users to communicate quickly by reducing social constraints. In this regard, one of the key points in this paper is the idea to adapt the user identity and its role in rapid communication. Furthermore, we integrate our design with a user social classification method using Bayesian Networks with an aim to effectively highlight the desired users and predict users characteristics. Through this approach, we investigate the social classification model and conduct a user study to probe the usefulness of social network.
    Keywords: transient social networking; social service middleware; avatar; privacy; vehicular ad-hoc networks (VANET); social classification.
  • Spectrum Sharing Model for OFDMA macro-femtocell networks   Order a copy of this article
    by Rebeca Estrada, Hadi Otrok, Zbigniew Dziong, Hassan Barada 
    Abstract: Enhancing the network throughput while supporting non-uniform user distribution and dense deployment of femtocells is a challenge in OFDMA networks. Previous research works provide approaches based on spectrum partitioning and spectrum sharing for macro-femtocell networks. Few proposed interference management approaches have been investigated without considering user mobility. In this paper, we target the optimization of resource allocation in macro-femtocell networks taking into account the user distribution over macrocell coverage area and femtocells dense deployment. We propose a spectrum sharing approach that aims to maximize the network throughput based on Linear Programming. Interference mitigation is performed through the power adaptation in both tiers while guaranteeing the QoS transmission requirements. Our solution is able to: (1) fairly allocate macrocell resources to each zone taking into account the user distribution over the macrocell coverage area, (2) optimally reuse of the bandwidth allocated to inner zone inside the femtocells located in outer zone, and (3) optimally determine the serving base station, subcarriers and respectiverntransmitted power for downlink transmissions per zone taking into account user locations and demands in any given period. Performance analysis is presented under incremental traffic load and realistic scenarios where user mobility is considered. Simulations are conducted to show a comparison of the proposed model with two spectrum partitioning approaches with and without partial bandwidth reuse.
    Keywords: Linear Programming; OFDMA macro-femtocell networks; Subcarrier Reuse; Power Control.
  • Cross Layer Trigger based Handover Scheme for Mobile WiMAX Networks   Order a copy of this article
    by sudesh pahal, Brahmjit Singh, Ashok Arora 
    Abstract: WiMAX networks have recently emerged to be a cost effective solution to provide broadband access over a large coverage area. To maintain service continuity and guarantee the QoS in real time applications for mobile users, handover delay is one of the main challenges while designing handover algorithms. In this paper, cross layer trigger based handover scheme is proposed which will be able to offer uninterrupted services to mobile users. The basic idea behind this scheme is to achieve a global optimality by utilizing the advantages of cross layer interactions between link layer and network layer. The cross layer triggers generated at lower layers, intimate higher layers about an imminent handover and allow execution of handover processes in Layer 2 (L2) and Layer 3 (L3) simultaneously. In addition, information about location and direction of movement of mobile is used to reduce scan delay. The analytical and simulation results show that the proposed mechanism enhances the handover performance in terms of handover delay and latency, which, in turn, reduces signaling overload and service disruption significantly.
    Keywords: Cross layer; Mobile WiMAX; FMIPv6; Handover; delay; Latency; Trigger;
  • SPEED-3D: a Geographic Routing Protocol for 6LoWPAN Networks   Order a copy of this article
    by Stefano Bocchino, Matteo Petracca, Paolo Pagano, Marco Ghibaudi, Giuseppe Lipari 
    Abstract: The integration of the Wireless Sensor Network (WSN) technology in the Internet world is a necessary step towards the full accomplishment of the Internet of Things (IoT) vision. In order to reach a seamless integration of tiny mote devices in Internet, the IPv6 addressing method and communication protocols developed for the IoT must be modi ed or adapted to match the WSN requirements. This adaptation process is started in the 2007 with the standardization of the IPv6 protocol over Low power Wireless Personal Area Networks (6LoWPAN). In such a scenario, we propose SPEED-3D, an extension of the SPEED geographic routing algorithm, adapted to 6LoWPAN networks that caters for 3D routing. SPEED- 3D avoids the creation of routing tables, and has a very low memory occupation; it also supports load balancing and ow shaping; nally, thanks to the presented extension, it is able to work seamlessly in a 3D setting (e.g., a tall building). In the paper, we rst present SPEED-3D in 6LoWPAN networks by detailing the encapsulation of all messages in the IEEE802.15.4 medium access control protocol and the new functionality provided thanks to the IPv6 standard, then we present its implementation on a real-time kernel and its performance in a realistic indoor scenario.
    Keywords: Wireless Sensor Networks; 6LoWPAN; IoT; Routing algorithm; Real-Time.
  • QoE Preserving Resource Scheduling for M2M Terminals and Human Users in LTE Networks   Order a copy of this article
    by Isam Abdalla, S. Venkatesan 
    Abstract: We study in this article the impact of supporting a large number of Machine to Machine (M2M) communication terminals in the 4th Generation (4G) Long Term Evolution (LTE) wireless networks. Our main focus in the study is on how to accommodate the large number of M2M devices without negatively impacting the human subscribers Quality of Experience (QoE). The LTE scheduler plays an important role in distributing the available radio resources to user equipment (UEs) and M2M terminals in each cell. We propose dividing the available radio resources between human users and M2M devices such that human users QoE is preserved. Our proposal adds new M2M-specific Quality of Service (QoS) Class Indicators (QCIs) for classifying M2M traffic bearers. We use the new classes in a new priority based scheduler to allocate radio resources to preserve human users QoE and fairly fulfill M2M terminals communication requests. Simulation results show that the proposed solution provides fair scheduling of M2M terminals without impacting human users QoE.
    Keywords: Machine to Machine communication; Machine Type Communication; LTE resource scheduling; M2M; MTC; QoE
  • RSSI-based Localization Algorithms using Spatial Diversity in Wireless Sensor Networks   Order a copy of this article
    by Abderrezak Rachedi, Abderrahim Benslimane, Safa Hamdoun 
    Abstract: Many localization algorithms in Wireless Sensor Networks (WSNs) are based on received signal strength indication (RSSI). Although these methods present some advantages in terms of complexity and energy consumption, RSSI values especially in indoor environments, are very unstable due to the fading induced by shadowing e ect and multipath propagation. In this paper, we propose a comparative study of RSSI-based localization algorithms using spatial diversity in WSNs. We consider di erent kinds of single/multiple antenna systems: Single Input Single Output (SISO) system, Single Input Multiple Output (SIMO) system, Multiple Input Single Output (MISO) system and Multiple Input Multiple Output (MIMO) system. We focus on the well known trilateration and multilateration localization algorithms to evaluate and compare di erent antenna systems. Exploiting spatial diversity by using multiple antenna systems improve signi cantly the accuracy of the location estimation. We use three diversity combining techniques at the receiver: Maximal Ratio Combining (MRC), Equal Gain Combining (EGC) and Selection Combining (SC). The obtained results show that the localization performance in terms of position accuracy is improved when using multiple antennas. Speci cally, using multiple antennas at both the transmitter and receiver sides present better performance than using multiple antennas at only one side. We also conclude that MRC diversity combining technique outperforms EGC that as well outperforms SC.
    Keywords: Wireless Sensor Networks, Indoor localization, Received Signal Strength Indicator, Spatial diversity, Trilateration, Multilateration.
  • Evaluating 3D wireless Grids as Parallel Platforms   Order a copy of this article
    by Amir Mansoor Kamali Sarvestani, Christopher Crispin-Bailey, Jim Austin 
    Abstract: To date, in computing technology, wireless connections have not been good choices for connecting processors in a massively parallel computer. This is mainly because wireless devices are considered to have both more energy demands and lower data communication rate compared to their wireline counterparts. In light of developments in wireless technologies in the last decade, this paper investigates if (and, to what extent) that assumption is still valid. Capacitive coupling, inductive coupling and radio frequency approaches are reviewed. They are compared with each other and with wireline technologies. We want to know how close we are to an efficient wireless parallel computer, especially in terms of energy consumption and link data-rate. For an evaluation case we utilise a simulated 3D wireless grid as a parallel platform, the Ball Computer. This model is the basis of research to test the viability of a concept 3D wireless interconnect network for a massively parallel computer. Simulation results are included in this manuscript to help explain the behaviour of the proposed platform under different situations. We then conclude that it is possible to proceed to the second stage of the long-term goal to build a prototype of Ball Computer.
    Keywords: Wireless networks, capacitive coupling, inductive coupling, on-chip radio communication, parallel computing, interconnect network
  • Reliable Multicast as a Bayesian Coalition Game for a Non-stationary Environment in Vehicular Ad Hoc Networks: A Learning Automata Based Approach   Order a copy of this article
    by Neeraj Kumar, Chun-Cheng Lin 
    Abstract: With advancement of various Internet-based technologies, vehicular ad hoc networks (VANETs) are offering a lot of services such as commercial, informative and entertaining services to the drivers and passengers in addition to their primary objective for passengers safety on the road for the benefits of community of users. For successful execution of all these services, reliable multicast is required keeping in view of various constraints such as constant topological changes and high velocity in VANETs. Due to the dynamic nature of VANETs, it is a challenging task to perform reliable multicast among vehicles. As a result, this paper proposes a new approach called reliable multicasting as a Bayesian coalition game using learning automata (RMBCG-LA) for VANETs. The concerned problem is formulated keeping in view of the non-stationary environment (due to constant topological changes) of vehicles in VANETs. To cope up with the non-stationary environmental conditions in VANETs, a new metric called probabilistic reliability index (PRI) has been computed by each player of the game. Each vehicle is assumed to be a player in the game having automaton deployed on each vehicle. A coalition among the players of the game is formed using Bayesian network with a threshold in each coalition based upon a conditional probability. Players can leave/join from one coalition to another. For each action performed by the automaton, its action is rewarded or penalized by the non-stationary environment in which it is operating. The performance of the proposed scheme is evaluated in comparison with the well-known existing schemes with respect to different parameters such as packet loss rate, end-to-end delay, packet delivery ratio, delivery cost and delivery delay. The results obtained show that our proposed scheme is better than the other schemes of its category.
    Keywords: Vehicular ad hoc network; learning automata; coalition game; Bayesian network

Special Issue on: "Advances in Transparent Computing,"

  • A cost-efficient architecture for the campus information system based on transparent computing platform   Order a copy of this article
    by Kehua Guo, Yizhe Xiao, Guihua Duan 
    Abstract: This paper presents a novel architecture named CISTC for the campus information system (CIS) based on transparent computing (TC) platform, as well as the development, deployment and maintenance experiences to improve the economic efficiency. Firstly, the system architecture of CISTC is introduced. Secondly, we describe the transmission of operating systems and applications, data management and interface release. Then the software development, deployment and maintenance processes in CISTC are described. Finally, we design some mathematical models to evaluate the economic efficiency of CISTC. The results show that using transparent computing platform as the campus information system constructing environment can enhance the economic efficiency and lead to increased user experience in comparison with the traditional approach.
    Keywords: campus information system; economical efficiency; transparent computing; software engineering
  • Cross Platform Computing and Its Application to Mobile Device in Transparent Computing   Order a copy of this article
    by Wei Liang, Yonghua Xiong, Min Wu, Yaoxue Zhang, Jinhua She 
    Abstract: Commercially available mobile devices with various kinds of hardware and software platforms have resulted in a huge amount of mobile applications. This provides a big challenge to design applications that are compatible with heterogeneous devices and operating systems (OSes). This paper presents a method of cross platform mobile transparent computing (CPMTC) for mobile devices. A mobile pre-boot firmware (MPBF) is designed to stream OS image data to the device through a network. Moreover, in application layer, we devise a method of designing applications based on HTML5, which ensures that applications are available for different OSes. We use the MPBF to load different OSes into the experimental tablet. After that, we use the CPMTC method to run and evaluate a knowledge collection e-learning (KCE) system for different OSes. Experiment results confirm that the CPMTC is effective in seperating OSes both from hardware and application programs for mobile devices.
    Keywords: transparent computing; cross platform; mobile device; HTML5.
  • Personalized content recommendation based on field authorities in transparent computing   Order a copy of this article
    by Wei Hu, Yaoxue Zhang, Yuezhi Zhou 
    Abstract: Transparent computing (TC) provides a large number of intelligent information services. Recommendation can help users rapidly locate their desired content. Collaborative filtering (CF) is a suitable recommending technology for TC, but data sparsity and noise problems have not been effectively solved. This study proposes a novel CF approach based on field authorities to achieve the genre tendency of items by mapping tags to genres and simulates a fine-grained word-of-mouth recommendation mode. Nearest neighbors are selected from sets of experienced users as field authorities in different genres, and weights are assigned to genres according to genre tendency. The method employed in this study can efficiently solve sparsity and noise problems and have high prediction accuracy. Experiments on MovieLens datasets show that the accuracy of this approach is significantly higher than that of traditional CF and expert CF in both mean absolute error and precision.
    Keywords: Transparent computing, Recommender system, Collaborative filtering, Field authority, Rating prediction
  • Performance Modeling for Transparent Computing using Stochastic Petri Nets   Order a copy of this article
    by Chao Xue, Chuang Lin 
    Abstract: Massive applications, large-scale and disparity of demands tend to be the main characteristics of information technology. Therefore, to define an efficient computing paradigm with high quality of service has become an urgent issue both in academia and industry. An effective approach named transparent computing paradigm is proposed to meet the demands, which leaves computation and storage in different places. This paper studies the performance evaluation of such computing paradigm. We propose the Stochastic Petri Net models of transparent computing, based on which mathematical analysis is provided. Furthermore, we compare transparent computing paradigm with some traditional computing paradigms, both quantitatively and qualitatively.
    Keywords: Transparent Computing; Computing Paradigm; Quality of Service; Performance Evaluation; Stochastic Petri Net; Stochastic Rendezvous Network;

Special Issue on: "Mobility Management and Wireless Access,"

  • Candidate Selection Algorithms in Opportunistic Routing based on Distance Progress   Order a copy of this article
    by Amir Darehshoorzadeh, Llorenç Cerdà-Alabern, Vicent Pla 
    Abstract: Opportunistic Routing (OR) is a new class of routing protocols that selects the next-hop forwarder on-the-fly. In contrast to traditionally routing, OR does not select a single node as the next-hop forwarder, but a set of forwarder candidates. When a packet is transmitted, the candidates coordinate such that the best one receiving the packet will forward it, while the others will discard the packet. The selection and prioritization of candidates, referred to as candidate selection algorithm, has a great impact on OR performance. In this paper we propose and study two new candidate selection algorithms based on the geographic position of nodes. This information is used by the candidate selection algorithms in order to maximize the distance progress towards the destination. We compare our proposals with other well-known candidate selection algorithms proposed in the literature through mathematical analysis and simulation. We show that candidate selection algorithms based on distance progress achieve almost the same performance as the optimum algorithms proposed in the literature, while the computational cost is dramatically reduced.
    Keywords: Opportunistic routing; Candidate selection; Maximum progress distances; Wireless network.
  • Improving Sensor Network Performance with Wireless Energy Transfer   Order a copy of this article
    by Constantinos Marios Angelopoulos, Sotiris Nikoletseas, Theofanis Raptis, Christoforos Raptopoulos, Filippos Vasilakis 
    Abstract: Through recent technology advances in the eld of wireless energy transmission Wireless Rechargeable Sensor Networks have emerged. In this new paradigm for wireless sensor networks a mobile entity called Mobile Charger traverses the network and replenishes the dissipated energy of sensors. In this work we rst provide a formal de nition of the charging dispatch decision problem and prove its computational hardness. We then investigate how to optimise the trade-o s of several critical aspects of the charging process such as a) the trajectory of the charger, b) the di erent charging policies and c) the impact of the ratio of the energy the Mobile Charger may deliver to the sensors over the total available energy in the network. In the light of these optimisations, we then study the impact of the charging process to the network lifetime for three characteristic underlying routing protocols; a greedy protocol, a clustering protocol and an energy balancing protocol. Finally, we propose a Mobile Charging Protocol that locally adapts the circular trajectory of the Mobile Charger to the energy dissipation rate of each sub-region of the network. We compare this protocol against several Mobile Charger trajectories for all three routing families by a detailed experimental evaluation. The derived ndings demonstrate signi cant performance gains, both with respect to the no charger case as well as the di erent charging alternatives; in particular, the performance improvements include the network lifetime, as well as connectivity, coverage and energy balance properties.
    Keywords: Sensor Networks; Energy Eciency; Wireless Charging; Wireless Energy Transfer; Mobility; Distributed Algorithms; Experimentation; Performance.
  • Subject-Independent Human Activity Recognition using Smartphone Accelerometer with Cloud Support   Order a copy of this article
    by Muhammad Arshad Awan, Zheng Guangbin, Hie-Cheol Kim, Shin-Dug Kim 
    Abstract: Human activity recognition is an important task in providing contextual user information and has become an emerging field of ubiquitous computing. In this study, we present a methodology to achieve human activity recognition using a Smartphone accelerometer independent of a subject compared to other user-dependent solutions. We developed a system to recognize human activities using a Smartphone accelerometer irrespective of the user for training and test data sets. Some basic activities have similar data patterns and are difficult to distinguish accurately during the recognition process. To improve recognition accuracy, a large amount of data for classification modeling is required. Therefore, we used a recursive approach for data collection and an incremental approach for classification modeling to improve the accuracy and obtain subject independence. The proposed system is composed of 4 components; a data collector, a data storage cloud, a workstation module and an activity recognizer. The data collector extracts a unique set of defined features from raw data and sends them to the data storage cloud. The workstation module receives the training data from the cloud and generates classification models which are uploaded to the cloud for activity recognition process. The activity recognizer determines the users current activity based on up-to-date available classifier from the cloud and also sends test data as training data to the cloud for incremental classification modeling. A prototype is implemented on an android platform to recognize a set of basic daily living activities by placing the Smartphone in different positions to the user and evaluated for offline and online testing. Average accuracy above 90% in recognizing all the defined set of subject-independent activities was achieved, showing the scalability and effectiveness of our proposed methodology.
    Keywords: human activity recognition; subject-independent; mobile cloud computing; context-awareness; ubiquitous computing.
  • How to be an efficient Asynchronous Neighbourhood Discovery protocol in opportunistic Cognitive Wireless Networks   Order a copy of this article
    by Sylwia Romaszko, Wim Torfs, Petri Mahonen, Chris Blondia 
    Abstract: In opportunistic Cognitive Radio Networks (CRNs) there is a need of on-demand searching for a control traffic channel by cognitive radio (CR) users in order to be able to initiate a communication. The neighbourhood discovery (ND) phase is challenging due to the dynamics of such networks. Lately, there has been a proliferation of different RDV protocols. However, most protocols have a narrow focus, which is usually a RDV guarantee in a single cycle. Very rarely asynchronism is exploited as a main factor, or considering channel heterogeneity in terms of quality. In this study we show how to add and benefit from an asynchronous RDV extension and its enhancement. Thanks to induced asynchronism, the ranking of channels is introduced, allowing nodes to stay longer on better quality channels. We analyse the behaviour of different selected ND protocols in terms of time-to-rendezvous and normalised RDV. We show that an asynchronism significantly improves the efficiency of the studied protocols.
    Keywords: Asynchronous, Channel hopping, Channel ranking, Cognitive radio networks
  • COME: Cost Optimization with Multi-chaining for Energy efficient communication in Wireless Sensor Networks   Order a copy of this article
    by Nadeem Javaid, Syed Hassan Ahmed, Dongkyum Kim, Ashfaq Ahmad 
    Abstract: In this paper, we present two new chain formation techniques: Multi-chain Energy-efficient routing (ME) and Cost Optimization with Multi-chaining for Energy efficient communication (COME) for Wireless Sensor Networks (WSNs)supported by linear programming based mathematical models for network representation and energy consumption. ME protocol divides network area into subareas of equal size, which contain equal number of randomly deployed nodes. Furthermore, minimum distance based next hop for data transmission is used and the sojourn locations are adjusted in a way that, at a time when data reaches to the last node of the chain (terminator node), BS moves to the possible nearest location of that node (sojourn location). ME protocol uses a shorter route for communication because of its multi-chain approach. COME protocol closely inspects the energy costs and selects route with minimum energy cost. We calculated dropped packets in each protocol. Furthermore, confidence interval calculation estimates the possible error bars within which results may vary. Simulations show; (i) improved results for our proposed protocols as compared to PEGASIS in terms of the stability period, network lifetime, dropped packets and throughput, and (ii) moderate decay for PEGASIS protocol, sharp and flat decays in case of the proposed ME and COME protocols, respectively, whenever these protocols are subjected up to 2 fold increase in network area as well as the number of nodes.
    Keywords: Chain Formation; Confidence Interval; Energy Efficient; LinearrnProgramming; Packet Loss; Routing Protocols; Wireless Sensor Networks
  • Smart Cross-Layer Protocol Integration for Efficient Wireless Communications   Order a copy of this article
    by Antonio M. Ortiz Torres, Teresa Olivares, Fernando Royo, Noel Crespi, Luis Orozco-Barbosa 
    Abstract: The integration of protocols from different layers enables efficient wireless communications. Wireless sensor networks represent the core of the Internet of Things. The growing number of nodes composing these networks requires effective node synchronization and a correct network organization in order to ensure data delivery to the destination nodes. This article presents a cross-layer approach that integrates a synchronous TDMA MAC protocol with a smart routing approach, oriented to guarantee efficient communications of a set of wireless devices in the Internet of Things. First, both approaches are detailed and individually tested by comparing them to similar approaches in the literature. Then, the cross-layer integration is described and tested, showing that both protocols are able to enhance the network performance when working together.
    Keywords: Protocol integration; cross layer; wireless sensor networks; efficient communications; TDMA MAC protocols; fuzzy-logic based routing protocols; Internet of Things

Special Issue on: "Localisation and Positioning for Healthcare Applications,"

  • Distributed Denial of Service (DDoS) Attack Detection Using Data Mining Approach in Cloud-Assisted Wireless Body Area Networks   Order a copy of this article
    by Rabia Latif, Haider Abbas, Seemab Latif 
    Abstract: Nowadays, Wireless Body Area Networks (WBANs) is emerging as a promising technology with a considerable potential in improving patients health care services. The integration of WBAN and cloud computing technology provides a platform to create a new digital paradigm with leading features called cloud-assisted WBAN. The foremost concern of cloud-assisted WBAN is the security and privacy of data either collected and stored by WBAN sensors or transmitted to cloud over an insecure network. Among these, data availability is the most nagging security issue. The major threat to data availability is distributed denial of service attack (DDoS). In order to assure the all time availability of patients data, we propose a distributed victim based DDoS attack detection mechanism based on Very Fast Decision Tree (VFDT) learning model in cloud-assisted WBAN. The evaluation and performance analysis shows that the proposed mechanism could detect DDoS attack with high accuracy, and reduced false positive and false negative ratio.
    Keywords: Cloud-Assisted Wireless Body Area Network, Data Mining, Distributed Denial of Service Attack, Sensor Localisation
  • iPil: Improving Passive Indoor Localization via Link-based CSI Features   Order a copy of this article
    by Liangyi Gong 
    Abstract: Passive indoor localization acts as a key enabler for various emerging applications such as secured region monitoring, smart homes, intelligent nursing, etc. Despite of years of research, their accuracy of localization still remains unsatisfactory for practical uses. The main hurdle lies in the coarse measurement of wireless channels, e.g., Received Signal Strength Indicator (RSSI), employed in most existing schemes. In this work, we explore the potential of using Channel State Information (CSI) for fine-grained passive indoor localization on a single communication link. To achieve high accuracy, we propose a solution based CSI fingerprint and devise two novel localization estimator approaches suited to different conditions:Weighted Bayesian and the Maximum Similarity Metric. Compared with RSSI, CSI has demonstrated itself with a high accuracy of location distinction. Experimental results show that our schemes can achieve a higher accuracy.
    Keywords: Passive Indoor Localization, Channel State Information (CSI), Physical Layer, Localization Estimator
  • Consumer Health Information Organizing and Mobile Acquiring Based on Topic Maps   Order a copy of this article
    by Junsheng Zhang, Yunchuan Sun, Yingying Li, Huilin Wang 
    Abstract: It is difficult for consumers to find, understand and share health information due to the limitations of the current health information systems. Major problems include the missing of connections between multilingual medical terms and the gap between obscure medical terminologies used by experts and common vocabularies used by consumers. This paper utilizes the Topic Maps model to organize consumer health information by linking professional medical terminologies in different languages and the corresponding common vocabularies. The proposed approach is applied into organizing bilingual (Chinese and English) consumer health information resources in the diabetes domain. Topic Maps tools designed by the Ontopia corporation are used to organize the consumer health information resources about diabetes mellitus. Experiment results show that Topic Maps of health information are suitable for bilingual health information organizing and mobile information acquiring on mobile devices.
    Keywords: Consumer Health Information; Multilingual; Mobile Device; Topic Maps; Diabetes
  • Patient localization with Smart Phones using Public Cloud   Order a copy of this article
    by Vaithianathan Geetha 
    Abstract: Todays world scenario has made evolution in healthcare domain as inevitable. Large number of people expires due to sudden medical emergencies like heart attacks and accidents. However, many of them could have survived if they could have reached medical care quickly. It is very difficult to extend immediate medical care at all places and at all times. Research is going on to improve the delivery time of medical care. It is found that usage of technology for healthcare is beneficial. Nowadays, electronic medical records are stored in cloud for real time access. However, ubiquitous patient localization poses a major problem. In this paper, a solution is proposed for patient localization with smart phones using public clouds. Here GPS tracking is used to locate the patients. As the current cloud infrastructure does not support sensing requests, a Smart Sensing as a Service (S2aaS) Framework is proposed to be added to the cloud infrastructure. The proposed system has the advantages of minimal interaction and high reliability. The patients need not remember the contact details of nearby hospitals. This system can be used anywhere in the world. The performance results of the proposed system are also evaluated.
    Keywords: Smart phones; Public cloud; Emergency healthcare; Healthcare applications; Global Positioning System(GPS);patient localization
  • A Range-free Localization Algorithm Based on Connectivity in Wireless Sensor Networks   Order a copy of this article
    by Liping Liu, Chunliang Chu, Feng Xia 
    Abstract: Sensor nodes position is very important in many Wireless Sensor Networks (WSNs) applications. In this paper, a novel range-free localization algorithm based on connectivity (LAC) is proposed. By exploiting the probabilistic regulation in cluster-based deployment, the theoretical number of a sensors neighbors from certain cluster is determined by distance between the sensor and the corresponding cluster head. So distances between sensors and cluster heads can be derived by minimizing the deviation between the theoretical number of neighbor sensors and the measurement. Using the optimal distance to each cluster head, the position of each sensor can be estimated with maximum likelihood (ML) multilateration. Compared with some existing range-free algorithms, LAC performs better in terms of localization accuracy, especially in beacon-less scenarios and reduces communication overhead and computation complexity to some extent. Extensive simulations are performed and the results are observed to be in good consistence with theoretical analysis.
    Keywords: range-free localization; probabilistic distribution; connectivity; wireless sensor networks.
  • Multi Sensor System for Pedestrian Tracking and Activity Recognition in Indoor Environments   Order a copy of this article
    by Juan Jose Marron, Miguel Labrador, Adrian Menendez-Valle, Daniel Fernandez-Lanvin, Martin Gonzalez-Rodriguez 
    Abstract: The widespread use of mobile devices and the rise of Global Navigation Satellite Systems (GNSS) have allowed mobile tracking applications to become very popular and valuable in outdoor environments. However, tracking pedestrians in indoor environments with Global Positioning System (GPS)-based schemes is still very challenging. Along with indoor tracking, the ability to recognize pedestrian behavior and activities can lead to considerable growth in location-based applications including pervasive healthcare, leisure and guide services (such as, hospitals, museums, airports, etc.), and emergency services, among the most important ones. This paper presents a system for pedestrian tracking and activity recognition in indoor environments using exclusively common off-the-shelf sensors embedded in smartphones (accelerometer, gyroscope, magnetometer and barometer). The proposed system combines the knowledge found in biomechanical patterns of the human body while accomplishing basic activities, such as walking or climbing stairs up and down, along with identifiable signatures that certain indoor locations (such as turns or elevators) introduce on sensing data. The system was implemented and tested on Android-based mobile phones. The system detects and counts steps with an accuracy of 97% and 96:67% in flat floor and stairs, respectively; detects user changes of direction and altitude with 98:88% and 96:66% accuracy, respectively; and recognizes the proposed human activities with a 95% accuracy. All modules combined lead to a total tracking accuracy of 91:06% in common human motion indoor displacements.
    Keywords: Smartphones, Sensor Fusion, Pervasive Computing, Inertial Navigation, Ubiquitous Localization

Special Issue on: "Advances in Mobile Computing and Applications,"

  • A method of cleaning RFID data streams based on Naive Bayes Classifier   Order a copy of this article
    by Qiaomin Lin 
    Abstract: Recently, the Radio Frequency Identification (RFID) technology has been widely used in many kinds of applications. However, RFID data streams contain false negative reads and false positive reads leading to the location uncertainty of RFID tags. So they have to be cleaned, or it cannot be used directly by applications. In view of these problems, we propose a method of cleaning RFID data streams based on Naive Bayes classifier, which could detect effectively tags of false negative reads and false positive reads in RFID data streams. Firstly, we construct a model of a RFID data stream as the basis of our method. Then we divide the method into three phases, i.e. preparation phase, training classifier phase and application phase. At last, the result of experiments illustrates that our method based on Naive Bayes classifier could get the lower percentage of false negative reads and the higher percentage of false positive reads than SMURF algorithm with the increase of the size of sliding window.
    Keywords: Data stream cleaning, Naive Bayes Classifier, False negative reads, False positive reads, RFID
  • Hybrid Cluster based Geographical Routing Protocol to Mitigate Malicious Nodes in Mobile Ad Hoc Network   Order a copy of this article
    by Sudhakar Sengan, S.Chenthur Pandian 
    Abstract: A Mobile Ad hoc Network (MANET) consists of assorted mobile devices in a network without centralized administration and infrastructure. Routing processes in MANETs rely on cooperation of independent nodes constituting the network. A number of efficient Geographic routing protocols are suggested for MANETs in the literature where most assume a trusted and cooperative environment. MANETs are highly susceptible to attacks both internally and externally, because of the cooperative nature of the network. In this paper, a three stage method has been proposed to address the performance degradation of Geographical Routing Protocol (GRP) due to the malicious nodes. The proposed method based on GRP creates clusters in the initial stage. In the second stage, malicious nodes are identified using modified hello message and secure keys are used to mitigate the effect of the maliciousness. It was observed that the delay for the proposed clustered GRP was less than the GRP. It was also apparent from the results that even when the size of the network increased, the end-to-end delay was significantly less for the proposed GRP. Cluster Heads (CHs) distribute public keys whose size is determined using fuzzy logic in the final stage. Simulations demonstrate the effectiveness of the proposed cluster GRP compared to the GRP
    Keywords: Mobile Ad hoc Networks (MANETs); Geographic Routing Protocol (GRP); Malicious Node; Clustering; Cluster Head (CH) and Fuzzy Logic.

Special Issue on: "Emergence of Large-scale Ubiquitous Contexts Analysis,"

  • Spatial query processing for skewed access patterns in nonuniform wireless data broadcast environments   Order a copy of this article
    by Jun-Hong Shen, Ming-Shen Jian 
    Abstract: Location-based services (LBSs) via wireless data broadcast can provide a huge number of mobile clients for simultaneously accessing spatial data according to their current locations. Under nonuniform wireless data broadcast, more popular data appear more times than regular ones, resulting in the decrease of the average client waiting time. In this paper, to efficiently support the processing of continuous window queries for LBSs, we propose a skewed spatial index considering clients skewed access patterns in the nonuniform wireless broadcast environments. The index information considering the nonuniform broadcast is interleaved with the spatial objects on the wireless channel to support efficient access. From our experimental study, we have shown that our proposed method outperforms the multi-leveled air index scheme.
    Keywords: Continuous window queries; skewed access patterns; spatial index; ubiquitous computing; wireless data broadcast

Special Issue on: "Advances in Mobile Computing and Applications"

  • Energy Consumption Model for Density controlled Divide-and-Rule Scheme for Energy Efficient Routing in Wireless Sensor Networks   Order a copy of this article
    by Nadeem Javaid, Malik Najmus Saqib, Zahoor Ali Khan, Nabil Alrajeh, Kamran Latif 
    Abstract: In Wireless Sensor Networks (WSNs), Sensor nodes (nodes) are equipped with limited energy source. Therefore, efficient energy utilization of nodes has become a hot research area in WSNs. In this paper, we introduce a new routing technique for WSNs in which, we solve the problem of unbalanced energy utilization, which causes energy and coverage holes in WSNs. Deployment area is divided into subareas; each subarea logically represents a static cluster. Dividing network field into subfields helps to control coverage hole problem whereas, static clustering helps to avoid energy hole problem. Mathematical formulation of the proposed work is provided to analyse and verify our technique. Simulation results show that our technique balances energy utilization of the network.
    Keywords: Energy; efficient; routing; static; clustering; energy hole.

Special Issue on: "Emerging Technologies for Ubiquitous Communications, Computing and Applications in Ad-hoc Networks,"

  • Towards Optimizing Routing Overhead in Wireless Multi-hop Networks   Order a copy of this article
    by Nadeem Javaid, Ayesha Bibi, Saad Noor Mohammad, Z.A. Khan, N. Alrajeh 
    Abstract: Routing protocols in Wireless Multi-hop Networks (WMhNs) are responsiblernfor efficient path calculations. Reduction in drop rates in WMhNs requires low bandwidth consumption as well as low delay which is caused by excessive transmissions and processing delays. Reactive routing protocols are aimed to optimize broadcast cost and time consumption during routing. In high dynamic WMhNs, reactive routing protocols provide quick convergence through faster route discoveries and route maintenances. In this paper, we select three most commonly used reactive protocols; Ad-hoc On-demand Distance Vector (AODV), Dynamic Source Routing (DSR) and DYnamic MANET Ondemand (DYMO) and model their energy cost and time cost of Expanding Ring Search (ERS) algorithm. A novel contribution of this work is tuning of route discovery and route maintenance parameters of chosen protocols to minimize routing overhead. For analytical comparison of selected protocols, we simulate default and enhanced versions of these protocols with three performance metrics; throughput, Normalized Routing Load (NRL) and End-to-End Delay (E2ED) using NS-2. From modeling and analytical comparison, we deduce that by adjusting Time-To-Live (TTL) in search sets of ERS algorithm withrnrespective waiting time are more useful for reducing bandwidth and locating time in chosen protocols. Moreover, for reliable transmission and efficient performance, reactive protocols need immediate detection of link breakage along with quick repairement strategies for re-establishment of routes such as Local Link Repair (LLR) and Packet Salvaging (PS).
    Keywords: Routing; AODV; DSR; DYMO; Discovery; Maintenance; Expanding; Ring; Search
  • A Transmission Protocol Based on Network Coding in Many-to-one Delay Tolerant Networks   Order a copy of this article
    by Chuang Ma, Chih-Yin Lee 
    Abstract: In Delay Tolerant Networks, the delay of packets is long due to the intermittent connections caused by the mobility of nodes. Epidemic Routing Protocol can reduce the delay time and raise the packet delivery rate by replicating and spread copies of source packets in the networks, but it inevitably exhaust memory resources and network bandwidth. In this paper, we propose a network coding with limited buffer routing protocol based on two network models, single packet network model and multiple packets network model. When a buffer of a node is full, two packets in the buffer are chosen randomly and encoded linearly together into a packet to save buffer space and improve the performance in many-to-one communications. Instead of applying network coding only to the packets that come from the same source nodes like in the unicast based models, we apply the network coding to the packets that are from multiple sources which are generated in the same period of time. Moreover, in the transmitting stage of our network coding routing protocol, we proposed two efficient approaches which can enhance the efficiency of information exchange and packets transmission in communications of delay tolerant networks.
    Keywords: Delay tolerant networks, epidemic routing, limited buffer, multicast, network coding
  • A Robust and Reliable Routing Based on Multi-hop Information in Industrial Wireless Sensor Networks   Order a copy of this article
    by Dariush Zolfaghari, Hassan Taheri, Amir Hossein Rezaie 
    Abstract: Due to considerable noise in the industrial environments, wireless packet transmission is usually unreliable. Designing an efficient routing algorithm for these environments poses significant challenges. Current routing algorithms consider the quality of service parameters such as node energies and delay, but packet losses need a novel strategy to compensate for the decline in signal to noise ratio (SNR) in noisy industrial environments. The proposed routing algorithm is based on multi-hop neighbor information. The multi-hop neighbor nodes provide vital information for the source node, enabling it to select the proper relay node. In noisy channel conditions the transmitted packets should meet the deadline and be delivered to the sink node on time. Performance evaluation via simulations indicates significant improvement in reliability, lifetime of network and real-time performance. The proposed algorithm is more robust than previous methods. The most beneficial features of the proposed algorithm are its uniform distribution of energy among nodes and deliverance of deadline packets with the lowest losses.
    Keywords: Industrial Wireless Sensor Network (IWSN), real-time routing, reliability, multi-hop information, noise.
  • The Correlation Study for Parameters in Four Tuples   Order a copy of this article
    by Fei Song, Yige Zhang, Zhaoxu An, Huachun Zhou, Ilsun You 
    Abstract: For analyzing the characteristics of current Internet connections, this paper proposed several analytical schemes to study the correlation of parameters inside four tuples. We extracted the real trace in packet level from campus network border routers. No sampling method is added to maintain the full information. Firstly, different time bins are employed for exploring the single parameter variations comprehensively. Then, the potential association of parameters inside four tuples is investigated two-by-two. Thirdly, three tuples properties are shown and compared. The significance of source port is also discussed. Fol-lowing that, the duration and size for connections, i.e. four tuples, are studied. Some interesting observations are presented and explained. The influence of three and four tuples fluctuation is checked based on a new statistical scheme we proposed. Finally, the service type classification of connections and packets are demonstrated respectively. The distribution properties of differ-ent services are also declared. The conclusions summarize several unexpected phenomenon and the future work is pointed out at the end.
    Keywords: network measurement, four tuples, real data trace, connection properties
  • Gateway pheromone based adaptive Internet access scheme for mobile ad hoc networks   Order a copy of this article
    by Huaqiang Xu, Xiaojun Cai, Lei Ju, Zhiping Jia 
    Abstract: Control messages produced in the gateway discovery process degrade the performance of hybrid mobile ad hoc networks. Thus, the optimization is required to release resources for the data transmissions. This paper proposes a novel adaptive gateway discovery scheme to improve the performance. In the scheme, active regions, which are delineated by gateway pheromone, are defined to optimize the propagation of control messages. To adapt to dynamic network topology, active regions are adjusted periodically to keep their availability by adaptive maintenance operations. Moreover, a link robustness evaluation model based on signal strength is integrated into the scheme to help build stable routes. Therefore, the control overhead can be further reduced because the messages generated due to the link breakages can be avoided. Extensive experiments have been conducted to evaluate the effectiveness of the proposed scheme in different scenarios. The results show that our scheme outperforms the existing gateway discovery mechanisms especially in terms of control overhead reduction.
    Keywords: Internet access; gateway pheromone; mobile ad hoc network; robustness evaluation; gateway discovery.
  • Construction and Analysis of a Green Clustered Architecture for RNG-Based Wireless Ad Hoc Networks   Order a copy of this article
    by Chih-Cheng Tseng, Kuo-Chang Ting, Hwang-Cheng Wang, Li-Hsun Chang 
    Abstract: The limited battery power available in the nodes of an ad hoc network makes it mandatory to reduce the energy expenditure. Thus, reducing the number of transmitted data and control messages is important in the design of green wireless ad hoc networks. To realize the goal, the concept of Relative Neighborhood Graph (RNG) is used to convert the original physical network to an RNG-based logical network. Since the distance between nodes in the RNG-based logical network is shortened, the energy required for transmitting messages is reduced. Then, a green clustering algorithm (GCA) is proposed to reorganize the RNG-based logical network into a clustered architecture in which the number of control messages is further reduced. The control messages are mainly for cluster maintenance and AODV routing. Finally, a first-order energy consumption model is applied to analyze the energy consumption in exchanging control messages and transmitting/receiving data packets. Through extensive simulations, it is shown that the proposed approaches effectively reduce energy consumption and extend the battery life time. Thus, a green wireless ad hoc network can be constructed by combining RNG and GCA.
    Keywords: Clustering algorithm, energy-efficient, relative neighborhood graph (RNG), wireless ad hoc networks
  • Erasure Coding-Based Message Forwarding to Multiple Destinations in Intermittently Connected Networks   Order a copy of this article
    by Yu-Feng Hsu, Chih-Lin Hu 
    Abstract: Intermittently connected networks are characterized by high node mobility, uncertainty of node existence, and intermittent connectivity in dynamic environments. Message forwarding in such networks resorts to new message forwarding paradigms instead of conventional end-to-end message forwarding paradigms in mobile ad hoc networks. Replication-based and coding-based paradigms are two typical sorts of message forwarding paradigms in intermittently connected networks. Compared with replication-based paradigms that depend on distributing replicas of messages to increase the probability of successful delivery to destinations, coding-based paradigms duplicate and scatter coded blocks of messages to improve robustness of message forwarding against network dynamics and unreliability. The study in this paper exploits the erasure coding-based model that has recently attracted lots of research attentions from the aspect of coding-based message forwarding in intermittently connected networks. Since previous erasure coding-based schemes were mainly dedicated to delivering messages to any single destination, this paper considers the other situation of delivering messages to multiple destinations in intermittently connected networks. This paper obtains a straightforward expression for the delay distribution of multiple destinations if the delay distribution of a single destination is given. Afterwards, this paper analyzes the delay distribution for message forwarding to not only a single destination but also multiple destinations. Upon delivery ratio and delay time, the examination of performance sensitivity results in many new inherent observations, properties and insights into the virtue of the erasure coding-based forwarding scheme, providing significant information for the design of erasure coding-based forwarding mechanisms in support of multiple destinations in intermittently connected networks.
    Keywords: Erasure coding; message forwarding; delay/disruption-tolerant networks; intermittently connected networks
  • Ego-Centric Social Network Routing in MANET   Order a copy of this article
    by Hung-Chin Jang, Pei-Hsuan Lee 
    Abstract: With the coming of information era, our lives have been filled with varied mobile devices. Due to the popularity of mobile devices, Mobile Ad Hoc Network (MANET) has been widespread more than ever. However, how to obtain trustworthy information from trusty nodes through social network is a significant issue. This research gears toward social aware assisted transmission in MANET. In this paper, social network analysis techniques are employed to analyze the relationship among users to select appropriate node for data forwarding. We propose an Ego-Centric Social Network Routing (ECSNR), which stems from the concept of ego network. ECSNR considers those neighbor nodes of either social aware or non-social aware nodes within its communication range for data forwarding. ECSNR uses degree centrality, betweenness centrality, interest similarity, and friend diversity to accelerate data transmission and enhance successful data delivery. Besides, ECSNR has built-in redundant plan for overloaded nodes. The plan uses candidate list, recommended list, and interest-similar list to help select alternative nodes without having to waste time in recalculating new delivery path. ECSNR is compared with SANE (Mei, 2011) through simulations. Simulation results show that ECSNR outperforms SANE in packet delivery ratio, end-to-end delay and average hop count.
    Keywords: social network; ego network; social analysis; centrality; betweenness; diversity
  • Using a Hybrid Algorithm and Active RFID to Construct a Seamless Infant Rooming-in Tracking Mechanism   Order a copy of this article
    by Lun-Ping Hung 
    Abstract: Due to the rapid development of sensor and wireless equipment which integrates with information technology to construct intelligent mechanism, the quality of healthcare has improved and the clinical care of puerperal and newborn infants has improved as well. To increase the ratio of requesting rooming-in service for puerperal and newborn infants, baby-friendly hospitals should prevent the mistake of identifying puerperal and infant and assure the safety of newborn babies. This paper proposes a mechanism that includes a hybrid algorithm combining Location Fingerprint and K-Nearest Neighbor(KNN) algorithm and active Radio Frequency Identification(RFID) using Received Signal Strength Indication (RSSI) transmission method to build a safer rooming-in environment. RFID technology, a kind of wireless equipment, is used in providing a seamlessly ubiquitous and constant medical care. This mechanism can effectively avoid the situation, like a stolen or switched baby, and be up to the standard certified by Baby-Friendly Hospital Initiative (BFHI). The nursing department can easily arrange routine nursing works and increase the quality of nursing cares. The hospitals benefit from using the system with increased ratio of 24-hourinfantrooming-in careand fulfill the requirement of a baby-friendly hospital more effectively.
    Keywords: Radio Frequency Identification, Received Signal Strength Indication, Infant Rooming-in, K-Nearest Neighbor, Location Fingerprinting.

Special Issue on: "Security aspects in pervasive and ubiquitous computing"

  • Principal component analysis-based data reduction model for wireless sensor networks   Order a copy of this article
    by Murad A. Rassam, Anazida Zainal, Mohd. Aizaini Maarof 
    Abstract: Wireless sensor networks (WSNs) are widely used in monitoring environmental and physical conditions, such as temperature, vibration, humidity, light and voltage. However, the high dimension of sensed data, especially in multivariate sensor applications, increases the power consumption in transmitting this data to the base station and hence shortens the lifetime of sensors. Therefore, efficient data reduction methods are needed to minimise the power consumption in data transmission. In this paper, an efficient model for multivariate data reduction is proposed based on the principal component analysis (PCA). The performance of the model was evaluated using Intel Berkeley Research Lab (IBRL) dataset. The experimental results show the advantages of the proposed model as it allows 50% reduction rate and 96% approximation accuracy after reduction. A comparison with an existing model shows the superiority of the proposed model in terms of approximation accuracy as the reconstruction error is always smaller for different datasets.
    Keywords: WSNs; wireless sensor networks; ad hoc networks; PCA; principal component analysis; data reduction; multivariate data analysis; energy consumption; modelling.
  • Designing for privacy in ubiquitous social networking   Order a copy of this article
    by Antonio Sapuppo, João Figueiras 
    Abstract: Improving human communication during face-to-face meetings is nowadays possible by transferring online social networking benefits to the physical world. This is enabled by the ubiquitous social networking services that became available by means of wirelessly interconnected smart devices, automatically exchanging personal user data. The main goal of these services is to facilitate the initialisation of relationships between people who do not know each other, but they probably should. Given that sharing of personal information is an intrinsic part of ubiquitous social networking, these services are subject to crucial privacy threats. Inspired by the usability and privacy limitations of existing design solutions, we identify, describe and qualitatively evaluate four drawbacks to be avoided when designing ubiquitous social networking applications. By addressing these drawbacks, services become more functional and more oriented to ensure the end users' privacy, thus contributing to the long-term success of this technology.
    Keywords: end user privacy; ubiquitous computing; information disclosure; social networking; design guidelines; personal information; information sharing; privacy protection.