# Forthcoming articles

International Journal of Ad Hoc and Ubiquitous Computing

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International Journal of Ad Hoc and Ubiquitous Computing (120 papers in press)

Regular Issues

•  Open Access Coherent, Automatic Address Resolution for Vehicular Ad Hoc Networks  ( Free Full-Text Access )
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.

• An Efficient Mutual Distance Bounding Protocol over a Binary Symmetric Noisy Communication Channel
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
by Leili Farzinvash, Mehdi Dehghan
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
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
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
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
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
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
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
by Ana Lucila Sandoval Orozco, Daniel Espino García, Roberto González de Armas, Jesús Antonio Puente Fernández, Luis Javier García Villalba, Fábio Mesquita Buiati
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
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
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
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
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
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 ecient 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
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
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
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
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
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
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

• HMMCCN:A Hierarchical Mobility Management Scheme for Content-Centric Networking
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
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
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
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
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
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
by Anfeng Liu, Yanling Hu, Zhigang Chen
Keywords: wireless sensor networks, target detection, duty cycles, energy-efficient, delay

• A secure and efficient time-bound hierarchical access control scheme for secure broadcasting
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
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
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
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
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 efficient admission control
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
by Ben-Jye Chang, Ying-Hsin Liang, Cheng-Hsin Liu
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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.

• Saturation Throughput Analysis of IEEE 802.11 DCF with Heterogeneous Node Transmit Powers and Capture Effect
by Lei Lei, Ting Zhang, Liang Zhou, Xiaoqin Song, Shengsuo Cai
Abstract: The transmit power control (TPC) schemes allow the wireless nodes to select a minimum required transmit power from all available power levels to access the medium. Consequently, from the viewpoint of the medium access control (MAC) layer, the nodes with TPC schemes actually transmit signals to their neighbors at randomized and heterogeneous power levels due to the randomness of the network topology and traffic distribution. In this paper, we focus on analyzing the saturation throughput performance of IEEE 802.11 DCF networks with heterogeneous node transmit power levels and the capture effect. We first analyze the capture effect among packets sent at different power levels and derive the analytical expression of the capture probability. Then, we propose a three-dimensional Markov chain to model the backoff procedure performed by a tagged sending node under the condition of heterogeneous transmit power levels, and compute the total saturation throughput of the network with the previously derived capture probability. Finally, we validate the accuracy of our model by comparing the analytical results with the simulation results, and analyze the impact of the capture effect on the saturation throughput performance of IEEE 802.11 DCF networks.
Keywords: IEEE 802.11 DCF networks; Heterogeneous power levels; Capture effects; Saturation throughput; Markov chain

• An M2M gateway-centric architecture for autonomic healing and optimizing of Machine-to-Machine overlay networks
by Amine Dhraief, Abdelfettah Belghith
Abstract: The Machine-to-Machine (M2M) technology, currently under standardization at both the ETSI and 3GPP, is expected to be one of the most promising revenue-generating services. However, to ensure the wide spread of this technology, M2M communications should be secure, fault-tolerant and self-managed. In this work, we add to the M2M gateway (an aggregator node in the M2M architecture) the self-healing and self-optimizing autonomic capabilities. We couple at the M2M gateway level the Host Identity Protocal (HIP) with the Reachability Protocol (REAP). REAP enables a self-healed M2M communication as it detects possible failures and seamlessly rehomes an M2M established session to a new working overlay path. Furthermore, we modify REAP to ensure self-optimized M2M communications. REAP continuously monitors M2M overlay paths and always selects the best available ones in terms of RTT. We implement our solution on the OMNeT++ network simulator. Results show that M2M sessions effectively resume after an outage affecting their currently used M2M overlay paths. Results also highlight that M2M sessions autonomically select the best available M2M overlay paths.
Keywords: Machine-to-Machine; M2M Gateway; Overlay network; Autonomic management; HIP; REAP; OMNeT++

• An Ubiquitous Solution for Advertising and Loyalty Purposes Using NFC Technology
by Gonzalo Cerruela García, Irene Luque Ruiz, Miguel Angel Gómez-Nieto
Abstract: In this paper we present an application based on Near Field Communication technology and oriented to advertising and user loyalty fields. The system combines NFC and in-air hand gestures with the purpose of creating an attractive leisure activity where customers are rewarded by shops with the possibility of obtaining a prize or discount on the purchases made. NFC is used for securing the participation of the user in the activity and for exchanging the prizes obtained. During the activity, users perform a fishing gesture (throwing and catching) with the mobile phone, simulating the capture of a prize that could be located anywhere in the shop. This gesture is recognized by mobile sensors. The tailoring of the system to specific business marketing strategies is also managed by the proposed solution.
Keywords: Near Field Communication, Air-Hand gestures, Advertising, Loyalty

• A Trustworthy Web Service Composition Method for Ubiquitous Computing
by shenghui zhao, Guilin Chen, Huibin Wang, Haibao Chen
Abstract: Mobile users using smart mobile device have a considerable amount of requirements of services from Mobile Cloud or Internet, due to its resource scarcity. It is a big challenge to select the services meeting users' all demands, as the user has both the demands of trust and lower cost. The existing methods [25][26] of trustworthy service composition cant balance the profits between service provider and consumer in mobile situation. Firstly, we design a heuristic algorithm, called FASG, to reduce the complexity of generating feasible allocation sets. Secondly, in order to balance the profits between service providers and consumers, a service composition method, based on the social surplus maximization is put forward and the corresponding heuristic algorithm, called RCA_H, is also designed to find the optimal feasible solution in polynomial time. Experiment results show that the proposed RCA_H algorithm guarantees the profits of both sides, and obtain more trusted service and better facilitate service providers to provide trustworthy services to meet users customized needs compared with another method [27] based on user utility maximization.
Keywords: Ubiquitous Computing; Service Composition; Social Surplus Maximization;Heuristic Algorithm

• Efficient data collection for self-organizing traffic signal systems based on vehicular sensor networks
by Bartłomiej Płaczek
Abstract: The development of traffic signal systems based on vehicular sensor networks (VSNs) requires new methods to enable real-time collection and processing of the data registered by sensor-equipped vehicles. Due to the large amounts of sensor readings, there is a necessity of selecting the data that have to be transferred to control nodes. Moreover, the control nodes need an appropriate algorithm to effectively utilise the information which is delivered from individual vehicles. This paper presents an approach, which enables efficient collection and utilisation of the detailed data from VSN for controlling traffic signals in a road network. A self-organizing control strategy is used in the analysed system. The amount of transmitted data is reduced by taking into account uncertainties estimated at control nodes. Results of simulation experiments show that the proposed approach outperforms state-of-the-art methods in terms of data transfers and average vehicle delay.
Keywords: vehicular sensor networks, vehicular ad-hoc networks, traffic signal control, data collection, self-organizing systems, traffic model

• Efficient Mobile Cloud Service Allocation For Mobile Commerce
by Li ChunLin
Abstract: Mobile systems, such as smart phones, become the primary computing platforms for many users. The mobile cloud computing helps the mobile devices to run the computation intensive applications, which consume a large amount of battery energy. This paper presents efficient mobile cloud service allocation for mobile commerce in mobile cloud. The contributions of this paper have three aspects. 1) Mobile cloud service allocation scheme considers both mobile clients and cloud datacenter providers. 2) The mobile commerce service scenario is taken as an example in mobile cloud environment, and our service allocation approach is applied to mobile cloud environment. 3) The paper proposes a distributed mobile cloud service allocation algorithm for mobile commerce. From the simulation results, the execution success ratio of our service allocation algorithm for mobile commerce (SAAMC) is better than GMCRA (Game-theoretic Mobile Cloud Resource Allocation) [13] and ARAA (Auction based Resource Allocation Algorithm) [17]. The allocation efficiency of SAAMC is better than GMCRA and ARAA. The energy consumption ratio of SAAMC is not good as GMCRA.
Keywords: mobile cloud, service allocation, mobile commerce

• The Diagnosis of Consensus Agreement in a MANET
by Mao-Lun Chiang
Abstract: For achieving the reliability, the fault-tolerance of distributed systems needs to be studied. One of the most important problems of fault-tolerance issues is the Fault Diagnosis Agreement (FDA). The goal of FDA is to make each fault-free processor detect/locate a common set of faulty processors. However, previous works cannot solve the FDA problem in a Mobile Ad-hoc NETwork (MANET). Therefore, the FDA problem is revised in this study by an evidence-based fault diagnosis protocol under dual failure characteristics on processors in a MANET. The proposed EMFDA protocol can detect/locate maximum number of faulty processors using minimum number of message exchange in a MANET.
Keywords: Byzantine Agreement; Fault Diagnosis Agreement; Fault-tolerance; Consensus; Mobile Ad-hoc Network

• Link Reliable Energy Efficient AOMDV routing protocol for mobile ad hoc networks
by Periyasamy P, Karthikeyan E
Abstract: Reliable data transmission has been an emerging issue in AOMDV routing protocol since the nodes are prone to link failures and route breaks in highly dynamic ad hoc networks due to the selection of multiple routes between any source and destination pair based on only minimal hop count. For eliminating such problems, we propose a novel node disjoint multipath routing protocol called Link Reliable Energy Efficient AOMDV (LR-EE-AOMDV) routing protocol which is the extension of a well known AOMDV routing protocol. The LR-EE-AOMDV finds multiple link reliable energy efficient paths between any source and destination pair for data transmission using three metrics such as Path Length,Path-Link Quality Estimator (P-LQE) and a novelPath-Node Energy Estimator (P-NEE). We evaluate the performance of LR-EE-AOMDV routing protocol using NS 2.34 with varying network flows and number of nodes under random waypoint mobility model and compare it with AOMDV and OMMRE-AOMDV routing protocols in terms of Quality of Service (QoS) metrics. When there is a hike in network flows, the LR-EE-AOMDV reduces 24% of routing overhead, 38% of packet loss ratio, 26% of normalized routing overhead and 23% of energy consumption. It also increases rather 17% of packet delivery ratio and 16% of throughput than AOMDV routing protocol. When there is a hike in number of nodes, the LR-EE-AOMDV reduces 21% of routing overhead, 20% of packet loss ratio, and 16% of normalized routing overhead. It also increases 13% of packet delivery ratio and 13% of throughput than AOMDV routing protocol. From our simulation results, we show that the LR-EE-AOMDV routing protocol outperforms AOMDV and OMMRE-AOMDV routing protocols.
Keywords: mobile ad hoc networks; multipath routing; AOMDV; hop count; Link Quality Estimator; Node Energy Estimator; QoS.

• DNAS: A Driver Nighttime Assistance System using Rear-View Smartphone
by Chunmei Ma, Haigang Gong, Nianbo Liu, Chao Song, Ming Liu
Abstract: Due to the poor visibility and improper behavior, driving at nighttime is much more dangerous. It has been pointed out that the overall nighttime crash rate is approximately 1.6 times than the daytime rate. Therefore, it is of great significance to design a driver nighttime assistance system that warns drivers of the imminent danger. An effective solution is monitoring nearby vehicles for potential safety hazards. However, existing driver assistance schemes require the deployment of dedicated sensors on vehicles and/or on the roadside, which limits their implementation in practice. In this paper, we present DNAS, a cost-effective nighttime driver assistance system, as an Android App running on smartphones. DNAS allows drivers to place their phones on the rear windshield, for periodically capturing road condition by the camera sensor, and warning the drivers of dangerous speeding or tailgating event. To achieve this function, we use the bright vehicle headlights and their dimension to determine the following vehicles from the captured images, analyze their temporal and spatial characteristics in the successive frames, and finally find out the safety-critical events to send out warning sounds. We evaluate the effectiveness of our system based on two different real driving routes, the results show that DNAS, on average, is able to detect speeding and tailgating with an accuracy of 87:7% and 83:3% recall, respectively.
Keywords: DNAS; Nighttime driving; Smartphone

• The Bottleneck Problem in Large Scale IEEE 802.15.4 / ZigBee Networks
by Chih-Min Chao, Hsin-Hsiang Wang
Abstract: In this paper, we handle the bottleneck problem of ZigBee-based networks. The bottleneck problem occurs at the nodes near the ZigBee coordinator since they have too many data to deliver during the data gathering process. This is a fundamental problem which reduces network throughput and prolongs transmission delay. A possible solution to this problem is to schedule each node's transmission/receiving time properly. Two fundamental problems we have to answer for such scheduling are when and how long a node should keep awake to transmit/receive packets. To achieve efficient scheduling, in this paper, we propose a centralized Top-Down-Maximum-Load-First (TDMLF) scheme which utilizes the contention-free Guaranteed Time Slots (GTS) defined in IEEE 802.15.4. By increasing the number of concurrent transmissions, the proposed scheme achieves high system utilization and thus alleviates the bottleneck problem. Through simulation and real system implementation, we verify that TDMLF successfully reduces the negative effects caused by the bottleneck problem.
Keywords: wireless sensor networks;IEEE 802.15.4;ZigBee;data collection;bottleneck;scheduling

• Towards an Observer/Controller and Ontology/Rules-Based Approach for Pervasive Healthcare Systems
by Amina Hameur Laine, Kenza Abdlaziz, Philippe Roose, Mohamed-Khireddine Kholladi
Abstract: This paper proposes new design approach for U-Healthcare systems. Our approach consists in combining the generic Observer/Controller architecture of Organic Computing, Ontologies and Rules-based paradigms. This combination brings three significant benefits. First, it allows keeping the system highly supervised and controlled by the Observer/Controller. Second, it enables the system to reason upon useful contextual information gathered from different and heterogeneous entities, and deduce new situations that require adaptation of the systems behavior. Finally, it enables the system to adapt its behavior dynamically to the context change by reasoning about this context and selecting the appropriate service to a specific user.
Keywords: pervasive computing; U-Healthcare systems; context-awareness; context-aware system; context modeling; context reasoning; ontologies; rules; Observer/Controller architecture.

• Hybrid alternative Receiver-Sender approach with a colored DR/BDR mechanism for the broadcast of safety messages in VANETs
by Amira Benaidja, Samira Moussaoui, Farid Nait Abdesselam
Keywords: VANETs; safety applications; hybrid alternative Receiver-Sender approach; colored DR/BDR mechanism; warning messages

• Lossless Compression for Transmitting ECG in SMS with High Quality for Mobile Telecardiology Systems
by Diana M, Deisy C
Abstract: This paper presents a novel Lossless Compression for ECG in SMS (LCES) deployable on resource-constrained devices like mobile phones for efficient use in remote health monitoring systems. Even losslessly compressed ECG suffers transmission loss in GSM networks due to use of special character set stated by the GSM Standards. The LCES overcomes these challenges by adopting the ETSI GSM 03.38 character set in the symbol substitution phase to abstain loss in ECG transmission. The LCES was implemented and tested as an Android App using MIT-BIH Arrhythmia and Compression Test Databases. An average compression-ratio (CR) of 7.03, Percentage-Root-mean-square-Distortion (PRD) as low as 0.022 proving superior compression performance and quality for real-time mobile based remote health monitoring systems was obtained.
Keywords: ECG Transmission; ECG in SMS; Lossless ECG Compression; Symbol substitution based Compression; Telecardiology.

• Incorporating Architectural Modeling with State-based Reliability Evaluation
by Luxi Chen, Linpeng Huang, Chen Li, Xiwen Wu
Abstract: In the system development, it is quite important to evaluate non-functional property qualities on the architecture for making early adjustment decisions. However, in current practice, functional architectural modeling and non-functional quality evaluation are often implemented separately. And most architecture description languages fail to specify architecture evolution to implement adjustment. It is essential to propose a mechanism implementing architecture-level evaluation, and supporting architecture evolution. Withrnthese considerations, we present an architectural evaluation and evolution framework, which is based on the architecture description language - Breeze/ADL. First, by using Breeze/ADL, the system architecture is specified with trustworthy properties. Second, Breeze/ADL specifications are turned into a state view Markov Chain model. This model helps to evaluate the reliability and conduct importance analysis to identify the critical module. Third, based on the evaluation result, the evolution mechanism by Breeze/ADL will raise an adjustment solution to improve the reliability.
Keywords: System Architecture; Breeze/ADL; Markov Chain Model; Reliability Evaluation

• Improving the QoS of IEEE 802.11e networks through imprecise computation
by Anna Lina Ruscelli, Gabriele Cecchetti
Abstract: IEEE 802.11e HCCA reference scheduler is based on fixed value parameters that do not adapt to traffic changes, thus Quality of Service for multimedia applications is a challenge, especially in the case of Variable Bit Rate streams, that require dynamic resource assignment. This paper is focused on Immediate Dynamic TXOP HCCA (IDTH) scheduling algorithm and its new evolution Immediate Dynamic TXOP HCCA plus (IDTH+). Their reclaiming mechanisms, refined by the monitoring of transmission duration, aim at overcoming the limits of fixed preallocation of resources by varying the stations transmission time and avoiding waste of resources. Simulations and theoretical analysis based on the imprecise computation model show that the integration of IDTH and IDTH+ can achieve improved network performance in terms of transmission queues length, mean access delay and packets drop rate and to efficiently manage bursty traffic. Moreover the performance improvements of IDTH+ with respect to IDTH are highlighted.
Keywords: Quality of Service; scheduling algorithms; WLAN

• On the Use of Centrality Measures to Determine Connected Dominating Sets for Mobile Ad hoc Networks
by Natarajan Meghanathan
Abstract: We investigate the use of centrality measures to determine connected dominating sets (CDSs) for mobile ad hoc networks (MANETs) whose topology changes dynamically with time. CDSs are preferred for performing network-wide broadcasts with reduced retransmissions. Though commonly used, degree centrality-based CDS has been observed to be quite unstable in the presence of node mobility. In this paper, we explore the use of other centrality measures (such as eigenvector centrality, betweenness centrality and closeness centrality that are commonly used for complex network analysis) as the underlying criterion for inclusion of nodes in a CDS for MANETs and evaluate the lifetime and node size of such CDSs in comparison to that incurred for the degree centrality-based CDS. We observe the eigenvector centrality-based CDS to be the most stable (but the CDS node size is also the largest); the betweenness centrality-based CDS is the least stable (but incurs the smallest CDS node size).
Keywords: Centrality, Connected Dominating Set, CDS Lifetime, CDS Node Size, Mobile Ad hoc Networks, Stability, Simulations

• CG-Fuzzing: A Comprehensive Fuzzy Algorithm for ZigBee
by Baojiang Cui, Ziyue Wang
Abstract: ZigBee defines several security services on the MAC layer, including sequential freshness, frame integrity, data encryption and access control. Unfortunately, there are still security vulnerabilities due to design defects of ZigBee that could result in serious network meltdown. Therefore, it is necessary to detect these defects of ZigBee by using a fuzzing test. However, fuzzing tests have usually been inefficient because test cases are either too numerous or invalid. In this paper, a novel comprehensive fuzzing test algorithm, CG-Fuzzing (Comprehensive Genetic-Based-Fuzzing) is proposed. The CG- Fuzzing algorithm contains three parts: structure-based, boundary-based and genetic algorithms. This paper establishes an evolutionary model for test cases that helps them achieve high rates of passing filtering rules and vulnerability triggering. Compared with the traditional fuzzing methods, the number of test cases is reduced and they are more efficient. Experimental results prove that the synthesized performance of CG-Fuzzing is outstanding. The fuzzing test with the algorithm takes only 4 minutes to exploit a previously known vulnerability of ZigBee.
Keywords: CG-Fuzzing, Fuzzing Test, ZigBee, IoT

• Joint Channel Assignment and Routing Protocol for Cognitive Radio Ad Hoc Networks
by Gin-Xian Kok, Chee-Onn Chow, Yi-Han Xu, Hiroshi Ishii
Abstract: Conventional single channel wireless ad hoc networks usually suffer from low network throughput due to the higher number of packet transmissions required for multi-hop communication. Using multiple channels within a single network can improve the network throughput. In multi-channel communication networks, the channels must be assigned appropriately to maximize network performance. Existing channel assignment methods are usually based on the approach of interference reduction/minimization, for example, by making a link operates on only one channel and different links operate on different channels. In this paper, we go in the opposite direction and propose to make links operate on more channels. A new distributed joint channel assignment and routing protocol for cognitive radio ad hoc networks called Cognitive Radio Enhanced AOMDV (CR-EAOMDV) is proposed. Simulation studies showed that our method outperforms other methods.
Keywords: distributed method; channel assignment; routing; multi-hop wireless networks; wireless mesh networks; cognitive radio ad hoc networks; interference; channel metric; performance evaluation; simulation

• An Efficient Data Dissemination and Handover Scheme for Vehicular Ad hoc Networks
by Ravi Shankar Shukla, Neeraj Tyagi, Ashutosh Gupta, Kamlesh Kumar Debey
Abstract: This paper presents a data dissemination and smooth handover scheme for vehicular ad hoc network. The data dissemination scheme is based on position based routing class protocol and uses optimize forwarding to find forwarding node along the road pattern to deliver the data packets. The proposed routing algorithm ensures that all data packets are received with minimal delay and higher delivery ratio. A heterogeneous network architecture is proposed in this paper to support seamless mobility of mobile network. Each vehicle is provided with mobility through different Internet Server Protocols (ISPs). The Mobile Router (MR) based handover scheme where MRs cooperatively receive packet destined for each other can provide no service disruption and significantly reduce packet loss during handover. It also makes the packet loss independent to handover latency. Simulation study shows the comparative performance of the proposed handover architecture in terms of throughput, handover latency service disruption time, packet loss and signaling overhead.
Keywords: Ad-Hoc Network; Routing Algorithms; Handover scheme; VANET.

• VPOD: Virtual Parking Overlay Network based Data Delivery in Urban VANETs
by Jinqi Zhu, Chunmei Ma, Nianbo Liu, Ming Liu, Weijia Feng
Abstract: Vehicular ad hoc networks (VANETs) have characteristics of intermittent connectivity, high mobility of vehicle nodes and dynamic topology, which make data delivery in VANETs very challenging. Pervious works that based on history traffic patterns(such as history data delivery delay for each trajectory) to predict the current traffic conditions on the roads are not accurate. Moreover, deploying roadside units (RSUs) is a possible solution to overcome the challenges, but it often requires a large amount of investment. Motivated by the fact that there are large amounts of outside parked vehicles in urban areas, we propose in this paper a virtual parking overlay network based data delivery scheme(VPOD), which does not need any RSUs but leverages a parking overlay network formed by outside parked vehicles to disseminate messages among moving vehicles.VPOD consists of two main parts. Firstly, to each road, parked vehicles both at the roadside and off-street are grouped into a parking cluster as far as possible. An urban overlay network is established based on these parking clusters for effective data transmission. We also investigate the connectivity of the overlay network through theoretic analysis. Secondly, novel message delivery algorithms are designed to efficiently transmit messages to the destination vehicle through the proposed overlay network. Simulation results based on a real city map and realistic traffic situations show that VPOD achieves high performance in data delivery, especially in sparse traffic and multiple requests conditions.
Keywords: VANETs; parked vehicle; overlay network; data delivery

Special Issue on: "Advances in Transparent Computing,"

• A cost-efficient architecture for the campus information system based on transparent computing platform
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

• Personalized content recommendation based on field authorities in transparent computing
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

• Cross platform method for ubiquitous computing and its application to mobile terminal
by Wei Liang, Yonghua Xiong, Min Wu, 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.

• Performance Modeling for Transparent Computing using Stochastic Petri Nets
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
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
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 Eciency; Wireless Charging; Wireless Energy Transfer; Mobility; Distributed Algorithms; Experimentation; Performance.

• Subject-Independent Human Activity Recognition using Smartphone Accelerometer with Cloud Support
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
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
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
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
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
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
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
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
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
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

• Robust Localization Algorithm for Large Scale 3D Wireless Sensor Networks
by Nasir Saeed, Biljana Risteska Stojkoska
Abstract: Nodes positioning has recently been of great interest in wireless networks due to its crucial role in many applications. In Wireless Sensor Networks (WSNs), the task of localizing sensor nodes with unknown position is important for efficient network configuration and operation. This challenge has stimulated research of various localization algorithms. In this paper we propose robust localization algorithm for large scale three-dimensional (3D) wireless sensor networks based on multidimensional scaling (MDS). Our approach has two main improvements over classical MDS algorithm. Firstly, it uses heuristic approach for distance matrix calculation, and secondly, it applies Levenberg-Marquardt (LM) method for absolute map refinement using received signal strength measurements (RSS). Furthermore, the performance of the proposed approach is compared to other 3D Wireless Sensor Network localization techniques and it is shown that the proposed approach outperforms other techniques for 3D localization.
Keywords: Wireless Sensor Network; 3D Localization; Node Positioning; Multidimensional Scaling; Levenberg-Marquardt

• Comparability of RF-based indoor localization solutions in heterogeneous environments: an experimental study
by Tom Van Haute, Eli De Poorter, Ingrid Moerman, Filip Lemic, Vlado Handziski, Niklas Wirström
Abstract: The growing popularity of indoor localization research has resulted in a significant amount of research papers describing and evaluating innovative localization solutions. Unfortunately, the results from most of these research papers can not easily be compared since they are evaluated in different environments, use different evaluation criteria and typically tailor their solutions towards a single testbed environment. To evaluate how these different conditions influence the localization performance, in this paper an exhaustive set of experiments has been set up in which three different localization solutions have been evaluated using multiple metrics in three different test environments: two types of office environments and an industry-like factory environment. None of the used localization solutions was previously optimized for any of these test environments and they were all evaluated under similar conditions, e.g. similar interference conditions and using the same evaluation points. The results reveal several weaknesses in the evaluation methods used in the majority of existing scientific nature of indoor localization solutions. More specifically, it is shown that (i) papers that use self-selected evaluation points can significantly influence their reported accuracy by artificially selecting those evaluation points that outperform other locations, (ii) the reported accuracy can decrease significantly, up to a factor 10, when evaluating an environment for which the localization solution is not specifically tweaked and (iii) many inherent trade-offs between different metrics, such as accuracy, energy consumption and response delay, are hidden by reporting only on the accuracy of the solutions.
Keywords: Indoor localization; Experimental comparison; Benchmarking methodology; Performance metrics; Fingerprinting; Time-of-arrival, RSSI-based localization; IEEE 802.11; IEEE 802.15.4; w-iLab.t testbed; TWIST testbed; Particle filter; Spray

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

• A method of cleaning RFID data streams based on Naive Bayes Classifier
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

• Leakage Resilient CCA Secure IBE with All-but-one Lossy Filter
by Zhiwei Wang
Abstract: Research on \emph{leakage resilient cryptography} is motivated by the side channel attacks in the real world, e.g., in mobile computing, a mobile device that is using \emph{Near Field Communication} (NFC) for payments or physical access could be attacked by someone who places a small coil of wire near the NFC reader. The goal of this paper is to design an ID-based encryption (IBE) scheme that can flexibly tolerate leakage bounds, by only increasing the size of secret key proportionally, and the security level can be achieved to be against chosen-ciphertext attacks (CCA). As our main technical tool for CCA security, we introduce an initiation of all-but-one lossy filter, which is a simple version of all-but-many lossy filter to the leakage resilient settings. As our main result, we use the all-but-one lossy filter to construct an IBE scheme that is secure against leakage resilient chosen-ciphertext attacks (CCA), and the leakage rate is $1/2-o(1)$.
Keywords: CCA secure, IBE, leakage rate, leakage resilient, ABO lossy function

• Routing and CDMA-MAC based Cross-Layering for Wireless Ad Hoc Networks
by Shweta R Malwe, G. P. Biswas
Abstract: Recently, cross-layered technique is getting more popularity, and static centralized code assignment for CDMA networks appears lesser efficient over dynamic and/or distributed ones. This paper proposed a cross-layered design for establishing source-destination routing along with route-based code assignment for CDMA MAC simultaneously. Since routing in wireless networks is dynamic and route based code assignment is proposed, it resulted in a distributed dynamic code assignment for efficient deployment of the said cross-layer implementation. In addition, we also improve some other related parameters like code assignment complexity, code requirement, control overhead, etc. The Pairwise Code Assignment (PCA) scheme for the assignment of codes is followed, where three different approaches such as route-based, source-based and source-destination based PCA are proposed. However, an assumption of periodic mobility of nodes, topology formation, routing and code assignment including data transmission through a cycle as a new wireless communication model is considered for its efficient implementation. The scheme is simulated on both traditional and proposed network model, and it is found that better performance in terms of code-requirement and confliction is achieved. It also shows that the routing, implemented on the proposed network model, performs better over standalone DSR (for instance) and other existing cross-layer routing protocols.
Keywords: CDMA; code division multiple access; MAC; medium access protocol; PCA; pairwise code assignment; cross-layer; periodic mobility; communication model; DSR; dynamic source routing.

• Information Dissemination in Mobile Social Networks with Gossip Algorithms
by Bo Yang, Demin Liu, Wenfeng Zhang
Abstract: This paper studies the information dissemination problem in the mobile social network, which comprises a set of smart phones and works in a distributed manner. Gossip algorithms are used to spread information over the mobile social network with simplicity and robustness. Two typical scenarios of information dissemination are analyzed. The corresponding upper bounds on the convergence time are derived, which show the relationship between mobility of users and convergence rate of gossip algorithms. The performances of gossip algorithms are examined in both scenarios. Simulation results indicate that the growth of communication cost is almost linear when the scale of mobile social networks becomes larger, which is a quite encouraging result for application.
Keywords: distributed information dissemination; mobile social network; gossip algorithms; random walk.

• Hybrid Cluster based Geographical Routing Protocol to Mitigate Malicious Nodes in Mobile Ad Hoc Network
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
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

• Optimal Deployment and Traffic Flows in Mobile Mesh Network after a Disaster
by Junbo Wang
Abstract: It is a critical research problem to quickly reconstruct a communication system for safety confirmation and information transfer after a disaster. One resolution is to deploy mobile mesh routers (MMR) or mobile base stations in the disaster area to guarantee the connection of users. However, it is still a challenge to find an optimal deployment of MMRs to maximally satisfy users while ensuring a fluent and reliable communication network. In this paper, we focus on the above problems and propose a communication-demand-oriented deployment method (CDODM) and a global-data-traffic routing optimization method (GTFROM) for a disaster. Our main contributions are (1) formalization and optimization of computation transmission cost in a Voronoi area in CDODM, (2) formalization and optimization traffic flows in GTFROM, and (3) implementation and evaluation in Matlab and NS3. Through the evaluation, we have shown the feasibility, performance and scalability of the proposed methods. More specifically, user satisfaction calculated based on recorded throughput in NS3 can be enhanced clearly in the proposed solutions. In scalability study, the proposed methods works well, with changing range of disaster areas, number of MMRs and user communication demands.
Keywords: Mobile mesh network; Anti-disaster network; Optimizations; Voronoi diagram; User demand; Congestion

Special Issue on: "Efficient and Secure Algorithms for Ubiquitous Computing,"

• Improved Algorithm for Secure Outsourcing of Modular Exponentiations with High Checkability
by Jun Ye, Xiaofeng Chen
Abstract: With the development of cloud computing, outsourcing computation becomes a hot issue recently. Outsourcing computation allows a resource-constrained client to outsource the complicated computing tasks to a cloud server which is powerful but not honest. Modular exponentiation with a large modulus, which is considered as the most expensive operation in discrete logarithm based cryptographic protocols, has been widely used in public key cryptosystems for secure data communications. In this paper we put forth a new improved outsourcing algorithm for secure outsourcing of modular exponentiations. In the proposed algorithm, the modular exponentiations need to be computed are hidden to the malicious server. In the computation procedure, the server cannot obain any information with respect to the input and output while the client can verify the returned result efficiently. Compared with the algorithms of Hohenberger and Lysyanskaya (2005) and Chen et al. (2012), ours are superior in checkability. In addition, the proposed algorithm can promote the efficiency of all security protocols based on discrete logarithm.
Keywords: Cloud Computing; Modular Exponentiations; Outsourcing Computation; Security

• Effective Algorithms for Vertical Mining Probabilistic Frequent Patterns In Uncertain Mobile Environments
by Yu Xiaomei
Abstract: Data uncertainty is inherent in mobile applications such as location-based services, wireless sensor monitoring systems and data integration. The traditional methods of mining frequent patterns are confronted with enormous challenges in uncertain mobile environments. The present achievements in this field have shown that vertical mining algorithms are promising approaches that are experimentally proved in effective mining expected support-based frequent pattern from uncertain data, while they have not captured much attention in mining probabilistic frequent patterns over mobile probabilistic databases. In this paper, we propose two Eclat-based vertical mining algorithms (UBEclat and NDUEclat) for probabilistic frequent patterns mining in uncertain mobile environments. With a kind of bidirectional process strategy, the UBEclat algorithm is applied to mine exact probabilistic frequent patterns in uncertain mobile environments efficiently. Furthermore, with the Normal distribution-based approach, the NDUEclat algorithm is suitable for mining probabilistic frequent patterns approximately in mobile environments with huge uncertain data. We test the two novel algorithms on a number of uncertain data sets, and compare them with well-known frequent patterns mining algorithms. The extensive evaluations on real and synthetic datasets show that the novel Eclat-based algorithms outperform the comparative ones in performance of efficiency and precision.
Keywords: Patter Mining; Uncertain Environment; Mobile Environment; Algorithm; Probabilistic Database.

• A Novel Key Pre-distribution Approach for High Security and Efficiency using LU-Decomposition of Matrix
by Sung Jin Choi, Kyung Tae Kim, Hee Yong Youn
Abstract: Wide-spread deployment of wireless sensor network (WSN) is emerging, which allows an economical solution for numerous applications. Most WSN applications require secure operation since serious consequences are encountered if the network is compromised or disrupted. For the security of communication network, asymmetric cryptography is usually employed. This approach is, however, often unsuitable to WSN due to limited computational and energy power of the sensor nodes. To address this issue, various approaches have been developed, and the random key pre-distribution approach is regarded as the most effective one. Here one shortcoming is that a common key is not guaranteed to be found between any two nodes wanting to communicate with each other. This paper proposes a new key pre-distribution scheme solving this problem, with which highly secure WSN is available. This is achieved by the keys obtained using LU-decomposition of a symmetric matrix. Mathematical analysis and computer simulation reveal that the proposed scheme significantly reduces the overhead required for secure connectivity and energy efficiency of the sensor nodes compared to the existing approaches. The superiority of the proposed scheme becomes more substantial when the memory size of the sensor nodes is small.
Keywords: Energy efficiency; key pre-distribution; LU decomposition; secure connectivity; wireless sensor network.

• Collaborative "Many to Many" DDoS Detection in Cloud
by Siqi Ma, David Lo, Ning Xi
Abstract: Cloud computing is a popular way to manage large amount of data. It providesrna scalable and cost-effective environment for users to store and process data through the Internet. However, the usage of Internet also causes lots of security issues, such as DDoS (Distributed Denial-of-Service) attacks. DDoS attacks are common threats to current networks or systems. Such attacks risk systems outages and intend to disable the service to legitimate users. In this paper, due to the nature of its large-scale and coordinated attacks, we propose a collaborative prediction approach for detecting DDoS in advance. Different from many state-of-the-art methods that mainly focus on packet level analysis and require much audit and monitoring information, our approach provides a clean and direct solution to attack defence.We believe that the DDoS attacks follow certain patterns when employing a large number of compromised machines (attackers) to request for service from the servers in the victim system. So we construct an attacker-server utility matrix by the number of packets and adopt matrix factorization to detect potential attackers collaboratively. We derive the latent attacker vectors and latent server vectors to predict the unknown entries in the matrix. Experimental results on the NS-2 simulation networks demonstrate the superiority of our approach.
Keywords: Cloud Computing; DDoS Detection; Collaborative detection; Matrix Factorization

• Rational Secure Two-party Computation Based on Social Network
by Yilei Wang, Yaqin Liu, Tao Li, Wei Gao, Qiuliang Xu
Abstract: The seminal notion of rational parties can lead to some positive results for secure two-party computation such as fairness, which is often neglected in traditional secure two-party computation. Previous works of rational computation protocol dedicate to improve its efficiency and applicability. However, little works study the incentives of rational parties in a realistic background. That is, how parties define the utility and choose proper strategies in reality. In this paper, we consider rational parties belonging to a social network, which is an ad hoc network presenting the social structure of parties or organizations. Here parties in social networks define their utilities and dynamically change their strategies according to conformity mechanism (CM). We propose a CM model and the simulation results show that the new model boost cooperation in social network. Then we build a RSTPC protocol, where parties abide by CM. Finally, we also propose a new paradigm between PD game and RSTPC trying to set up a generalized relationship in order to prove that fairness can be achieved whenever there is a Nash equilibrium.
Keywords: Game theory; Social network; Conformity mechanism; Nash equilibrium

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
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.