# Forthcoming articles

International Journal of Ad Hoc and Ubiquitous Computing

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 International Journal of Ad Hoc and Ubiquitous Computing (92 papers in press)  Regular Issues  Assessment of heuristics for self-stabilization in real-time interactive communication overlays   by Pelayo Nuño, Juan C. Granda, Francisco J. Suárez Abstract: Self-stabilization is an autonomic behavior closely related to self-healing. In multimedia communication overlays, self-stabilization copes with network disruptions by dynamically restoring data links and communication paths. The restoration of links may require reorganizing the overlay by establishing new connections among members or modifying existing ones. Self-stabilization techniques are usually triggered asynchronously, either on use (during reorganizations of the overlay) or on event (as a response to a failure), and several heuristics may be used when selecting link peers. In this work several heuristics to perform on event self-stabilization in multimedia communication overlays are assessed. A real-time communication overlay deployed according to a full-mesh topology interconnecting a set of multicast groups is used as assessment framework to evaluate the heuristics. Intensive tests have been carried out to compare and assess heuristics under several overlay topologies and network conditions. Keywords: self-stabilization; overlay networks; multimedia communications; autonomic computing.DOI: 10.1504/IJAHUC.2016.10001909  A State-of-Art approach to misbehavior detection and revocation in VANET:Survey   by Dinesh Singh, Ranvijay Ranvijay, Rama Shankar Yadav Abstract: With the increased popularity of Internet application and smart cities, Vehicular Ad hoc Networks (VANETs) have become one of the prominent research area and ample of researchers have addressed the many issues in the past decade. Among the many issues involves with e ective VANET, misbehavior detection and revocation is required to address with full attention. It is rst and foremost step towards dealing with safety applications in VANETs. The vehicle misbehavior is responsible for malfunctioning of many network activities (e.g. trac jam, road accidents etc.). The misbehavior detection problem becomes more severe for safety critical applications in VANETs. The misbehaved vehicle must be revoked from the network as early as possible to reduce injuries. Thus, inconjuction of misbehavior detection, revocation problem also needs to be explored. This paper is addressed to provide state-of-art to misbehavior detection and revocation for safety critical VANETs. Here we present a detailed survey on relevant research done in the area of misbehavior detection and revocation with other related issues. Keywords: Vehicular Ad hoc Network (VANETs); safety applications; misbehavior detection; revocation.DOI: 10.1504/IJAHUC.2016.10001911  An Energy Model of 4G Smartphone Oriented Towards Typical Network Applications   by TunDong Liu, Yun Lin, ZhuoBin Xu, Yi Xie, FuFeng Chen, GuoZhi Xue Abstract: In the wave of wireless technologies, 4G has achieved considerable success because of its high data rate and great potential. But the short battery lifetime of mobile device hinders the development of 4G. The energy scheme in the LTE protocol based on Radio Resource Control (RRC) states in some degree optimizes the energy consumption of 4G smartphone, but it is still far from satisfaction. Therefore, many efforts have been done to study the process of energy consumption in 4G smartphone which is helpful to improve the energy efficiency. Some hardware-based methods using expensive instruments are correct but unhandy. Some software-based methods are flexible but incorrect because they often omit the influences from communication performance. Up to now, most energy models have paid little attention to application layer without considering the quality of wireless communication. This paper proposes an energy model of 4G smartphone where two typical applications (HTTP and FTP) and the data flow of wireless traffic are considered. In order to verify the energy model, an experimental testbed has been set up to capture the data flow and power records during one application. Experiment results have shown that the energy model accurately estimates the energy consumption of 4G smartphone in one operation of the application, whose accuracy rate is higher than 90%. The work described can be considered the first step toward the implementation of a new softwarebased method to accurately estimate the energy consumption of 4G smartphone. Keywords: 4G; Energy consumption; Model; State machine; Smartphone.DOI: 10.1504/IJAHUC.2016.10001912  NetBAN, a concept of Network of BANs for Cooperative Communication: energy awareness routing solution   by Audace Manirabona, Saadi Boudjit, Lamia Chaari Fourati Abstract: In this paper a NetBAN which is a concept of network of BANs (Body Area Networks) or WBANs (Wireless BANs) is introduced and a routing solution intending to help a group of WBANs to cooperate for relaying packets according to the energy consumption rate and the communication link quality is proposed. The main goal is to provide to the sensors a technique that helps them deliver their data even when the coordinators battery is very low or empty or else the connection to the access point is lost, what leads to balancing energy consumption between cooperating coordinators. For this purpose, an energy threshold based technique is used and energy-aware optimized link state routing (EA-OLSR) is defined and used. Simulation results show interesting performances in terms of network lifetime with a gain of about 30% and data delivery about 20%. Keywords: Network of BANs; WBAN; Cooperation; Relay; OLSR; Routing; Energy Aware.DOI: 10.1504/IJAHUC.2016.10001913  ADiDA: Adaptive Differential Data Aggregation for Cluster Based Wireless Sensor Networks   by Rabia Enam, Rehan Qureshi Abstract: In dynamic cluster based Wireless Sensor Networks (WSNs), clusters are formed dynamically and repeatedly to uniformly consume the energy of the nodes. It has been observed in large scale dynamic cluster based WSNs that the size of clusters vary significantly in terms of number of nodes. The data aggregation mechanisms used at the cluster heads do not adapt adequately to such variance in cluster sizes and incur considerable losses specially in clusters with large number of nodes. In this paper we propose a novel and an \emph{Adaptive Differential Data Aggregation} (ADiDA) method that can minimise the complexity of aggregating large amount of data into small sized data packets. The main feature of ADiDA is that in addition to reducing the cost of redundant data transfer in the network, it also optimally utilises the available space in a packet at each cluster head. We have analysed ADiDA on four different types of sensing environments with multiple types of data-values. The results have shown that ADiDA can reduce the payload size requirement to almost one-fourth of the non-compressed payload and the distortion percentage in the aggregated data decreases by 16\% to 41\% when compared with the summary based aggregation of data. Keywords: Cluster based WSN; Adaptive Data Aggregation; Spatial Correlation; Variable sized Clusters.DOI: 10.1504/IJAHUC.2016.10001914  MT-SECURER: Multi Factors Trust for Secure and Reliable Routing in MANETs   by Zakir Ullah, Muhammad Hasan Islam, Adnan Ahmed Khan, Imran Shafi Abstract: Routing, having a pivotal role in MANETs successful working, assumes nodes cooperation for its processes. However, this assumption of nodes cooperation makes routing vulnerable to various insider and outsider attackers. Therefore, enforcing nodes cooperation to secure routing from such attackers is stipulated as a challenging research issue in MANETs. In this paper a trust management scheme named MT-SECURER (Multi Factors Trust for SECUre and REliable Routing in MANETs) is proposed to make routing secure and reliable against insider attackers to launch greyhole and blackhole attacks. The proposed scheme develops trust using multiple factors, i.e., nodes cooperation from communication networks and nodes relationship maturity and mutual friends from social networks. These factors are acquired using observer nodes personal observations and neighbors recommendations. Furthermore, neighbors recommendations are passed through a dissimilarity factor based filter to remove false recommendations. As a test case, the proposed scheme is integrated in AODV routing protocol and extensive simulations are conducted to examine the effectiveness and competence of the proposed scheme in presence of insider attackers to launch blackhole and greyhole attacks. Experimental results show significant improvement in packet delivery ratio, throughput and normalized routing load with slightly increased average end-to-end delay when compared to contemporary schemes in presence of attacks asserted. Keywords: Attacks; MANETs; Routing; Trust; Trust Management.DOI: 10.1504/IJAHUC.2016.10001915  An Energy-Efficient Point-Coverage-Aware Clustering Protocol in Wireless Sensor Networks   by Tri Gia Nguyen, Chakchai So-In Abstract: Preserving coverage is one of the most essential functions to guarantee quality of service in wireless sensor networks. With this key constraint, the energy consumption of the sensors including their transmission behaviour is a challenging problem in term of how to efficiently use them while achieving good coverage performance. This research proposes a clustering protocol, point-coverage-aware (PCACP), based on point-coverage awareness with energy optimizations that focuses on a holistic view with respect to activation sensors, network clustering, and multi-hop communication, to improve energy efficiency, i.e., network lifetime extension while preserving coverage and maximizing the network coverage. The simulation results demonstrate the effectiveness of PCACP, which strongly improves the performance. Given a diversity of deployments with scalability concerns, PCACP outperformed other competitive protocols i.e., LEACH, CPCP, EADC, and ECDC in terms of conserving energy, sensing point coverage ratios, and overall network lifetime. Keywords: coverage-aware; point coverage; sensor activation; clustering; energy-efficient; wireless sensor networks; WSNs.DOI: 10.1504/IJAHUC.2016.10001976  An Optimal Algorithm for Small Group Multicast in Wireless Sensor Networks   by Weizhong Luo, Jianxin Wang, Zhaoquan Cai, Gang Peng, Jiong Guo, Shigeng Zhang Abstract: We propose an optimal algorithm to construct a delay-bounded minimum energy routing tree for small group multicast in wireless sensor networks. Finding the minimum energy multicast tree with constrained delay in general case has been proved to be a NP-hard optimization problem. Existing works mainly focus on developing approximation or heuristic algorithms to find approximate solutions. We formally define the Min-power h-Multicast problem - to find a minimum energy multicast tree in which the path from the source to every destination node is less than h hops - and translate it into a minimum Steiner tree problem. We then develop a dynamic programming algorithm to get an optimal solution to the problem in O(3^k(n+m)h+2^k (n+m)^2h) time, where k is the size of the multicast group, n and m denote the numbers of vertices and edges of the graph characterizing the network, respectively. Simulation results show that, compared with existing heuristic or approximation algorithms, our algorithm saves energy consumption by factors between 19% and 42% with comparable running time for small group multicast. Keywords: Delay-bounded multicast; energy consumption optimization; fixed parameter tractable; NP-hard.DOI: 10.1504/IJAHUC.2016.10001916  Direction-Based Urban Broadcast Protocol for Vehicular Ad hoc Networks   by Gui-Sen Li, Xu-Hui Chen, Ke-Shou Wu, Ren Chen Abstract: Multi hop broadcast for vehicular ad hoc networks in urban environments is a difficult task for the impact of the intersections. The forward of the next relay will face the problem that some branches of the intersection will not be covered in time. In this paper, we propose a novel broadcast protocol for urban environments. The proposed protocol considers the transmission direction of broadcasting message and the moving direction of forwarding vehicle for delivering the message over the intersection. It delivers the message to all road directions at the intersection by an efficient and fast way. Using the direction information, an agent vehicle mode also has been proposed to cope with the disconnected problem. Performance evaluation results show that the proposed protocol improves the reachability and speeds up the broadcast process. Keywords: VANET; urban broadcast; intersection; transmission direction; moving direction.DOI: 10.1504/IJAHUC.2016.10001978  Modelling and Mitigating Spectrum Sensing Non-cooperation Attack in Cognitive Radio Network   by Roshni Rajkumari, Ningrinla Marchang Abstract: Collaborative spectrum sensing (CSS) is known to improve spectrum sensing performance in Cognitive Radio Network. In CSS, secondary users participate by sharing their local sensing results. They participate in the sensing process at their own cost, i.e., they expend some amount of energy and time for sensing and sharing. But, a selfish user may refrain from collaborating in the spectrum sensing process in order to save up energy, which results in improper sensing. While this problem is widely known, we call this as the spectrum sensing non-cooperation (SSNC) attack for easy reference. In this paper, a collective action prisoners dilemma game is used to model the SSNC attack. To handle this attack, repeated game punishment mechanisms, namely Tit-for-Tat and Grim strategies are used. In addition, modified Tit-for-Tat and modified Grim strategies are proposed to handle this attack in the presence of reporting channel error. Keywords: Cognitive radio network; collaborative spectrum sensing; spectrum sensing; non-cooperation attack; game theory; fusion rules.DOI: 10.1504/IJAHUC.2016.10001917  Enhanced Identity Privacy in UMTS   by Hiten Choudhury, Basav Roychoudhury, Dilip Kr. Saikia Abstract: Identity privacy in mobile networks has been an active and exciting research area for quite some time. Earlier, researchers were focused on protecting the subscriber's identity over the radio access link between the mobile device and the visited serving network. Whereas now, they are considering the need for protecting the identity from the serving network itself, due to the security and flexibility that it promises to bring into roaming situations. Towards this, numerous protocols have been proposed for mobile networks in general. In UMTS, one of the most popular and widely deployed mobile networks across the globe, the status of identity privacy is no different. However, a surprising fact is that not much research, that tries to protect the subscriber's identity from the serving network, has been conducted with regards to UMTS in specific. Even recent works in this area seems to ignore this important security aspect. In this paper, we make an effort to fill in this gap by proposing an identity privacy ensuring extension that can be easily adapted in UMTS, without disturbing the current protocol flow. We also establish the security, robustness and correctness of this extension through statistical, security and formal analysis. Keywords: UMTS; Identity Privacy; Identity Confidentiality; Anonymity; Security.DOI: 10.1504/IJAHUC.2016.10001918  A new hybrid routing protocol for Wireless Sensor Networks   by Slaheddine Chelbi, Habib Dhahri, Majed Abdouli, Claude Duvallet, Rafik Bouaziz Abstract: Wireless Sensor Networks (WSN) differ from traditional wireless communication networks in several characteristics. One of these characteristics is power awareness, due to the fact that the batteries of sensor nodes have a restricted lifetime and are difficult to be replaced. In order to save the overall energy of the system and to fairly balance the load among nodes, we propose a New Hybrid Routing Protocol, called NHRP, which incorporates two modules: (1) a scheduling mechanism, called Advanced Energy efficient Coverage Control Algorithm (AECCA), based on binary particle swarm optimization (PSO). This approach aims to activate only the necessary number of sensor nodes while preserving full coverage. (2) A cluster based protocol using Fuzzy C-Means (FCM) method named Advanced FCM (AFCM). Several works prove that FCM algorithms assists to optimize the clusters based on minimizing the distance between the sensor node and the cluster centre. Yet, in cluster based approach, the cluster head is usually selected amongst the sensor nodes which can die quickly for this extra workload. To mitigate this problem, the second module is based on the use of some special and mobile nodes with controllable trajectories which acts as gateways.\\\\ \r\nFirst, AECCA and AFCM results are compared to ECCA and FCM, respectively. We prove that AECCA and AFCM give better performance than ECCA and FCM respectively in prolonging network lifetime. Second, simulation results show that our new hybrid routing protocol improves the fairness energy consumption among all sensor nodes and achieves an obvious improvement on the network lifetime. Keywords: Wireless Sensor Networks; Energy Saving; particle swarm optimization; Fuzzy C-Means; mobile nodes.DOI: 10.1504/IJAHUC.2016.10001982  A Dynamic Trust Evolution Model for MANETs based on Mobility   by Vijender Busi Reddy, Venkataraman S, Atul Negi Abstract: Mobile Ad-hoc Networks (MANETs) are said to be open, anonymous, dynamic and mobile in nature which makes them vulnerable to several types of attacks. Mobility of a node is a source of vulnerability and raises challenges in setup and maintenance of secure and reliable communication. Present literature does not seem to adequately address these concerns. We propose here a trust computation model that enables a node in a network to assess confidence in its immediate and extended neighbourhood. We derive a trust parameter called as Mobility Factor to assess a nodes mobility without using any extra hardware. Our model improves upon existing schemes when assessing trustworthy behaviour. The effects of mobility are included as an integral parameter in the total trust evaluation. The improved trust assessment allows identification of capricious behaviour of a node using the concept of trust flutter. A formal proof presented here supports the adequacy of the proposed approach. ns-2 simulations with mobility and malicious nodes show better performance of proposed approach as compared to recent work (TSR [1]). Improved resilience against packet-dropping/modification attack and on-off attacks was observed. Keywords: Ad-hoc; Trust; Mobility; MANETs.DOI: 10.1504/IJAHUC.2016.10001919  An Efficient Mobile Grid Scheme for Service Tracking in VANETs   by Chyi-Ren Dow, Yu-Hong Lee, Shiow-Fen Hwang, Van-Tung Bui Abstract: The majority of modern vehicles are equipped with various sensors to enhance the driving experience. With these sensors, a vehicles can be considered as an integrated sensor system that can sense data in intelligent transportation systems. However, compared with legacy networks, information cannot be easily exchanged through a vehicular ad hoc network. Intelligent transportation systems deployed on a vehicular ad hoc network are usually highly distributed and depend on metadata exchanging, data sharing, and service tracking mechanisms. This study focused on the mobile grid scheme and service tracking protocol. In the conventional scheme, the geo grid scheme is used to divide a map into grids. Each grid elects its grid leader to manage the information of the grid. However, the initial design has a fixed grid size and therefore network maintenance may be expensive. We designed the mobile grid sequence scheme as follows. Mobile grid structures use the characteristic of group mobility to increase grid structure flexibility and reduce maintenance costs. In a mobile environment, the location of a service provider is not fixed. When the service provider moves to another location of the road, users may need to re-perform the discovery process. The tracking protocol is used to manage the service footprint information and continuously track the target service. Indicators manage the footprint of the service providers in their branches. Users can simply rely on the footprint information to locate target services. According to the experimental results, the mobile grid sequences effectively extended the service time and information was reliably shared in the mobile grid sequences. Our service tracking scheme is more efficient than other schemes in terms of success rate and service tracking time. Keywords: Vehicular Ad Hoc Networks; Mobile Grid; Service Tracking.DOI: 10.1504/IJAHUC.2016.10001948  Routing Problems for Vehicle Ad-Hoc Networks using the Virtual Message Ferry Routing Scheme   by Chu-Fu Wang, Yang-Chih Chiu Abstract: The communication links between vehicles in Vehicle Ad-Hoc Networks (VANETs) suffer from the intermittent connection problem due to node mobility, and consequently the routing design is very challenging. The virtual message ferry routing scheme is one of the efficient approaches for aiding the routing decisions in VANETs to cope with the routing problem. The role of the Virtual Message Ferry (VMF) can be played by any vehicle on the road, and the current VMF role-playing vehicle will be switched to another vehicle when it drives away from the preplanned VMF trajectory. The considered VMF routing scheme will not alter the driving behavior of any chosen vehicle, which includes its driving speed, the original relocating plan, etc. This paper considers routing problems in the VMF backbone network that are formed by trajectories of multiple VMFs. A network optimization problem formulation and transformation are given. Heuristic algorithms to find near optimal solutions are also proposed. Keywords: VANET; routing; multiple virtual message ferry; backbone network; intermittent connected routing.DOI: 10.1504/IJAHUC.2016.10001983  An Efficient Fine-grained Access Control Scheme for Hierarchical Wireless Sensor Networks   by Santanu Chatterjee, Sandip Roy Abstract: Fine-grained access control is used to assign unique access privilege to a particular user for accessing the real-time and mission critical data directly from the nodes inside wireless sensor network (WSN) and protecting sensitive sensor information from unauthorized access in WSN. In this paper, we propose a new fine-grained access control scheme based on Key policy attribute-based encryption (KP-ABE) suitable for hierarchical wireless sensor networks. The strengths of the proposed protocol are that it provides fine-grained access control with authentication and achieves some good properties such as efficient user revocation and new node deployment at any time without incurring large overheads. Our proposed scheme takes significantly low computational, communication, storage and energy cost compared to other related fine-grained access control schemes. In addition, the proposed scheme provides unconditional security against privileged-insider key abuse attack, node capture attack, forward and backward secrecy and also prevents other attacks such as denial-of-service attack, replay attack and man-in-the-middle attack. We also simulate this proposed scheme for formal security verification using the widely-accepted Automated Validation of Internet Security Protocols and Applications (AVISPA) tool. Using the AVISPA model checkers, we show that our scheme is secure against possible passive and active attacks. Keywords: Attribute-based encryption; Fine-grained access control; Bilinear maps; Hierarchical WSNs; AVISPA.DOI: 10.1504/IJAHUC.2016.10001987  Joint Time Synchronization and Localization of Multiple Source Nodes in Wireless Sensor Networks   by Yan Changhong Abstract: In an asynchronous network, the local clock of sensor node has clock drift with respect to the real clock for imperfectrnhardware. So time synchronization and localization shouldrnbe jointly conducted for time-based source location estimates. Inrnthis paper semidefinite programming (SDP), complexity-reducedrnSDP and linear least square (LLS) estimator are proposed forrntime synchronization and localization of multiple source nodes.rnThe proposed algorithms provide joint estimates for the sourcernlocations and clock parameters and avoid the shortcoming ofrnmaximum likelihood (ML) estimator which requires an initialrnsolution. Then a location refinement (LR) technique is introducedrnto refine the estimated parameters for the estimators.rnThe simulations show that the original SDP algorithm providesrnbetter accuracy performance than the complexity-reduced SDP.rnHowever the complexity-reduced SDP runs faster than SDP.rnAlthough the complexity of LLS estimator is lowest amongrnthree proposed algorithms, the convex optimization algorithmsrnincluding the original SDP and complexity-reduced SDP havernmore robust performance compared with the LLS estimator. Keywords: Wireless sensor networks; localization; time synchronization; convex optimization; semidefinite programming.DOI: 10.1504/IJAHUC.2016.10001988  Cloud-based Mobile Service Provisioning For System Performance Optimization   by ChunLin Li, Jing Zhang Abstract: Currently, the mobile applications require intensive computational resources, particularly CPUs, RAMs, storage, and battery to successfully complete the expected computing operation. Although distant clouds feature high availability and elastic scalability, and performance gain of utilizing such resources is decreased by high communication latency due to large number of intermediate hops between the mobile device and the distant public clouds. Therefore, local cloud is suitable choice for some mobile devices. In this paper, hybrid cloud-assisted mobile service optimization model is proposed to tackle limited resources of mobile devices and enhance the overall system performance. The aim of hybrid cloud-assisted mobile service optimization is that mobile cloud system utility is optimized while satisfying huge number of mobile requests and improving individual user's QoS and reducing system overheads. The hybrid cloud-assisted mobile service scheduling algorithm enables mobile applications conducted on mobile devices to complete all tasks by leveraging computing resources of public cloud and local cloud. The proposed algorithm is validated through a series of experiments. Keywords: cloud-assisted; mobile service optimization; context awareness.DOI: 10.1504/IJAHUC.2016.10001991  Congestion Control and Fairness with Dynamic Priority for Ad hoc Networks   by Tapas Mishra, Sachin Tripathi Abstract: Ad hoc sensor network is a compilation of ad hoc nodes with sensing capability. Recently, the network structure has changed rapidly in modern applications and has imposed priority for heterogeneous applications. In some scenarios, the priorities of the flows need to change in the middle of the communication. However, the major problem is that the packets of different applications are not served at the destination by their expected priority ratio even if the priority does not change. Considering the above problem, this paper presents a fair packet scheduling policy which collects information from each individual flow according to its priority and auto-updates the priorities of flows when required. Moreover, a hybrid congestion control technique based on queue occupancy and channel utilization is framed to control congestion. The presented work focuses on the prioritized packet scheduling policy with the help of multiple queues, whose lengths are determined with the help of priority of each application. The proposed model has been simulated using NS2 for two applications, where each application carries multiple flows. The simulation result shows, the internal buffer is occupied by their respective packets and transmitted according to their priority ratio. Moreover, it reduces overall packet loss which leads to serve more packets at destination than the existing fairness protocols and the packet service rate reflects instantly soon after the priority changes. Keywords: Active queue monitoring; Ad hoc networks; Fair queuing; Packet scheduling; Congestion control; Transmission control protocol.DOI: 10.1504/IJAHUC.2016.10001992  UAVs Assisted Queue Scheduling in Ground Ad Hoc Networks   by Vishal Sharma, Rajesh Kumar Abstract: Hybrid networks provide a vast range of applications in areas of military and civilian activities. A combined operation of two or more networks can provide reliable connectivity and guaranteed Quality of Service (QoS) to end users. One of the examples of hybrid network formations is Unmanned Aerial Vehicles (UAVs) assisted ground ad hoc networks. These networks comprise of two variedly operating network units comprising of aerial and ground nodes. Efficient coordination between these networks can resolve complex issues such as coverage, proper connectivity, scalability, and QoS. However, reliable data transmission with enhanced QoS is one of the key challenges in these type of hybrid ad hoc formations. Efficient QoS provisioning provides transmission at higher data rate, low jitters, and enhanced connectivity. Considering this as a problem, an efficient queue scheduling approach is proposed that allows improved QoS to end users. The proposed queue scheduling approach is developed in two parts. The first part utilizes the Quaternion based Kalman Filter to find the appropriate locations for placement of each UAV. This allows proper connectivity between the ground nodes and the UAVs using a scheduling cost function. In the second part, Satisfied Importance Analysis (SIA) is used to find the governing rules for the selection of appropriate queue to be transmitted. The proposed approach allows enhanced connectivity between ground nodes and UAVs that act as aerial relays. Enhanced connectivity and efficient transmission are attained using the proposed approach. The effectiveness of the proposed model is demonstrated using simulations. Keywords: UAVs; Positioning; Quality of Service; Delays; Throughput.DOI: 10.1504/IJAHUC.2016.10001993  Rendezvous in Cognitive Radio Ad hoc Networks: A Survey   by Aishwarya Ukey, Meenu Chawla Abstract: Cognitive radio networks (CRNs) in conjunction with dynamic spectrum access cope with spectrum scarcity and underutilization problem through the opportunistic sharing of spectrum, and provide dynamic access to the free portions of spectrum allotted to licensed users. The functionality of CRN relies on the cognitive capability and reconfigurability of cognitive radios (CRs) that enable secondary users (SUs) to sense and figure out unused spectrum and allow dynamic access between different spectrum bands. Fundamental process in the formation of CRN is the neighbor discovery process, also referred as the rendezvous of SUs where SUs meet on commonly available channels and establish communication links for information exchange, spectrum management, and data communication. Rendezvous on a common channel is non-trivial as SUs do not have any network related information and are unaware of the presence of other SUs before the rendezvous. Also, due to the dynamics in licensed users activity and diversities in the temporal and geographical location of SUs, free available channels sensed by SUs usually differs. Thus, it is quite difficult to figure out a channel commonly available to all SUs. Absence of central authority, multi-hop architecture and mobility of nodes further complicates the rendezvous process. This paper focuses on the taxonomy and challenges relevant to rendezvous phenomena of SUs and provides a brief overview and comparative qualitative analysis of state-of-art rendezvous algorithms designed for cognitive radio networks. Keywords: CRN; cognitive radio network; ad hoc network; neighbor discovery; rendezvous phenomena; survey of rendezvous algorithm; synchronous and asynchronous rendezvous algorithm; channel hopping; rendezvous algorithm taxonomy and challenges.DOI: 10.1504/IJAHUC.2016.10002293  A Service Oriented Adaptive Trust Evaluation Model for Ubiquitous Computing Environment   by Jagadamba Gurappa Abstract: The increased participation of various devices and networks in the Ubiquitous Computing Environment exposed a bigger challenge in running the high-end cryptographic algorithms with larger key sizes when resources are varying by time. These cryptographic algorithms make the application highly platform dependent, susceptible to confidentiality attacks and unreliable services for the applications. The involvement of heterogeneous system, devices, and context-awareness raises a significance of trust and trust evaluation in the computing environment. Thus, the trust evaluation based on the context and service requirements can be adapted to decide the applicable level of services and the corresponding security. Hence, this paper presents a service-oriented adaptive trust evaluation model in the ubiquitous network according to the security requirement of the services. The proposed trust evaluation model computes direct trust based on various interaction properties and recommendation trust by filtering the dishonest recommenders on the time context. A fine tuning of trust is done by evaluating the adaptive trust base on the service request made by an entity. A balanced blending of direct and recommendation trust are done with trust weights to make them relevant to current application scenarios. The results are compared with some of the available schemes and found to be a consistently good in performance for the todays ubiquitous network. Keywords: Ubiquitous Computing Environment; Service-oriented; Context-aware; Trust; Direct trust; Recommendation trust; Adaptive trust; Adaptive security.DOI: 10.1504/IJAHUC.2016.10002303  High performance target tracking scheme with low prediction precision requirement in WSNs   by Anfeng Liu, Shaona Zhao Abstract: Tracking mobile target is one of the most important applications in wireless sensor networks for surveillance system. Researchers heavily believe that: selecting proactive nodes in the region where the target may arrive in the next moment can obtain good performances in terms of energy efficiency, tracking probability and tracking precision. However, it is a great challenge that how to predict the movement of a mobile target accurately. This paper proposed a high-performance tracking scheme with a low requirement of prediction accuracy (low prediction precision requirement target tracking, LPPT), which can work with a pre-existing target prediction algorithm. In LPPT scheme, the residual energy is employed to select more proactive nodes in the non-hotspots area, while less proactive nodes are selected in the hotspots area. Both theoretical and numerical simulation results show that the proposed scheme significantly improved the probability of target detection and energy efficiency, decreased the detection delay, meanwhile guaranteed the network lifetime. Keywords: wireless sensor networks; target prediction; sleep scheduling; network lifetime; energy efficient. A Cross-Layer Interference and Delay-aware Routing Metric for Infrastructure Wireless Mesh Networks   by Narayan D G, Uma Mudenagudi Abstract: In this paper, we propose a new cross-layer interference and delay aware routing metric for multi-radio infrastructure Wireless Mesh Networks (WMNs). WMNs are an emerging technology and are used as a backbone networks to connect various types of networks to the Internet. These networks use Multi-Channel Multiple Radio (MCMR) capabilities of mesh routers to achieve high performance. However, the MCMR nodes introduce inter-flow and intra-flow interference in the multi-hop mesh networks and can degrade QoS. Thus the design of routing protocols combined with routing metrics to improve the QoS has become an important research issue. Towards this, several cross-layer routing metrics have been proposed by considering types of interferences and other link quality parameters. However, most of these metrics have their own disadvantages and lack the analytical model in their design. To address this, we analytically derive our routing metric by using 802.11 Distributed Coordination Function (DCF) basic access mechanism. Using this model, we design and implement a routing metric called Cross-layer Interference and Delay Aware (CL-IDA) by estimating delay, inter-flow and intra-flow interference. We implement this metric in well known routing protocol Optimized Link State Routing (OLSR) using NS2. The results reveal that proposed routing metric performs better in terms of throughput, average end-to-end delay, routing overhead and route stability compared to well known routing metrics. Keywords: Wireless mesh networks; Multi-radio; Routing metrics; Cross-layer; CL-IDA.DOI: 10.1504/IJAHUC.2016.10002304  History Based Multi-Node Collaborative Localization in Mobile Wireless Ad Hoc Networks   by Wenyuan Chen, Songtao Guo, Fei Wang Abstract: Recent years have witnessed a growing interest in the study of localization algorithm for wireless ad hoc networks. In most localization algorithms, increasing the density of anchor nodes is one of the main strategies to improve the localization accuracy in dense networks. In this paper, based on the number of reference nodes, we propose a distributed localization algorithm, i.e., history based multi-node collaborative localization algorithm (HMCL), which provides a potential approach for localization in sparse ad hoc wireless networks. In the proposed HMCL algorithm, we exploit a new motion model to filter the imprecise estimation values based on the historical position information of nodes, which can improve the localization accuracy and reduce the computation overhead and energy consumption. Moreover, we utilize different strategies to achieve the localization of nodes with different priorities measured by the distance information between neighbor nodes.We verify through experiment that the proposed algorithm provides better performance in terms of localization precision and energy consumption. Besides, we also analyze the effect of the number of neighbor nodes, node density and moving speed of nodes on localization precision. Keywords: Wireless ad hoc networks; Collaborative Localization; Historical constraints; Neighbor information. A Low Complexity DWT module and CRS Minimal Instruction Set Computer Architecture for Wireless Visual Sensor Networks   by Jia Jan Ong, Li-Minn Ang Abstract: Transmitting cost, processing complexity and data security are three important elements in Wireless Visual Sensor Networks (WVSNs). This paper presents a complete low complexity processing system that performs data compression, data correction and data encryption. In this system, the Discrete Wavelet Transform (DWT) first decomposes the original image into DWT coefficients to ensure low transmitting cost, then the coefficients are encrypted using the Cauchy Reed Solomon CRS(20,16) coding scheme to ensure data security. A CRS Minimal Instruction Set Computer architecture with a DWT filtering module is proposed to perform the compression, encryption and error correction encoding in a low complexity processing system. The proposed system is then implemented in a field programmable gate array (FPGA) to demonstrate the feasibility of the proposed system for implementation in WVSNs. Results on a Xilinx Spartan FPGA show that the proposed system requires a lower implementation complexity of 2536 slices as compared to other existing systems such as Crypto-Processor (4828 slices) and SPIHT CRS MISC (5017 slices) Keywords: Wireless Visual Sensor Networks; Discrete Wavelet Transform; Cauchy Reed Solomon; Minimal Instruction Set Computer. TLS: Traffic Load Based Scheduling Protocol for Wireless Sensor Networks   by Prasan Kumar Sahoo, Hiren Kumar Thakkar Abstract: In Wireless Sensor Networks (WSNs), nodes are usually deployed over the monitoring region randomly and densely and are supposed tornmonitor the region for longer duration. These sensors are normally powered by battery and therefore it is essential to regulate the power utilization of the nodes efficiently. Although most of the current protocols reduce the power utilization by regulating the sleep and wake up schedules, they fail to make an adaptive sleep or wake up schedule for the nodes based on their traffic load. This article proposes a traffic load based adaptive node scheduling protocol to determine the active and sleep schedules of the nodes. The entire network is partitioned into set of virtual zones and a routing path selection algorithm is proposed considering the residual power of the next hop nodes. Simulation results show that the energy consumption and packet overhead of our protocol are considerably less as compared to similar quorum-based medium access control (MAC) protocols. Keywords: Wireless Sensor Networks; MAC protocol; scheduling. EFF-FAS: Enhanced Fruit Fly Optimization Based Search and Tracking By Flying Ad Hoc Swarm   by Vishal Sharma, Roberto Sabatini, Subramanian Ramasamy, Kathiravan Srinivasan, Rajesh Kumar Abstract: Flying an ad hoc swarm configuration refers to a network formed by autonomously operated robots. These robots can be simple aerial nodes or specifically configured Unmanned Aircraft (UA). The network formation between the aerial nodes allows for realizing a number of civil and military applications. Such networks are autonomous, temporary, and mission dependent, and are configured based on the specifications of the mission and safety-critical tasks. One of the major applications of these ad hoc swarm formations is the efficient search and tracking of an area without any redundancy and overlapping. Non-redundant cell tracking is a computationally expensive task, which requires optimization strategies to be adopted during a search process. Incorporating Fruit Fly Optimization Algorithm (FOA) to a strategic search and track operation simplifies the complexity of the overall system. In the proposed approach, FOA is extended in terms of its applicability by modifying the procedure and features of the algorithm to allow its applicability to an aerial swarm for performing a non-redundant search over a predefined area with lower complexity. Modeling and simulation activities presented demonstrate the effectiveness of the proposed approach towards search and track operations. Keywords: Ad Hoc Swarm; Searching; Tracking; Fruit Fly Optimization. Friend Circle Identification in Ego Network based on Hybrid Method   by Ma TingHuai, Fan Xing, Meili Tang, Donghai Guan Abstract: The ego network, which is a network of a user with his/her friends, is large-scale and tanglesome, and nowadays it is imperative to find a suitable method to automatically administrate it. The social network analysis method has provided some methods to help users classify their friends, including manually categorizing friends into social circles or system classification. Whereas, categorizing friends manually is time consuming for users and the results are not accurate enough. In this paper, we will discuss how to realize community identification automatically and accurately. To achieve this, we propose a method which utilizes not only the similarity of user attributes but also the features of network structure and friends contact frequency. On the basis of the users' profile, we identify the relationship between them firstly. Second, we solve the problem of community identification using of the structure features while profiles losing. Third, we introduce a concept, contact frequency, which will help us identify the relationship between users and their friends more accurately. Extensive experiments on real-world data show that our approach outperforms the state-of-the-art technique, in terms of balance error rate and F1 score. Keywords: ego networks; communities; user attribute; network structure; contact frequency. Delay-Tolerant Forwarding Strategy for Named Data Networking in Vehicular Environment   by Meng Kuai, Xiaoyan Hong, Qiangyuan Yu Abstract: Named Data Networking (NDN) has been considered as a promising networking architecture for Vehicular Ad-Hoc Networks (VANETs). However, Interest forwarding in NDN suffers severe issues in vehicular environment. Broadcast storms result in much packet loss and huge transmission overhead. Also, link disconnection caused by highly dynamic topology leads to low packet delivery ratio and extreme long delay in data retrieval. Thus, an efficient NDN forwarding strategy to retrieve data is urgently required. In this paper, we propose the Density-Aware Delay-Tolerant (DADT) Interest forwarding strategy to retrieve traffic data in vehicular NDN. DADT specifically addresses data retrieval during network disruptions using Delay Tolerant Networking (DTN). It makes retransmission decisions based on directional network density. Also, DADT mitigates broadcast storms by using a rebroadcast deferring timer. We compared DADT against other strategies through simulation and the results show that it can achieve a higher satisfaction ratio while maintaining low transmission overhead. Keywords: Density-Aware; Delay-Tolerant; Interest Forwarding; Named Data Networking; Vehicular Networks.DOI: 10.1504/IJAHUC.2017.10013072  Link-Preserving Channel Assignment Game for Wireless Mesh Networks   by Li-Hsing Yen, Bo-Rong Ye Abstract: To deliver user traffic in a wireless mesh network, mesh stations equipped with multiple interfaces communicate with one another utilizing multiple orthogonal channels. Channel assignment is to assign one channel to each interface to minimize co-channel interference among wireless links while preserving link connectivity. The interference and connectivity objectives are generally conﬂicting. This paper ﬁrst analyzes the probability of link connectivity when channels are randomly assigned to interfaces. We then propose a game-theoretic approach that jointly considers the two objectives with a uniﬁed payoff function. We prove that the proposed approach is an exact potential game, which guarantees stability in a ﬁnite time. We also prove the link-preserving property of the approach. Simulation results show that the proposed approach generally outperforms counterparts in terms of network interference when a moderate number of channels are available. For fairness of link interference, both the proposed approach and its variant outperform the counterparts. Keywords: channel assignment; wireless mesh network; interference; connectivity; game theory. Performance Analysis of truncated ARQ and HARQ I protocols for cooperative networks using Smart Amplify and Forward Relaying   by Nadhir Ben Halima, Hatem Boujemaa Abstract: In this paper, we evaluate the theoretical performance of truncated Automatic Repeat reQuest (ARQ) and Hybrid ARQ I protocols with and without packet combining in cooperative networks using smart amplify and forward relaying. In cooperative networks, the retransmission can be done by the source or by a selected relay. The selected relay is the one which offers the best instantaneous Signal to Noise Ratio (SNR) of the relaying link. We provide a theoretical framework when there is a combination of source and relays transmission for a destination using a Maximum Ratio Combining of the received packets from the source and the relays. Smart relays are studied in this paper. These relays selected the best packet from the source. We will show that the performance is better for smart relays that continuously supervise the transmissions from the source compared to conventional relays overhearing only the first source transmission. We also suggest smart relays listening to each other. Keywords: HARQ; Cooperative Systems; Amplify and Forward. Convex Hull Based Trajectory Design for Mobile Sink in Wireless Sensor Networks   by Kumar Nitesh Abstract: Data collection through mobile sink (MS) is an efficient solution to solve hotspot/sinkhole problem which is usually caused by data collection using a static sink In this paper, we propose an algorithm for designing a delay bound path for MS which is based on convex hull and therefore we refer it a concentric convex hull (CCH) algorithm For a given set of sensor nodes, the CCH generates a set of convex hull as the potential paths and selects one of them as the nal path for MS fulfilling certain optimizing criteria Unlike other existing techniques, the proposed technique does not use traveling sales person (TSP) tour This, in turn, reduces hop count and restricts the time complexity of the proposed technique to O(n^2) for n sensor nodes We simulate the proposed algorithm, compare and analyze the results with some of the existing algorithms over diverse network performance metrics. Keywords: Wireless sensor networks;  convex hull;  rendezvous points;  mobile sink;  delay bound path;  computational geometry.DOI: 10.1504/IJAHUC.2017.10006693  Efficient two-party certificateless authenticated key agreement protocol under GDH assumption   by Xie Yong Abstract: Security and Efficiency are two key requirements for most of authentication protocol, especially for mobile wireless network. However, Security and efficiency are a contradiction for the design of authentication protocol, it is hard to meet the two requirements simultaneously. Since certificateless public key cryptography (CL-PKC) has an advantage in wiping off key escrow problem, many certificateless authentication key agreement (CL_AKA) protocols have been proposed. The existing CL_AKA protocols may meets security requirement well or efficiency requirement well, but cannot meet the two well. In this paper, we propose an efficient two-party CL_AKA protocol with strong security. we perform an in-depth security analysis in extended Canetti-Krawczyk (eCK) model to show the proposed CL_AKA protocol is provably secure. The performance analysis shows that the proposed protocol can meet the strong security and efficiency requirements simultaneously. Keywords: Authentication key agreement,CL-PKC,pairing-free,GDH,eCK model.DOI: 10.1504/IJAHUC.2017.10006694  Resource-Constrained Task Assignment for Event-Driven Sensing Using Public Bicycles in Smart Cities   by Chiu-Ping Chang Abstract: Many cities have provided public bicycle services to reduce traffic congestion and air pollution. Mobility of public bicycles makes them very suitable for event-driven sensing for smart cities, i.e. collecting data relevant to special events such as car accidents or street parades. The problem is how to assign a set of bicycles to best fulfill the sensing mission, considering the constrained storage, battery energy, and communication capability of bicycles. The problem is referred to as the resource-constrained task assignment for event-driven sensing (ReConTAES). The goal is to minimize the number of bicycles used, while balancing the energy consumption of the selected bicycles. We first formulate the problem as a mixed integer programming and then propose a set of greedy heuristics to solve the problem. We evaluate the proposed algorithms by using real trajectories to show their feasibility. Keywords: smart city; urban sensing; data collection; Public Bicycle System(PBS)  .DOI: 10.1504/IJAHUC.2017.10006695  MAP: Ef?cient Cooperation Induced Routing Scheme for a Delay Tolerant Multi-hop Mobile Network   by Oladayo Olakanmi Abstract: In multi-hop network the efficiency of the transmission depends solely on the cooperation of all nodes in the network in relaying neighbouring nodes data packets. Some nodes may be selfish, mischievous by dropping received packets or refuse to accept packet from other nodes whereas using other nodes resources to transmit their packets. This drastically affects the performance of the network. In this paper, a fair and effective incentive mechanism, which induces cooperation among nodes in the network is proposed. The mechanism applies auction scheme by initiating auction between the node and its immediate neighbouring nodes. The neighbouring node(s) competitively purchase packet transmission liability from the source and re-auctions it to the neighbouring node. The scheme uses hash operations to secure the payment transaction made in each auction session. The performance characterisation and evaluation against fairness and some possible attacks demonstrated that the scheme strongly stimulates fairness and competitiveness in message relaying among the intermediary nodes unlike other routing based schemes. The simulation results showed that there are some other performance metrics which are needed to be considered in order to have an optimum performance. Keywords: Multi-hop; auction policy; competitve backpressure;; wireless network;routing;protocol;  network; wireless.DOI: 10.1504/IJAHUC.2017.10006696  Dynamic Utility-Based Buffer Management Strategy for Delay-tolerant Networks   by Ababou Mohamed Abstract: Delay tolerant network is a new networking concept characterized by intermittent connections between nodes communicating through the store-carry-and-forward mechanism. Indeed, the nodes may keep a message in its buffer for long periods until a communication opportunity occurs and then to transmit it to other relays or to its final destination. Accordingly, the use of many messages can induce buffer congestion of some nodes due to the limited capacity of the storage space. To manage properly the use of network resources, particularly bandwidth and buffer space of nodes, we propose in this paper a new buffer management strategy which consists of messages scheduling and dropping policies based on a multi-criteria utility function. The simulations results under the ONE simulator have shown that the proposed buffer management strategy achieves a higher delivery ratio, reduces the average delivery delay and generates minimal overhead when compared to the Random, MOFO and FIFO usual strategies. Keywords: DTN; Buffer Management; Delivery; Scheduling Policy; Dropping Policy; Utility.DOI: 10.1504/IJAHUC.2017.10006697  On the Performance Analysis of Wireless Communication Systems over ∞-µ/∞-µ Composite Fading Channels   by Osamah Badarneh Abstract: The ∞-µ/∞-µ fading channel model is the result of the product of two independent and nonidentically distributed (i.n.i.d.) ∞-µ variates. As such, in order to study the performance of wireless communication systems in such fading model, the envelopes of the probability density function (pdf) and cumulative distribution function (cdf) must be obtained. To this end, simple and general closed-form expressions for the pdf and cdf of the product of two independent and non-identically distributed (i.n.i.d.) ∞-µ variates are obtained. Then based on these expressions, we derive closed-form expressions for the outage probability, the average symbol error probability (SEP) and the nth moment of the signal-to-noise ratio (SNR), and the ergodic channel capacity. The derived expressions are then used to analyze the performance of a wireless communication system. Analytical results are sustained through Monte-Carlo simulations, and a perfect match is reported over a wide range of SNR values and for several values of fading parameters. Keywords: Composite fading channels; multi-path fading; shadowing; ∞-µ distribution.DOI: 10.1504/IJAHUC.2017.10006698  Dynamic Group-based Scheduling of Machine-to-Machine Communication for Uplink Traffic in LTE Networks   by Yen-Yin Chu Abstract: In wireless machine-to-machine communication, the signaling load and radio resource allocation are critical to successful service because the technology features a large number of connected devices that introduce significant connection- and resource-related signaling overheads to eNodeB. This paper proposes an uplink scheduling scheme to minimize signaling overhead and maximize system throughput in machine-type communication devices in long-term evolution networks. The proposed scheme dynamically adjusts group members by considering channel conditions and quality of service and applies the allocation-before-request concept to allocate the residual bandwidth and realize the above objectives. Exhaustive simulations were conducted to examine the performance of the proposed scheme. The simulation results showed that the proposed scheme achieves not only better system throughput but also decreased buffer status report signaling when compared with the static group-based scheme. Keywords: buffer status report; channel conditions; long-term evolution; machine-to-machine; resource allocation.DOI: 10.1504/IJAHUC.2017.10006699  On the Parallel Programmability of JavaSymphony for Multi-cores and Clusters   by Muhammad Aleem Abstract: This paper explains the programming aspects of a promising Java-based programming and execution framework called JavaSymphony. JavaSymphony provides unified high-level programming constructs for applications related to shared, distributed, hybrid memory parallel computers, and co-processors accelerators. JavaSymphony applications can be executed on a variety of multi-/many-core conventional and data-parallel architectures. JavaSymphony is based on the concept of dynamic virtual architectures, which allows programmers to define a hierarchical structure of the underlying computing resources and to control load-balancing and task-locality. In addition to GPU support, JavaSymphony provides a multi-core aware scheduling mechanism capable of mapping parallel applications on large multi-core machines and heterogeneous clusters. Several real applications and benchmarks (on modern multi-core computers, heterogeneous clusters, and machines consisting of a combination of different multi-core CPU and GPU devices) have been used to evaluate the performance. The results demonstrate that the JavaSymphony outperforms the Java implementations, as well as other modern alternative solutions. Keywords: Parallel programming; Java; Multi-core Scheduler; GPU computing.DOI: 10.1504/IJAHUC.2017.10006700  An Efficient Node Deployment Method for Indoor Passive Localization   by Jinjun Liu Abstract: Most existing studies on device-free indoor localization aim to improve localization performance by deploying a large number of sensor nodes in indoor environments, thereby resulting in high hardware cost, more energy consumption and other drawbacks. This paper proposes a wrapper, heuristic and sensor-based node deployment method, which reduces the number of deployed sensors while achieving a high localization accuracy by selecting the fittest link feature subset in localization datasets. The performance results reveal that the proposed method outperforms existing work in terms of the number of deployed nodes, consequently can greatly thins out the extra nodes, shortens the localization response time and saves energy. Furthermore, the method can easily adjust the number of specific nodes by flipping the coefficient ratio of transmitters and receivers in fitness function. Keywords: Indoor passive localization; Node deployment; Localization response time; Energy consumption.DOI: 10.1504/IJAHUC.2017.10006701  Acoustic Energy-based Sensor Localization With Unknown Transmit Energy Levels   by Xiaoping Wu Abstract: When the transmit energy levels are unavailable, semidefinite programming (SDP), mixed second order cone programming and semidefinite programming (SOC/SDP) and the linear least square estimator with source-anchor measurements (LLS-SA) are proposed to estimate the source locations in the wireless sensor networks. The proposed three algorithms avoid the shortcoming of the maximum likelihood (ML) estimator which requires the initial solution guess to ensure the global convergence. By relaxing the acoustic energy-based localization model into convex optimization, the SDP, SOC/SDP algorithms provide the robust solutions to the source location estimates for the cooperative localization. The non-cooperative LLS-SA represents the source location estimates as algebraic closedform solutions which are further improved by using location refinement (LR) technique. The simulations show that the convex optimization algorithms including the SDP and SOC/SDP provide more robust solutions to the source location estimates compared with the linear estimator of LLS-SA. However the proposed LLS-SA runs faster than the SDP and SOC/SDP. The accuracy performance of the designed SOC/SDP is similar to that of the SDP, but the complexity of the SOC/SDP is greatly lower than that of the SDP for the same network configuration. Keywords: wireless sensor networks; sensor localization; acoustic energy-based; convex optimization.DOI: 10.1504/IJAHUC.2017.10006702  Amazon Cloud Computing Platform EC2 and VANET Simulations   by Muhammad Aleem Abstract: Network simulations are resource and time intensive tasks due to the involvement of a number of factors attributable to scalability with respect to computation time, cost, and energy. Keywords: Academic Clouds; VANET Simulations; Amazon EC2; Large-scale Simulations.DOI: 10.1504/IJAHUC.2017.10006703  A Hybrid Intelligent Control based Cyber-Physical System for Thermal Comfort in Smart Homes   by Jiawei ZHU Abstract: With the fast development of human society, as environmental issues have drawn incomparable attention, energy efficiency is playing a significant role in residential buildings. Meanwhile, spending more time in homes leads people to constantly improve comfort there. Considering the fact that space heating makes a great contribution to residential energy consumption and thermal comfort, this paper presents a novel hybrid intelligent control system to manage space heating devices in a smart home with advanced technologies to save energy while to increase thermal comfort level. The approach combines a meta-heuristic algorithm used to compute a setpoint from the Predicted Mean Vote model with a Proportional-Integral-Derivative controller for indoor temperature regulation. In order to validate the system, computer simulations are conducted and analyzed. The results indicate the proposed control system can provide better thermal comfort comparing with other conventional and intelligent control methods, and consume less energy when demand response is considered. Keywords: thermal comfort; demand response; smart home; cyber-physical system; particle swarm optimization.DOI: 10.1504/IJAHUC.2017.10006704  A Smart Proactive Routing Protocol in Cognitive Radio Networks   by Mahsa Soheil Shamaee, Mohammad Ebrahim Shiri, Masoud Sabaei Abstract: In this paper, we propose a smart proactive routing protocol based on Q-learning to find the most stable routes which impose minimum interference on the primary users. Unlike the traditional proactive routing protocols, in our proposed method, control packets are not broadcast whenever the network topology changes. Indeed, we apply a generalized version of Q-learning to predict the model of the routes stability. This model is used to prevent the floods of state information that is ineffective for routing decisions. The frequency of changes in the model is much less than that in the network topology. In our protocol, secondary users broadcast control packets with any changes in the model which reduces the routing overhead. The simulation results show that our routing protocol outperforms the existing ones in terms of throughput and the imposed interference on the primary users' spectrum as well as overhead. Keywords: Proactive Routing; Routes Stability; Control Overhead; Q-learning; Reinforcement Learning; Cognitive Radio; Primary Users; Secondary Users; Opportunistically Access; Channel Availability. Farmland Multiparameter Wireless Sensor Network Data Compression Strategy   by Feifei Li Abstract: A certain correlation exists among farmland wireless sensor network(WSN) monitored parameter data. Analyzing and utilizing parameter correlation can improve data compression efficiency and reduce network communication power. A data compression algorithm for multi-parameter farmland WSN is proposed. Firstly, a compression matrix of each cluster is built up based on clustering analysis among parameters and internal correlation analysis between categories. Then the parameter sorting scheme is determined based on the structured matrix which had strong correlation among rows and columns. It conducted characteristic analysis of parameter sequences. Operators between parameters are built in order to enhance the correlation and reduce high-frequency component of the matrix. By doing these the information loss during compression process could be reduced, and realized the goals of elevating compression ratio and reducing compression errors. Compression test shows that the proposed algorithm can effectively reduce network data redundancy and energy consumption. Keywords: wireless sensor network; data compression; correlation between parameters; wavelet transform.DOI: 10.1504/IJAHUC.2017.10007545  A Scalable Middleware for Context-aware Mobile Applications   by Loris Belcastro, Fabrizio Marozzo, Paolo Trunfio Abstract: A core functionality of context-aware mobile applications is storing, indexing, and retrieving information about users, places, events and other resources. The goal of this work is to design and provide a service-oriented middleware, called Geocon, which can be used by mobile developers to implement such functionality. To represent information about users, places, events and resources of context-aware applications, Geocon defines a metadata model that can be extended to match specific application requirements. The middleware includes a geocon-service for storing, searching and selecting metadata about users, resources, events and places of interest, and a geocon-client library that allows mobile applications to interact with the service through the invocation of local methods. The paper describes the Geocon middleware and presents an experimental evaluation of its scalability on a cloud platform with a real-world mobile application. Keywords: Context-aware; Mobile applications; Middleware; Scalability; Cloud computing. A new Scheme for RPL to handle Mobility in Wireless Sensor Networks   by Leila Ben Saad Abstract: Mobile wireless sensor networks are characterized by dynamic changes in the network topology leading to route breaks and disconnections. The IPv6 Routing Protocol for Low power and lossy networks (RPL), which has become a standard, uses the Trickle timer algorithm to handle changes in the network topology. However, neither RPL nor Trickle timer are well adapted to mobility. This paper investigates the problem of supporting mobility when using RPL. It enhances RPL to t with sensors' mobility by studying two cases. Firstly, it proposes to modify RPL in order to t with a dynamic and hybrid topology in the context of medical applications. Secondly, it investigates a more general case and introduces a new adaptive timer for RPL. The proposed approach is validated through extensive simulations and compared with existing protocols in the literature. Results show that our proposal signi cantly reduces disconnections and increases packet delivery ratio while maintaining low overhead. Keywords: Wireless sensor networks; RPL protocol; Node mobility; Trickle timer.DOI: 10.1504/IJAHUC.2017.10008392  Automatic String Deobfuscation Scheme for Mobile Applications Based on Platform-level Code Extraction   by WooJong Yoo, Minkoo Kang, Myeongju Ji, Jeong Hyun Yi Abstract: The Android operating system is vulnerable to various security threats owing to structural problems in Android applications. String obfuscation is one of the required protection schemes developed to protect Android application code. However, string obfuscation is being thwarted by malware makers and malware analysis is becoming more difficult and time-consuming. This paper proposes an automatic string deobfuscation and application programming interface (API) hiding neutralisation scheme that requires no encryption algorithm analysis or encryption key information. The proposed scheme has its own independent obfuscation tool. Further, it extracts and analyses code from the Android platform while the application is being executed and inserts only a return string value from the extracted code into the DEX file. The results of experiments conducted, in which commercial obfuscation tools Allatori, DexGuard, and DexProtector were applied to sample applications, verify the efficacy of the proposed method. Keywords: Reverse Engineering; Deobfuscation; Mobile Malware; Android;. ACFC: Ant Colony with Fuzzy Clustering Algorithm for Community Detection in Social Networks   by Marjan Naderan, Marjan Naderan, Seyed Enayatollah Alavi Abstract: In this paper, we suggest a bipartite algorithm, namely ACFC, for finding communities in social networks. First, we use artificial ants to traverse the network modeled by a graph based on a set of rules to find a "good region" of edges. Next, we construct the communities after which local optimization methods are used to further improve the solution quality. Finally, we use the Fuzzy C-Means (FCM) clustering algorithm to fine tune the result. In our method ants are only used to identify good regions of the search space and construction methods are used to build the final solution. Experimental results on several synthetic graphs and four real world social networks compared to six other well-known methods show that our ACFC algorithm is very competitive against current state-of-the-art techniques for community detection and it is more accurate than existing algorithms as it performs well across many different types of networks. Keywords: Community Detection; Social Networks; Ant Colony; Q modularity; Fuzzy Clustering.DOI: 10.1504/IJAHUC.2017.10008798  An Adaptable CS-Based Transmission Scheme in Wireless Sensor Network   by Hao Yang, Keming Tang Abstract: As the essential requirement of wireless sensor network, energy-efficient data transmission has been paying a lot attention. Compressive Sensing(CS) has been currently utilized to save consumption of sensors. However, a vital problem still remains unclear that whether the execution costs of sensors employing CS is not worth being considered, motivating us to explore the answer from a point of real deployment platform view. Presenting observations from our operating sensor network, we verify two important facts: 1) The power costs of measure processing of sensors cannot be negligible as the increasing of samplings. 2) Measurements will constantly change along the routing and force relay sensors to consume more. Based on our findings, we propose an adaptable CS-based transmission scheme, ACS. With our experiments, energy is economized at least 15%. Our work gives a potential guideline for future designs of WSN in practice. Keywords: Compressive sensing; Data transmission; Adaptable transmission; Wireless sensor network. Energy Aware Optimal Slot Allocation Scheme for Wearable Sensors in First Responder Monitoring Systemby Mahin K. Atiq, Kashif Mehmood, Muhammad Tabish Niaz, Hyung Seok Kim Abstract: In recent advances in first response techniques, the uniform of each first responder working at the emergency field may be equipped with sensors and a gateway. These wearable sensors in conjunction with the gateway constitute a first responder monitoring system (FRMS). FRMS gathers data about the first responders's vitals and the surrounding environment, which is then transmitted to the incident commander. For the energy-constrained nature of the FRMS, an energy-ecient slot allocation scheme is proposed. The energy-ecient scheme involves the design of an optimal slot allocation scheme based on Hungarian algorithm for sensor data collection and an energy-aware sensing and transmission scheme for sensor nodes. Simulation results demonstrate the superiority of proposed scheme in terms of lifetime, residual energy, and energy delay product as compared to greedy and first-in-first-out (FIFO) slot allocation schemes. Keywords: Slot allocation; Hungarian algorithm; Sensing and transmission scheme; Wearable sensor systems; First responder monitoring. A Statistical Detection Mechanism for Node Misbehaviors in Wireless Mesh Networks (WMNs)   by Rida Khatoun Abstract: Wireless mesh networks (WMNs) have become an increasingly popular wireless networking technology for establishing the last-mile connectivity for home and neighbourhood networkings. In such networks, packet dropping may be due to either an attack, or normal loss events such as bad channel quality. Furthermore, in the route discovery phase, path stability is not always considered. We consider a special case of denial of service (DoS) attack in WMNs known as the greyhole attack. In this attack, a node selectively drops some packets which it has to forward along the path. To mitigate this attack, we propose a dropping detection mechanism allowing a mobile node to select a most reliable route to the destination. Our detection module detects misbehaving nodes by comparing the observed packet loss distribution of nodes to the expected ones when they are well-behaved. We validate the proposed approach via extensive simulations through R software and Matlab. Keywords: Wireless Mesh Networks; Misbehavior; Detection.DOI: 10.1504/IJAHUC.2017.10009416  Malicious User Detection with Local Outlier Factor during Spectrum Sensing in Cognitive Radio Network   by Suchismita Bhattacharjee Abstract: In collaborative sensing, multiple secondary users (SUs) cooperate for a more accurate sensing decision to detect spectrum holes in cognitive radio networks (CRNs). This technique, however, can be adversely affected by malicious users (MUs) who route falsified spectrum sensing data to the fusion centre (FC). This attack is known as the spectrum sensing data falsification (SSDF) attack. The task of the FC is to aggregate local sensing reports and is thereby responsible for making the final sensing decision. In this paper, we propose a detection and isolation scheme based on local outlier factor (LOF) to detect and reduce the unfavourable effects of SSDF attack. The key feature of this scheme is that for each SU a metric is calculated, which is called the LOF. Based on the LOF, a decision is made about whether an SU is an attacker or not. We support the validity of the proposed scheme through extensive simulation results. Keywords: Cognitive Radio Networks; Local Outlier Factor; Collaborative Spectrum Sensing; SSDF Attack; Independent Attack; Colluding Attack; Fusion Center.DOI: 10.1504/IJAHUC.2017.10009417  A Critical Review of Quality of Service Models in Mobile Ad hoc Networks   by Nadir Bouchama, Djamil Aïssani, Natalia Djellab, Nadia Nouali-Taboudjemat Abstract: Quality of service (QoS) provisioning in mobile ad hoc networks (MANETs) consists of providing a complex functionality in a harsh environment where resources are scarce. Thus, it is very challenging to build an efficient solution to address this issue. The proposed solutions in the literature are broadly classified into four categories, namely: QoS routing protocols, QoS signalling, QoS-aware MAC protocols and QoS models, which are the main concern of our study. The contribution of this paper is threefold: Firstly,wepropose a set of guidelines to deal with the challenges facing QoS models design in ad hoc networks. Secondly, we propose a new taxonomy for QoS models in ad hoc networks. Finally, we provide an in-depth survey and discussion of the most relevant proposed frameworks. Keywords: Mobile ad hoc networks; Quality of service; IntServ; DiffServ; QoS models; QoS routing; Hard QoS; Soft QoS.DOI: 10.1504/IJAHUC.2017.10009418  Detection of Malicious Packet Dropping Attacks in RPL-based Internet of Things   by Sooyeon Shin, Kyounghoon Kim, Taekyoung Kwon Abstract: The Internet of Things (IoT) may involve a large number of devices highly constrained in their resources in terms of power, memory, computation, and communication. To cover an increasing number of IoT devices, the IPv6 paradigm is essentially required. RPL (Routing Protocol for Low-Power and Lossy Networks) is an IPv6-based routing protocol optimized for IoT environments and it supports a powerful and flexible routing framework for a variety of application scenarios of IoT. However, it is susceptible to various security threats including a malicious packet dropping attack, which uses internal compromised nodes to threaten the operation of network. If a node with a lower rank closer to the root node attempts a malicious packet dropping, it may disrupt basic data transmission, or even the entire IoT application service. In this paper, we present a novel detection method for malicious packet dropping attacks against RPL-based networks. The proposed method is based on the anomaly IDS approach and detects a malicious packet dropping in the presence of normal packet losses caused by collisions or channel errors. We evaluate the performance of the proposed method on Contiki's network simulator, Cooja. The evaluation results show that it has good performance to detect malicious packet dropping attacks in the RPL-based networks. In every case, the successful detection rate is more than 94% and the false alarm rate is less than 3%. Keywords: Internet of Things; IPv6; RPL; 6LowPAN; Packet Dropping; Detection; ContikiOS; Cooja simulator. GPU-based distributed bee swarm optimization for dynamic vehicle routing problem   by Maroua Grid, Noureddine Djedi, Salim Bitam Abstract: Nowadays, there is still a large gap between the requirements and the performance of decision support systems for many problems such as the vehicle routing problem, consists in conceiving a set of optimal routes for a fleet of vehicles, aiming at serving a given number of customers. Nevertheless, new customer orders could be introduced while a prior plan is in progress. Therefore, routes should be recalculated in a dynamic way. In this paper, we propose a new parallel combinatorial optimization method based on Graphic Processing Unit (GPU) called Parallel Bees Life Algorithm (P-BLA) to solve efficiency the Dynamic Capacitated vehicle routing problem (DCVRP) in terms of execution time, and to reduce computational complexity often considered as the major drawback of conventional optimization methods. P-BLA is developed using CUDA framework performed on island-based GPU. After a set of comparisons against conventional methods namely; genetic algorithm, ant system, Tabu search and sequential BLA, P-BLA has provided efficient results reached from the most tested DCVRP benchmarks. Keywords: DCVRP; k-means; P-BLA; Parallel optimization; GPGPU. Linear Closed-Form Estimator for Sensor Localization Using RSS and AOA Measurements   by Jian Zhang Abstract: Using the hybrid received signal strength (RSS) and angle of arrival (AOA) measurements, a position estimation model is proposed for senor localization in three-dimensional plane. Then the unconstraint linear least square (ULLS) estimator is designed to obtain a closed-form solution to the positions of source nodes by considering the known transmit power. To improve the accuracy performance of the ULLS estimator, the constraint linear least square (CLLS) estimator is introduced by utilizing the constraint condition. When the transmit power is unavailable, a global linear least square (GLLS) estimator is also put forward to estimate the positions of source nodes along with the transmit power. The simulations show that the computational complexity of the proposed linear estimators is greatly lower than that of the convex semidefinite programming (SDP) method. When the measurement noises are small, the linear ULLS, CLLS and GLLS estimators perform better than that of the SDP method. Due to the exploiting of constraint condition, the accuracy performance of the CLLS estimator can approach the Cram'{e}r-Rao Lower Bound (CRLB) of position estimation. Keywords: Wireless sensor networks (WSNs); localization; received signal strength (RSS); angle of arrival (AOA); linear least square. Reverse-biform Game based Resource Sharing Scheme for Wireless Body Area Networks   by Sungwook Kim Abstract: Current advances in wireless sensor technologies have contributed to the development of Wireless Body Area Network (WBAN). It has been considered for applications in medical, healthcare and sports fields. Due to specific features and reliability requirements in WBAN, a number of new challenges have been introduced to design novel WBAN protocols. In order to cope with these challenges, game theoretic approach can allow WBANs to improve their performance while increasing their flexibility and adaptability. In this paper, we develop a new WBAN resource sharing scheme based on the reverse-biform game model. Based on the dual-level phases, the limited WBAN resource is effectively shared by employing a coordinate-and-competitive game manner. In particular, we consider the unique features of WBAN applications, and provide a generalized solution for the resource sharing problem. The simulation results demonstrate that our game-theoretic framework can provide the ability to practically respond to current WBSN conditions. This approach is suitable for real WBAN operations, particularly for the energy efficiency, network throughput, and QoS provisioning. Keywords: Wireless body area networks; Power control algorithm; Data-tuning mechanism; Quality of Service; Reverse-biform game. Implementation of an Autonomous Intelligent Mobile Robot for Climate Purposes   by Mohammad Samadi Gharajeh Abstract: One of the main requirements in humans lifecycle is to predict environmental situations (e.g., pollution density) over various areas. Since determining the climate information by using traditional electromechanical devices is very expensive, autonomous robots can be used to organize this mission. This paper proposes an autonomous intelligent mobile robot for climate purposes, called ClimateRobo, to notify the weather condition based on environmental data. An ATmega32 microcontroller is used to measure temperature, gas, light intensity, and distance to obstacles using the LM35DZ, MQ-2, photocell, and infrared (IR) sensors. A utility function is proposed to calculate the weather condition according to the temperature and gas data. Afterwards, the weather condition will be monitored on a liquid crystal display (LCD), an appropriate light-emitting diode (LED) will be illuminated, and an audio alarm would be enabled when weather condition is emergency as well as ambient brightness is high. The ambient brightness is calculated by a proposed supervised machine learning using sensed data of the photocell sensor. A fuzzy decision system is proposed to adjust the speed of DC motors based on weather condition and light intensity. The robot can detect and pass stationary obstacles with the six reflective sensors installed in the left, front, and right sides under six detection scenarios. Simulation results show performance of the proposed supervised machine learning, fuzzy decision system, and obstacle detection mechanism under various simulation parameters. The robot, initially, is simulated in the Proteus simulator and, then, is implemented by electronic circuits and mechanical devices. It would be used in the future by bureau organizations, rescue teams, etc. Keywords: Autonomous Intelligent Robot; Weather Condition; Utility Function; Supervised Machine Learning; Fuzzy Decision System; Sensor. Trust Management in Vehicular Ad hoc Networks: a survey   by Ilhem Souissi, Nadia Ben Azzouna, Tahar Berradia Abstract: The vehicular ad hoc networks (VANETs) provide a variety of applications that aim to ensure a safe and comfort driving experience. These applications rely on the communication and the exchange of data between vehicles. These entities are exposed to many security threats that may affect the reliability of the provided applications. Accordingly, there is a need for a trust management scheme that has to cope with the security threats and the high dynamicity of the network topology. In this paper, we survey the recent advances in trust management for VANETs. The aim of this paper is to show the importance of an adaptive trust model that can deal with the requirements of each class of applications. Therefore, we have presented well-defined criteria to point out the key issues of the existing studies and to set up some insights for research within this scope. Keywords: VANET; security; trust management; attacks; reputation; similarity; behavior; utility. Multi-constraint Zigbee Routing to Prolong Lifetime of Mobile Wireless Sensor Networks   by Chhagan Lal, Pallavi Kaliyar, Chotmal Choudhary Abstract: Due to the recent developments in hardware technology and deployment techniques, Mobile Wireless Sensor Networks (MWSNs) are attracting a large array of real-world applications. However, practical realization of these applications is still constrained due to inherent characteristics of MWSNs such as highly dynamic topology, low bandwidth, and finite energy of nodes. These characteristics causes threat to MWSNs basic functionalities, which includes network formation, self-organization, route discovery, and communication management. Hence, improving the lifetime of MWSNs, and minimizing the mobility induced route breaks are the key issues in MWSNs. Zigbee is an advanced technology that works on IEEE standard 802.15.4 and it is suitable for contrainted networks such as MWSNs as well. The main features of Zigbee such as low energy and network bandwidth consumption, and lower deployment cost greatly helps to prolong network lifetime in MWSNs. To this end, in this paper, we propose a multi-constraint Zigbee based Reactive Routing (MZRR) protocol for MWSNs to prolong the network lifetime. Our MZRR protocol uses node energy and hop-to-hop transmission efficiency along with network mobility as metrics during its route discovery process to discover highest remaining lifetime routes. MZRR protocol ensures that the discovered routes has high transmission efficiency which leads to low energy and link bandwidth consumption in the network. By keeping the energy utilization of sensors balanced, MZRR protocol avoids the dead zones in the surveillance areas, this could be very important in data-critical applications. We fully implement MZRR protocol on NS-3 simulator, and the results obtained are compared with traditional AODV and state-of-the-art routing algorithms in terms of relevant parameters such as energy consumption, end-to-end delay, packet delivery ratio, network life-time and network routing overhead. Keywords: Wireless Sensor Network; Zigbee; Energy Efficiency; Network Mobility; Link Lifetime; IEEE 802.15.4. Reliable Sense Maintenance Scheme by Sense Holes Recognized and Self-healing in Sensor Networks of Internet of Things   by J.U.N. LIU, Xu Lu, Tao Wang Abstract: Sense holes recognized and repaired in sensor networks have important significance for sense performance. Most of the existing researches are based on the assumption that the sensor can provide the location or other ideal condition. In this paper, a distributed reliable sense maintenance scheme by sense holes recognized and self-healing was presented. Firstly, it reduced the required nodes density limit to maintain a reliable sense by mathematical analysis. Then, sense holes recognized algorithm based on the Hamiltonian graph and computation geometry was proposed in this paper. It could identify triangular holes and realize a good recognition rate without an accurate position. Based on virtual forces strategy, sense holes self-healing algorithm was presented. Simulation results showed the algorithm was superior to others in energy-balancing. The sense holes recognized algorithm could efficiently and quickly detect sense holes in sensor networks as shown in simulations. Keywords: Sensor networks; Sense hole recognized; Self-healing; Nodes deployment. Application of Congestion Avoidance Mechanism in Multimedia Transmission over Mesh Networks   by Biaokai Zhu, Jumin Zhao, Deng-ao Li, Ruiqin Bai Abstract: The unreliable nature and shared multi-media of multi-hop communications cause the deployment of multi-media applications in wireless mesh network a thorny problem. For instance, video is usually compressed into a group of frames before transmission, resulting in unrecoverable destruction during the display process. The importance of different frames' type is quite different. However, they are considered as same in most existing wireless mesh networks. In this paper, we propose a novel Congestion Avoidance Mechanism for multimedia transmission over 802.11e mesh networks. In our mechanism, we added priority for video packets. According to the significance of frames, we proposed an adaptive mechanism involves the mapping of H.264 video packets to appropriate access categories in IEEE 802.11e standard. Simulation results show that our mechanism improves Quality of Service (QoS) of multimedia transmission.rn Keywords: Multimedia transmission; 802.11e; wireless mesh network. Efficient Data Dissemination Approach For QoS Enhancement in VANETs   by Sachin Khurana, Gaurav Tejpal, Sonal Sharma Abstract: Vehicular ad hoc networks (VANETs) have seen tremendous growth in the last decade, providing a vast range of applications in both military and civilian activities. The temporary connectivity in the vehicles can also increase the driver's capability on the road. However, such applications require heavy data packets to be shared on the same spectrum without the requirement of excessive radios. Thus, efficient approaches are required which can provide improved data dissemination along with the better quality of services to allow heavy traffic to be easily shared between the vehicles. In this paper, an efficient data dissemination approach is proposed which not only improves the vehicle to vehicle connectivity but also improves the QoS between the source and the destination. The proposed approach is analyzed and compared with the existing state-of-the-art approaches. The effectiveness of the proposed approach is demonstrated in terms of the significant gains attained in the parameters namely, end to end delay, packet delivery ratio, route acquisition time, throughput, and message dissemination rate in comparison with the existing approaches. Keywords: VANETs; delay; QoS; Data Dissemination; Fuzzy sets. A Challenge-Response Mechanism for Securing Online Social Networks against Social Bots   by Mohamed Torky, Ali Meligy, Hani Ibrahim Abstract: Social bots is fast becoming a serious security threat to Online Social Networks (OSNs). Social bots are automated software tools able to execute malicious activities in OSNs systems in an automated fashion. It can perform auto-sharing and posting, sending fake friend requests, harvesting private information, etc. There is evidence that social bots play a crucial role in penetrating privacy and security of social networks. Hence, these malicious software tools represent a big security challenge against Social Network Service Provider (SNSP). In this paper, we introduce a novel anti-bot mechanism called Necklace CAPTCHA for securing OSNs platforms against the automated behaviors of social bots. Necklace CAPTCHA is an Image-based CAPTCHA, which utilizes the functionality of Necklace Graph approach to generate its challenge-response tests in a novel fashion. The results demonstrated that Necklace CAPTCHA is an effective and secure anti-bot mechanism compared with other CAPTCHAs in the literature with respect to the usability and security metrics. Keywords: Online Social Networks (OSNs); Security and Privacy; System Usability; Social Bots ; CAPTCHA; Necklace Graph. Design of a Monitoring and Safety System for Underground Mines Using Wireless Sensor Networks   by Coert Jordaan, Reza Malekian Abstract: A mine safety system using a wireless sensor network is implemented. Sensor nodes and a monitoring system are developed to be used in the underground mining environments. Investigations are done into sensor design for underground mines, as well as the use of sensors to profile the underground mining environment and the use of wireless communication in the underground mining environment. The information is used to design and implement a robust hardware-based sensor node with standalone microcontrollers that sample data from six different sensors, namely temperature, humidity, airflow speed, noise, dust and gas level sensors, and transmit the processed data to a graphical user interface, developed using Qt Creator. The system reliability and accuracy is tested in a simulated mine. The wireless mine profiling sensor node, with its monitoring software and receiver unit was successfully implemented. It provided linear and accurate results over nearly a month of daily testing in the simulated mine. It is observed that critical success factors for the wireless sensor node is its robust design, which does not easily fail or degrade in performance. The node also has strong, self-adaptive networking functionality, to recover in the case of a node failure. Keywords: Mine safety system; wireless sensors; temperature sensor; humidity sensor; airflow speed sensor; noise sensor; dust sensor; gas sensor; error detection. Signal Technique for Friend or Foe Detection of Intelligent Malicious User in Cognitive Radio Network   by Saifur Rahman Sabuj, Masanori Hamamura Abstract: To address spectrum scarcity, cognitive radio networks have been proposed as a means to improve spectrum utilization and effciency. In regulation policy for cognitive radio networks, unlicensed users (secondary users) are allowed to utilize unoccupied spectrum when it is not being used by licensed users (primary users). In point of fact, security issues arise when intelligent malicious users can attack cognitive radio networks and decrease the permitted channel for secondary users. In this paper, we propose a novel scheme, based on friend or foe (FoF) detection technique with physical layer network coding, to enable discrimination between secondary users and intelligent malicious users. Theoretical expressions are derived for probabilities of detection of secondary user, miss detection, and false alarm. In addition, the effectiveness of the proposed approach is evaluated by theoretical analysis and Monte Carlo simulation. Furthermore, an algorithm is proposed for distinguishing between secondary user and intelligent malicious user. Finally, based on the outcome of simulation of probabilities and normalized cross- correlation, it is determined that the proposed scheme outperforms in terms of OFDM signal compared with QPSK signal over cognitive radio network. Keywords: Cognitive radio network; Friend or foe detection; Physical-layer network coding; Cross-correlation. Designing Secure and Reliable Mobile Agent Based System for Reliable MANET   by Moumita Roy, Chandreyee Chowdhury, Munshi Navid Anjum, Sarmistha Neogy Abstract: Mobile Adhoc NETwork (MANET) provides a promising platform for pervasive computing applications. Mobile agents are found to be effective for executing such pervasive computing applications. The motivations behind this are advancement in technology, wireless networking, sensor network, ambient intelligence etc. However, since MANET is inherently more vulnerable to security threats and prone to topology changes, reliability and security issues must be addressed before mobile agents are commercially deployed. There are few works on securing mobile agents but even fewer focuses on MANET. This work is our attempt to design a lightweight trust based reputation scheme to protect the agents against network layer threats. The scheme is based on Dempster-Shafer belief theory. Performance of the trust based reputation scheme with respect to network and system reliability is analyzed. The work is simulated and the results show that even for a fairly hostile MANET, the effective reliability of distributed application can be increased using mobile agent based system. Keywords: Reputation; Trust; Demster-Shafer Belief Theory; Reliability; Monte Carlo Simulation. Energy Efficient Hierarchical Multi-Path Routing Protocol to Alleviate Congestion in WSN   by Sunitha GP, Dilip Kumar S M, Vijay Kumar B P Abstract: Congestion easily occurs in wireless sensor networks (WSN) due to it's centralized traffic pattern. It has a negative impact on the network performance in terms of decreasing throughput and increasing energy consumption. %In WSN, the main concern is to control congestionrnIn order to achieve high energy efficiency, network longevity, better fairness and quality of service, it is important to detect congestion in (WSN) in a timely manner. In this paper, an energy efficient hierarchical multi-path routing protocol to alleviate congestion and energy balancing problems is proposed.rn The algorithm is designed by partitioning the network into equal sized zones to achieve complete network connectivity and to reduce packet transmissions. The zone leaders ((ZL's)) selected are shifted on different nodes on network dynamic conditions to avoid hotspots and to provide energy balancing. For efficient data transmission quicker and optimal multiple paths are established using merged zone and Hierarchical network ((HiNet)) topology structure. The proposed algorithm detects the congestion by monitoring the path quality. The detected congestion is a result of overloaded links or nodes on the path. In addition, the algorithm proactively controls the congestion by dynamically shifting the transmission paths on their quality and alleviate it reactively using traffic splitting approach. The goal of this approach is to control resources instead of controlling the network load. The simulation results demonstrate that the proposed algorithm performs better as compared to other congestion control algorithms in terms of throughput, energy consumption and packet delivery ratio in a resource constraint wireless sensor network Keywords: Congestion control; Multi-path routing; Energy efficiency; Load balancing; WSN. An Adaptive Wi-Fi Indoor Localization Scheme using Deep Learning   by Chih-Shun Hsu, Yuh-Shyan Chen, Tong-Ying Juang, Yi-Ting Wu Abstract: Indoor localization is an important issue for many indoor applications. Many deep learning-based indoor localization schemes have been proposed. However, these existing schemes cannot adjust according to different environment. To improve the existing schemes, a novel indoor localization scheme, which can adaptively adopt the proper fingerprint database according to the collected signals, is proposed in this paper. The proposed scheme consists of the off-line and the on-line phases. A deep learning architecture with seven hidden layers is designed for the off-line phase. Two consecutive hidden layers form a Restricted Boltzmann Machine, which uses the ${k}$-step contrastive divergence algorithm for the layer-by-layer training. The proposed Wi-Fi indoor localization scheme uses two fine-tuning algorithms, namely the cross entropy and the mean squared algorithms, to build the corresponding fingerprint databases. As for the on-line phase, the Bayesian probability algorithm is used for position estimation. The fingerprint databases built during the off-line phase are adaptively adopted during the on-line phase. When the standard deviation of the collected signals does not exceed the threshold, the fingerprint database built by the cross entropy algorithm is adopted; when the standard deviation of the collected signals exceed the threshold, the fingerprint database built by the mean squared algorithm is adopted. The experiments were implemented and validated in a noisy and noise free indoor environment. The experimental results show that the proposed scheme can improve the accuracy of the training data and reduce the localization error. Keywords: deep belief network; deep learning; indoor positioning; Wi-Fi; fingerprinting localization. An Incentive Mechanism with Privacy Protection and Quality Evaluation in Mobile Crowd Computing   by Hao Long, Shukui Zhang Abstract: In order to achieve good service quality for mobile crowd computing (MCC), incentive mechanism need to attract more users to participate in the task while avoiding leakage of privacy. We proposed an incentive mechanism with privacy protection and quality evaluation (IMPPQE). Combining the advantages of offline and online incentive mechanisms, we design improved two-stage auction to select the winners, while protecting participants'privacy. Finally, the sensing reports are evaluated by quantitative calculation to ensure the objectivity of evaluation. Extensive simulations show that our proposed method can improve the efficiency and utility of MCC and obtain higher satisfaction rate of data quality. Keywords: Mobile crowd computing; privacy protection; quality evaluation; incentive mechanism; two-stage auction. A Novel Faster Failure Detection Strategy for Link Connectivity using Hello Messaging in Mobile Ad Hoc Networks   by Alamgir Naushad, Ghulam Abbas, Ziaul Haq Abbas, Lei Jiao Abstract: Faster failure detection is one of the main steps responsible for efficient link connectivity in mobile ad hoc networks (MANETs). Under a random behavior of network nodes and link/node failure, there must be a unified approach to describe an adequate Hello messaging strategy for link connectivity in MANETs. In order to tackle this issue, we present a strategy for achieving faster failure detection, and derive algorithmic attributes of the proposed strategy on the basis of multiple parameters of interest after modelling it as a Markov process. We also present novel algorithms to minimize the biggest chunk of delay incurred as a result of link re-connectivity and, thus, improve network connectivity in MANETs. Simulation and analytical results indicate efficacy of the proposed strategy in achieving faster failure detection and efficient link re-connectivity. Keywords: Faster failure detection; Hello messages; MANETs; Stochastic processes; Link connectivity. Mitigating SSDF Attack using Distance-based Outlier approach in Cognitive Radio Networks   by Wangjam Niranjan Singh, Ningrinla Marchang, Amar Taggu Abstract: Collaborative spectrum sensing is employed in cognitive radio networks for improving the spectrum sensing accuracy. The collaborating cognitive radios send their individual sensing results to the fusion center (FC) which aggregates the results to come to a final sensing decision. Malicious radios may adversely influence the final sensing decision by transmitting false spectrum sensing results to the FC. This attack is commonly known as the spectrum sensing data falsification (SSDF) attack. Hence, in the light of such a threat, it is pertinent for the FC to identify any such malicious radios, if any and isolate them from the decision process. In this paper, a distance-based outlier detection approach is proposed which mines the sensing reports at the FC for detection and isolation of such malicious users. Numerical simulations results support the validity of the proposed approach. Keywords: SSDF attack; distance-based outlier detection; cognitive radio network; data mining. IOT Enabled Adaptive Clustering based Energy Efficient Routing Protocol For Wireless Sensor Networks   by Muhammad Asad, Aslam Hayat, Yao Nianmin, Naeem Ayoub, Khalid Ibrahim Qureshi, Ehsan Ullah Munir Abstract: Wireless Sensor Networks (WSNs) consists of hundreds and thousands of micro-sensor nodes which are distributed in the sensing field to sense the uncertain events. These sensor nodes plays an important role in Internet of Things (IoT). Energy consumption has been a major issue in WSNs, various energy efficient conventional routing protocols are proposed to minimize the communication energy cost of sensor nodes. In IoT enabled WSNs, these sensor nodes are resource controlled in various ways, such as energy, storage, computing, communication and so on. In conventional routing protocols clustering technique is performing superiorly but due to the limited characteristics, suggested routing protocols are not as much smart and flexible to generate a perfect Cluster-Head (CH) because these routing protocols are limited to centralized and distributed or homogeneous and heterogeneous networks. In this paper, we propose a new IoT enabled Multi Adaptive Clustering (MAC) energy efficient routing protocol for WSNs to minimize the energy dissipation and improve the network performance. This new technique holds the hybrid cluster formation algorithm in which the network topology is divided into two regions the first region is centralized and the second region is distributed. Both regions contains homogeneous and heterogeneous nodes while the sink is static and located in the center of both networks. Specifically, proposed IoT enabled MAC routing protocol holds the major three properties: Enabling of resources to sensor nodes through IoT, hybrid cluster formation to distribute the network load evenly among sensor nodes and a new mechanism to minimize the energy consumption in long range data transmission. Our simulation results give significant proof that MAC performs better than state-of-the-art routing protocols such as LEACH-C, DEEC, D-DEEC and E-DEEC. In addition, performance evaluation proofs that MAC is suitable for the network which requires longer network lifetime. Keywords: Internet of Things; Wireless Sensor Networks; Energy Efficient; Routing Protocols. A new approach for the recognition of human activities   by SALIMA SABRI, AlOUI Abdelouhab Abstract: The evaluation of a patient\'s functional ability to perform daily living activities is an essential part of nursing and a powerful predictor of a patient\'s morbidity, especially for the elderly. In this article, we describe the use of a machine learning approach to address the task of recognizing activity in a smart home.We evaluate our approach by comparing it to aMarkov statistical approach and using several performance measures over three datasets. We show how our model achieves signi cantly better recognition performance on certain data sets and with different representations and discretisation methods with an accuracy measurement that exceeds 92%and accuracy of 68%. The experiments also showa signi cant improvement in the learning time which does not exceed one second in the totality of the experiments reducing the complexity of the approach. Keywords: Ubiquitous applications; automatic learning; Katz ADL; activity recognition; probabilistic models; wireless sensor network. A Novel Method for Time Delay Prediction in Networked Control Systems   by Pei XU, Jianguo WU Abstract: Time delay prediction is a crucial issue of networked control systems. Previous methods mainly use individual model to predict time delay, which causes the limitation that the proposed model can only be suitable applied to either linear or nonlinear data. This paper proposed a novel method to predict time delay in networked control systems which considers several different individual models as the component models to form a combined model and takes full advantages of these component models. By applying Lagrange multiplier method to minimize prediction error, the proposed OW (optimal weight) algorithm is able to calculate the proper weight coefficients of component models in order to improve the prediction performance. Compared with the existing methods, the proposed combined model can improve the prediction accuracy and support robustness, variability and scalability. The simulation experiments verify the effectiveness of the proposed method. Keywords: networked control systems; time delay prediction; RBF neural network; ARMA model; optimal weight; combined model. A reputation-based truthfulness paradigm for multi-hop transmission in cognitive radio networksby Trupil Limbasiya, Debasis Das, Ramnarayan Yadav Abstract: Cognitive radio networks (CRNs) consist of numerous intellectual users with the capability of sensing and sharing underutilized spectrum, and they are called as cognitive users (CUs). The spectrum is allocated to licensed users or primary users (PUs) but, generally, they do not utilize it completely. To overcome the ever-increasing spectrum demand and utilize the underutilized licensed spectrum, the cognitive radio plays a major role. In this distributed environment, the communication among CUs becomes more challenging due to channel heterogeneity, uncontrolled environment, a need of cooperative sensing for accurate sensing result, etc. Additionally, there are different attacks, e.g., primary user emulation (PUE), control channel saturation DoS (CCSD), selfish channel negotiation (SCN), spectrum sensing data falsification (SSDF), modification, and man-in-the-middle. Then, this affects and degrades system and CRN performance, which creates an opportunity for a trust management model to manage the CRNs properly. In this paper, we propose an efficient trust management protocol for centralized and distributed CRNs that are to build a trust-based system over the complete cognitive cycle to protect against security attacks brought by the unreliable individuals. To address the security issues, a clustering scheme is used in the distributed environment for effective cooperation among CUs. The security analysis and simulation results represent that the proposed protocol can identify malicious behavior and enhance fairness and powerfulness of the network in centralized and distributed circumstances. Keywords: Attacks; Cognitive radio networks; Integrity; Trust management Throughput of Cooperative HARQ protocols for Underlay Cognitive Radio Networks using Adaptive and Fixed Transmit Powerby Nadhir Ben Halima, Hatem Boujemaa Abstract: In this paper, we study theoretically and by simulations the throughput of cooperative Hybrid Automatic Repeat reQuest protocolsrnfor underlay cognitive radio networks. Both fixed and adaptive power transmission are studied. Different relay selection techniques with Amplify and Forward (AF) and Decode and Forward (DF) relaying are investigated.rnFor fixed transmit power, some relays are not available since they generate an interference to primary receiver larger than a predefined value T.rnThe best relay is selected among the available ones.rnFor adaptive transmit power, all relays adapt their power so that interference to primary receiver is always lower than a predefined threshold $T$. In this case, all relays will be available for retransmitting the secondary source packet.rnBoth Average Interference Power (AIP) and Peak Interference Power Constraints (PIP) are studied. We also analyze the effect of primary interference on secondary throughput. Keywords: Cognitive Radio Networks; HARQ GOOSE: Goal Oriented Orchestration for Smart Environmentsby Vincenzo Catania, Gaetano La Delfa, Giuseppe La Torre, Salvatore Monteleone, Davide Patti, Daniela Ventura Abstract: Smart environment scenarios are characterized by the presence of users, with different needs and preferences, and everyday life objects exploited to meet the expectations of users themselves. Connecting objects to the Internet and making them accessible from remote is not sufficient to make an environment "smart" since such ecosystems should also be able to enable context-sensitive actions along with a management of the interaction between objects and users. In this work, we propose GOOSE, a platform which aimed at interpreting users goals expressed in natural language in order to generate, select, and safely enforce a set of plans to be executed to fulfill target goals. After highlighting the main challenges affecting typical Machine to Machine (M2M) communication scenarios, we show how the use of a semantic reasoner can be used to allow the composition of plans consisting of sequences of services to be called on the smart environment objects. Finally, we address the issue of secure communications between platform and objects, and the management of potentially inconsistent goals. Keywords: Machine to Machine; RESTful services; Goal-oriented Architecture; User-object interactions; Semantic descriptions; Indoor localization; Special Issue on: Emerging Pervasive and Ubiquitous Networking Internet of Things: a Research Oriented Introductory   by RAJA S P, SAMPRADEEPRAJ T Abstract: The world has shrunk considerably with the dramatic growth in Internet usage. Every computer and mobile phone in the world can be connected together through Internet technology. As a result, intelligent devices are connected and communicate together. The Internet of Things envisions a future where people and intelligent systems cooperate and work together. In the IoT, machine-to-machine communication helps devices exchange data, requiring power, efficiency, security and reliability. This paper advances new ideas for designing a security protocol in the IoT so as to facilitate secure machine-to-machine communication. Keywords: Internet of Things; Architecture; Protocols; D2D Communication; Security. Proficient Communication among Sensor Devices using Heuristic Approaches in IoT Environment   by Nandhakumar Ramachandran, Varalakshmi Perumal Abstract: Collecting data in an IoT environment is difficult and the redundancy among the data from the sensors tends to decrease the lifetime of the network and also increase the latency. Collecting data from heterogeneous sensors could involve the translation between the different types of values for the different types of sensors. The system comprises of dynamic and heterogeneous sensors. The proposed system aims at achieving an efficient communication among sensor devices by choosing the most optimal node at every stage of the communication, namely, data dissemination, data aggregation and routing. The base station releases a query, according to which clustering is done using Particle Swarm Optimization (PSO). The Cluster Head is elected using PSO based on many factors like position, velocity, energy and the neighbor density. It also eliminates the formation of residual nodes. Principle Component Analysis is used at relay node to aggregate heterogeneous data of multiple dimensions. It reduces the dimensionality of data sent thus reducing the packets sent. It does away with the translation of data of one type to another during forwarding of data. Ant Colony Optimization (ACO) is used to forward data at every level by considering the energy of the node, distance from base station and the velocity. The technique helps in choosing reliable, energy efficient path and also decreases the delay. Thus proposed system can be helpful in overcoming the resource constraint problem, limited transmission range, eliminating the formation of residual nodes, and redundancy among data. This in turn improves the network lifetime. Keywords: IoT; Heuristic Approaches; Proficient Communication; Heterogenous sensors; Energy efficient; PSO; ACO; PCA. A Novel Group Ownership Proof and Transfer Scheme for B2B, B2C and C2C Transactions   by Meng-Lin Tsai, Yu-Yi Chen Abstract: In the field of supply chain management, Radio Frequency Identification (RFID) tags have attracted widespread popularity in the process from raw material acquisition, manufacturing, logistics, warehousing, retailing to consumers. As raw materials or products are purchased, an inventory flow for products is completed once the ownership is transferred to the customer. Based on RFID tagged inventory, ownership transfer is a critical issue in the supply chain management. The ownership of RFID tagged items should be seamlessly transferred. As the transaction occurs, the ownership of the tagged product should be transferred from the current owner to the new owner. This paper proposes a novel RFID ownership transfer scheme suitable for products with multiple components attached with tags that need to be shipped together as a group. This is the first group ownership transfer scheme to emphasis the proof of ownership is critical for purchase reliability. Buyers can confirm that the seller is the owner before purchasing. The ownership of the product can be verified and then be transferred successfully in business-to-business (B2B), business-to-customer (B2C) and customer-to-customer (C2C) transactions. Keywords: RFID; group ownership transfer; ownership proof; grouping proof; security; privacy; authentication; authorization; supply chain; protocol. Adaptive Sink Mobility for Energy-Efficient Data Collection in Grid-Based Wireless Sensor Networks   by Sarra Messai, Zibouda Aliouat, Hamida Seba, Abdallah Boukerram Abstract: Many recent studies show that sink mobility in Wireless Sensor Networks (WSNs) preserves the energy of the sensors for a longer network lifetime. These approaches require generally a logical organization of the network within clusters, such as a grid. However, constructing such a grid is costly and requires several rounds of messages exchanged between sensors which outbalance the benefits of the approach. To tackle this drawback, we propose an energy-based cell-head (CH) selection combined with a sink mobility algorithm to minimize energy consumption of sensor nodes and optimize data collection. The proposed approach is termed EASY for Energy-Aware Sink mobilitY. Experimentation results confirm that our solution offers better performance compared to existing approaches. Keywords: energy saving; grid-based wireless sensor networks; sink mobility. Spider Monkey Optimisation based Energy Efficient Clustering in Heterogeneous Underwater Wireless Sensor Networks   by Madhuri Rao, Narendra Kumar Kamila Abstract: Underwater Wireless Sensor Network (UWSN) enables ubiquitous computing but is a system with unique constraints. Longer delay in propagation time of acoustic signals requires multi hop routing to be avoided in such networks. Multi Hop propagation cause more energy drainage of the nodes. A trade-off has to be made between the numbers of nodes deployed for optimal coverage while achieving lesser propagation delays. The denser a network is, the more likely it is demonstrate multi hop propagation thereby leading to more energy drainage. On the other hand, UWSN is prone to dynamic topology changes due to node mobility. Node mobility is inevitable and results due to water current. It leads to transmission errors, link loss, collisions and congestion if not well handled. Enhanced routing techniques that could reduce energy consumption, reduce delay and avoid multi-hop transmission are needed. Moreover, a routing technique that could adapt to the changing topology is needed in UWSN. A clustering approach based on Spider Monkey Optimisation (SMO) is proposed here that addresses these issues that arise in topology changes due to node mobility. The proposed approach is found to enhance the average network lifetime of nodes by 0.01579 Joules and achieves a network gain of 1.35%. Further a significant reduction in average delay of messaging packets by 19.82% is achieved. The proposed approach is far more optimised as it reduces the average hops between sender and receiver by 20%. Keywords: Heterogeneous Underwater Wireless Sensor Networks; dynamic clusters; Spider Monkey optimisation; Fission –Fusion Social Structure. Optimal mobile beacon trajectories for nodes localization in wireless sensor networks   by Sara Benkouider, Nasreddine Lagraa, Abderrahim Benslimane, Mohamed Bachir Yagoubi Abstract: The random deployment of nodes is commonly used in Wireless Sensor Networks (WSNs), because of either the hostility of the monitored area or its large scale. However, many applications and protocols are position- based. Hence, its necessary to determine the position of sensors even after their deployment. Localization techniques using mobile beacon have been proposed in this context, to localize unknown sensor nodes. However, to save nodes energy its useful to send an optimal number of messages. Thus, an optimal trajectory of mobile beacon helps to achieve such objective. In this paper, we propose two novel optimal mobile beacon trajectories based on Hilbert curve. The ﬁrst proposal aims at minimizing the trajectory length and improving the localization accuracy, moreover, the second one minimizes both the trajectory and the energy consumption. In this study, we compare the proposed techniques with mobile Hilbert beacon trajectory. The analytical analysis and the performance evaluation with simulations show that our proposed methods improve, compared to the existing methods, the accuracy, the length of trajectories and the energy consumption. Keywords: WSNs; Localization; Mobile beacon; Virtual beacons; Hilbert trajectory. An Intelligent Routing Protocol in VANET   by Ghassan Samarah Abstract: Vehicular Ad hoc Networks (VANET) is one of the new promising and most challenging research area in the mobile computing field; this technology suffers from the high mobility which results in broken links and continuously changing routs. In this research, a new and Intelligent Routing Protocol (IRP) using position based proactive message transmission in Vehicular ad hoc Networks environment will be deployed. The proposed protocol aims to supply vehicles with live and quick information about the current links between road vehicles and hence better message routing, channel utilization, error free, congestion free channel with less broken links using position based, multi-hop routing and best first search algorithm, simulation results show that the proposed protocol achieves better performance when compared with other protocols. Keywords: Intelligent Protocol; Best First Search; Multi hop routing; VANET. Time Slotted Channel Hopping with Collision Avoidance   by Sarra Hammoudi, Saad Harous, Zibouda Aliouat, Lemia Louail Abstract: The Time Slotted Channel Hopping mode proposed by the IEEE 802.15.4e2015 standard enhances the reliability of low-power and lossy networks. The TSCH supports the critical applications embedded in harsh environments with high-efficiency. The multi-channel hopping and the time slotted access nature of this mode provides deterministic latency for applications and achieves a greater throughput capacity. On the other hand, the shared links nature of this mode risks the packets transmission to fail when the participating nodes of this shared link are colliding nodes. Retransmitting the packets randomly risks the packets retransmission to fail several times, which influences negatively on the sensor energy and packet latency. To ensure collision avoidance in the presence of hidden nodes, this paper provides two intelligent algorithms(Time Slotted Channel Hopping with Correct Collision Avoidance backoff algorithm(TSCH-CCA) and Enhanced Priority Channel Access Backoff Algorithm(E-PCA)) applied respectively to both normal packets and critical events packets. Our proposed solution shows significant improvements in terms of latency, network congestion, network lifetime, critical event packets lifetime, and collision avoidance. Keywords: Internet of Things; Wireless Sensor Networks; MAC layer; IEEE 802.15.4E; Time Slotted Channel Hopping; collisions; channel hopping; shared links; dedicated links. An Adaptive Energy Efficient Flow Coverage Scheme for Mobile Crowd Sensing in Urban Streets   by Ahmed Gad-Elrab, Almohammady Alsharkawy Abstract: With the rapid growth of sensor technology, smartphone sensing has become an effective approach to improve the quality of applications in smartphones. \textit{Mobile Crowd Sensing} (MCS) is a new paradigm which takes advantage of pervasive smartphones to efficiently collect data in the urban streets, enabling numerous novel applications. To achieve a good service quality for a MCS application, coverage mechanisms are necessary to achieve the sensing task requirements and collect a reliable sensing data from the urban streets. The key idea of MCS is to employ so many users carrying heterogeneous devices to collect and share sensed data using their mobile phones. The main problem in data collection process is how to cover all segments in the street sides and select a minimal number of participants in each street segment preserve the mobile devices' energy and prolong the MCS network lifetime. To solve this problem, a flow coverage scheme is proposed to cover a specific street and achieve the sensing task requirements. The proposed scheme is based on using a modified localization method that uses a minimal of GPS sensors and utilizes the Zigbee technology to communicate with the neighbor nodes and estimate the distance between nodes by using the Time of Arrival method. Finally, we have compared our proposed scheme with existing methods via extensive simulations based on the real movement traces of students in our university. Extensive simulation results well justify the effectiveness and robustness of our scheme. Keywords: Mobile crowd sensing; Mobile sensors; Mobile localization; Flow coverage. Security Scheme for Mobility Management in the Internet of Things   by Oryema Brian, Cheol Woo Jung, Jong Tae Park Abstract: A mobility management protocol based on the constrained application protocol (CoAP), called the CoAP-based mobility management protocol (CoMP), was suggested to counteract the constraints of mobile internet protocol version 6 (MIPv6) in the Internet of Things (IoT) environment. CoMP exchanges Binding Update (BU) messages to manage location changes, but BU messages are subject to security vulnerabilities, such as denial of service (DoS), false BU, session hijacking, and man-in-the-middle (MITM) attacks. In this paper, we extend CoMP by proposing a security scheme based on a private key to protect the BU CoMP messages exchanged between the mobile nodes and clients, referred to as private key-based BU for CoMP (PKBU-CoMP). PKBU-CoMP ensures that mobile nodes check and confirm the address ownership and validity of mobile nodes before performing any BU operation. The performance of PKBU-CoMP is analyzed both mathematically and using Cooja simulations. Keywords: Security in Internet of Things; Secure Mobility; Secure Binding; Private Key in IoT. Smart Vehicles for Urban Sensing based on Content-centric Approach   by Raja Priya V.K. Abstract: Today IoT(Internet of Things) plays a major role in interconnecting physical devices, vehicles, etc. to collect, exchange data through networks. Smart Vehicles collect, store and exchange monitoring sensory content about urban streets. Uploading such monitoring data by all vehicles to the infrastructure is challenging. In-order to avoid such situations, the appropriate vehicles important for different urban sensing tasks is identified by measuring its relative importance in the network. First the different location-aware content is autonomously ranked by a vehicle. It then uses a content importance and its mobility pattern to find its importance in the network. Based on the vehicles centrality score the best content hubs in the network are identified to provide efficient collect, storage and exchange of sensory data based on Content-centric Networking (CCN) where content request/response data are characterized. Due to limited bandwidth resources the response data is routed to specified vehicle based on the geo-based routing technique. Keywords: IoT; Content-centric Networking; Vehicular Ad-Hoc Network; Smart Vehicles; Content-centric vehicular networking; urban sensing; urban monitoring; location-aware content; sensory data; geo-based routing. CLPS: Context-based Location Privacy Scheme for VANETs   by Ines Khacheba, Mohamed Bachir Yagoubi, Nasreddine Lagraa, Abderrahmane Lakas Abstract: In the last few decades, location privacy preservation is considered by researchers as a challenge for enabling the deployment of Vehicular Ad Hoc Networks (VANETs). In fact, the continuous periodical broadcast of spatiotemporal information contained in beacons permits to a global passive adversary to link pseudonyms and reconstruct all vehicle traces. This attack breaches the drivers privacy. Consequently, it is imperative that a vehicle selects the right context to change its pseudonym in order to confuse the adversary and ensure unlinkability of pseudonyms. In this paper, we propose a Context-based Location Privacy Scheme (CLPS) that makes the following contributions: (i) We propose a pseudonym changing strategy that permits to a vehicle to effectively change its pseudonyms based on its context. (ii) We present a new linkability threat, called cheating attack, and show the vulnerability of the proposed pseudonym changing strategy to this attack. To confront the cheating attack, we propose developing a cheating detection mechanism that allows a vehicle to detect misbehaving vehicles that are responsible of launching the cheating attack, and assess whether the change of pseudonym is successful after a pseudonym is changed. Finally, we evaluate by simulations the proposed scheme against the global passive adversary using the privacy extension, PREXT, in Veins VANET simulator, and we compare it against different privacy schemes proposed in the literature. Keywords: VANET; Security; Location Privacy; Changing Pseudonyms; Linkability; Cooperation; Cheating Detection.