Showing papers in "Wireless Networks in 2016"
TL;DR: An algorithm called fuzzy based unequal clustering is proposed in this paper to enhance the execution of the current algorithms and is compared with two algorithms, one with an equivalent clustering algorithm called LEACH and another with an unequal clusters algorithm called EAUCF.
Abstract: The primary challenges in outlining and arranging the operations of wireless sensor networks are to enhance energy utilization and the system lifetime. Clustering is a powerful approach to arranging a system into an associated order, load adjusting and enhancing the system lifetime. In a cluster based network, cluster head closer to the sink depletes its energy quickly resulting in hot spot problems. To conquer this issue, numerous algorithms on unequal clustering are contemplated. The drawback in these algorithms is that the nodes which join with the specific cluster head bring overburden for the cluster head. So, we propose an algorithm called fuzzy based unequal clustering in this paper to enhance the execution of the current algorithms. The proposed work is assessed by utilizing simulation. The proposed algorithm is compared with two algorithms, one with an equivalent clustering algorithm called LEACH and another with an unequal clustering algorithm called EAUCF. The simulation results using MATLAB demonstrate that the proposed algorithm provides better performance compared to the other two algorithms.
191 citations
TL;DR: This paper presents an approach which attempts to control the randomness present in LEACH’s clustering algorithm, and makes the cluster head count stable.
Abstract: Battery power is a critical resource of Wireless Sensor Networks (WSNs). Therefore, an effective operation of WSNs depend upon the efficient use of its battery resource. Cluster based routing protocols are proven to be more energy efficient as compared to other routing protocols. Most of the cluster based routing protocols, especially Low Energy Adaptive Clustering Hierarchy (LEACH) protocol, follows Dynamic, Distributed and Randomized (DDR) algorithm for clustering. Due to the randomness present in clustering algorithms, number of cluster heads generated varies highly from the optimal count. In this paper, we present an approach which attempts to control the randomness present in LEACH's clustering algorithm. This approach makes the cluster head count stable. NS-2 simulation results show that proposed approach improved the First Node Death (FND) time and Last Node Death (LND) time by 21 and 24 % over LEACH, 10 and 20 % as compared to Advance LEACH (ALEACH) and 5 and 35 % over LEACH with Deterministic Cluster Head Selection (LEACH-DCHS) respectively.
119 citations
TL;DR: An energy efficient clustering mechanism, based on artificial bee colony algorithm and factional calculus is proposed in this paper to maximize the network energy and life time of nodes by optimally selecting cluster-head.
Abstract: Due to the promising application of collecting information from remote or inaccessible location, wireless sensor networks pose big challenge for data routing to maximize the communication with more energy efficient. Literature presents different cluster-based energy aware routing protocol for maximizing the life time of sensor nodes. Accordingly, an energy efficient clustering mechanism, based on artificial bee colony algorithm and factional calculus is proposed in this paper to maximize the network energy and life time of nodes by optimally selecting cluster-head. The hybrid optimization algorithm called, multi-objective fractional artificial bee colony is developed to control the convergence rate of ABC with the newly designed fitness function which considered three objectives like, energy consumption, distance travelled and delays to minimize the overall objective. The performance of the proposed FABC-based cluster head selection is compared with LEACH, PSO and ABC-based routing using life time, and energy. The results proved that the proposed FABC maximizes the energy as well as life time of nodes as compared with existing protocols.
117 citations
TL;DR: TC-QS (Quick Start) from the TCP protocol control is put forward in this paper in order to improve the performance of congestion control mechanism.
Abstract: With the development of Internet, various kinds of new applications appear constantly. They all have high requirements to the time delay, throughput, especially strong real-time applications such as mobile monitoring, video calls. The satellite network in Navigation Satellite System, which is necessary for the mobile monitoring, has many disadvantages such as asymmetric bandwidth, unstable network, high bit error rate and so on. This is a new challenge to the existing congestion control method. In order to improve the performance of congestion control mechanism, we put forward TCP-QS (Quick Start) from the TCP protocol control in this paper. TCP-QS algorithm mainly optimize the slow start stage. At the beginning of the connection, the value of parameter cwnd is set as a larger value according to the detected network bandwidth in which way, the time of the slow start stage is shortened during the transmission, and is adjusted the value of parameter ssthresh dynamically according to the change of network. When packet loss occurs, it takes different methods according to the different reasons.
113 citations
TL;DR: An efficient and privacy-preserving DA scheme for the SG against internal attacks is proposed and shows that the proposed DA scheme not only overcome the key leakage problem in Fan et al.
Abstract: With fast advancements of communication, systems and information technologies, a smart grid (SG) could bring much convenience to users because it could provide a reliable and efficient energy service. The data aggregation (DA) scheme for the SG plays an important role in evaluating information about current energy usage. To achieve the goal of preserving users' privacy, many DA schemes for the SG have been proposed in last decade. However, how to withstand attacks of internal adversaries is not considered in those schemes. To enhance preservation of privacy, Fan et al. proposed a DA scheme for the SG against internal adversaries. In Fan et al.'s DA scheme, blinding factors are used in evaluating information about current energy usage and the aggregator cannot get the consumption information of any individual user. Fan et al. demonstrated that their scheme was secure against various attacks. However, we find that their scheme suffers from the key leakage problem, i.e., the adversary could extract the user's private key through the public information. To overcome such serious weakness, this paper proposes an efficient and privacy-preserving DA scheme for the SG against internal attacks. Analysis shows that the proposed DA scheme not only overcome the key leakage problem in Fan et al.'s DA scheme, but also has better performance.
111 citations
TL;DR: The main design issues based on the model of wireless sensor networks: structure-free and structured for data collection and aggregation where role of clustering and routing is discussed for energy conservation and enhancing network lifetime are reviewed.
Abstract: In past decade, wireless sensor networks have gained attention by researchers, manufacturers as well as the users for remotely monitoring tasks and effective data gathering in diverse environment. The wireless sensor nodes are tiny battery powered devices having limited lifetime, hence for longevity and reliability, the foremost concern is minimizing energy consumption and maximizing network lifetime while designing protocols and applications. In this paper, we review the main design issues based on the model of wireless sensor networks: structure-free and structured for data collection and aggregation where role of clustering and routing is discussed for energy conservation and enhancing network lifetime. These design strategies are the foundation of any networking protocol from the energy saving point of view. A comprehensive tabular overview of different approaches under structure-free and structured wireless sensor networks for data collection and aggregation, clustering and routing is presented with key issues.
89 citations
TL;DR: The results of the multiple simulations were able to show that LTAWSN, in comparison with the previous ant colony based routing algorithm, energy aware ant colony routing algorithms for the routing of wireless sensor networks, ant colony optimization-based location-aware routing algorithm for wireless Sensor networks and traditional ant colony algorithm, increase the efficiency of the system, obtains more balanced transmission among the nodes and reduce the energy consumption of the routing and extends the network lifetime.
Abstract: Reducing the energy consumption of network nodes is one of the most important problems for routing in wireless sensor networks because of the battery limitation in each sensor. This paper presents a new ant colony optimization based routing algorithm that uses special parameters in its competency function for reducing energy consumption of network nodes. In this new proposed algorithm called life time aware routing algorithm for wireless sensor networks (LTAWSN), a new pheromone update operator was designed to integrate energy consumption and hops into routing choice. Finally, with the results of the multiple simulations we were able to show that LTAWSN, in comparison with the previous ant colony based routing algorithm, energy aware ant colony routing algorithms for the routing of wireless sensor networks, ant colony optimization-based location-aware routing algorithm for wireless sensor networks and traditional ant colony algorithm, increase the efficiency of the system, obtains more balanced transmission among the nodes and reduce the energy consumption of the routing and extends the network lifetime.
88 citations
TL;DR: This paper investigates the potential of mobile sensor nodes such as unmanned aerial vehicles and human patrols to fortify the barrier-coverage quality of a WSN of cheap and static sensor nodes and uses a single variable first-order grey model, GM(1,1), based on the intruder detection history from the sensor nodes to determine which parts of the barrier is more vulnerable.
Abstract: A wireless sensor network (WSN) provides a barrier-coverage over an area of interest if no intruder can enter the area without being detected by the WSN. Recently, barrier-coverage model has received lots of attentions. In reality, sensor nodes are subject to fail to detect objects within its sensing range due to many reasons, and thus such a barrier of sensors may have temporal loopholes. In case of the WSN for border surveillance applications, it is reasonable to assume that the intruders are smart enough to identify such loopholes of the barrier to penetrate. Once a loophole is found, the other intruders have a good chance to use it continuously until the known path turns out to be insecure due to the increased security. In this paper, we investigate the potential of mobile sensor nodes such as unmanned aerial vehicles and human patrols to fortify the barrier-coverage quality of a WSN of cheap and static sensor nodes. For this purpose, we first use a single variable first-order grey model, GM(1,1), based on the intruder detection history from the sensor nodes to determine which parts of the barrier is more vulnerable. Then, we relocate the available mobile sensor nodes to the identified vulnerable parts of the barrier in a timely manner, and prove this relocation strategy is optimal. Throughout the simulations, we evaluate the effectiveness of our algorithm.
87 citations
TL;DR: A closer look is taken at the algorithmic approaches of various important fine-grained mobile anchor assisted localization techniques applicable in WSNs, and the error refinement mechanisms adopted by the state-of-the-art works associated with their approaches are highlighted.
Abstract: Identifying locations of sensor nodes in wireless sensor networks (WSNs) is significant for both network operations and most application level tasks. Although, geographical positioning system (GPS) based localization schemes are used for determining node locations but the cost of GPS devices and non-availability of GPS signals in indoor environments prevent their use in large scale WSNs. A substantial amount of research work exist that intend at obtaining precise and relative spatial locations of sensor nodes without requiring large amount of specialized hardware. Mobile anchor assisted localization is one typical approach that significantly reduces the implementation cost by using limited number of mobile anchors. In this survey, we present key issues and inherent challenges faced by the mobile anchor assisted localization techniques in WSNs. We take a closer look at the algorithmic approaches of various important fine-grained mobile anchor assisted localization techniques applicable in WSNs. In addition, we highlight the error refinement mechanisms adopted by the state-of-the-art works associated with their approaches. Well known mobile anchor trajectories presented in existing works are also reviewed. Finally, open research issues are discussed for future research scope in this field.
75 citations
TL;DR: A Cross Layer-Low Energy Adaptive Clustering Hierarchy model (CL-LEACH), an efficient routing protocol to increase the lifetime of the battery and provides an energy efficient transmission schemes for WSN.
Abstract: Energy efficiency is an important parameter in the research area related to the design of routing protocols for Wireless Sensor Networks (WSNs). The consumption of energy during transmission and processing of data is more which makes the sensor network to erroneous state. In WSN, Low Energy Adaptive Clustering Hierarchy (LEACH) is a popular hierarchical routing protocol, which is responsible for energy storage in nodes. The residual energy and distance between the base station and node are not considered for selection of cluster head in traditional methods. This paper proposes a Cross Layer-Low Energy Adaptive Clustering Hierarchy model (CL-LEACH), an efficient routing protocol to increase the lifetime of the battery. CL-LEACH considers residual energy and for cluster head selection and provides an energy efficient transmission schemes for WSN. The cross-layer design delivers adaptive modulation by abusing intersegment dependencies across Medium Access Control, Physical, and Application layers. Moreover, CL-LEACH utilizes the remaining energy of the node for cluster head selection which preserves the overall energy. The proposed method provides better results in terms of number of live nodes, energy dissipation, message cost when compared to the traditional LEACH protocol.
66 citations
TL;DR: Simulation results show that the performance of DC over traditional backhaul connections is close to that achievable with inter-site carrier aggregation (CA) and virtually zero-latency fronthaul connections, and in any case it is significantly higher compared to the case without DC.
Abstract: Dual connectivity (DC) allows user equipments (UEs) to receive data simultaneously from different eNodeBs (eNBs) in order to boost the performance in a heterogeneous network with dedicated carrier deployment. Yet, how to efficiently operate with DC opens a number of research questions. In this paper we focus on the case where a macro and a small cell eNBs are inter-connected with traditional backhaul links characterized by certain latency, assuming independent radio resource management (RRM) functionalities residing in each eNB. In order to fully harvest the gain provided by DC, an efficient flow control of data between the involved macro and small cell eNBs is proposed. Moreover, guidelines for the main performance determining RRM algorithms such as UE cell association and packet scheduling are also presented. It is demonstrated how proper configuration of the proposed flow control algorithm offers efficient trade-offs between reducing the probability that one of the eNBs involved in the DC runs out of data and limiting the buffering time. Simulation results show that the performance of DC over traditional backhaul connections is close to that achievable with inter-site carrier aggregation (CA) and virtually zero-latency fronthaul connections, and in any case it is significantly higher compared to the case without DC.
TL;DR: The hot spot problem is addressed and a grid based clustering and routing algorithms, combinedly called GFTCRA (grid based fault tolerant clusteringand routing algorithms) which takes care the failure of the CHs are proposed which follow distributed approach.
Abstract: Energy conservation of the sensor nodes is the most important issue that has been studied extensively in the design of wireless sensor networks (WSNs). In many applications, the nodes closer to the sink are overburdened with huge traffic load as the data from the entire region are forwarded through them to reach the sink. As a result, their energy gets exhausted quickly and the network is partitioned. This is commonly known as hot spot problem. Moreover, sensor nodes are prone to failure due to several factors such as environmental hazards, battery exhaustion, hardware damage and so on. However, failure of cluster heads (CHs) in a two tire WSN is more perilous. Therefore, apart from energy efficiency, any clustering or routing algorithm has to cope with fault tolerance of CHs. In this paper, we address the hot spot problem and propose grid based clustering and routing algorithms, combinedly called GFTCRA (grid based fault tolerant clustering and routing algorithms) which takes care the failure of the CHs. The algorithms follow distributed approach. We also present a distributed run time management for all member sensor nodes of any cluster in case of failure of their CHs. The routing algorithm is also shown to tolerate the sudden failure of the CHs. The algorithms are tested through simulation with various scenarios of WSN and the simulation results show that the proposed method performs better than two other grid based algorithms in terms of network lifetime, energy consumption and number of dead sensor nodes.
TL;DR: A new algorithm is suggested which enhances the security of AODV routing protocol to encounter the black hole attacks and tries to identify malicious nodes according to nodes’ behaviours in an Ad Hoc network and delete them from routing.
Abstract: Ad Hoc network is a temporal network which is managed by autonomous nodes which have the ability to communicate with each other without having fixed network infrastructure or any central base station. Due to some reasons such as dynamic changes of the network topology, trusting the nodes to each other, lack of fixed substructure for the analysis of nodes' behaviours and loss of specific offensive lines, this type of networks is not supportive against malicious nodes' attacks. One of these attacks is black hole attack. In this attack, the malicious nodes absorb data packets and destroy them. Thus, it is essential to present an algorithm against the black hole attacks. This article suggests a new algorithm which enhances the security of AODV routing protocol to encounter the black hole attacks. This algorithm tries to identify malicious nodes according to nodes' behaviours in an Ad Hoc network and delete them from routing. The suggested algorithm is simulated by NS2. The simulation results show some improvements in end-to-end delay and packet delivery rate in the suggested algorithm.
TL;DR: A solution that sufficiently maintains energy efficiency and congestion control for energy-harvesting WSNs is presented and an optimizing routing algorithm based on congestion control (CCOR) is proposed.
Abstract: Along with the increasing demands for the applications running on the wireless sensor network (WSN), energy consumption and congestion become two main problems to be resolved urgently. However, in most scenes, these two problems aren't considered simultaneously. To address this issue, in this paper a solution that sufficiently maintains energy efficiency and congestion control for energy-harvesting WSNs is presented. We first construct a queuing network model to detect the congestion degree of nodes. Then with the help of the principle of flow rate in hydraulics, an optimizing routing algorithm based on congestion control (CCOR) is proposed. The CCOR algorithm is designed by constructing two functions named link gradient and traffic radius based on node locations and service rate of packets. Finally, the route selection probabilities for each path are allocated according to the link flow rates. The simulation results show that the proposed solution significantly decreases the packet loss rate and maintains high energy efficiency under different traffic load.
TL;DR: The result of the simulation which has been done in MATLAB simulator indicates that Stable Election Protocol based on fuzzy logic is more energy efficient and improves the lifetime and throughput of the network by 73.2 and 68.54 % respectively comparing with the existing SEP protocol.
Abstract: In this paper a new protocol using fuzzy logic control has been proposed. The protocol is based on Stable Election Protocol (SEP). Fuzzy logic control based on three variables, distance of nodes form base station, density of nodes and the battery level of nodes along with the traditional threshold values used in SEP are used to enhance the process of cluster head election in the existing SEP protocol and improve the lifetime and throughput of the Wireless Sensor Network. The result of the simulation which has been done in MATLAB simulator indicates that Stable Election Protocol based on fuzzy logic is more energy efficient and improves the lifetime and throughput of the network by 73.2 and 68.54 % respectively comparing with the existing SEP protocol.
TL;DR: A novel virtual nodes-based range-free localization scheme, i.e., VN-APIT, is proposed to improve the APIT scheme and is shown to be more robust and has a lower average localization error (ALE) than the conventional APit scheme.
Abstract: As an important supporting technology, the localization technology has become the basis of the practical applications of wireless sensor networks for information acquisition and processing . APIT (approximate Point-In-Triangulation) localization scheme is widely used for localization estimation in wireless sensor networks due to the advantages of the high localization accuracy and easy to deploy. However, there are some inherent defects caused by the uneven distribution of sensor nodes in APIT scheme. To overcome the problem, in this paper a novel virtual nodes-based range-free localization scheme, i.e., VN-APIT, is proposed to improve the APIT scheme. By rationally deploying virtual nodes in sensor network according to the proposed VN-APIT test theory, VN-APIT localization scheme can determine independently that whether a target node is inside or outside the triangle formed by three certain anchor nodes. Therefore, it will not subject to the effect of the density and distribution of sensor nodes and there is no the problem of the In-to-Out error and the Out-to-In error in VN-APIT scheme. Simulation evaluation shows that the proposed VN-APIT scheme is more robust and has a lower average localization error (ALE) than the conventional APIT scheme.
TL;DR: A survey on existing literatures on QoE of video streaming is conducted to gain a deeper and more complete understanding ofQoE quality metrics and to inspire new research directions in defining better QOE and improving QoEs in existing and new streaming services such as adaptive streaming and 3D video streaming.
Abstract: The deployment of 3G/LTE networks and advancements in smart mobile devices had led to high demand for multimedia streaming over wireless network. The rapid increasing demand for multimedia content poses challenges for all parties in a multimedia streaming system, namely, content providers, wireless network service providers, and smart device makers. Content providers and mobile network service providers are both striving to improve their streaming services while utilizing advancing technologies. Smart device makers endeavor to improve processing power and displays for better viewing experience. Ultimately, the common goal shared by content providers, network service providers, and smart device manufactures is to improve the QoE for users. QoE is both an objective and a subjective metric measuring the streaming quality experience by end users. It may be measured by streaming bitrate, playback smoothness, video quality metrics like Peak to Signal Noise Ratio, and other user satisfaction factors. There have been efforts made to improve the streaming experiences in all these aspects. In this paper, we conducted a survey on existing literatures on QoE of video streaming to gain a deeper and more complete understanding of QoE quality metrics. The goal is to inspire new research directions in defining better QoE and improving QoE in existing and new streaming services such as adaptive streaming and 3D video streaming.
TL;DR: A cross-layer analysis of error-control strategies for nanonetworks in the THz band shows that, despite their simplicity, EPCs outperform traditional ARQ and FEC schemes, in terms of error correcting capabilities, which results in further energy savings and reduced latency.
Abstract: Nanonetworks consist of nano-sized communicating devices which are able to perform simple tasks at the nanoscale. The limited capabilities of individual nanomachines and the Terahertz (THz) band channel behavior lead to error-prone wireless links. In this paper, a cross-layer analysis of error-control strategies for nanonetworks in the THz band is presented. A mathematical framework is developed and used to analyze the tradeoffs between Bit Error Rate, Packet Error Rate, energy consumption and latency, for five different error-control strategies, namely, Automatic Repeat reQuest (ARQ), Forward Error Correction (FEC), two types of Error Prevention Codes (EPC) and a hybrid EPC. The cross-layer effects between the physical and the link layers as well as the impact of the nanomachine capabilities in both layers are taken into account. At the physical layer, nanomachines are considered to communicate by following a time-spread on-off keying modulation based on the transmission of femtosecond-long pulses. At the link layer, nanomachines are considered to access the channel in an uncoordinated fashion, by leveraging the possibility to interleave pulse-based transmissions from different nodes. Throughout the analysis, accurate path loss, noise and multi-user interference models, validated by means of electromagnetic simulation, are utilized. In addition, the energy consumption and latency introduced by a hardware implementation of each error control technique, as well as, the additional constraints imposed by the use of energy-harvesting mechanisms to power the nanomachines, are taken into account. The results show that, despite their simplicity, EPCs outperform traditional ARQ and FEC schemes, in terms of error correcting capabilities, which results in further energy savings and reduced latency.
TL;DR: This paper presents a clustering protocol named Hybrid, Game Theory based and Distributed clustering, which outperforms LEACH, CROSS and LGCA in terms of network lifetime and proves it terminates in finite iterations.
Abstract: Clustering has been well known as an effective way to reduce energy dissipation and prolong network lifetime in wireless sensor networks. Recently, game theory has been used to model clustering problem. Each node is modeled as a player which can selfishly choose its own strategies to be a cluster head (CH) or not. And by playing a localized clustering game, it gets an equilibrium probability to be a CH that makes its payoff keep equilibrium. In this paper, based on game theory, we present a clustering protocol named Hybrid, Game Theory based and Distributed clustering. In our protocol, we specifically define the payoff for each node when choosing different strategies, where both node degree and distance to base station are considered. Under this definition, each node gets its equilibrium probability by playing the game. And it decides whether to be a CH based on this equilibrium probability that can achieve a good trade-off between minimizing energy dissipation and providing the required services effectively. Moreover, an iterative algorithm is proposed to select the final CHs from the potential CHs according to a hybrid of residual energy and the number of neighboring potential CHs. Our iterative algorithm can balance the energy consumption among nodes and avoid the case that more than one CH occurs in a close proximity. And we prove it terminates in finite iterations. Simulation results show that our protocol outperforms LEACH, CROSS and LGCA in terms of network lifetime.
TL;DR: This work proposes a generic algorithm to generate conflict graphs which is independent of the underlying interference model, and proposes the notion of radio co-location interference, which is caused and experienced by spatially co-located radios in multi-radio multi-channel WMNs.
Abstract: Wireless Mesh Networks (WMNs) have evolved into a wireless communication technology of immense interest. But technological advancements in WMNs have inadvertently spawned a plethora of network performance bottlenecks, caused primarily by the rise in prevalent interference. Conflict Graphs are indispensable tools used to theoretically represent and estimate the interference in wireless networks. We propose a generic algorithm to generate conflict graphs which is independent of the underlying interference model. Further, we propose the notion of radio co-location interference, which is caused and experienced by spatially co-located radios in multi-radio multi-channel WMNs. We experimentally validate the concept, and propose a new all-encompassing algorithm to create a radio co-location aware conflict graph. Our novel conflict graph generation algorithm is demonstrated to be significantly superior and more efficient than the conventional approach, through theoretical interference estimates and comprehensive experiments. The results of an extensive set of ns-3 simulations run on the IEEE 802.11g platform strongly indicate that the radio co-location aware conflict graphs are a marked improvement over their conventional counterparts. We also question the use of total interference degree as a reliable metric to predict the performance of a Channel Assignment scheme in a given WMN deployment.
TL;DR: The overall review of all the existing communication models in VANET and in addition to that WVANET (Web VANet) communication model is presented and the authors portray that WvANET will be the everlasting research field in future.
Abstract: The most ever growing research field is vehicular ad hoc network. This prominent research field has the widely known communication models such as RoadSide Unit Communication, Vehicle to Vehicle Communication, and Cluster based Communication models. In addition to that M. Milton Joe and B. Ramakrishnan et al. have proposed a new communication model known as WVANET (Web VANET) for vehicular ad hoc network communication. The authors portray that WVANET will be the everlasting research field in future. This WVANET (Web VANET) communication model is fundamentally different from other communication models as it makes use of web signals to disseminate the messages among vehicles. Of course, each communication model in VANET will have its own various pros and cons. This paper provides the overall review of all the existing communication models in VANET and in addition to that WVANET (Web VANET) communication model is also presented. Further this paper discusses the various future research that can be done in WVANET (Web VANET) communication model.
TL;DR: An effort has been made in this paper to formulate a hybrid model to calculate the trustworthiness of service providers and the proposed approach is efficient and considerably improves service-selection process in cloud applications.
Abstract: Cloud computing, a new paradigm in distributed computing, has gained wide popularity in a relatively short span of time. With the increase in the number, functionality and features of cloud services, it is more and more mind-boggling for the cloud users to find a trustworthy provider. Cloud users need to have confidence in cloud providers to migrate their critical data to cloud computing. There must be some means to determine reliability of service providers so that users can choose services with the assurance that the provider will not act malignantly. An effort has been made in this paper to formulate a hybrid model to calculate the trustworthiness of service providers. Cloud services are evaluated and trust value is calculated based on compliance and reputation. Service logs based compliance reflects dynamic trust. The reputation has been computed from collective user feedback. Feedback rating is the view of each user about the invoked services. The discovered services that fulfill the user requirements are ranked based on their trust values and top-k cloud services are recommended to the user. The proposed approach is efficient and considerably improves service-selection process in cloud applications.
TL;DR: A novel light-weight data mining algorithm is proposed to detect road surface events and transmit potential pothole information to a central server, and can effectively detect road potholes and evaluate road roughness levels using hardware modules mounted on distributed vehicles.
Abstract: Detecting road potholes and road roughness levels is key to road condition monitoring, which impacts transport safety and driving comfort. We propose a crowdsourcing-based road surface monitoring system, simply called CRSM. CRSM can effectively detect road potholes and evaluate road roughness levels using hardware modules mounted on distributed vehicles. These modules use low-end accelerometers and GPS devices to obtain vibration patterns, locations, and vehicle velocities. Considering the high cost of onboard storage and wireless transmission, a novel light-weight data mining algorithm is proposed to detect road surface events and transmit potential pothole information to a central server. The central server gathers reports from multiple vehicles, and makes a comprehensive evaluation on road surface quality. We have implemented a product-quality system, and have deployed it on 100 taxies in the Shenzhen urban area. The results show that CRSM can detect road potholes with 90 % accuracy, with nearly zero false alarms. CRSM can also evaluate road roughness levels correctly, even with some interferences from small bumps or potholes.
TL;DR: A method of cluster formation is proposed which will take into account two most vital factor node degree and bandwidth requirement for construction of the cluster and selection of the Cluster Head in order to enhance the performance.
Abstract: Cluster based routing in Mobile AdHoc Networks are considered one of the convenient method of routing. Existence of Cluster Head (CH) in a group of nodes for data forwarding improves the performance of routing in terms of routing overhead and power consumption. However, due to the movement of CH and frequent change in cluster members, cluster reformation is required and increases cluster formation overhead. The stability of the cluster highly dependent of stability of the CH and hence during CH selection special care should be taken so that the cluster head survives for longer time. In this paper a method of cluster formation is proposed which will take into account two most vital factor node degree and bandwidth requirement for construction of the cluster and selection of the cluster head. Further, when two clusters come closer to each other they merge and form a single cluster. In such case out of two CHs one has to withdraw the role and other will take over. A new mechanism of merging two clusters is also proposed in the paper. We call this method as an Improved Cluster Maintenance Scheme and primarily focused on minimizing CH changing process in order to enhance the performance. The stated method makes cluster more stable, and minimizes packet loss. The proposed algorithm is simulated in ns-2 and compared with Least Cluster head Change (LCC) and CBRP. Our algorithm shows better behavior in terms of number of clusterhead changes or number of cluster member changes.
TL;DR: A novel trust establishment algorithm is proposed, designed, and implemented specifically for opportunistic routing protocols which benefits from direct interactions between wireless nodes.
Abstract: Opportunistic routing is a promising research area in the context of wireless network communications. Security and trustworthy of routing in this field, however, needs to be considerably researched . In this paper, a novel trust establishment algorithm is proposed, designed, and implemented specifically for opportunistic routing protocols which benefits from direct interactions between wireless nodes. The proposed trust model benefits from a novel watchdog mechanism considering not only forwarding behaviour of nodes but also the quality of links between them. Furthermore, three different metrics for next hop selection is introduced enabling nodes to select their next hop forwarders more sophisticatedly using quality of links, geographical location of nodes, and their trust level. Extensive simulation results represent that proposed model can significantly improve the performance of network communications when malicious nodes try to collapse the system.
TL;DR: A localized movement control actor relocation (MCAR) algorithm that strives to improve connected coverage while minimizing movement overhead and connected coverage compared to contemporary schemes is presented.
Abstract: Wireless sensor and actor networks (WSAN) are captivating significant attention because of their suitability for safety---critical applications. Efficient actor placement in such applications is extremely desirable to perform effective and timely action across the deployment region. Nonetheless, harsh application environment inherently favors random placement of actors that leads to high concentration deployment and strangles coverage. Moreover, most of the published schemes lack rigorous validation and entirely rely on informal techniques (e.g., simulation) for evaluating nonfunctional properties of algorithms. This paper presents a localized movement control actor relocation (MCAR) algorithm that strives to improve connected coverage while minimizing movement overhead. MCAR pursues post-deployment actor repositioning in such a way that actors repel each other for better coverage while staying connected. We employ complementary formal and informal techniques for MCAR verification and validation. We model WSAN as a dynamic graph and transform MCAR to corresponding formal specification using Z notation. The resulting specification is analyzed and validated using Z eves tool. We simulate the specification to quantitatively demonstrate the efficiency of MCAR. Simulation results confirm the efficiency of MCAR in terms of movement overhead and connected coverage compared to contemporary schemes. The results show that MCAR can reduce distance movement up to 32 % while improving coverage up to 29 % compared to published schemes.
TL;DR: The proposed SEAD protocol presents a robust data dissemination mechanism which is suitable either for safety applications or for other kinds of application, and is able to adapt the protocol performance in terms of packet delivery ratio to the application’s requirements.
Abstract: Vehicular ad-hoc network (VANET) is becoming a promising technology for improving the efficiency and the safety of intelligent transportation systems by deploying a wide variety of applications Smart vehicles are expected to continuously exchange a huge amount of data either through safety or non-safety messages dedicated for road safety or infotainment and passenger comfort applications, respectively One of the main challenges posed by the study of VANET is the data dissemination design by which messages have to be efficiently disseminated in a high vehicular speed, intermittent connectivity, and highly dynamic topology In particular, broadcast mechanism should guarantee fast and reliable data delivery within a limited wireless bandwidth in order to fit the real time applications' requirements In this work, we propose a simple and efficient adaptive data dissemination protocol called "SEAD" On the one hand, the originality of this work lies in its simplicity and efficiency regardless the application's type Simplicity is achieved through a beaconless strategy adopted to take into account the surrounding vehicles' density Thanks to a metric locally measured, each vehicle is able to dynamically define an appropriate probability of rebroadcast to mitigate the broadcast storm problem Efficiency is manifested by reducing excessive retransmitted messages and hence promoting the network capacity and the transmission delay The simulation results show that the proposed protocol offers very low packet drop ratio and network load while still maintaining a low end-to-end delay and a high packet delivery On the other hand, SEAD protocol presents a robust data dissemination mechanism which is suitable either for safety applications or for other kinds of application This mechanism is able to adapt the protocol performance in terms of packet delivery ratio to the application's requirements
TL;DR: A method was proposed that constantly selects the next node and considers the number of copies a node can deliver and significant enhancement is obtained with the proposed method when measuring metrics such as delay, delivery ratio and copy do comparisons with similar methods.
Abstract: Due to the instability and intermittent connectivity of links among the nodes and the lack of connectivity in opportunistic network, it is not feasible to use common routing for delivering messages . The only practical method for routing and delivering messages is to use the store-carry-forward routing method. As a case in point, spray and wait is considered to be one of the most appropriate routing methods. The efficiency of this method depends directly on the proper selection of the next hop and the number of copies when it encounters a node. In this paper, a method was proposed that constantly selects the next node and considers the number of copies a node can deliver. In the proposed method, the selection of the next node and the number of message copies to be transmitted by the next hop are based on message carrying time and the probability of message delivery. The network model, based on Markov chain, is extended for analysis. Simulation and analysis results showed that significant enhancement is obtained with the proposed method when measuring metrics such as delay, delivery ratio and copy do comparisons with similar methods.
TL;DR: This work presents the design and implementation of a house-build experimental platform, named Energy Management System for Wireless Sensor Networks (EMrise) for the energy management and exploration on wireless sensor networks.
Abstract: Due to reliance on batteries, energy consumption has always been of significant concern for sensor node networks. This work presents the design and implementation of a house-build experimental platform, named Energy Management System for Wireless Sensor Networks (EMrise) for the energy management and exploration on wireless sensor networks. Consisting of three parts, the SystemC-based simulation environment of EMrise enables the HW/SW co-simulation for energy evaluation on heterogeneous sensor networks. The hardware platform of EMrise is further designed to facilitate the realistic energy consumption measurement and calibration as well as accurate energy exploration. In the meantime, a generic genetic algorithm based optimization framework of EMrise is also implemented to automatically, quickly and intelligently fine tune hundreds of possible solutions for the given task to find the best suitable energy-aware tradeoffs.
TL;DR: A social-based particle swarm optimization approach which additionally includes a social-supporting vector to direct low- loading mesh routers to support the heavy-loading mesh routers in the same topology subgraph component (community), so as to dynamically adopt to the social community behavior of mesh clients.
Abstract: The problem of dynamic router node placement (dynRNP) in wireless mesh networks (WMNs) is concerned with determining a dynamic geographical placement of mesh routers to serve mobile mesh clients at different times, so that both network connectivity (i.e., the greatest topology subgraph component size) and client coverage (i.e., the number of the served mesh clients) are maximized. Mesh clients are wireless devises associated with users, and in real world, the users with same interests or some social relationship have higher chance to gather and move together geographically, i.e., they form a community, and the WMN with multiple communities can be regarded as a social network. Therefore, this paper investigates the so-called social-aware WMN-dynRNP problem assuming that mesh routers should be aware of the social community structure of mesh clients to dynamically adjust their placement to improve network performance. To cope with this problem, this paper proposes a social-based particle swarm optimization approach, which additionally includes a social-supporting vector to direct low-loading mesh routers to support the heavy-loading mesh routers in the same topology subgraph component (community), so as to dynamically adopt to the social community behavior of mesh clients. As compared with the previous approach, our experimental results show that the proposed approach is capable of effectively reducing number of the unserved mesh clients and increasing network connectivity in dynamic social scenarios.