Journal of Computer Networks and Communications The latest articles from Hindawi © 2017 , Hindawi Limited . All rights reserved. Energy Efficient Clustering Based Network Protocol Stack for 3D Airborne Monitoring System Thu, 16 Feb 2017 09:17:47 +0000 Wireless Sensor Network consists of large number of nodes densely deployed in ad hoc manner. Usually, most of the application areas of WSNs require two-dimensional (2D) topology. Various emerging application areas such as airborne networks and underwater wireless sensor networks are usually deployed using three-dimensional (3D) network topology. In this paper, a static 3D cluster-based network topology has been proposed for airborne networks. A network protocol stack consisting of various protocols such as TDMA MAC and dynamic routing along with services such as time synchronization, Cluster Head rotation, and power level management has been proposed for this airborne network. The proposed protocol stack has been implemented on the hardware platform consisting of number of TelosB nodes. This 3D airborne network architecture can be used to measure Air Quality Index (AQI) in an area. Various parameters of network such as energy consumption, Cluster Head rotation, time synchronization, and Packet Delivery Ratio (PDR) have been analyzed. Detailed description of the implementation of the protocol stack along with results of implementation has been provided in this paper. Abhishek Joshi, Sarang Dhongdi, Rishabh Sethunathan, Pritish Nahar, and K. R. Anupama Copyright © 2017 Abhishek Joshi et al. All rights reserved. Enabling LTE and WiFi Coexisting in 5 GHz for Efficient Spectrum Utilization Thu, 09 Feb 2017 00:00:00 +0000 Due to the increasing mobile traffic demands in cellular network, researchers have proposed the coexistence of LTE and WiFi technologies in 5 GHz unlicensed bands. Therefore, how to efficiently utilize the spectrum in 5 GHz becomes extremely important. To avoid the channel access conflicts, current LTE Unlicensed (LTE-U) technology introduces the duty cycle of LTE, while License-Assisted Access (LAA) technology introduces Listen-Before-Talk (LBT) mechanism. While these two technologies improve the spectrum utilization by using time division access schema, we believe that more efficient spectrum utilization can be achieved by enabling simultaneous transmissions from LTE and WiFi. In this paper, we propose a novel method (i.e., Low Amplitude Stream Injection (LASI) method) to enable the simultaneous transmissions of WiFi and LTE frames in the same channel and recover the data from the conflicts. To further utilize the LASI method, we introduce the Conflict-Tolerant Channel Allocation (CTCA) algorithm to optimize the channel allocation and achieve more efficient spectrum utilization in 5 GHz. Extensive simulation results show that our approach achieves lower latency and higher throughput. Compared with the state-of-the-art LTE-U and LAA technologies, our approach can improve the spectrum efficiency 2.9 times. Hongyu Sun, Zhiyi Fang, Qun Liu, Zheng Lu, and Ting Zhu Copyright © 2017 Hongyu Sun et al. All rights reserved. Analytical Computation of Information Rate for MIMO Channels Wed, 08 Feb 2017 00:00:00 +0000 Information rate for discrete signaling constellations is significant. However, the computational complexity makes information rate rather difficult to analyze for arbitrary fading multiple-input multiple-output (MIMO) channels. An analytical method is proposed to compute information rate, which is characterized by considerable accuracy, reasonable complexity, and concise representation. These features will improve accuracy for performance analysis with criterion of information rate. Jinbao Zhang, Zhenhui Tan, and Song Chen Copyright © 2017 Jinbao Zhang et al. All rights reserved. Cloud-Based DDoS HTTP Attack Detection Using Covariance Matrix Approach Tue, 24 Jan 2017 00:00:00 +0000 In this era of technology, cloud computing technology has become essential part of the IT services used the daily life. In this regard, website hosting services are gradually moving to the cloud. This adds new valued feature to the cloud-based websites and at the same time introduces new threats for such services. DDoS attack is one such serious threat. Covariance matrix approach is used in this article to detect such attacks. The results were encouraging, according to confusion matrix and ROC descriptors. Abdulaziz Aborujilah and Shahrulniza Musa Copyright © 2017 Abdulaziz Aborujilah and Shahrulniza Musa. All rights reserved. IoT in Action: Design and Implementation of a Building Evacuation Service Sun, 22 Jan 2017 00:00:00 +0000 With the development of sensor technologies, various application areas have emerged. The usage of these technologies and exploitation of recent improvements have clear benefits on building applications. Such use-cases can improve smart functions of buildings and can increase the end-user comfort. As a similar notion, building automation systems (BAS) are smart systems that target to provide automated management of various control services and to improve resource usage efficiency. However, buildings generally contain hardware and control services from a diverse set of characteristics. The automated and central management of such functions can be challenging. In order to overcome such issues, an Emergency Evacuation Service is proposed for BAS, where requirements of such central management model are analyzed and model content and subservice definitions are prepared. A crucial scenario, which could be a necessity for future BAS, is defined and an approach for evacuation of people in the buildings at emergency situations is proposed. For real-life scenarios, the Evacuation Service is implemented by using a low-cost design, which is appropriate for Internet of Things (IoT) based BAS applications. As demonstrated, the proposed service model can provide effective performance in real-life deployments. Selahattin Gokceli, Nikolay Zhmurov, Gunes Karabulut Kurt, and Berna Ors Copyright © 2017 Selahattin Gokceli et al. All rights reserved. Robust Preamble-Based Timing Synchronization for OFDM Systems Mon, 02 Jan 2017 12:53:57 +0000 This study presents a novel preamble-based timing offset estimation method for orthogonal frequency division multiplexing (OFDM) systems. The proposed method is robust, immune to the carrier frequency offset (CFO), and independent of the structure of the preamble. The performance of the new method is demonstrated in terms of mean square error (MSE) obtained by simulation in multipath fading channels. The results indicate that the new method significantly improves timing performance in comparison with existing methods. Yun Liu, Fei Ji, Hua Yu, Dehuan Wan, Fangjiong Chen, and Ling Yang Copyright © 2017 Yun Liu et al. All rights reserved. An Architecture for Anonymous Mobile Coupons in a Large Network Sun, 18 Dec 2016 13:34:05 +0000 A mobile coupon (m-coupon) can be presented with a smartphone for obtaining a financial discount when purchasing a product or a service. M-coupons are a powerful marketing tool that has enjoyed a huge growth and diffusion, involving tens of millions of people each year. We propose an architecture which may enable significant improvements over current m-coupon technology, in terms of acceptance of potential customers and of marketing actions that become feasible: the customer does not need to install any dedicated app; an m-coupon is not bound to any specific device or customer; an m-coupon may be redeemed at any store in a set of potentially many thousands of stores, without any prior arrangement between customer and store. We are not aware of any proposal with these properties. Alberto Bartoli and Eric Medvet Copyright © 2016 Alberto Bartoli and Eric Medvet. All rights reserved. Dynamic Clustering Algorithm for Tracking Targets with High and Variable Celerity (ATHVC) Sun, 18 Dec 2016 06:12:21 +0000 Target tracking with the wireless sensors networks is to detect and locate a target on its entire path through a region of interest. This application arouses interest in the world of research for its many fields of use. Wireless sensor networks, thanks to their versatility, can be used in many hostile and inaccessible to humans environments. However, with a limited energy, they cannot remain permanently active, which can significantly reduce their lifetime. The formation of a cluster network seems an effective mechanism to increase network lifetime. We propose to build optimal dynamic clusters on the target trajectory. For increasing energy efficiency, our algorithm integrates for the first time, to our knowledge, strategies to avoid overlapping clusters and a model to wake up the sensors, adapting to the context of targets with large and variable speed. Mohamed Toumi, Abderrahim Maizate, Mohammed Ouzzif, and Med Said Salah Copyright © 2016 Mohamed Toumi et al. All rights reserved. Performance Analysis of the Effect of Nonlinear Low Noise Amplifier for Wideband Spectrum Sensing in the Poisson Field of Interferers Thu, 24 Nov 2016 12:21:34 +0000 A cognitive radio (CR) device likely consists of a low-cost low noise amplifier (LNA) due to the mass-production reason. Nevertheless, the operation of a low-cost LNA becomes highly nonlinear causing intermodulation (IM) interference. The most important task of CR devices is to sense the wideband spectrum to increase opportunistic throughput. In noncooperative secondary networks, the IM interference usually can be ignored for the narrowband spectrum sensing, while the IM interference needs to be taken into account along with interference from other CR devices in the wideband case. Our contribution is to study the effects of a nonlinear LNA for the second case in environments modeled by Poisson field of interferers reflecting more realistic scenario. As shown in the simulation results, the performance of the receiver is degraded in all the cases due to the nonlinearity of LNA. The adaptive threshold setting based on the multivariate Gaussian mixture model is proposed to improve the receiver performance. Bipun Man Pati and Attaphongse Taparugssanagorn Copyright © 2016 Bipun Man Pati and Attaphongse Taparugssanagorn. All rights reserved. Performance Analysis of Reuse Distance in Cooperative Broadcasting Tue, 15 Nov 2016 12:35:10 +0000 Cooperative broadcasting is a promising technique for robust broadcast with low overhead and delay in mobile ad hoc networks. The technique is attractive for mission-oriented mobile communication, where a majority of the traffic is of broadcast nature. In cooperative broadcasting, all nodes simultaneously retransmit packets. The receiver utilizes cooperative diversity in the simultaneously received signals. The retransmissions continue until all nodes are reached. After the packet has traveled a specific number of hops out from the source, denoted as reuse distance, the source node transmits a new broadcast packet in the time slot used for the previous broadcast packet. If the reuse distance is too small, interference causes packet loss in intermediate nodes. In the literature, a reuse distance of three is common. With an analysis based on a realistic interference model and real terrain data, we show that a reuse distance of at least four is necessary to avoid packet loss in sparsely connected networks, especially for high spectral efficiencies. For frequency hopping, widely used in military systems, we propose a novel method. This method almost eliminates interference for a reuse distance of three, increasing the throughput by 33% compared to systems with a reuse distance of four. Jimmi Grönkvist, Anders Hansson, and Arwid Komulainen Copyright © 2016 Jimmi Grönkvist et al. All rights reserved. Wormhole Detection Based on Ordinal MDS Using RTT in Wireless Sensor Network Mon, 07 Nov 2016 08:08:37 +0000 In wireless communication, wormhole attack is a crucial threat that deteriorates the normal functionality of the network. Invasion of wormholes destroys the network topology completely. However, most of the existing solutions require special hardware or synchronized clock or long processing time to defend against long path wormhole attacks. In this work, we propose a wormhole detection method using range-based topology comparison that exploits the local neighbourhood subgraph. The Round Trip Time (RTT) for each node pair is gathered to generate neighbour information. Then, the network is reconstructed by ordinal Multidimensional Scaling (MDS) followed by a suspicion phase that enlists the suspected wormholes based on the spatial reconstruction. Iterative computation of MDS helps to visualize the topology changes and can localize the potential wormholes. Finally, a verification phase is used to remove falsely accused nodes and identify real adversaries. The novelty of our algorithm is that it can detect both short path and long path wormhole links. Extensive simulations are executed to demonstrate the efficacy of our approach compared to existing ones. Saswati Mukherjee, Matangini Chattopadhyay, Samiran Chattopadhyay, and Pragma Kar Copyright © 2016 Saswati Mukherjee et al. All rights reserved. Creating Values out of Internet of Things: An Industrial Perspective Wed, 19 Oct 2016 06:48:39 +0000 Internet of Things based cloud is envisaged to extract values other than the specified purpose for which it is to be utilized. It is hereby apprehended that different genre of values, rather business values, could efficiently be assimilated from the Internet of Things cloud platforms. It is also investigated to identify numerous domains of applications that are currently being associated with the similar cloud platforms. A case study on various types of value generation methods has been performed. A novel Internet of Things cloud stack is proposed to disseminate and aggregate the business values. Few research challenges are observed that shall need appropriate indulgence to generate more business values out of Internet of Things based cloud. This paper also seeks few research and industry related problems that need to be resolved. It further recommends several key parameters to the enterprise and government policymakers that should immediately be dealt with for long-term success. Partha Pratim Ray Copyright © 2016 Partha Pratim Ray. All rights reserved. Measurement of Mobile Switching Centres Throughput in GSM Network Integrating Sliding Window Algorithm with a Single Server Finite Queuing Model Thu, 13 Oct 2016 07:47:42 +0000 The sliding window algorithm proposed for determining an optimal sliding window does not consider the waiting times of call setup requests of a mobile station in queue at a Mobile Switching Centre (MSC) in the Global System for Mobile (GSM) Communication Network. This study proposes a model integrating the sliding window algorithm with a single server finite queuing model, referred to as integrated model for measurement of realistic throughput of a MSC considering the waiting times of call setup requests. It assumes that a MSC can process one call setup request at a time. It is useful in determining an optimal sliding window size that maximizes the realistic throughput of a MSC. Though the model assumes that a MSC can process one call setup request at a time, its scope can be extended for measuring the realistic throughput of a MSC that can process multiple call setup requests at a time. Dinaker Babu Bollini, Mannava Muniratnam Naidu, and Mallikharjuna Rao Nuka Copyright © 2016 Dinaker Babu Bollini et al. All rights reserved. A Quantitative Risk Evaluation Model for Network Security Based on Body Temperature Wed, 12 Oct 2016 13:52:17 +0000 These days, in allusion to the traditional network security risk evaluation model, which have certain limitations for real-time, accuracy, characterization. This paper proposed a quantitative risk evaluation model for network security based on body temperature (QREM-BT), which refers to the mechanism of biological immune system and the imbalance of immune system which can result in body temperature changes, firstly, through the -contiguous bits nonconstant matching rate algorithm to improve the detection quality of detector and reduce missing rate or false detection rate. Then the dynamic evolution process of the detector was described in detail. And the mechanism of increased antibody concentration, which is made up of activating mature detector and cloning memory detector, is mainly used to assess network risk caused by various species of attacks. Based on these reasons, this paper not only established the equation of antibody concentration increase factor but also put forward the antibody concentration quantitative calculation model. Finally, because the mechanism of antibody concentration change is reasonable and effective, which can effectively reflect the network risk, thus body temperature evaluation model was established in this paper. The simulation results showed that, according to body temperature value, the proposed model has more effective, real time to assess network security risk. Y. P. Jiang, C. C. Cao, X. Mei, and H. Guo Copyright © 2016 Y. P. Jiang et al. All rights reserved. A Persistent Structured Hierarchical Overlay Network to Counter Intentional Churn Attack Wed, 12 Oct 2016 11:21:57 +0000 The increased use of structured overlay network for a variety of applications has attracted a lot of attention from both research community and attackers. However, the structural constraints, open nature (anybody can join and anybody may leave), and unreliability of its participant nodes significantly affect the performance of these applications and make it vulnerable to a variety of attacks such as eclipse, Sybil, and churn. One attack to compromise the service availability in overlay network is intentional churn (join/leave) attack, where a large number of malicious users will join and leave the overlay network so frequently that the entire structure collapses and becomes unavailable. The focus of this paper is to provide a new robust, efficient, and scalable hierarchical overlay architecture that will counter these attacks by providing a structure that can accommodate the fleeting behaviour of nodes without causing much structural inconsistencies. The performance evaluation showed that the proposed architecture has more failure resilience and self-organization as compared to chord based architecture. Experimental results have demonstrated that the effect of failures on an overlay is proportional to the size of failure. Ramanpreet Kaur, Amrit Lal Sangal, and Krishan Kumar Copyright © 2016 Ramanpreet Kaur et al. All rights reserved. Human Depth Sensors-Based Activity Recognition Using Spatiotemporal Features and Hidden Markov Model for Smart Environments Tue, 04 Oct 2016 14:24:14 +0000 Nowadays, advancements in depth imaging technologies have made human activity recognition (HAR) reliable without attaching optical markers or any other motion sensors to human body parts. This study presents a depth imaging-based HAR system to monitor and recognize human activities. In this work, we proposed spatiotemporal features approach to detect, track, and recognize human silhouettes using a sequence of RGB-D images. Under our proposed HAR framework, the required procedure includes detection of human depth silhouettes from the raw depth image sequence, removing background noise, and tracking of human silhouettes using frame differentiation constraints of human motion information. These depth silhouettes extract the spatiotemporal features based on depth sequential history, motion identification, optical flow, and joints information. Then, these features are processed by principal component analysis for dimension reduction and better feature representation. Finally, these optimal features are trained and they recognized activity using hidden Markov model. During experimental results, we demonstrate our proposed approach on three challenging depth videos datasets including IM-DailyDepthActivity, MSRAction3D, and MSRDailyActivity3D. All experimental results show the superiority of the proposed approach over the state-of-the-art methods. Ahmad Jalal, Shaharyar Kamal, and Daijin Kim Copyright © 2016 Ahmad Jalal et al. All rights reserved. Corrigendum to “Hole Detection for Quantifying Connectivity in Wireless Sensor Networks: A Survey” Wed, 14 Sep 2016 09:08:41 +0000 Pearl Antil and Amita Malik Copyright © 2016 Pearl Antil and Amita Malik. All rights reserved. Exact SER Analysis of DFrFT-Based QPSK OFDM System over Frequency Selective Rayleigh Fading Channel with CFO Tue, 06 Sep 2016 09:11:38 +0000 We present the exact symbol error rate (SER) expression for quadrature phase shift keying (QPSK) modulation in frequency selective Rayleigh fading channel for discrete fractional Fourier transform- (DFrFT-) based orthogonal frequency division multiplexing (OFDM) system in the presence of carrier frequency offset (CFO). The theoretical result is confirmed by means of Monte Carlo simulations. It is shown that the performance of the proposed system, at different values of the DFrFT angle parameter “,” is better than that of OFDM based on discrete Fourier transform. Atul Kumar, Maurizio Magarini, Hem Dutt Joshi, and Rajiv Saxena Copyright © 2016 Atul Kumar et al. All rights reserved. Developing an On-Demand Cloud-Based Sensing-as-a-Service System for Internet of Things Tue, 30 Aug 2016 09:30:54 +0000 The increasing number of Internet of Things (IoT) devices with various sensors has resulted in a focus on Cloud-based sensing-as-a-service (CSaaS) as a new value-added service, for example, providing temperature-sensing data via a cloud computing system. However, the industry encounters various challenges in the dynamic provisioning of on-demand CSaaS on diverse sensor networks. We require a system that will provide users with standardized access to various sensor networks and a level of abstraction that hides the underlying complexity. In this study, we aim to develop a cloud-based solution to address the challenges mentioned earlier. Our solution, SenseCloud, includes a sensor virtualization mechanism that interfaces with diverse sensor networks, a multitenancy mechanism that grants multiple users access to virtualized sensor networks while sharing the same underlying infrastructure, and a dynamic provisioning mechanism to allow the users to leverage the vast pool of resources on demand and on a pay-per-use basis. We implement a prototype of SenseCloud by using real sensors and verify the feasibility of our system and its performance. SenseCloud bridges the gap between sensor providers and sensor data consumers who wish to utilize sensor data. Mihui Kim, Mihir Asthana, Siddhartha Bhargava, Kartik Krishnan Iyyer, Rohan Tangadpalliwar, and Jerry Gao Copyright © 2016 Mihui Kim et al. All rights reserved. A Data Mining Classification Approach for Behavioral Malware Detection Tue, 26 Jul 2016 12:22:02 +0000 Data mining techniques have numerous applications in malware detection. Classification method is one of the most popular data mining techniques. In this paper we present a data mining classification approach to detect malware behavior. We proposed different classification methods in order to detect malware based on the feature and behavior of each malware. A dynamic analysis method has been presented for identifying the malware features. A suggested program has been presented for converting a malware behavior executive history XML file to a suitable WEKA tool input. To illustrate the performance efficiency as well as training data and test, we apply the proposed approaches to a real case study data set using WEKA tool. The evaluation results demonstrated the availability of the proposed data mining approach. Also our proposed data mining approach is more efficient for detecting malware and behavioral classification of malware can be useful to detect malware in a behavioral antivirus. Monire Norouzi, Alireza Souri, and Majid Samad Zamini Copyright © 2016 Monire Norouzi et al. All rights reserved. ZigBee’s Received Signal Strength and Latency Evaluation under Varying Environments Tue, 28 Jun 2016 12:18:23 +0000 Being self-configured, self-organized, and self-healing low power technology, ZigBee has obtained significant attention in last few years for achieving ubiquitous communication among various devices within a Personal Area Network (PAN). Even after a decade of its emergence, it has been well serving the communication needs of numerous modern applications belonging to multiple industries and is still a spotlight for the researchers working on certain aspects to enhance productivity along with a major cost reduction. Despite its robust communication nature, it heavily depends upon the context and is prone to the external effects that may cause a serious threat to prospective applications. This paper presents the novel experimental analysis conducted on real test beds to evaluate the impact of continuously changing communication environment on various parameters, for example, RSSI (Received Signal Strength Indicator) and latency in the presence of multiple obstacles that may lead to severe degradation in the overall performance. Eventually, we suggest a suitable frame size for ZigBee based on our results deduced from the experimental study. H. H. R. Sherazi, Razi Iqbal, Sana Ul Hassan, M. H. Chaudary, and Syed Asfandyar Gilani Copyright © 2016 H. H. R. Sherazi et al. All rights reserved. Design and Implementation of a Chaotic Scheme in Additive White Gaussian Noise Channel Thu, 23 Jun 2016 08:52:15 +0000 A new chaotic scheme named Flipped Chaotic On-Off Keying (FCOOK) is proposed for binary transmission. In FCOOK, the low correlation value between the stationary signal and its mirrored version is utilized. Transmitted signal for binary 1 is a chaotic segment added to its time flipped (mirrored) version within one bit duration, while in binary 0, no transmission takes place within the same bit duration. The proposed scheme is compared with the standard chaotic systems: Differential Chaos Shift Keying (DCSK) and Correlation Delay Shift Keying (CDSK). The Bit Error Rate (BER) of FCOOK is studied analytically based on Gaussian approximation method. Results show that the BER performance of FCOOK outperforms DCSK and CDSK in AWGN channel environment and with various levels. Additionally, FCOOK offers a double bit rate compared with the standard DCSK. Nizar Al Bassam and Oday Jerew Copyright © 2016 Nizar Al Bassam and Oday Jerew. All rights reserved. Joint Channel Assignment and Routing in Multiradio Multichannel Wireless Mesh Networks: Design Considerations and Approaches Mon, 20 Jun 2016 14:27:50 +0000 Multiradio wireless mesh network is a promising architecture that improves the network capacity by exploiting multiple radio channels concurrently. Channel assignment and routing are underlying challenges in multiradio architectures since both determine the traffic distribution over links and channels. The interdependency between channel assignments and routing promotes toward the joint solutions for efficient configurations. This paper presents an in-depth review of the joint approaches of channel assignment and routing in multiradio wireless mesh networks. First, the key design issues, modeling, and approaches are identified and discussed. Second, existing algorithms for joint channel assignment and routing are presented and classified based on the channel assignment types. Furthermore, the set of reconfiguration algorithms to adapt the network traffic dynamics is also discussed. Finally, the paper presents some multiradio practical implementations and test-beds and points out the future research directions. Omar M. Zakaria, Aisha-Hassan A. Hashim, Wan H. Hassan, Othman O. Khalifa, M. Azram, Lalitha B. Jivanadham, Mistura L. Sanni, and Mahdi Zareei Copyright © 2016 Omar M. Zakaria et al. All rights reserved. Reliable and Energy Efficient Protocol for MANET Multicasting Wed, 08 Jun 2016 08:01:00 +0000 A mobile ad hoc network (MANET) consists of a self-configured set of portable mobile nodes without any central infrastructure to regulate traffic in the network. These networks present problems such as lack of congestion control, reliability, and energy consumption. In this paper, we present a new model for MANET multicasting called Reliable and Energy Efficient Protocol Depending on Distance and Remaining Energy (REEDDRE). Our proposal is based on a tone system to provide more efficiency and better performance, and it combines solutions over the Medium Access Control (MAC) layer. The protocol consists of a new construction method for mobile nodes using a clustering approach that depends on distance and remaining energy to provide more stability and to reduce energy consumption. In addition, we propose an adjustment to the typical multicast flow by adding unicast links between clusters. We further present in our model a technique to provide more reliability based on a busy tone system (RMBTM) to reduce excessive control overhead caused by control packets in error recovery. We simulate our proposal using OPNET, and the results show enhancement in terms of reliability, packet delivery ratio (PDR), energy consumption, and throughput. Bander H. AlQarni and Ahmad S. AlMogren Copyright © 2016 Bander H. AlQarni and Ahmad S. AlMogren. All rights reserved. On Internet Traffic Classification: A Two-Phased Machine Learning Approach Mon, 06 Jun 2016 06:31:25 +0000 Traffic classification utilizing flow measurement enables operators to perform essential network management. Flow accounting methods such as NetFlow are, however, considered inadequate for classification requiring additional packet-level information, host behaviour analysis, and specialized hardware limiting their practical adoption. This paper aims to overcome these challenges by proposing two-phased machine learning classification mechanism with NetFlow as input. The individual flow classes are derived per application through -means and are further used to train a C5.0 decision tree classifier. As part of validation, the initial unsupervised phase used flow records of fifteen popular Internet applications that were collected and independently subjected to -means clustering to determine unique flow classes generated per application. The derived flow classes were afterwards used to train and test a supervised C5.0 based decision tree. The resulting classifier reported an average accuracy of 92.37% on approximately 3.4 million test cases increasing to 96.67% with adaptive boosting. The classifier specificity factor which accounted for differentiating content specific from supplementary flows ranged between 98.37% and 99.57%. Furthermore, the computational performance and accuracy of the proposed methodology in comparison with similar machine learning techniques lead us to recommend its extension to other applications in achieving highly granular real-time traffic classification. Taimur Bakhshi and Bogdan Ghita Copyright © 2016 Taimur Bakhshi and Bogdan Ghita. All rights reserved. SEMAN: A Novel Secure Middleware for Mobile Ad Hoc Networks Mon, 23 May 2016 12:26:38 +0000 As a consequence of the particularities of Mobile Ad Hoc Networks (MANETs), such as dynamic topology and self-organization, the implementation of complex and flexible applications is a challenge. To enable the deployment of these applications, several middleware solutions were proposed. However, these solutions do not completely consider the security requirements of these networks. Based on the limitations of the existing solutions, this paper presents a new secure middleware, called Secure Middleware for Ad Hoc Networks (SEMAN), which provides a set of basic and secure services to MANETs aiming to facilitate the development of distributed, complex, and flexible applications. SEMAN considers the context of applications and organizes nodes into groups, also based on these contexts. The middleware includes three modules: service, processing, and security. Security module is the main part of the middleware. It has the following components: key management, trust management, and group management. All these components were developed and are described in this paper. They are supported by a cryptographic core and behave according to security rules and policies. The integration of these components provides security guarantees against attacks to the applications that usethe middleware services. Eduardo da Silva and Luiz Carlos Pessoa Albini Copyright © 2016 Eduardo da Silva and Luiz Carlos Pessoa Albini. All rights reserved. A Hybrid Energy Efficient Protocol for Mobile Ad Hoc Networks Tue, 17 May 2016 13:42:47 +0000 We proposed an energy conservation technique called Location Based Topology Control with Sleep Scheduling for ad hoc networks. It uses the feature of both topology control approach and power management approach. Like the topology control approach, it attempts to reduce the transmission power of a node, which is determined from its neighborhood location information. A node goes to sleep state based on the traffic condition as that of power management approach. In the proposed scheme, a node goes to sleep state only when its absence does not create local partition in its neighborhood. We preformed extensive simulation to compare the proposed scheme with existing ones. Simulation results show that the energy consumption is lower with increase in the network lifetime and higher throughput in the proposed scheme. Niranjan Kumar Ray and Ashok Kumar Turuk Copyright © 2016 Niranjan Kumar Ray and Ashok Kumar Turuk. All rights reserved. Performance Analysis of Cooperative Spectrum Sensing under Guaranteed Throughput Constraints for Cognitive Radio Networks Mon, 09 May 2016 13:06:55 +0000 One of the main challenges in cognitive radio networks is the ability of secondary users to detect the primary user presence with high probability of detection. In previous research, optimizing cooperative sensing in cognitive radio networks is performed for either a targeted probability of detection or a false alarm. After setting one of the probabilities as an optimization constraint, the other is optimized. In this paper, a guaranteed constant throughput at the secondary users is introduced as a target while optimizing probability of detection for cooperative sensing. Both sensing time values and number of cooperated cognitive radio secondary users are investigated to maximize the probability of detection of primary user. AND and OR hard decision schemes are considered and compared with soft decision scheme which is weighted modified deflection coefficient scheme (W-MDC). It is illustrated that cooperation of all users and utilizing full frames for sensing time will not provide maximum probability of detection. A tradeoff between performances of cognitive radio networks with and without optimization is presented. The effects of varying network sizes, normalized target throughput, maximum frame duration times, and received signal-to-noise ratio at the fusion center are investigated for different fusion rules. H. F. Al-Doseri and M. A. Mangoud Copyright © 2016 H. F. Al-Doseri and M. A. Mangoud. All rights reserved. An Overview on SDN Architectures with Multiple Controllers Wed, 27 Apr 2016 14:04:19 +0000 Software-defined networking offers several benefits for networking by separating the control plane from the data plane. However, networks’ scalability, reliability, and availability remain as a big issue. Accordingly, multicontroller architectures are important for SDN-enabled networks. This paper gives a comprehensive overview of SDN multicontroller architectures. It presents SDN and its main instantiation OpenFlow. Then, it explains in detail the differences between multiple types of multicontroller architectures, like the distribution method and the communication system. Furthermore, it provides already implemented and under research examples of multicontroller architectures by describing their design, their communication process, and their performance results. Othmane Blial, Mouad Ben Mamoun, and Redouane Benaini Copyright © 2016 Othmane Blial et al. All rights reserved. Bounds on Worst-Case Deadline Failure Probabilities in Controller Area Networks Thu, 21 Apr 2016 08:42:42 +0000 Industrial communication networks like the Controller Area Network (CAN) are often required to operate reliably in harsh environments which expose the communication network to random errors. Probabilistic schedulability analysis can employ rich stochastic error models to capture random error behaviors, but this is most often at the expense of increased analysis complexity. In this paper, an efficient method (of time complexity ) to bound the message deadline failure probabilities for an industrial CAN network consisting of periodic/sporadic message transmissions is proposed. The paper develops bounds for Deadline Minus Jitter Monotonic (DMJM) and Earliest Deadline First (EDF) message scheduling techniques. Both random errors and random bursts of errors can be included in the model. Stochastic simulations and a case study considering DMJM and EDF scheduling of an automotive benchmark message set provide validation of the technique and highlight its application. Michael Short Copyright © 2016 Michael Short. All rights reserved.