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Article Citation - WoS: 11Citation - Scopus: 15A Study on the Performance Evaluation of Wavelet Decomposition in Transient-Based Radio Frequency Fingerprinting of Bluetooth Devices(Wiley, 2022) Almashaqbeh, Hemam; Dalveren, Yaser; Kara, AliRadio frequency fingerprinting (RFF) is used as a physical-layer security method to provide security in wireless networks. Basically, it exploits the distinctive features (fingerprints) extracted from the physical waveforms emitted from radio devices in the network. One of the major challenges in RFF is to create robust features forming the fingerprints of radio devices. Here, dual-tree complex wavelet transform (DT-CWT) provides an accurate way of extracting those robust features. However, its performance on the RFF of Bluetooth transients which fall into narrowband signaling has not been reported yet. Therefore, this study examines the performance of DT-CWT features on the use of transient-based RFF of Bluetooth devices. Initially, experimentally collected Bluetooth transients from different smartphones are decomposed by DT-CWT. Then, the characteristics and statistics of the wavelet domain signal are exploited to create robust features. Next, the support vector machine (SVM) is used to classify the smartphones. The classification accuracy is demonstrated by varying channel signal-to-noise ratio (SNR) and the size of transient duration. Results show that reasonable accuracy can be achieved (lower bound of 88%) even with short transient duration (1024 samples) at low SNRs (0-5 dB).Conference Object Citation - Scopus: 1Development of a Digital Communications Course Enriched by Virtual and Remote Laboratory Tools(2011) Kara,A.; Kara, Ali; Cagiltay,N.; Çağıltay, Nergiz; Dalveren,Y.; Dalveren, Yaser; Kara, Ali; Çağıltay, Nergiz; Dalveren, Yaser; Department of Electrical & Electronics Engineering; Software Engineering; Department of Electrical & Electronics Engineering; Software EngineeringDigital communications is a basic concept for rapidly growing fields of Electrical, Computer and Electronics Engineering like wireless and mobile communication systems, radar and electronic warfare, telemetry and many signal processing techniques. A re-designed digital communications course with ICT (Information and Communication Technologies) based diverse tools including matlab assignments, remote experiments and interactive simulators is described in this study. First, the objectives of the course, learning outcomes and evaluation methods are described. The re-designed course is offered in the last semester at Atilim University, and performance increase in students is compared with the previous year's offering, and by evaluating the course on a topic-based approach. © 2011 IEEE.Article Citation - WoS: 8Citation - Scopus: 15Distributed denial-of-service attack mitigation in network functions virtualization-based 5G networks using management and orchestration(Wiley, 2021) Koksal, Sarp; Dalveren, Yaser; Maiga, Bamoye; Kara, AliThe fifth generation (5G) technology is expected to allow connectivity to billions of devices, known as Internet of Things (IoT). However, IoT devices will inevitably be the main target of various cyberattack types. The most common one is known as distributed denial-of-service (DDoS) attack. In order to mitigate such attacks, network functions virtualization (NFV) has a great potential to provide the benefit of elasticity and low-cost solutions for protecting 5G networks. In this context, this study proposes a new mechanism developed to mitigate DDoS attacks in 5G NFV networks. The proposed mechanism utilizes intrusion prevention system's (IPS) virtual machines (VMs) to intercept the queries. Based on the volume of DDoS traffic, IPS's VMs are dynamically deployed by means of management and orchestration (MANO) in order to balance the load. To evaluate the effectiveness of the mechanism, experiments are conducted in a real 5G NFV environment built by using 5G NFV environment tools. To our best knowledge, this is the first time that NFV-based mechanism is experimentally tested in a real 5G NFV environment for mitigating DDoS attacks in 5G networks. The experimental results verify that the proposed mechanism can mitigate DDoS attacks effectively.Article A Case Study on the Assessment of Rf Switch and Splitter Options for Coupling of Transceiver Modules To Bidirectional Antennas Employed in Linear Wireless Sensor Networks(Wiley, 2021) Dalveren, Yaser; Durukan, Ahmet Mert; Kara, AliRecently, a concept of linear wireless sensor networks (LWSNs) has attracted much attention. For such networks, one of the key challenges in sensor node design is to couple transceiver modules with bidirectional antennas placed back-to-back for opposite radiation. As is known, simply, this can be achieved by using well-known coupling options like radio frequency (RF) switch or splitter. However, it is important to decide between two seemingly equally good options according to the system requirements such as RF performance, power consumption, and cost. Therefore, this study aims to comparatively assess these options from the system level point of view to find out what advantages or disadvantages either provides as per the other from widespread use of them in a LWSN-based cathodic protection monitoring of oil and natural gas pipelines in extreme environments. Preliminary field tests are also conducted to validate the efficiency of coupling options for LWSN links. Results show that RF splitter offers low power consumption and cost whereas RF switch has advantages of low loss. Thus, it is believed that this study may provide useful insights to design bidirectional sensor links for LWSNs.Article Citation - WoS: 7Citation - Scopus: 8Flexible and Lightweight Mitigation Framework for Distributed Denial-Of Attacks in Container-Based Edge Networks Using Kubernetes(Ieee-inst Electrical Electronics Engineers inc, 2024) Koksal, Sarp; Catak, Ferhat Ozgur; Dalveren, YaserMobile Edge Computing (MEC) has a significant potential to become more prevalent in Fifth Generation (5G) networks, requiring resource management that is lightweight, agile, and dynamic. Container-based virtualization platforms, such as Kubernetes, have emerged as key enablers for MEC environments. However, network security and data privacy remain significant concerns, particularly due to Distributed Denial-of-Service (DDoS) attacks that threaten the massive connectivity of end-devices. This study proposes a defense mechanism to mitigate DDoS attacks in container-based MEC networks using Kubernetes. The mechanism dynamically scales Containerized Network Functions (CNFs) with auto-scaling through an Intrusion Detection and Prevention System (IDPS). The architecture of the proposed mechanism leverages distributed edge clusters and Kubernetes to manage resources and balance the load of IDPS CNFs. Experiments conducted in a real MEC environment using OpenShift and Telco-grade MEC profiles demonstrate the effectiveness of the proposed mechanism against Domain Name System (DNS) flood and Yo-Yo attacks. Results also verify that Kubernetes efficiently meets the lightweight, agile, and dynamic resource management requirements of MEC networks.Conference Object An Experimental Study Towards Examining Human Body Movements in Indoor Wave Propagation at 18-22 Ghz(Ieee, 2018) Alabish, Ahmed; Kara, Ali; Dalveren, YaserAs 5G communication may use Millimeter waves (mmWave) bands, it is necessary to evaluate short-range indoor links from the link blockage point of view. This paper presents some initial studies for characterizing effects of human body movements on short range indoor links at 18 - 22 GHz. Firstly, measurement system is described, and then, calibration measurements along with initial results of the impact of human body movement on the channel are presented for some scenarios. To the best of our knowledge, this study is the first to experimentally examine the effects of human body movements at this band. Yet, as this study constitutes a part of an ongoing research, further results will be anticipated to present the effects of objects over and around the link on the directional propagation at mmWave bands (28 - 30 GHz).Conference Object Citation - WoS: 2Spectrum Analysis of Parabolic Range Gate Pull-Off (rgpo) Signals(Ieee, 2015) Ozturk, M. Talha; Dalveren, Yaser; Kara, AliDigital Radio Frequency Memory (DRFM) is a method that is used to capture radar threat signals, and retransmit them by changing their parameters in order to deceive or manipulate radar threats. Range gate pull-off (RGPO) technique is widely used in DRFM methods. RGPO can be either linear or parabolic RGPO according to the applied pull-off function. In this study, firstly, analytical derivations for temporal and spectral analysis of discrete form of linear and parabolic RGPO signals are presented. Then, various scenarios dependent on the parameters of pull-off function are created. Finally, simulation results regarding the scenarios are presented.Conference Object Internet-Of Smart Transportation Systems for Safer Roads(Ieee, 2020) Derawi, Mohammad; Dalveren, Yaser; Cheikh, Faouzi AlayaFrom the beginning of civilizations, transportation has been one of the most important requirements for humans. Over the years, it has been evolved to modern transportation systems such as road, train, and air transportation. With the development of technology, intelligent transportation systems have been enriched with Information and Communications Technology (ICT). Nowadays, smart city concept that integrates ICT and Internet-of-Things (IoT) have been appeared to optimize the efficiency of city operations and services. Recently, several IoT-based smart applications for smart cities have been developed. Among these applications, smart services for transportation are highly required to ease the issues especially regarding to road safety. In this context, this study presents a literature review that elaborates the existing IoT-based smart transportation systems especially in terms of road safety. In this way, the current state of IoT-based smart transportation systems for safer roads are provided. Then, the current research efforts undertaken by the authors to provide an IoT-based safe smart traffic system are briefly introduced. It is emphasized that road safety can be improved using Vehicle-to-Infrastructure (V21) communication technologies via the cloud (Infrastructure-to-Cloud - I2C). Therefore, it is believed that this study offers useful information to researchers for developing safer roads in smart cities.Conference Object Citation - WoS: 3Comparative Analysis of Tdoa-Based Localization Methods in the Presence of Sensor Position Errors(Ieee, 2017) Dalveren, Yaser; Kara, AliIt is widely known that localization of emitters can be efficiently achieved by time difference of arrival (TDOA) techniques in a multiple sensor system. Several studies have been proposed in the literature to improve the localization accuracy of TDOA techniques. Among these, very few of them have considered the error in the sensor positions although the accuracy of localization is very sensitive to sensor position errors. In this study, existing TDOA-based localization methods in the presence of sensor position errors are briefly discussed, and then they are comparatively analyzed for specific scenarios. To this end, simulations are performed to compare the localization accuracy of the methods, specifically, with high level of sensor positional errors. It is intended to decide an efficient and robust estimator to be used for an ongoing research on passive localization of radar emitters in dense scattering environments.Article Citation - WoS: 6Citation - Scopus: 7An Enhanced Course in Digital Communications(Tempus Publications, 2014) Kara, Ali; Cagiltay, Nergiz Ercil; Dalveren, Yaser; Department of Electrical & Electronics Engineering; Software EngineeringToday technological improvements provide several alternatives and opportunities for improving traditional educational systems. However, integrating these technologies in an appropriate and successful way into the curriculum of traditional systems is a challenge. This work presents the enhancements added to an undergraduate course on Digital Communications which is an introductory course offered to senior undergraduates or first year graduate students. The Digital Communications course covers some essential stages in a typical digital communication system, namely, signal formatting such as analog to digital conversion, baseband modulation and bandpass modulation by concentrating on demodulation and detection at the receiver end. The enhancements include computer simulations, web-based simulation tools and remote laboratory experiments along with several out of class activities. The enhancements have improved the course significantly by supporting constructivist and blended learning methods. The improvement to the course was demonstrated over two years, from the student progress assessed from the collated results of the student evaluation forms and a questionnaire on the course learning outcomes, and a comparison of their performance in the written exams. The results show that there is a significant improvement both in the progress and satisfaction of the students on the enhanced course curriculum. This study shows how different technologies have been successfully integrated to the curriculum of Digital Communications course in a higher education organization and concludes its success factors.
