Researcher:
Uçar, Seyhan

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PhD Student

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Seyhan

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Uçar

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Uçar, Seyhan

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2013 - 202016

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Researcher Of Publications: search.filters.isAuthorOfPublication.82593df8-c614-4141-89ee-bb8a7834b823

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    SecVLC: secure visible light communication for military vehicular networks
    (Association for Computing Machinery (ACM), 2016) Tsonev, Dobroslav; Burchardt, Harald; N/A; Department of Electrical and Electronics Engineering; Department of Computer Engineering; Uçar, Seyhan; Ergen, Sinem Çöleri; Özkasap, Öznur; PhD Student; Faculty Member; Faculty Member; Department of Electrical and Electronics Engineering; Department of Computer Engineering; Graduate School of Sciences and Engineering; College of Engineering; College of Engineering; N/A; 7211; 113507
    Technology coined as the vehicular ad hoc network (VANET) is harmonizing with Intelligent Transportation System (ITS) and Intelligent Traffic System (ITF). An application sce- nario of VANET is the military communication where ve- hicles move as a convoy on roadways, requiring secure and reliable communication. However, utilization of radio fre- quency (RF) communication in VANET limits its usage in military applications, due to the scarce frequency band and its vulnerability to security attacks. Visible Light Communi- cation (VLC) has been recently introduced as a more secure alternative, limiting the reception of neighboring nodes with its directional transmission. However, secure vehicular VLC that ensures confidential data transfer among the participat- ing vehicles, is an open problem. In this paper, we propose a secure military light communication protocol (SecVLC) for enabling efficient and secure data sharing. We use the directionality property of VLC to ensure that only target vehicles participate in the communication. Vehicles use full- duplex communication where infra-red (IR) is utilized to share a secret key and VLC is used to receive encrypted data. We experimentally demonstrate the suitability of SecVLC in outdoor scenarios at varying inter-vehicular distances with key metrics of interest, including the security, data packet delivery ratio and delay.
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    Visible light communication assisted safety message dissemination in multiplatoon
    (Institute of Electrical and Electronics Engineers (IEEE), 2018) N/A; Department of Electrical and Electronics Engineering; Department of Computer Engineering; Uçar, Seyhan; Ergen, Sinem Çöleri; Özkasap, Öznur; PhD Student; Faculty Member; Faculty Member; Department of Electrical and Electronics Engineering; Department of Computer Engineering; Graduate School of Sciences and Engineering; College of Engineering; College of Engineering; N/A; 7211; 113507
    Platooning is a promising vehicle formation where autonomous vehicles are accessing each others information and grouped within a close proximity. Multiplatoon, on the other hand, is an enhanced version of platooning that refers to the chain of platoons where platoons follow one another. One of the primary objectives for the multiplatoon system is to support data dissemination for different information types. Multiplatoon systems usually adopt the current dominant radio frequency (RF) technology IEEE 802.11p for communication. However, IEEE 802.11p suffers from problems of performance degradation due to the congestion, the scarcity of RF and security that may degrade the delay and delivery ratio of safety application. Visible Light Communication (VLC), on the other hand, is a promising complementary technology with the potential to address IEEE 802.11p problems. In this paper, we propose an IEEE 802.11p and VLC based hybrid safety dissemination protocol and investigate the hybrid safety message dissemination scheme in the presence of application level data traffic. We develop a simulation platform to realize the hybrid multiplatoon. We demonstrate that the packet loss results in low packet delivery ratio in IEEE 802.11p based multiplatoon. Although VLC increases the safety message dissemination performance, hybrid multiplatoon architecture still suffers from the disconnected network.
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    Dimming support for visible light communication in intelligent transportation and traffic system
    (Institute of Electrical and Electronics Engineers (IEEE), 2016) N/A; N/A; Department of Electrical and Electronics Engineering; Department of Computer Engineering; Department of Electrical and Electronics Engineering; Uçar, Seyhan; Turan, Buğra; Ergen, Sinem Çöleri; Özkasap, Öznur; Ergen, Mustafa; PhD Student; PhD Student; Faculty Member; Faculty Member; Faculty Member; Department of Computer Engineering; Department of Electrical and Electronics Engineering; Graduate School of Sciences and Engineering; Graduate School of Sciences and Engineering; College of Engineering; College of Engineering; College of Engineering; N/A; N/A; 7211; 113507; N/A
    The automotive industry is under a major change and new vehicles are being enriched by the recent advances in communication. Not only business plans are changing due to connected and urbanized lifestyle, but also transportation is becoming more intelligent with smart roads that connect smart cars. Technology coined as the vehicular ad-hoc network (VANET) is harmonizing with Intelligent Transportation System (ITS) and Intelligent Traffic System (ITF). However, ITS and ITF systems suffer from the scarcity of radio frequency spectrum. Visible light communication (VLC) that uses modulated optical radiation in the visible light spectrum is an alternative medium being researched. To date, the majority of research on vehicular VLC was aimed at achieving high data rates provided that high lighting quality is achieved without any concern on dimmable LED lights. Auto-dimmable headlights gain attention due to danger caused by sudden glare on drivers at night conditions which makes dimming in VLC necessary. In this paper, we first present the latest concept of vehicular VLC on ITS and ITF systems and address dimming utility. We then demonstrate experimentally that dimming is a key parameter in VLC which affects data dissemination and received power signal strength.
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    Data-driven anomaly detection in autonomous platoon
    (Institute of Electrical and Electronics Engineers (IEEE), 2018) N/A; Department of Electrical and Electronics Engineering; Department of Computer Engineering; Uçar, Seyhan; Ergen, Sinem Çöleri; Özkasap, Öznur; PhD Student; Faculty Member; Faculty Member; Department of Electrical and Electronics Engineering; Department of Computer Engineering; Graduate School of Sciences and Engineering; College of Engineering; College of Engineering; N/A; 7211; 113507
    Technology brings autonomous vehicles into a reality where vehicles cruise themselves without human input. Vehicular platoon, on the other hand, is a group of autonomous vehicles that are organized into close proximity through wireless communication. In an autonomous platoon, vehicles cooperatively send data to each other to adjust their speed and distance to the leader, the first vehicle in the platoon. However, this cooperative data exchange can lead to security risks. A misbehaving platoon member could alter the data packets which may cause platoon instability. Therefore, identifying the modified packets has become an important requirement. In this paper, we investigate data-driven anomaly detection mechanisms for the autonomous platoon. We propose a novel statistical learning based technique to detect the modified packets and misbehaving vehicles. We demonstrate that the distance change to the leader would be sufficient to detect anomalies and misbehavior.
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    Multihop-cluster-based IEEE 802.11p and LTE hybrid architecture for VANET safety message dissemination
    (Institute of Electrical and Electronics Engineers (IEEE), 2016) N/A; N/A; Department of Electrical and Electronics Engineering; Department of Computer Engineering; Uçar, Seyhan; Ergen, Sinem Çöleri; Özkasap, Öznur; PhD Student; Faculty Member; Faculty Member; Department of Electrical and Electronics Engineering; Department of Computer Engineering; Graduate School of Sciences and Engineering; College of Engineering; College of Engineering; N/A; N/A; 7211; 113507
    Several vehicular ad hoc network (VANET) studies have focused on communication methods based on IEEE 802.11p, which forms the standard for wireless access for vehicular environments. In networks employing IEEE 802.11p only, the broadcast storm and disconnected network problems at high and low vehicle densities, respectively, degrade the delay and delivery ratio of safety message dissemination. Recently, as an alternative to the IEEE 802.11p-based VANET, the usage of cellular technologies has been investigated due to their low latency and wide-range communication. However, a pure cellular-based VANET communication is not feasible due to the high cost of communication between the vehicles and the base stations and the high number of handoff occurrences at the base station, considering the high mobility of the vehicles. This paper proposes a hybrid architecture, namely, VMaSC-LTE, combining IEEE 802.11p-based multihop clustering and the fourth-generation (4G) cellular system, i.e., Long-Term Evolution (LTE), with the goal of achieving a high data packet delivery ratio (DPDR) and low delay while keeping the usage of the cellular architecture at a minimum level. In VMaSC-LTE, vehicles are clustered based on a novel approach named Vehicular Multihop algorithm for Stable Clustering (VMaSC). The features of VMaSC are cluster head (CH) selection using the relative mobility metric calculated as the average relative speed with respect to the neighboring vehicles, cluster connection with minimum overhead by introducing a direct connection to the neighbor that is already a head or a member of a cluster instead of connecting to the CH in multiple hops, disseminating cluster member information within periodic hello packets, reactive clustering to maintain the cluster structure without excessive consumption of network resources, and efficient size-and hop-limited cluster merging mechanism based on the exchange of cluster information among CHs. These features decrease the number of CHs while increasing their stability, therefore minimizing the usage of the cellular architecture. From the clustered topology, elected CHs operate as dual-interface nodes with the functionality of the IEEE 802.11p and LTE interface to link the VANET to the LTE network. Using various key metrics of interest, including DPDR, delay, control overhead, and clustering stability, we demonstrate the superior performance of the proposed architecture compared with both previously proposed hybrid architectures and alternative routing mechanisms, including flooding and cluster-based routing via extensive simulations in ns-3 with the vehicle mobility input from the Simulation of Urban Mobility. The proposed architecture also allows achieving higher required reliability of the application quantified by the DPDR at the cost of higher LTE usage measured by the number of CHs in the network.
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    IEEE 802.11p and visible light hybrid communication based secure autonomous platoon
    (IEEE-Inst Electrical Electronics Engineers Inc, 2018) N/A; Department of Electrical and Electronics Engineering; Department of Computer Engineering; Uçar, Seyhan; Ergen, Sinem Çöleri; Özkasap, Öznur; PhD Student; Faculty Member; Faculty Member; Department of Electrical and Electronics Engineering; Department of Computer Engineering; Graduate School of Sciences and Engineering; College of Engineering; College of Engineering; N/A; 7211; 113507
    Autonomous vehicle platoon is an enhancement of autonomous behavior, where vehicles are organized into groups of close proximity through wireless communication. Platoon members mostly communicate with each other via the current dominant vehicular radio frequency (RF) technology, IEEE 802.11p. However, this technology leads security vulnerabilities under various attacks from adversaries. Visible light communication (VLC) has the potential to alleviate these vulnerabilities by exploiting the directivity and impermeability of light. Utilizing only VLC in vehicle platoon, on the other hand, may degrade platoon stability since VLC is sensitive to environmental effects. In this paper, we propose an IEEE 802.11p and VLC-based hybrid security protocol for platoon communication, namely SP-VLC, with the goal of ensuring platoon stability and securing platoon maneuvers under data packet injection, channel overhearing, jamming, and platoon maneuver attacks. We define platoon maneuver attack based on the identification of various scenarios where a fakemaneuver packet is transmitted by amalicious actor. SP-VLC includesmechanisms for the secret key establishment, message authentication, data transmission over both IEEE 802.11p and VLC, jamming detection and reaction to switch to VLC only communication and secure platoon maneuvering based on the joint usage of IEEE 802.11p and VLC. We develop a simulation platform combining realistic vehicle mobility model, realistic VLC and IEEE 802.11p channel models, and vehicle platoon management. We show the functionality of the SP-VLC protocol under all possible security attacks by performing extensive simulations. Ourfindings demonstrate that SP-VLC protocol generates less than 0.1% difference in the speed of and distance between platoon members during security attacks in comparison to 25% and 10% in that of previously proposed IEEE 802.11p and IEEE 802.11p-VLC hybrid protocols, respectively.
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    Dual channel visible light communications for enhanced vehicular connectivity
    (IEEE Computer Society, 2016) N/A; N/A; Department of Electrical and Electronics Engineering; Department of Computer Engineering; Turan, Buğra; Uçar, Seyhan; Ergen, Sinem Çöleri; Özkasap, Öznur; PhD Student; PhD Student; Faculty Member; Faculty Member; Department of Electrical and Electronics Engineering; Department of Computer Engineering; Graduate School of Sciences and Engineering; Graduate School of Sciences and Engineering; College of Engineering; College of Engineering; N/A; N/A; 7211; 113507
    Visible Light Communication (VLC) has recently been proposed as a low-cost and low-complexity technology for vehicular communications. In this paper, we propose the usage of dual channel VLC with the goal of providing enhanced vehicular connectivity to disseminate safety-critical messages and perform an experimental study to determine the spatial and angular limits of an off-the-shelf automotive Light Emitting Diode (LED) fog light. Single channel VLC refers to the independent transmission of different data packets from each LED fog light, while the dual channel VLC offers the concurrent transmission of the same data packet from both lights. There is a trade-off between increasing the angular limitation and the performance of dual channel VLC, which needs to be experimentally evaluated to identify its efficient usage. We first show the dependency of the received optical power of single channel VLC on the angle and distance, and demonstrate that Lambertian model does not represent the automotive LED fog light radiation pattern accurately. We then demonstrate that dual channel usage increases the angular limitation by up to 10° compared to the single channel VLC. We also show that dual channel improves the packet delivery error rate performance at only short distances due to the photodiode (PD) saturation led by light intensity overlapping at higher distances.
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    Online client assignment in dynamic real-time distributed interactive applications
    (Ieee, 2013) N/A; N/A; Department of Computer Engineering; Uçar, Seyhan; Güler, Hüseyin; Özkasap, Öznur; PhD Student; PhD Student; Faculty Member; Department of Computer Engineering; Graduate School of Sciences and Engineering; Graduate School of Sciences and Engineering; College of Engineering; N/A; N/A; 113507
    Qulaity of user experience in Distributed Interactive Applications (DIAs) highly depends on the network latencies during the system execution. In DIAs, each user is assigned to a server and communication with any other client is performed throught its assigned server. Hence, latency measured between two clients, called interaction time, consists of two components. One is the latency between the client and its assigned server, and the other is the inter-server latency, that is the latency between servers that the clients are assigned. In this paper, we investigate a real-time client to server assignment scheme in a DIA where the objective is to minimize the interaction time among clients. The client assignment problem is known to be NP-complete and heuristics play an important role in finding near optimal solutions. We propose two distributed heuristic algorithms to the online client assignment problem in a dynamic DIA system. We utilized real-time Internet latency data on PlanetLab platform and performed extensive 3 experiments using geographically distributed PlanetLab nodes where nodes can arbitrarily join/leave the system. The experimental results demonstrate that our proposed algorthims can reduce the maximum interaction time among clients up to 45% compared to an exiting baseline technique.
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    Security vulnerabilities of autonomous platoons
    (Institute of Electrical and Electronics Engineers (IEEE), 2017) N/A; Department of Electrical and Electronics Engineering; Department of Computer Engineering; Uçar, Seyhan; Ergen, Sinem Çöleri; Özkasap, Öznur; PhD Student; Faculty Member; Faculty Member; Department of Electrical and Electronics Engineering; Department of Computer Engineering; Graduate School of Sciences and Engineering; College of Engineering; College of Engineering; N/A; 7211; 113507
    Previous studies have shown that autonomous vehicles have the potential of fundamentally changing the Intelligent Transportation System (ITS) and substantially affecting the safety in vehicular ad hoc networks (VANET). Cooperative Adaptive Cruise Control System (CACC) in conjunction with vehicular communication paves the way of vehicle platooning where autonomous vehicles are organized into groups with close proximity. From this perspective, platoon management using the current dominant IEEE 802.11p (DSRC) and hybrid DSRC-Visible Light Communication (VLC) is an active research field to ensure the platoon stability. However, before the practical deployment of vehicular platoons, the DSRC and hybrid DSRC-VLC based management protocols need to be analyzed in the presence of attackers. In this paper, we investigate the security vulnerabilities of DSRC and DSRC-VLC based platoons under the jamming and fake platoon maneuver attacks. We demonstrate that DSRC is highly vulnerable to such attacks. Although VLC limits the effect of adversaries, hybrid architecture still suffers from the jamming and fake maneuver attacks.
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    Data-driven abnormal behavior detection for autonomous platoon
    (IEEE Computer Society, 2018) N/A; Department of Electrical and Electronics Engineering; Department of Computer Engineering; Uçar, Seyhan; Ergen, Sinem Çöleri; Özkasap, Öznur; PhD Student; Faculty Member; Faculty Member; Department of Electrical and Electronics Engineering; Department of Computer Engineering; Graduate School of Sciences and Engineering; College of Engineering; College of Engineering; N/A; 7211; 113507
    Autonomous platoon is a technique where co-operative adaptive cruise control (CACC) enabled vehicles are organized into groups of close following vehicles through communication. It is envisioned that with the increased demand for autonomous vehicles, platoons would be a part of our life in near future. Although many efforts have been devoted to implement the vehicle platooning, ensuring the security remains challenging. Due to lack of security, platoons would be subject to modified packets which can mislead the platoon and result in platoon instability. Therefore, identifying malicious vehicles has become an important requirement. In this paper, we investigate a data-driven abnormal behavior detection approach for an autonomous platoon. We propose a novel statistical learning based technique to detect data anomalies. We demonstrate that shared speed value among platoon members would be sufficient to detect the misbehaving vehicles.