@article{singh_sichitiu_guvenc_bhuyan_2023, title={Minimizing Ground Risk in Cellular-Connected Drone Corridors With mmWave Links}, volume={59}, ISSN={["1557-9603"]}, url={https://doi.org/10.1109/TAES.2023.3301824}, DOI={10.1109/TAES.2023.3301824}, abstractNote={Unmanned Aircraft Systems (UASs) have been receiving significant interest and support from academia, industry, and regulatory bodies over the past decade due to their various use cases. To safely integrate UAS operations into the national airspace, particularly overpopulated regions, the risk posed to ground users, buildings, and vehicles due to unmanned aerial vehicle (UAV) flight should be minimized. This risk can be represented by a numerical metric, which we refer to in this article as the “ground risk.” Many UAS applications also depend on the presence of a reliable wireless communication link between the UAV and a control station for the transmission of UAV position, surveillance video, UAV payload commands, and other mission-related data. Such wireless communication requirements also need to be considered in the design of UAS operations. In this article, we consider both these aspects and study the design of nonintersecting trajectories for UAS operations to minimize ground risk, subject to constraints on the wireless signal strength and geometry of the trajectory, specified in terms of: 1) an enclosing cylinder within which the trajectory must lie and 2) an integrated angular change along the UAV's trajectory. The performance of a computationally expensive optimal algorithm is compared with that of a computationally faster heuristic approach within the dense urban environment of Manhattan, NY, USA. Performance evaluation using ray-tracing simulations shows that the heuristic approach performs close to the optimal algorithm at a reduced computation cost. This research can be utilized to make UAS operations safe and reliable and accelerate their adoption.}, number={6}, journal={IEEE TRANSACTIONS ON AEROSPACE AND ELECTRONIC SYSTEMS}, author={Singh, Simran and Sichitiu, Mihail L. and Guvenc, Ismail and Bhuyan, Arupjyoti}, year={2023}, month={Dec}, pages={7923–7937} }
 @article{singh_lee_tran_zhou_sichitiu_guvenc_bhuyan_2021, title={FPV Video Adaptation for UAV Collision Avoidance}, volume={2}, ISSN={["2644-125X"]}, url={https://doi.org/10.1109/OJCOMS.2021.3106274}, DOI={10.1109/OJCOMS.2021.3106274}, abstractNote={First person view (FPV) technology for unmanned aerial vehicles (UAVs) provides an immersive experience for pilots and enables various personal and commercial applications such as aerial photography, drone racing, search and rescue operations, agricultural surveillance, and structural inspection. While real time video streaming from a UAV and vision-based collision avoidance strategies have been studied in literature as separate topics, in this paper we tackle collision avoidance in FPV scenarios, taking into account network delays and real time video parameters. We present a theoretical model for obstacle collisions that considers the current communication channel conditions, the real time video parameters, and the UAV’s position relative to the closest obstacle. A video adaptation algorithm is then designed, using this metric, to tune the FPV video resolution, number of re-transmission attempts, and the modulation scheme to maximize the probability of avoiding collisions. This algorithm also takes into account specific latency constraints of the application. This video algorithm was evaluated in various scenarios and its ability to respond to both distances to the obstacle as well as the communication channel conditions was demonstrated. It was found that, for the considered scenarios, the performance of the proposed adaptive algorithm was, on an average, 58.63% higher than the closest non-adaptive one in terms of maximizing the probability of avoiding collision. Such collision avoidance strategies could be used to make UAV FPV applications safer and more reliable.}, journal={IEEE OPEN JOURNAL OF THE COMMUNICATIONS SOCIETY}, publisher={Institute of Electrical and Electronics Engineers (IEEE)}, author={Singh, Simran and Lee, Hee Won and Tran, Tuyen X. and Zhou, Yu and Sichitiu, Mihail L. and Guvenc, Ismail and Bhuyan, Arupjyoti}, year={2021}, pages={2095–2110} }
 @article{singh_bhattacherjee_ozturk_guvenc_dai_sichitiu_bhuyan_2021, title={Placement of mmWave Base Stations for Serving Urban Drone Corridors}, DOI={10.1109/VTC2021-Spring51267.2021.9448923}, abstractNote={As the use of unmanned aerial vehicles (UAVs) in various commercial, civil, and military applications increases, it becomes important to study the design of aerial drone corridors that can support multiple simultaneous UAV missions. In this work, we study the placement of base stations (BSs) to serve aerial drone corridors while satisfying specific UAV mission requirements, such as the geometrical waypoints for the UAV to fly through and the minimum data rate to be supported along the mission trajectory. We develop a mathematical model of the drone corridor and propose a brute force algorithm that leverages A* search to meet the quality of service (QoS) requirements of the corridor by choosing the minimal set of BS locations from a pre-determined initial set. Using raytracing simulations, BS placement results are presented for various antenna array sizes in a dense urban region in East Manhattan. It was found that, for the scenario under consideration, a single BS equipped with an 8x8 antenna array is sufficient to satisfy the given QoS requirements of the corridor, while two BSs are required when using 4x4 antenna arrays.}, journal={2021 IEEE 93RD VEHICULAR TECHNOLOGY CONFERENCE (VTC2021-SPRING)}, author={Singh, Simran and Bhattacherjee, Udita and Ozturk, Ender and Guvenc, Ismail and Dai, Huaiyu and Sichitiu, Mihail and Bhuyan, Arupjyoti}, year={2021} }
 @article{bhuyan_guvenc_dai_sichitiu_singh_rahmati_maeng_2021, title={Secure 5G Network for a Nationwide Drone Corridor}, ISSN={["1095-323X"]}, DOI={10.1109/AERO50100.2021.9438162}, abstractNote={5G can provide the multiplicative capacity gains needed to support a large number of drones/UAS (Unmanned Aircraft Systems). 5G cellular networks with newly available millimeter wave (mmWave) frequency bands can provide wireless communication links for control as well as data traffic for drones and drone swarms. Drones are becoming increasingly important for commercial uses such as delivery and transportation as well as for public safety search and rescue of natural disaster victims, surveillance of remote critical infrastructure, surveys of environmental quality in protected regions, and detection of threats during major public events. This paper presents research findings in the following areas critical to validating the effectiveness of providing required 5G access to the drones with security, reliability, and spectral efficiency: 1) Radio coverage for the drone corridor by adding a separate set of antennas for coverage in the air while the conventional set of antennas continues to provide coverage on the ground. Beam transmission and validation with ray-tracing simulations are covered. 2) Optimization of uplink communication from a swarm of drones with a single mmWave beam by grouping the drones with power allocations for non-orthogonal multiple access (NOMA). 3) Optimization of the network lifetime of a swarm of drones resulting in suitable trajectories in the presence of interference. 4) Methods including precoding that can enhance physical layer security with channel information about the interference source. The paper concludes with plans for future research to provide further scientific basis for the proposed cellular drone network.}, journal={2021 IEEE AEROSPACE CONFERENCE (AEROCONF 2021)}, author={Bhuyan, Arupjyoti and Guvenc, Ismail and Dai, Huaiyu and Sichitiu, Mihail L. and Singh, Simran and Rahmati, Ali and Maeng, Sung Joon}, year={2021} }
 @article{kumbhar_binol_singh_guvenc_akkaya_2020, title={Heuristic approach for jointly optimising FeICIC and UAV locations in multi-tier LTE-advanced public safety HetNet}, volume={14}, ISSN={["1751-8636"]}, DOI={10.1049/iet-com.2019.1315}, abstractNote={UAV enabled communications and networking can enhance wireless connectivity and support emerging services. However, this would require system-level understanding to modify and extend the existing terrestrial network infrastructure. In this paper, we integrate UAVs both as user equipment and base stations into existing LTE-Advanced heterogeneous network (HetNet) and provide system-level insights of this three-tier LTE-Advanced air-ground HetNet (AG-HetNet). This AG-HetNet leverages cell range expansion (CRE), ICIC, 3D beamforming, and enhanced support for UAVs. Using system-level understanding and through brute-force technique and heuristics algorithms, we evaluate the performance of AG-HetNet in terms of fifth percentile spectral efficiency (5pSE) and coverage probability. We compare 5pSE and coverage probability, when aerial base-stations (UABS) are deployed on a fixed hexagonal grid and when their locations are optimized using genetic algorithm (GA) and elitist harmony search algorithm based on genetic algorithm (eHSGA). Our simulation results show the heuristic algorithms outperform the brute-force technique and achieve better peak values of coverage probability and 5pSE. Simulation results also show that trade-off exists between peak values and computation time when using heuristic algorithms. Furthermore, the three-tier hierarchical structuring of FeICIC provides considerably better 5pSE and coverage probability than eICIC.}, number={20}, journal={IET COMMUNICATIONS}, author={Kumbhar, Abhaykumar and Binol, Hamidullah and Singh, Simran and Guvenc, Ismail and Akkaya, Kemal}, year={2020}, month={Dec}, pages={3585–3598} }
 @article{singh_atrey_sichitiu_viniotis_2019, title={Clearer than Mud: Extending Manufacturer Usage Description (MUD) for Securing IoT Systems}, volume={11519}, ISBN={["978-3-030-23356-3"]}, ISSN={["1611-3349"]}, DOI={10.1007/978-3-030-23357-0_4}, abstractNote={Internet of Things (IoT) devices, expected to increase exponentially over the next several years, are easy targets for attackers. To make these devices more secure, the IETF’s draft of Manufacturer Usage Description (MUD) provides a means for the manufacturer of an IoT device to specify its intended purpose and communication patterns in terms of access control lists (ACLs), thereby defining the device’s normal behaviour. However, MUD may not be sufficient to comprehensively capture the normal behaviour specification, as it cannot incorporate variable operational settings that depend on the environment. Further, MUD only supports limited features. Our approach overcomes these limitations by allowing the administrator to define the normal behaviour by choosing combinations from a wider set of features that includes physical layer parameters, values of packet headers, and flow statistics. We developed and implemented a learning-based system that captures and demodulates wireless packets from IoT devices over a period of time, extracts the features specified in the normal behaviour specification, and uses a learning algorithm to create a normal model of each device. Our implementation also enforces these normal models by detecting violations and taking appropriate actions, in terms of ACLs on an Internet Gateway, against the misbehaving devices. Hence, our framework makes the specification tighter and clearer than what is possible with MUD alone, thereby making IoT systems more secure.}, journal={INTERNET OF THINGS - ICIOT 2019}, author={Singh, Simran and Atrey, Ashlesha and Sichitiu, Mihail L. and Viniotis, Yannis}, year={2019}, pages={43–57} }
 @article{kumbhar_guvenc_singh_tuncer_2018, title={Exploiting LTE-advanced HetNets and FeICIC for UAV-assisted public safety Communications}, volume={6}, journal={IEEE Access}, author={Kumbhar, A. and Guvenc, I. and Singh, S. and Tuncer, A.}, year={2018} }
 @article{kumbhar_singh_guvenc_2017, title={UAV Assisted Public Safety Communications with LTE-Advanced HetNets and FeICIC}, DOI={10.1109/pimrc.2017.8292564}, abstractNote={Establishing a reliable communication infrastructure at an emergency site is a crucial task for mission-critical and real-time public safety communications (PSC). To this end, use of unmanned aerial vehicles (UAVs) has recently received extensive interest for PSC to establish reliable connectivity in a heterogeneous network (HetNet) environment. These UAVs can be deployed as unmanned aerial base stations (UABSs) as part of the HetNet infrastructure. In this article, we explore the role of agile UABSs in LTE-Advanced HetNets by applying 3GPP Release-11 further-enhanced inter-cell interference coordination (Fe-ICIC) and cell range expansion (CRE) techniques. Through simulations, we compare the system-wide 5th percentile spectral efficiency (SE) when UABSs are deployed in a hexagonal grid and when their locations are optimized using a genetic algorithm, while also jointly optimizing the CRE and the FeICIC parameters. Our simulation results show that at optimized UABS locations, the 3GPP Release-11 FeICIC with reduced power subframes can provide considerably better 5th percentile SE than the 3GPP Release-10 with almost blank subframes.}, journal={2017 IEEE 28TH ANNUAL INTERNATIONAL SYMPOSIUM ON PERSONAL, INDOOR, AND MOBILE RADIO COMMUNICATIONS (PIMRC)}, author={Kumbhar, Abhaykumar and Singh, Simran and Guvenc, Ismail}, year={2017} }