In recent years, Unmanned Aerial Vehicles (UAVs)have been used extensively in military and civilian fields, making the research on cellular-connected UAVs a popular topic forFifth Generation (5G) and beyond communications. In order to support the increasing amount of applications, it is essential to evaluate the performance of UAV communications. In this work, the end-to-end delay, packet success rate, and through put of Air-to-Ground (A2G) communications are evaluated based on a realistic channel model obtained from measurements. The measurement campaign, conducted in a suburban environment, includes both Line-of-Sight (LoS) and Obstructed Line-of-Sight(OLoS) scenarios. From the results, it can be seen that architectural elements close to the flight route can severely decrease the communications performance even when the visibility between the Base Station (BS) and the UAV is permanently ensured. Moreover, we have shown that the Quality of Service (QoS) requirements for critical communications proposed by 3rd Generation Partnership Project (3GPP) can be fulfilled by establishing a threshold on the received Signal to Interference and Noise Ratio (SINR). This way, the SINR can be used as a condense dperformance metric for the design of safe flight routes for critical communications for UAVs.
— The National Academy of Engineering’s “Fourteen Grand Challenges for Engineering in the Twenty-First Century” identifies challenges in science and technology that are both feasible and sustainable to help people and the planet prosper. Four of these challenges are: advance personalized learning, enhance virtual reality, make solar energy affordable and provide access to clean water. In this work, the authors discuss developing of applications using immersive technologies, such as Virtual Reality (VR) and Augmented Reality (AR) and their significance in addressing four of the challenges. The Drinking Water AR mobile application helps users easily locate drinking water sources inside Auburn University (AU) campus, thus providing easy access to clean water. The Sun Path mobile application helps users visualize Sun’s path at any given time and location. Students study Sun path in various fields but often have a hard time visualizing and conceptualizing it, therefore the application can help. Similarly, the application could possibly assist the users in efficient solar panel placement. Architects often study Sun path to evaluate solar panel placement at a particular location. An effective solar panel placement helps optimize solar energy cost. The Solar System Oculus Quest VR application enables users in viewing all eight planets and the Sun in the solar system. Planets are simulated to mimic their position, scale, and rotation relative to the Sun. Using the Oculus Quest controllers, disguised as human hands in the scene, users can teleport within the world view, and can get closer to each planet and the Sun to have a better view of the objects and the text associated with the objects. In a camp held virtually, due to Covid-19, K12 students were introduced to the concept and usability of the applications. Likert scales metric was used to assess the efficacy of application usage. The data shows that participants of this camp benefited from an immersive learning experience that allowed for simulation with inclusion of VR and AR.
Ensuring human life safety is inexorably the most critical objective of Intelligent Transportation System (ITS), which makes Intelligent Vehicular Network (IVN) the cornerstone of such system. Hence, in order to overcome network Quality of Service (QoS) degradation issues, several networking models for IVN have been proposed in the literature, namely clusterbased construction, cloud-based construction and platoon-based construction. Nevertheless, such constructions present several limitations, in terms of timeliness, connectivity and reliability, especially in critical environments. Therefore, we propose in this paper the design of a distributed construction based on “cohorts” and Neighbor-to-Neighbor (N2N) Communication, and we present the required cohort-managements distributed algorithms that ensure optimal IVN cohort-structuring and efficiency. Keywords–Cohort; Intelligent Vehicular Network; CyberPhysical System; Safety.
—Communication after natural disasters is paramount. Disasters such as earthquakes, hurricanes and tsunamis leave the affected area reachable only to wireless devices. In such conditions, Mobile Ad-hoc Networks (MANETs) play a critical role. The issue of MANETs communication backbone can be addressed by self-organized cluster-based algorithms. The virtual backbone will maintain an efficient communication on the MANET, adapting to the dynamic topology changes thanks to its self-organized nature. Nevertheless, they do not take into account the node’s mobility. If a node moves away from its neighboring nodes, connectivity will be lost and thus, network segmentation will occur. Therefore, it is fundamental to maintain the connectivity and the communication between nodes while exploring the area. In this paper, we propose the application of a mass-spring system on the Energy-Efficient Self-Organized Algorithm (EESOA) for Disaster Area applications. Results will show that our proposal performs best when deployment of MANET’s nodes is dense while maintaining a connected network.
In this paper, the performance of the first and the second order of wireless three-hop relay communication system operating over Rayleigh multipath fading environment are determined. The observed first order performance are: probability density function (PDF), cumulative distribution function, outage probability (OP) and moments. The analyzed second order characteristics are: level crossing rate (LCR) and average fade duration (AFD). A few graphics are plotted and the parameters' influence is studied.
As Orthogonal Frequency Division Multiplex (OFDM) signal is essentially a sum of multiple subcarrier signals aligned in frequency domain, its waveform in time domain is a waveform that changes like Gaussian noise, and thus the amplitude of time-domain waveform has high Peak-toAverage Power Ratio (PAPR). Constant Amplitude Zero AutoCorrelation (CAZAC) waveform precoding transforms from an OFDM waveform into a waveform kind of single-carrier modulation signal. In this paper, a new technique of symbol synchronization for OFDM systems with CAZAC precoding is proposed. By the CAZAC precoding, the waveform of one OFDM symbol can be changed to the waveform of Zadoff-Chu sequence by inputting proper data sequence. Here, the ZadoffChu sequence, known as one of CAZAC sequence, has excellent autocorrelation characteristics and is utilized as a strong tool for symbol synchronization in 4G-LTE systems. KeywordsOFDM; Zadoff-Chu sequence; CAZAC precorder; symbol synchronization;
The Internet of Things (IoT) is today separated by different vertically oriented platforms for integration of all the different devices. Developers who aim to access other platforms and access that data are forced to manually adapt their interfaces to the specific platform API and data models. This paper highlights the work of the BIG IoT project that aims at launching an IoT marketplace and ecosystem as part of the European Platform Initiative (IoT EPI). The project finished end of 2018, so I will be able to present the setup of and the final results of the integration of the use cases that have been implemented in Northern Germany, Italy and Barcelona. Please refer to www.big-iot.eu for further details.
- For the last couple of years, Blockchain has been the most talked about technology across a range of industries, e.g., currency markets, banks and financial services, supply chain, logistics, manufacturing, etc. The telecom industry has also shown huge uptake for Blockchain-based solution. Plenty of use cases for telecom networks are already proposed and proof of concepts solutions are available via many vendors, operators, and telecom software companies. Identity management, Fraud prevention, Smart contract, Internet of Things (IoT) Security, Mobile data tokenization and Initial coin offering are some of the use cases which will be offered by telecom operators/companies in the very near future. This paper discusses in detail some of the important use cases and their implementation complexities. This paper also addresses how smaller or startup telecom companies/operators can leverage the Blockchain opportunity and disrupt the markets they are based in.
This paper is concerned with a challenging problem of channel estimation and equalization for orthogonal frequency division multiplexing (OFDM) systems in underwater acoustic (UWA) communications in the presence of Rician fading. The ambient noise is modeled as a correlated Gaussain noise. We combine the matching pursuit (MP), for the Doppler shift and the channel path delays estimation, along with the maximum a posteriori (MAP) estimation for the channel path gains and call the resulting algorithm MP-MAP algorithm. As a prior distribution for the sparse complex-valued channel gains, we choose a Rician distribution with unknown means and variances. They are in turn estimated by the maximum likelihood technique. After the channel equalization, detection of data is implemented at the receiver. Computer simulations show that the UWA channel is estimated very effectively and the proposed algorithm exhibits excellent symbol error rate and channel estimation performance. Keywords–Underwater acoustic communications; channel estimation; equalization; detection.
This paper investigates the possibility of virtualizing and distributing the functionality that runs on top of residential wireless communications. Specifically, we propose, describe and test a solution that transports USB communications to remote locations, for scenarios in which the in-home wireless interfaces are consumed at the server side through this type of general-purpose and widely used interfaces. We frame this study in a general architecture by which Software Defined Networking (SDN) and Network Functions Virtualization (NFV) bring economies of scale, flexibility and programmability to residential Internet of Things (IoT) environments. As a result of our tests, we prove the feasibility of the remote presence of the IoT systems through the Universal Serial Bus (USB) tunnels, and we obtain approximate bandwidth measurements that serve as a hint on the type of services that can be offloaded to the cloud. For those functionalities that would need more bandwidth, we propose to embed a lightweight virtualization environment in home and to execute in it part of the virtualized components, something that is in line with the recent fog computing approaches.
—This work illustrates the generalization of a previously developed Indoor Positioning System (IPS) based on the combination of WiFi Positioning System (WPS) and depth maps. This generalization extends the use of the proposed system to scenarios containing multiple rooms and several people, in contrast to the more simpler initial version. The combination of both technologies improves the efficiency of existing methods, based uniquely on wireless positioning techniques, for estimating the location of people. Users just require the use of smart-phones, besides the installation of RGB-D devices in the sensing area. But some problems arise when multiple RGB-D sensors and access points must be located in a large area composed of several rooms. The paper exposes how the necessary devices are placed minimizing the total uncovered area. Experimental results for an office space composed by nine differently sized rooms are shown.
