Browsing by Author "De Rango, Floriano"

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    <> proposal of efficient routing techniques and intelligent vehicular traffic management in the smart cities context, through distributed wireless networks
    (2016-02-02) Sottile, Cesare; Pantano, Pietro Salvatore; De Rango, Floriano; Marano, Salvatore
    In this thesis, the design of e cient techniques for routing protocol suitable to Vehicular Ad-hoc NETworks (VANETs) has been pro- posed. In particular, the aims of the proposed protocols are to reduce interference issues, due to the data transmissions in wireless environ- ment. The proposed protocols use time series prediction models and also multi-objective metric, based on the evaluation of co-channel in- terference levels, end-to-end delay, and link duration probability along the di erent links from sources towards destinations. These param- eters are modelled through an optimization problem. The key fac- tors are to exploit the advantages available to the Standard 802.11p, based on a dynamic allocation mechanism of the DSRC spectrum, aimed at the reduction of the co-channel interference and the maxi- mization of the link duration probability (two key issues in vehicular environments). Another topic discussed in this thesis is related to the smart vehicular tra c management through VANETs infrastructure and communications(V2I and V2V). A distributed algorithm with the aim to build less congested path for the vehicles in a urban scenario has been developed. It is also considered the problem regarding to enhance air quality around the cities reducing the vehicles CO2 emis- sions. There are di erent causes related to the CO2 emissions such as the average travelled time spent by vehicles inside the city and their average speed. Hence, with a better tra c management the average time spent by the vehicles in the city will be considerably reduced as well as CO2 emissions. These results are demonstrated in a discrete event simulator by using also real tra c data
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    Analisi della socialità multi-livello nelle reti opportunistiche per la propagazione dei messaggi
    (2019-06-08) Caputo, Antonio; Crupi, Felice; Marano, Salvatore ,; De Rango, Floriano
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    Analysis and development of physical and MAC Layer protocols in mobile ad Hoc networks involving directional antenna communications
    (2019-06-20) Inzillo, Vincenzo; Crupi, Felice; De Rango, Floriano
    Most recent Studies and Researches in IT (Information Technology) are bringing to an increasing development of Pervasive Communication Environments Systems such as MANET and Sensor Networks that assumed great importance, since 802.1X development IEEE Standards, due to their features based on nodes mobility and power consumption that lead to the rise of several protocols which implements different designs about routing algorithms and QoS (Quality of Service) specifications. Conventionally, these kinds of network environments are equipped in their physical layer with Isotropic and Omnidirectional Antennas Systems, that lead to a radiation pattern with a constant gain in all TX/RX directions so it results in a non-directive behavior of nodes. In this context there are lots drawbacks that heavily affect and reduce protocols efficiency and SNR (Signal to Noise Ratio) such as: communication reliability, latency, scalability, power and energy consumption. For example, using an isotropic antenna in nodes, without position knowing mechanism, bring to a notable waste of consumption energy due to the non-directive behavior because the same power is transmitted/received in all directions. To overlapping this drawback are developed in last years the so called Smart Antenna Systems that usually consists of several directive radiation elements implementing adaptive algorithms for the estimation of DOA (Direction of Arrival) and SOI (Signal Of interest); for this purpose are employed beamforming techniques that are largely used in Radar Communication Systems and Phased Array Systems. The resulted radiation pattern generates a beam that should be electronically controlled, and the main beam should be pointed towards the direction of interest in communication transmission/reception. The beam is generated according an adaptive algorithm (i.e. Least Mean Square) that models the weight vector as Smart Antenna input System. Beamforming techniques take lots advantages in medium access control, effectively, employing of SDMA (Spatial Division Multiple Access) allows a great efficiency protocol growth. MANET performance can be enhanced if more efficient antenna systems such as Massive MIMO (Multiple Input Multiple Output) systems are employed; indeed, massive MIMO underlie the development of 5G Mobile Wireless Network environments. However, despite of their capability to improve network performance they introduce different kinds of issues especially in terms of energy consumption that should be addressed. The main purpose of this thesis is to limit most of the mentioned issues related to directional communications in MANET in order to improve the current state of art referring both to protocols and network performance. From a protocol point of view, important to highlight that the most of the overall contribution of the present work aims to address energy efficiency, deafness problem and finally, mobility issues occurring at physical and MAC (Medium Access Layer) layer. The reminder of the thesis is the following: Chapter 1: introduces main concepts about network communications using directional and omnidirectional antennas in MANET and their common related issues. Chapter 2: gives basics and fundamentals theoretical notions about Smart Antenna Systems (SAS) and Massive MIMO with particular emphasis to beamforming algorithms. Chapter 3: essentially, this chapter is divided into two parts. The first one, illustrates basic features of the main instrument used for experimental analysis that is the Omnet++ network simulator. The second part exposes the most significant works produced to extend the default Omnet++ framework for enabling simulation scenarios supporting SAS and massivo MIMO systems. Chapter 4: provides a detailed discussion about deafness problem in MANET directional communications and subsequently illustrates the most significant proposals in this field with a special focus on designed Round-Robin based approaches. Chapter 5: describes main issues related to mobility and energy consumption of nodes in directional MANET with particular attention to handoff problem. Nevertheless, it illustrates novel proposed strategies aiming to mitigate energy consumption in very high gain beamforming communications employing SAS and massive MIMO systems. All of the above chapters are organized in a similar way. More specifically, each chapter consists of three main parts: Background: gives a briefly theoretical explanation of the most important concepts mentioned in the chapter. State of art: illustrates the most significant works related to topics encountered in the chapter. Personal contribution: highlights the main contribution achieved (by author of this thesis) allowing to improve the current state of art related to a particular topic.
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    Enhancements of Autonomous Vehicles Environment based on smart communication systems
    (2019-06-20) Reimondo, Pierfrancesco; De Rango, Floriano; Santamaria, Amilcare F.
    The first part of this thesis is focused on the vehicular networks and on the different protocols that are used in vehicular environment to exchange information and data. A description of the most used protocols of Vehicular Ad-hoc NETwork (VANET) is presented along with their positive and negative aspects, their issues and some improvements. The capability of exchange data and information is one of the most important features to improve everything making objects smart. Obviously this is valid also for vehicles that can be improved using connectivity and networks. New paradigms and architecture are growing in interest thanks also to new technologies such as lightway protocols or 5G giving birth to new Internet of Vehicles (IoV). Autonomous vehicles are a special kind of vehicles able to move in an urban environment without any human interaction thanks to several sensors equipped onboard. These sensors can detect obstacles and possible dangerous situations on the road during a journey. To ensure a high reliability it is necessary a cooperation between all equipped sensors like cameras, Lidar, Radar and GPS. Image and video elaboration is made through computer vision algorithms that are able to identify and track objects moving inside sensors line of sight while lidar and radar create a threedimensional model of the surrounding environment. These gathered information have only a local scope. In order to solve this problem a “collaborative” approach could be used to establish a communication network among these vehicles. In this way every autonomous vehicle could be able to handle warning situations and traffic jam in a better way exploiting information exchange with others. It is important to build a robust network infrastructure in order to achieve a reliable message exchange. Vehicles , equipped with on board units, are starting to be considered part of the IoT domain, where instead of classical smart objects we consider smart vehicles. These smart vehicles can exchange messages among themselves to improve their useful environment knowledge. New routing protocols and optimization algorithms are necessary in order to make the network infrastructure more flexible and able to adapt to changes. Furthermore vehicles move at a very high speed in comparison to other common devices and the link low stability makes the network high dynamic and unstable. To resolve these issues it will be necessary to investigate actual VANET protocols and improve them to better manage its high dynamism and link quality using also technologies that belong to Internet of Things domain. Integrating these heterogeneous technologies together it will be possible the creation of a middleware between the IoT layer and On Board Units. These solutions, based on evolutive algorithms and adaptive protocols have to be verified through simulations and mathematical models. To do so, a deep study on mobility models and simulation tools has been necessary. The future of mobility is, taking into consideration the recent trends, electric. Fuel propelled vehicles will some day disappear from our city to leave plate to this new kind of vehicles with electric engine and powered by batteries. Electrical mobility will be a very important part of the future and also autonomous vehicles will be electric. The consumption of on-board vehicle sensors must be taken into account and must be modeled by simulation tools that are used to describe future mobility scenarios. In the end a possible application of all studied research fields is proposed, summarized inside the proposition of a platooning application for autonomous vehicles. A platoon consists of a set of vehicles that moves at the same speed along the road with a low inter-vehicle gap. In this the members of the platoon will benefit of several advantages that will be treated in the body of this thesis.
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    Using multi-layer social networks for opportunistic routing
    (2012-10-24) Socievole, Annalisa; Palopoli, Luigi; Marano, Salvatore; De Rango, Floriano