Analysis and performance improvement of consumer-grade millimeter wave wireless networks

Millimeter-wave (mmWave) networks are one of the main key components in next cellular and WLANs (Wireless Local Area Networks). mmWave networks are capable of providing multi gigabit-per-second rates with very directional low-interference and high spatial reuse links. In 2013, the first 60 GHz wireless solution for WLAN appeared in the market. These were wireless docking stations under theWiGig protocol. Today, in 2019, 60 GHz communications have gained importance with the IEEE 802.11ad amendment with different products on the market, including routers, laptops and wireless Ethernet solutions. More importantly, mmWave networks are going to be used in next generation cellular networks, where smartphones will be using the 28 GHz band. For backbone links, 60 GHz communications have been proposed due to its higher directionality and unlicensed use. This thesis fits in this frame of constant development of themmWave bands to meet the needs of latency and throughput that will be necessary to support future communications. In this thesis, we first characterize the cost-effective design of COTS (commercial off-the-shelf) 60 GHz devices and later we improve their two main weaknesses, which are their low link distance and their non-ideal spatial reuse. It is critical to take into consideration the cost-effective design of COTS devices when designing networking mechanisms. This is why in this thesis we do the first-of-its-kind COTS analysis of 60 GHz devices, studying the D5000 WiGig Docking station and the TP-Link Talon IEEE 802.11ad router. We include static measurements such as the synthesized beam patterns of these devices or an analysis of the area-wide coverage that these devices can fulfill. We perform a spatial reuse analysis and study the performance of these devices under user mobility, showing how robust the link can be under user movement. We also study the feasibility of having flying mmWave links. We mount a 60 GHz COTS device into a drone and perform different measurement campaigns. In this first analysis, we see that these 60 GHz devices have a large performance gap for the achieved communication range as well as a very low spatial reuse. However, they are still suitable for low density WLANs and for next generation aerial micro cell stations. Seeing that these COTS devices are not as directional as literature suggests, we analyze how channels are not as frequency stable as expected due to the large amount of reflected signals. Ideally, frequency selective techniques could be used in these frequency selective channels in order to enlarge the range of these 60 GHz devices. To validate this, we measure real-world 60 GHz indoor channels with a bandwidth of 2 GHz and study their behavior with respect to techniques such as bitloading, subcarrier switch-off, and waterfilling. To this end, we consider a Orthogonal Frequency-Division Multiplexing (OFDM) channel as defined in the IEEE 802.11ad standard and show that in point of fact, these techniques are highly beneficial in mmWave networks allowing for a range extension of up to 50%, equivalent to power savings of up to 7 dB. In order to increase the very limited spatial reuse of these wireless networks, we propose a centralized system that allows the network to carry out the beam training process not only to maximize power but also taking into account other stations in order to minimize interference. This system is designed to work with unmodified clients. We implement and validate our system on commercial off-the-shelf IEEE 802.11ad hardware, achieving an average throughput gain of 24.67% for TCP traffic, and up to a twofold throughput gain in specific cases.Programa de Doctorado en Multimedia y Comunicaciones por la Universidad Carlos III de Madrid y la Universidad Rey Juan CarlosPresidente: Andrés García Saavedra.- Secretario: Matilde Pilar Sánchez Fernández.- Vocal: Ljiljana Simi

Privacy-Aware Opportunistic Wi-Fi

Over the past decade Internet connectivity has become an increasingly essential feature on modern mobile devices. Many use-cases representing the state of the art depend on connectivity. Smartphones, tablets, and other devices alike can even be seen as access devices to Internet services and applications. Getting a device connected requires either a data plan from a mobile network operator (MNO), or alternatively connecting over Wi-Fi wherever feasible. Data plans offered by MNO's vary in terms of price, quota size, and service quality based on regional causes. Expensive data, poor cell coverage, or a limited quota has driven many users to look for free Wi-Fis in hopes of finding a decent connection to satisfy the ever-growing transmission need of modern Internet applications. The standard for wireless local area networks (WLAN, IEEE 802.11) specifies a network discovery protocol for wireless devices to find surrounding networks. The principle behind this discovery protocol dates back to the early days of wireless networking. However, the scale at which Wi-Fi is deployed and being utilized today is magnitudes larger than what it used to be. In more recent years it was realized that the primitive network discovery protocol combined with the large scale can be used for privacy violations. Device manufacturers have acknowledged this issue and developed mechanisms, such as MAC address randomization, for preventing e.g. user tracking based on Wi-Fi background traffic. These mechanisms have been proven to be inefficient. The contributions of this thesis are two-fold. First, this thesis exposes problems related to the 802.11 network discovery protocol. It presents a highly efficient Wi-Fi traffic capturing system, through which we can show distinct characteristics in the way how different mobile devices from various brands and models scan for available networks. This thesis also looks at the potentially privacy-compromising elements in these queries, and provides a mechanism to quantify the information leak. Such collected information combined with public crowdsourced data can pinpoint locations of interest, such as home, workplace, or affiliation without user consent. Secondly, this thesis proposes a novel mechanism, WiPush, to deliver messages over Wi-Fi without association in order to avoid network discovery entirely. This mechanism leverages the existing, yet mostly inaccessible Wi-Fi infrastructure to serve a wider scope of users. Lastly, this thesis provides a communication system for privacy-preserving, opportunistic, and lightweight Wi-Fi communication without association. This system is built around an inexpensive companion device, which makes the concept adaptable for various opportunistic short-range communication systems, such as smart traffic and delay-tolerant networks.Internet-yhteyksistä on viime vuosikymmenen aikana muodostunut olennainen osa mobiililaitteita. Useat nykyaikaiset käyttötapaukset edellyttävät yhteyttä Internetiin. Älypuhelimia, tabletteja, sekä muita mobiililaitteita voidaan pitää jopa päätelaitteina Internet-palveluihin sekä verkkopohjaisiin sovelluksiin. Yhteyden muodostaminen kuitenkin vaatii joko datayhteyden mobiilioperaattorilta, tai vaihtoehtoisesti käytettävissä olevan Wi-Fin. Mobiilioperaattoreiden tarjoamat datayhteydet vaihtelevat niin hinnan, datakaton, sekä palvelun laadun suhteen alueellisista tekijöistä riippuen. Kallis data, huono kattavuus, tai rajallinen kiintiö ovat omiaan ajamaan käyttäjiä etsimään ilmaisia Wi-Fi-verkkoja tyydyttääkseen verkkosovellusten jatkuvan datansiirtotarpeen. Langattomien lähiverkkojen standardi (WLAN, IEEE 802.11) määrittelee protokollan ympäröivien verkkojen havaitsemiseksi. Kyseisen protokollan toimintaperiaate juontaa juurensa langattomien lähiverkkojen alkuajoille, jolloin langattomien verkkojen levinneisyys ja käyttöaste oli pieni murto-osa nykyiseen verrattuna. Vasta viime vuosina on huomattu, että alkeellinen verkonetsintäprotokolla yhdistettynä laajaan Wi-Fin levinneisyyteen saattaa uhata käyttäjän yksityisyyttä. Laitevalmistajat ovat tunnistaneet ongelman, ja sen seurauksena kehittäneet menetelmiä, kuten MAC-osoitteen satunnaistamisen, estääkseen käyttäjien jäljittämisen Wi-Fin taustaliikenteen perusteella. Nämä menetelmät ovat kuitenkin osoittautuneet tehottomiksi. Tämän väitöskirjatutkimuksen tarkoituksena on käsitellä ongelmia liittyen 802.11 verkonetsintäprotokollaan. Tutkimus esittelee efektiivisen datankeruumenetelmän Wi-Fin taustaliikenteelle, joka mahdollistaa uuden tavan laitteiden yksilöinnille. Tämä tutkimus tarkastelee myös potentiaalisesti yksityisyyttä vaarantavia elementtejä verkonetsintäprotokollan datakehyksen sisällä. Jälkimmäinen puolisko väitöstutkimuksesta esittää uudenlaisen tiedonvälitysmenetelmän, WiPush, joka hyödyntää Wi-Fi-laitteita tiedonvälityksessä ilman assosiaatiota verkonetsintäprotokollan välttämiseksi. Lopuksi tämä väitöstutkimus esittelee yksityisyyttä varjelevan, opportunistisen, langattoman tiedonvälitysmenetelmän kevyeen tiedonsiirtoon

Survey of smart parking systems

The large number of vehicles constantly seeking access to congested areas in cities means that finding a public parking place is often difficult and causes problems for drivers and citizens alike. In this context, strategies that guide vehicles from one point to another, looking for the most optimal path, are needed. Most contributions in the literature are routing strategies that take into account different criteria to select the optimal route required to find a parking space. This paper aims to identify the types of smart parking systems (SPS) that are available today, as well as investigate the kinds of vehicle detection techniques (VDT) they have and the algorithms or other methods they employ, in order to analyze where the development of these systems is at today. To do this, a survey of 274 publications from January 2012 to December 2019 was conducted. The survey considered four principal features: SPS types reported in the literature, the kinds of VDT used in these SPS, the algorithms or methods they implement, and the stage of development at which they are. Based on a search and extraction of results methodology, this work was able to effectively obtain the current state of the research area. In addition, the exhaustive study of the studies analyzed allowed for a discussion to be established concerning the main difficulties, as well as the gaps and open problems detected for the SPS. The results shown in this study may provide a base for future research on the subject.Fil: Diaz Ogás, Mathias Gabriel. Universidad Nacional de San Juan. Facultad de Ciencias Exactas, Físicas y Naturales; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Juan; ArgentinaFil: Fabregat Gesa, Ramon. Universidad de Girona; EspañaFil: Aciar, Silvana Vanesa. Universidad Nacional de San Juan. Facultad de Ciencias Exactas, Físicas y Naturales; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Juan; Argentin

Numerical fluid dynamics simulation for drones’ chemical detection

The risk associated with chemical, biological, radiological, nuclear, and explosive (CBRNe) threats in the last two decades has grown as a result of easier access to hazardous materials and agents, potentially increasing the chance for dangerous events. Consequently, early detection of a threat following a CBRNe event is a mandatory requirement for the safety and security of human operators involved in the management of the emergency. Drones are nowadays one of the most advanced and versatile tools available, and they have proven to be successfully used in many different application fields. The use of drones equipped with inexpensive and selective detectors could be both a solution to improve the early detection of threats and, at the same time, a solution for human operators to prevent dangerous situations. To maximize the drone’s capability of detecting dangerous volatile substances, fluid dynamics numerical simulations may be used to understand the optimal configuration of the detectors positioned on the drone. This study serves as a first step to investigate how the fluid dynamics of the drone propeller flow and the different sensors position on-board could affect the conditioning and acquisition of data. The first consequence of this approach may lead to optimizing the position of the detectors on the drone based not only on the specific technology of the sensor, but also on the type of chemical agent dispersed in the environment, eventually allowing to define a technological solution to enhance the detection process and ensure the safety and security of first responders

Characterizing and Removing Oscillations in Mobile Phone Location Data

IEEE WoWMoM 2019, 20th IEEE International symposium on a World of Wireless, Mobile and Multimedia Networks, Washington, ETATS-UNIS, 10-/06/2019 - 12/06/2019International audienceHuman mobility analysis is a multidisciplinary research subject that has attracted a growing interest over the last decade. A substantial amount of such recent studies is driven by the availability of original sources of real-world information about individual movement patterns. An important task in the analysis of mobility data is reliably distinguishing between the stop locations and movement phases that compose the trajectories of the monitored subjects. The problem is especially challenging when mobility is inferred from mobile phone location data: here, oscillations in the association of mobile devices to base stations lead to apparent user mobility even in absence of actual movement. In this paper, we leverage a unique dataset of spatiotemporal individual trajectories that allows capturing both the user and network operator perspectives in mobile phone location data, and investigate the oscillation phenomenon. We present probabilistic and machine learning approaches for detecting oscillations in mobile phone location data, and a filtering technique for removing those. Our analyses and comparison with state-of-the-art approaches demonstrate the superiority of our solution, both in terms of removed oscillations and of error with respect to ground-truth trajectories

Practical application of mesh opportunistic networks

This research was funded by Department of Technological Innovation of Institute RTVE (Spanish Public Television, RTVE), the Almagro Classical Theater Festival and Observatory for News Innovation in the Digital Society (OI2).Opportunistic networks allow for communication between nearby mobile devices through a radio connection, avoiding the need for cellular data coverage or a Wi-Fi connection. The limited spatial range of this type of communication can be overcome by using nodes in a mesh network. The purpose of this research was to examine a commercial application of electronic mesh communication without a mobile data plan, Wi-Fi, or satellite. A mixed study, with qualitative and quantitative strategies, was designed. An experimental session, in which participants tested opportunistic networks developing different tasks for performance, was carried out to examine the system. Different complementary approaches were adopted: a survey, a focus group, and an analysis of participants' performance. We found that the main advantage of this type of communication is the lack of a need to use data networks for one-to-one and group communications. Opportunistic networks can be integrated into professional communication workflows. They can be used in situations where traditional telephones and the Internet are compromised, such as at mass events, emergency situations, or in the presence of frequency inhibitors

Blockchain for automotive: An insight towards the IPFS blockchain-based auto insurance sector

The advancing technology and industrial revolution have taken the automotive industry by storm in recent times. The auto sector’s constantly growing demand has paved the way for the automobile sector to embrace new technologies and disruptive innovations. The multi-trillion dollar, complex auto insurance sector is still stuck in the regulations of the past. Most of the customers still contact the insurance company by phone to buy new policies and process existing insurance claims. The customers still face the risk of fraudulent online brokers, as policies are mostly signed and processed on papers which often require human supervision, with a risk of error. The insurance sector faces a threat of failure due to losing and misconception of policies and information. We present a decentralized IPFS and blockchain-based framework for the auto insurance sector that regulates the activities in terms of insurance claims for automobiles and automates payments. This article also discusses how blockchain technology’s features can be useful for the decentralized autonomous vehicle’s ecosystem

Design of Wireless Sensors for IoT with Energy Storage and Communication Channel Heterogeneity

Autonomous Wireless Sensors (AWSs) are at the core of every Wireless Sensor Network (WSN). Current AWS technology allows the development of many IoT-based applications, ranging from military to bioengineering and from industry to education. The energy optimization of AWSs depends mainly on: Structural, functional, and application specifications. The holistic design methodology addresses all the factors mentioned above. In this sense, we propose an original solution based on a novel architecture that duplicates the transceivers and also the power source using a hybrid storage system. By identifying the consumption needs of the transceivers, an appropriate methodology for sizing and controlling the power flow for the power source is proposed. The paper emphasizes the fusion between information, communication, and energy consumption of the AWS in terms of spectrum information through a set of transceiver testing scenarios, identifying the main factors that influence the sensor node design and their inter-dependencies. Optimization of the system considers all these factors obtaining an energy efficient AWS, paving the way towards autonomous sensors by adding an energy harvesting element to them

Design and application of intelligent reflecting surface (IRS) for beyond 5G wireless networks: a review

The existing sub-6 GHz band is insufficient to support the bandwidth requirement of emerging data-rate-hungry applications and Internet of Things devices, requiring ultrareliable low latency communication (URLLC), thus making the migration to millimeter-wave (mmWave) bands inevitable. A notable disadvantage of a mmWave band is the significant losses suffered at higher frequencies that may not be overcome by novel optimization algorithms at the transmitter and receiver and thus result in a performance degradation. To address this, Intelligent Reflecting Surface (IRS) is a new technology capable of transforming the wireless channel from a highly probabilistic to a highly deterministic channel and as a result, overcome the significant losses experienced in the mmWave band. This paper aims to survey the design and applications of an IRS, a 2-dimensional (2D) passive metasurface with the ability to control the wireless propagation channel and thus achieve better spectral efficiency (SE) and energy efficiency (EE) to aid the fifth and beyond generation to deliver the required data rate to support current and emerging technologies. It is imperative that the future wireless technology evolves toward an intelligent software paradigm, and the IRS is expected to be a key enabler in achieving this task. This work provides a detailed survey of the IRS technology, limitations in the current research, and the related research opportunities and possible solutions