Title

Radio Access and Core Functionalities in Self-deployable Mobile Networks

Abstract

Self-deployable mobile networks are a novel family of cellular networks, that can be rapidly deployed, easily installed, and operated on demand, anywhere, anytime. They target diverse use cases and provide network services when the classical network fails, is not suitable, or simply does not exist: when the network saturates during crowded events, when first responders need private broadband communication in disaster-relief and mission-critical situations, or when there is no infrastructure in areas with low population density.

These networks are challenging a long-standing vision of cellular networks by eliminating the physical separation between the radio access network (RAN) and the core network (CN). In addition to providing RAN functionalities, such as radio signal processing and radio resource management, a base station can also provide those of the CN, such as session management and routing, in addition to housing application servers. As a result, a base station with no backhaul connection to a traditional CN can provide local services to users in its vicinity. To cover larger areas, several base stations must interconnect. With the CN functions co-located with the RAN, the links interconnecting the BSs form the backhaul network. Being setup by the BSs, potentially in an ad hoc manner, the latter may have a limited bandwidth.

In this thesis, we build on the properties distinguishing self-deployable networks to revisit classical RAN problems but in the self-deployable context, and address the novel challenges created by the core network architecture. Starting with the RAN configuration, we propose an algorithm that sets a frequency and power allocation scheme. The latter outperforms conventional frequency reuse schemes in terms of the achieved user throughput and is robust facing variations in the number of users and their distribution in the network. Once the RAN is configured, we move to the CN organization, and address both centralized and distributed CN functions placements. For the centralized placement, building on the shortages of state of the art metrics, we propose a novel centrality metric that places the functions in a way that maximizes the traffic that can be exchanged in the network. For the distributed placement, we evaluate the number of needed instances of the CN functions and their optimal placement, considering the impact on the backhaul bandwidth. We further highlight the advantages of distributing CN functions, from a backhaul point of view. Accordingly, we tackle the user attachment problem to determine the CN instances serving each user when the former are distributed. Finally, with the network ready to operate, and users starting to arrive, we tackle the user association problem. We propose a novel network-aware association policy adapted to self-deployable networks, that outperforms a traditional RAN-based policy. It jointly accounts for the downlink, the uplink, the backhaul and the user throughput request.

Jury

• Claudio CASETTI,  Associate Professor, Politecnico di Torino, Rapporteur

• Hakima CHAOUCHI, Professeure des Universités, Telecom Sud Paris, Rapporteure

• Xavier LAGRANGE, Professeur des Universités, IMT Atlantique Rapporteur

• Vania CONAN, Habilité à Diriger des Recherches, Thales, Examinateur

• Serge FDIDA, Professeur des Universités, UPMC, Examinateur

• Nancy PERROT, Docteure, Orange Labs, Examinatrice

• Fabrice VALOIS, Professeur des Universités, NSA LYON, Directeur de Thèse

• Razvan STANICA, Maître de Conférences, INSA LYON, Co-encadrant de Thèse

Title

Bidirectional Visible Light Communications for the Internet of Things

Abstract

With the exponential growth of the Internet of Things, people now expect every household appliance to be smart and connected. At the same time, smartphones have become ubiquitous in our daily life. Their continuous performance improvement and their compatibility with a broad range of radio protocols as WiFi, Bluetooth Low Energy (BLE) or NFC make them the most convenient way to interact with these smart objects. However, providing wireless connectivity with BLE or NFC means adding an extra chipset and an antenna, increasing the object size and price. Previous works already have demonstrated the possibility of receiving information through visible light using an unmodified smartphone thanks to its camera. Also, LED-to-LED communication for smart devices like toys has been shown previously. However, past efforts in LED to camera communication for IoT device communication have been limited.

In this work, we design LightIoT, a bidirectional visible-light communication (VLC) system between a low-cost, low-power colored LED that is part of an IoT device and an off-the-shelf smartphone. The IoT device is thus able to send and receive information through its LED, while the smartphone uses its camera to receive data and its flashlight to send information. We implement and experimentally evaluate a LED-to-camera VLC system, designed specifically for small LEDs. The proposed solution exploits the rolling shutter effect of unmodified smartphone cameras and an original decoding algorithm, achieving a throughput of nearly 2 kb/s.
Based on the insight gained from an extensive experimental study, we model, for the first time in the literature, the LED-to-camera communication channel. We propose a Markov-modulated Bernoulli process model, which allows us to easily study the performance of different message retransmission strategies. We further exploit this model to implement a simulator for LED-to- Camera communications performance evaluation.

In order to achieve bi-directional communications, we evaluate flashlight-to- LED communications using non-rooted smartphones and small LEDs. With these constraints, our implementation achieves a throughput of 30 bits/second. While limited, this is enough for a feed-back channel coming to support the required redundancy mechanisms. Some of these redundancy mechanisms are based on random linear coding, never tested previously in VLC.
Therefore, we design and implement, for the first time in the literature, a pseudo random linear coding scheme especially fitted for line-of-sight LED-to-camera conditions. Experimental evaluation highlights that this type of approach increases the goodput up to twice compared to classical retransmission strategies.

Finally, we compare the energy consumption of LightIoT with the one of a BLE module with similar activity. Our results show that using the LED for communication purposes reduces the energy consumption under a normal usage behavior.

Jury

• Emmanuel CHAPUT, Professeur des Universités, INP Toulouse, Rapporteur
• Anne JULIEN-VERGONJANNE, Professeur des Universités Univ. Limoges, Rapporteur
• Josep PARADELLS ASPAS, Professeur UPC, Rapporteur
• Luc CHASSAGNE, Professeur des Universités UVSQ, Examinateur
• Valeria LOSCRI, Chargé de Recherche INRIA Lille, Examinateur
• Hervé RIVANO, Professeur des Universités INSA Lyon, Directeur de thèse
• Razvan STANICA Maître de Conférences INSA Lyon, co Directeur de thèse

Title

Ultra Narrow Band based IoT networks

Abstract

Sigfox rises as a promising candidate dedicated for long-distance and low-power transmissions in the IoT backgrounds. Ultra Narrow Band (UNB), being the communication technology chosen by Sigfox, allows to transmit information through signals whose bandwidth is very limited, typically 100 Hz. Due to the imprecision restraint on electronic devices, it is impossible to transmit UNB signals in orthogonal channels. The natural radio access for this kind of system is thus random ALOHA, in both time and frequency domain. This random access can induce collisions which degrades the networks performance.

The aim of this thesis is to characterize the capacity of UNB based networks, as well as to enhance its performance, by considering the randomness in time and frequency.

The first contribution of the thesis, is the theoretical and numerical capacity evaluation under idealized and realistic channel conditions, for mono base station (BS) case. Under idealized conditions, we have quantified this capacity for generalized ALOHA case and extended for replications. We highlight the time-frequency duality in UNB systems, and that there exists an optimum replication number for a given network parameter set.

Under realistic conditions, we have taken into account the specific spectral interference of UNB systems and propagation path loss (without and with Rayleigh fading) to characterize the performance, with the aid of stochastic geometry.

The second contribution is the enhancement of UNB network performance in single BS case. We propose to use successive interference cancellation (SIC) in UNB networks, which allows to mitigate the interference. We have provided a theoretical analysis by considering both SIC and the spectral interference, for mono-BS case. We bring to light the efficiency of SIC in enhancing UNB system performance.

The third contribution is the improvement of UNB systems, by exploiting the multiple BS diversity. An analytical performance evaluation considering the simplest selection combining is conducted. In particular, we consider the interference viewed by all the BSs are correlated. Then we apply more complex signal combining technologies such as MRC (max ratio combining) and EGC (equal gain combining), and even interference cancellation across multi-BS in UNB networks. We evaluate the performance improvement that each technology can bring, and compare them with each other. We highlight the efficiency of these multi-BS technologies which allow us to achieve significant performance enhancement compared to mono-BS (e.x. 125 times better performance with global SIC).

Last but not least, we experimentally verify the the spectral interference model and network capacity on a cognitive radio testbed.

Jury

• Mr. ANTON-HARO Carles, Directeur de Recherch, à Centre technology de Telecommunications de Catalunya (Reviewer)
• Mr. DI RENZO Marco, HDR à Université Paris-Saclay (Reviewer)
• Mme. HELARD Maryline, Professeur à l’INSA-Rennes (Member)
• Mr. VERDONE Roberto, Professeur à University of Bologna (Member)
• Mr. GORCE Jean-Marie, Professeur à l’INSA-Lyon (Supervisor)
• Mme. GOURSAUD Claire, HDR à l’INSA-Lyon (Co-Supervisor)

Title

Middleware and programming models for multi-robot systems

Abstract

Despite many years of work in robotics, there is still a lack of established software architecture and middleware for multi-robot systems. A robotic middleware should be designed to abstract the low-level hardware architecture, facilitate communication and integration of new software. This PhD thesis is focusing on middleware for multi-robot system and how we can improve existing frameworks for fleet purposes by adding multi-robot coordination services, development and massive deployment tools. We expect robots to be increasingly useful as they can take advantage of data pushed from other external devices in their decision making instead of just reacting to their local environment (sensors, cooperating robots in a fleet, etc).

This thesis first evaluates one of the most recent middleware for mobile robot(s), Robot operating system (ROS) and continues with a state of the art about the commonly used middlewares in robotics. Based on the conclusions, we propose an original contribution in the multi-robot context, called SDfR (Service discovery for Robots), a service discovery mechanism for Robots. The main goal is to propose a mechanism that allows highly mobile robots to keep track of the reachable peers inside a fleet while using an ad-hoc infrastructure. Another objective is to propose a network configuration negotiation protocol. Due to the mobility of robots, classical peer to peer network configuration techniques are not suitable. SDfR is a highly dynamic, adaptive and scalable protocol adapted from Simple Service Discovery Protocol (SSDP). We conduced a set of experiments, using a fleet of Turtlebot robots, to measure and show that the overhead of SDfR is limited.

The last part of the thesis focuses on programming model based on timed automata. This type of programming has the benefits of having a model that can be verified and simulated before deploying the application on real robots. In order to enrich and facilitate the development of robotic applications, a new programming model based on timed automata state machines is proposed, called ROSMDB (Robot Operating system Model Driven Behaviour). It provides model checking at development phase and at runtime. This contribution is composed of several components: a graphical interface to create models based on timed automata, an integrated model checker based on UPPAAL and a code skeleton generator. Moreover, a ROS specific framework is proposed to verify the correctness of the execution of the models and to trigger alerts. Finally, we conduct two experiments: one with a fleet of Parrot drones and second with Turtlebots in order to illustrates the proposed model and its ability to check properties.

Jury

•  Prof. Abderrafiaa KOUKAM, Université de Technologie de Belfort-Montbéliard (Reviewer)
• Prof. Philippe LALANDA, Université́ Joseph Fourier, Saint-Martin-d’Hères (Reviewer)
• Prof. Noury BOURAQADI, Institut Mines-Telecom, IMT Lille Douai (Member)
• Dr. Stéphanie CHOLLET, ESISAR, Valence (Member)
• Prof. Olivier SIMONIN, INSA Lyon (Supervisor)
• Dr. Julien PONGE, INSA Lyon (Co-Supervisor)

Jury

• Prof. Michèle WIGGER, Reviewer, Télécom Paristech, France.
• Prof. Abdellatif ZAIDI, Reviewer, Université Paris-Est Marne la Vallée, France.
• Prof. Inbar FIJALKOW, Examiner, Université de Cergy-Pontoise, France.
• Prof. H. Vincent POOR, Examiner, Princeton University, USA.
• Prof. Gerhard KRAMER, Examiner, Technische Universität München, Germany.
• Prof. David GESBERT, Examiner, Eurecom, France.
• Prof. Jean-Marie GORCE, Thesis Director, Université de Lyon, France.
• Dr. Samir M. Perlaza, Thesis Advisor, INRIA, France.
• Prof. Iñaki Esnaola, Guest, University of Sheffield, UK.

Abstract
In this thesis, the two-user Gaussian interference channel with noisy channel-output feedback (GIC-NOF) is studied from two perspectives: centralized and decentralized networks.

From the perspective of centralized networks, the fundamental limits of the two-user GIC- NOF are characterized by the capacity region. One of the main contributions of this thesis is an approximation to within a constant number of bits of the capacity region of the two-user GIC-NOF. This result is obtained thanks to the analysis of a simpler channel model, i.e., a two-user linear deterministic interference channel with noisy channel-output feedback (LDIC- NOF). The analysis to obtain the capacity region of the two-user LDIC-NOF provides the main insights required to analyze the two-user GIC-NOF.

From the perspective of decentralized networks, the fundamental limits of the two-user decentralized GIC-NOF (D-GIC-NOF) are characterized by the η-Nash equilibrium (η-NE) region. Another contribution of this thesis is an approximation to the η-NE region of the two-user GIC-NOF, with η > 1. As in the centralized case, the two-user decentralized LDIC-NOF (D-LDIC-NOF) is studied first and the lessons learnt are applied in the two-user D-GIC-NOF. The final contribution of this thesis consists of a closed-form answer to the question: “When does channel-output feedback enlarge the capacity or η-NE regions of the two-user GIC-NOF or two-user D-GIC-NOF?”. This answer is of the form: Implementing channel-output feedback in transmitter-receiver i enlarges the capacity or η-NE regions if the feedback SNR is beyond SNRi*, with i∈{1,2}. The approximate value of SNRi* is shown to be a function of all the other parameters of the two-user GIC-NOF or two-user D-GIC-NOF.

Jury

Reviewers :
Nguyen, Benjamin, Professeur des universités, INSA Centre Val de Loire
Rasmussen, Kasper, Associate professor, University of Oxford

Members:
Chrisment, Isabelle, Professeur des universités, Université de Lorraine
Risset, Tanguy, Professeur des universités, INSA Lyon
Neumann, Christoph, Principal scientist, Technicolor

Supervisors :
Minier, Marine, Professeur des universités, Université de Lorraine
Cunche, Mathieu, Maître de conférences, Insa Lyon

Abstract

Wi-Fi Tracking: Fingerprinting Attacks and Counter-Measures

The recent spread of everyday-carried Wi-Fi-enabled devices (smartphones, tablets and wearable devices) comes with a privacy threat to their owner, and to society as a whole. These devices continuously emit signals which can be captured by a passive attacker using cheap hardware and basic knowledge. These signals contain a unique identifier,
called the MAC address. To mitigate the threat, device vendors are currently deploying a countermeasure on new devices: MAC address randomization. Unfortunately, we show that this mitigation, in its current state, is insufficient to prevent tracking.

To do so, we introduce several attacks, based on the content and the timing of emitted signals. In complement, we study implementations of MAC address randomization in some recent devices, and find a number of shortcomings limiting the efficiency of these implementations at preventing device tracking.

At the same time, we perform two real-world studies. The first one considers the development of actors exploiting this issue to install Wi-Fi tracking systems. We list some real-world installations and discuss their various aspects, including regulation, privacy implications, consent and public acceptance. The second one deals with the spread of MAC address randomization in the devices population.

Finally, we present two tools: an experimental Wi-Fi tracking system for testing and public awareness raising purpose, and a tool estimating the uniqueness of a device based on the content of its emitted signals even if the identier is randomized.

Jury

• Pr Philippe CIBLAT, Telecom Paris Tech, Université de Paris-Saclay (reviewer)
• Pr Mischa DOHLER, King’s College London (reviewer)
• Pr Visa KOIVUNEN, Aalto University (reviewer)
• Pr Inbar FIJALKOW, Université Paris Seine, Université Cergy Pontoise
• Pr André-Luc BEYLOT, Toulouse INP
• Pr Isabelle GUERIN LASSOUS, Université Claude Bernard – Lyon 1
• Pr Jean-Marie GORCE, INSA Lyon

Abstract

My research activities are focused on the uplink in Wireless Sensor Networks, BAN, and IoT networks.
In particular, I have focused on the joint study of the PHY and MAC layers, so as to improve the network perfomance. The main hypothesis of my work is that no resources are to be spent for channel estimation or access protocol organization. The data transmission has thus to be performed such as the receiver is able to take advantage of all diversity at disposal, either introduced by the source, any relaying node, or intrinsic diversity.

In the first part, WBAN (Wireless Body Area Networks) are considered. Measurements campaigns have been conducted to create a data set with correlated channel conditions within a BAN, and among several BANs. With these data, we have proposed and evaluated dedicated frame constructions, when localization is performed with 3WR (3 Way Ranging) protocol using UWB (Ultra Wide Band). Such protocol, designed for static nodes, suffers from the intrinsic mobility of WBAN nodes. The challenge was thus to propose a strategy to ensure distance accuracy, position accuracy, and good positioning success probability, even though no channel information is available prior to the transmission. We have also theoretically evaluated how to optimally distribute the available power among a node and a potential relay.

Furthermore, we have considered IoT applications. Within this context, Fountain Codes and intraflow Network Coding were first studied to improve the transmission reliability. Secondly, the specific interference pattern observed in UNB (Ultra Narrow Band) transmission such as in SigFox network was also considered. In this context, the objective is to take advantage of all available diversity in the signal (temporal, spectral, signal strength, multi-receiver, …) to improve the system performance.

These aforementioned challenges are addressed in this HdR dissertation manuscript. I exposed the solutions we proposed during this last decade and the related obtained results through theoretical analysis, simulation and/or experimentation; as well as other potential directions.

The defense will take place on Thursday 6th April at 14:00 in the Chappe Amphitheater, Claude Chappe building, INSA Lyon.
The presentation will be held in English with slides in English.

Jury

Reviewers

Paolo IENNE, EPFL Lausanne
Roselyne CHOTIN-AVOT, UPMC Paris

Examiners

David THOMAS, Imperial College London
Frédéric PETROT, ENSIMAG, Saint Martin d’Hères
Olivier SENTIEYS, ENSSAT, Lannion

Advisors

Florent DE DINECHIN, INSA Lyon

Abstract

The defense will take place on Monday 19th December at 10:00 in the Chappe Amphitheater, Claude Chappe building, INSA Lyon.
The presentation will be held in French with slides in English.

Jury

Reviewers

Thierry TURLETTI, Inria- Sophia Antipolis
Pascale MINET, Inria- Paris

Examiners

Pascal THUBERT, Cisco Systems
Philippe OWEZARSKI, CNRS- Toulouse
Isabelle GUÉRIN-LASSOUS, Lyon 1 University

Advisors

Dominique BARTHEL, Orange Labs- Meylan
Fabrice VALOIS, INSA Lyon
Fabrice Theoleyre, CNRS- ICube

This thesis work has been done in collaboration between Orange Labs, INSA Lyon, ICube, and Inria UrbaNet in the CITI Lab.

Abstract