Category: Defenses

PhD Defence: “Medium Access Control Layer for Dedicated IoT Networks”, Abderrahman Ben Khalifa, 30th of July 2020 at 2PM

The defense will be available at https://join.skype.com/dbnmuw06rBou

Title

Medium Access Control Layer for Dedicated IoT Networks

 

Abstract

Les réseaux dédiés pour l’Internet des Objets sont apparus avec la promesse de connecter des milliers de nœuds, voire plus, à une seule station de base dans une topologie en étoile. Cette nouvelle logique représente un changement fondamental dans la façon de penser les réseaux, après des décennies pendant lesquelles les travaux de recherche se sont focalisés sur les réseaux multi-sauts.
Les réseaux pour l’Internet des Objets se caractérisent par la longue portée des transmissions, la vaste couverture géographique, une faible consommation d’énergie et un bas coût de mise en place. Cela a rendu nécessaire des adaptations à tous les niveaux protocolaires afin de satisfaire les besoins de ces réseaux. Plusieurs acteurs sont en concurrence sur le marché de l’Internet des Objets, essayant chacun d’établir la solution la plus efficiente. Ces acteurs se sont concentrés sur la modification de la couche physique, soit au niveau de la partie matérielle, soit par la proposition de nouvelles techniques de modulation. Toutefois, en ce qui concerne la solution de contrôle d’accès au canal (connue sous le nom de couche MAC), toutes les solutions proposées par ces acteurs se fondent sur des approches classiques, tel que Aloha et CSMA.
L’objectif de cette thèse est de proposer une solution MAC dynamique pour les réseaux dédiés à l’Internet des Objets. La solution proposée a la capacité de s’adapter aux conditions du réseau. Cette solution est basée sur un algorithme d’apprentissage automatique, qui apprend de l’historique du réseau afin d’établir la relation entre les conditions du réseau, les paramètres de la couche MAC et les performances du réseau en termes de fiabilité et de consommation d’énergie. La solution possède également l’originalité de faire coexister des nœuds utilisant de différentes configurations MAC au sein du même réseau. Les résultats de simulations ont montré qu’une solution MAC basée sur l’apprentissage automatique pourrait tirer profit des avantages des différents protocoles MAC classiques. Les résultats montrent aussi qu’une solution MAC cognitive offre toujours le meilleur compromis entre fiabilité et consommation d’énergie, tout en prenant en compte l’équité entre les nœuds du réseau. La solution MAC cognitive testée pour des réseaux à haute densité a prouvé des bonnes propriétés de passage à l’échelle par rapport aux protocoles MACs classiques, ce qui constitue un autre atout important de notre solution.

 

Jury

  • M. Antoine GALLAIS, Professeur Université Polytechnique Hauts de France, Rapporteur
  • M. Congduc PHAM, Professeur Université de Pau et des Pays de l’Adour, Rapporteur
  • Mme. Nancy EL RACHKIDY, Maître de Conférences Université Clermont Auvergne, Examinateur
  • M. Mickael MAMAN, Ingénieur de Recherche CEA LETI, Examinateur
  • M. Hervé RIVANO, Professeur INSA Lyon, Directeur de thèse
  • M. Razvan STANICA, Maître de Conférences INSA Lyon, Co-directeur de thèse

PhD Defence: “Autonomous Wireless Sensor Network Architecture for Vehicular traffic monitoring at an Intersection”, Domga Komguem, 6th of July 2020 at 10AM

The defense will take place at the University of Yaoundé I and will be available at https://join.skype.com/EVc3J1aGhASf

Title

Autonomous Wireless Sensor Network Architecture for Vehicular traffic monitoring at an Intersection

 

Abstract

In many countries, because of the limited financial budget, the growth of road infrastructures is low compared to the growth of population and the number of vehicles in urban areas. Such a context does not make the task easy for authorities in charge of the management of transportation systems. The introduction of information and communication technologies (ICT) allows to better address these issues. Vehicular traffic management at intersections has an impact on the traffic jam observed in the whole city. In this thesis, our goal is to propose a low-cost, lightweight and autonomous Wireless Sensors Network (WSN) architecture for vehicular traffic monitoring, especially at an intersection. Vehicular traffic data collected can be used, for instance, for intelligent traffic lights management. In the WSN architecture proposed in the literature for vehicular traffic monitoring, underground sensors are used. In terms of network communication, these architectures are not realistic. Nowadays, surface-mounted sensors are proposed by manufacturers.

The first contribution of this thesis is an experimental characterization of wireless links in a WSN with sensors deployed at the ground level. We evaluate the impact of several parameters like the proximity of the ground surface, the communication frequency and the message size on the link quality. Results show a poor link quality at ground level. Based on the conclusions of the experiments, the second contribution of this thesis is WARIM, a new WSN architecture for vehicular traffic monitoring at an intersection. In WARIM, the sensors deployed on a lane form a multi-hop WSN with a linear topology (LWSN). In this network, all the data are forwarded toward the sink. In a network with such properties, the computation and communication requirements are highest in the neighborhood of the sink. Thus, the third contribution of this thesis is a virtual nodes-based and energy efficient sensors deployment strategy for LWSN. Compared to a uniform deployment, this deployment improves the network lifetime by 40%. In our intersection monitoring application, it is important to correlate the messages generated by a sensor to its position with respect to the intersection. Therefore,the fourth contribution of this thesis is, a centroid-based algorithm for sensors ranking in a LWSN. We evaluate the performance of this algorithm considering a realistic channel model, a uniform deployment, as well as the virtual nodes based-deployment proposed in this thesis. Finally, putting all our contributions together, simulations show that WARIM can be used for reliable and real-time vehicular traffic monitoring at an intersection.

 

Jury

  • Marcel FOUDA, Professor, Université de Yaoundé I, President
  • Thomas DJOTIO, Associate Professor, Université de Yaoundé I, Reviewer
  • Nathalie MITTON, Research Director, INRIA, Reviewer
  • Bernard TOURANCHEAU, Professor, Université Grenoble Alpes, Reviewer
  • André-Luc BEYLOT, Professor, ENSEEIHT Toulouse, Examinator
  • René NDOUNDAM, Associate Professor, Université de Yaoundé I, Examinator
  • Razvan STANICA, HDR, INSA Lyon, Examinator
  • Maurice TCHUENTE, Professor, Université de Yaoundé I, Co-Supervisor
  • Fabrice VALOIS, Professor, INSA Lyon, Co-Supervisor

PhD Defence: “Dynamic Heterogeneous Memory Allocation for embedded devices”, Tristan Delizy, Chappe Amphitheater, CITI, 19th of December 2019 at 10h00

Title

Dynamic Heterogeneous Memory Allocation for embedded devices

Abstract

Reducing energy consumption is a key challenge to the realisation of the Internet of Things. While emerging memory technologies may offer power reduction and high integration density, they come with major drawbacks such as high latency or limited endurance. As a result, system designers tend to juxtapose several memory technologies on the same chip. We aim to provide the embedded application programmer with a transparent software mechanism to leverage this memory heterogeneity. This work studies the interaction between dynamic memory allocation and memory heterogeneity. We provide cycle accurate simulation of embedded platforms with various memory technologies and we show that different dynamic allocation strategies have a major impact on performance. We demonstrates that interesting performance gains can be achieved even for a low fraction of memory using low latency technology, but only with a clever placement strategy between memory banks. We propose an efficient strategy based on application profiling in our simulator.

 

Jury

  • Olivier Sentieys, Professeur des Universités, Université de Rennes – Examinateur
  • Cécile Belleudy, Maitre de Conférence HDR, Université de Nice Sophia Antipolis – Rapporteure
  • Lionel Torres, Professeur des Universités, Université de Montpellier – Rapporteur
  • Guillaume Salagnac, Maitre de Conférences, INSA de Lyon – Examinateur, Encadrant
  • Tanguy Risset, Professeur des Universités, INSA de Lyon – Examinateur, Co-directeur de thèse
  • Matthieu Moy, Maitre de Conférences HDR, Université Claude Bernard Lyon 1 – Examinateur, Co-directeur de thèse

PhD Defence: “High-level synthesis and arithmetic optimizations”, Yohann Uguen, Chappe Amphitheater, CITI, 13th of November 2019 at 13h30

Title

High-level synthesis and arithmetic optimizations

Abstract

High-level synthesis (HLS) tools offer increased productivity regarding FPGA programming. However, due to their relatively young nature, they still lack many arithmetic optimizations. This thesis proposes safe arithmetic optimizations that should always be applied. These optimizations are simple operator specializations, following the C semantic. Other require to a lift the semantic embedded in high-level input program languages, which are inherited from software programming, for an improved accuracy/cost/performance ratio. To demonstrate this claim, the sum-of-product of floating-point numbers is used as a case study. The sum is performed on a fixed-point format, which is tailored to the application, according to the context in which the operator is instantiated.

In some cases, there is not enough information about the input data to tailor the fixed-point accumulator. The fall-back strategy used in this thesis is to generate an accumulator covering the entire floating-point range. This thesis explores different strategies for implementing such a large accumulator, including new ones. The use of a 2’s complement representation instead of a sign+magnitude is demonstrated to save resources and to reduce the accumulation loop delay.

Based on a tapered precision scheme and an exact accumulator, the posit number systems claims to be a candidate to replace the IEEE floating-point format. A throughout analysis of posit operators is performed, using the same level of hardware optimization as state-of-the-art floating-point operators. Their cost remains much higher that their floating-point counterparts in terms of resource usage and performance.

Finally, this thesis presents a compatibility layer for HLS tools that allows one code to be deployed on multiple tools. This library implements a strongly typed custom size integer type along side a set of optimized custom operators.

 

Jury

  • Philippe Coussy, Professeur des Universités, UBS, Lorient, France : Rapporteur
  • Olivier Sentieys, Professeur des Universités, Univ. Rennes, Inria, IRISA, Rennes : Rapporteur
  • Laure Gonnord, Maître de conférence, Université Lyon 1, France : Examinatrice
  • Frédéric Pétrot, Professeur des Universités, TIMA, Grenoble, France : Examinateur
  • Martin Kumm, Professeur des Universités, Université de Fulda, Allemagne : Examinateur
  • Florent de Dinechin, Professeur des Universités, INSA Lyon, France : Directeur de thèse

PhD Defence: “Contributions Théoriques sur les Communications Furtives”, David KIBLOFF, Chappe Amphitheater, CITI, 17th of September 2019 at 14h00

Title

Information Theoretic Contributions to Covert Communications

Abstract

The problem of covert communications, also known as communications with low-probability of detection has gained interest in the information theory community in the last years. Since Bash et. al. showed in 2012 that the square-root law applied in the point-to-point case for such communications systems, the number of contributions on the topic did not cease to grow. In this thesis, two new problems of covert communications are introduced. First, the problem of covert communications over a point-to-point link where a warden observes only a fraction of channel outputs in order to try to detect the communications is studied. An achievability bound in the finite block-length regime is derived for this problem. Second, the problem of embedding covert information into a given broadcast code is introduced. Given a broadcast code to transmit a common message to two receivers, the goal is to determine the maximum number of information bits that can be reliably sent to one receiver while remaining covert with respect to the other receiver. For this problem, both an achievability and converse bound in the asymptotic block-length regime are derived for a particular class of channels, i.e., symmetric channels. Together these bounds characterize the maximum number of information bits that can be covertly embedded in a given broadcast code for symmetric channels.

 

Jury

  • Dr. Albert Guillen i Fabregas, Université Pompeu Fabra, Espagne. Rapporteur.
  • Dr. Aline Roumy, INRIA, France. Rapporteure.
  • Dr. Laurent Clavier, IMT Lille Douai, France. Examinateur.
  • Dr. Inbar Fijalkow, Université de Cergy-Pontoise, France. Examinatrice.
  • Dr. Jean-Marie Gorce, INSA de Lyon, France. Examinateur.
  • Dr. Ligong Wang, CNRS, France. Examinateur.
  • Dr. Guillaume Villemaud, INSA de Lyon, France. Directeur de thèse.
  • Dr. Samir M. Perlaza, INRIA, France. Encadrant de thèse.
  • Dr. Ronan Cosquer, DGA, France. Invité.

PhD Defence: “Radio Access and Core Functionalities in Self-deployable Mobile Networks”, Jad Oueis, Amphitheater, Chappe Building, 27th of October 2018, at 10h00

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


PhD Defence: “Bidirectional Visible Light Communications for the Internet of Things”, Alexis DUQUE, Amphitheater, Chappe Building, 9th of October 2018, at 14h00

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

PhD Defence: “Ultra Narrow Band based IoT networks”, Yuqi MO, Amphitheater, Chappe Building, 26th of September 2018, at 14h00

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)

 


PhD Defence: “Middleware and programming models for multi-robot systems”, Stefan-Gabriel Chitic, Vitrine/RobIot room, Chappe Building, 15th of March 2018, at 10h:30

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)

PhD Defense: “Noisy Channel-Output Feedback in the Interference Channel” by Victor Quintero, 12th of December 2017, at 14h, in the amphitheater Émilie du Châtelet – Marie Curie Library – INSA de Lyon

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.