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Metasurfaces, the two-dimensional counterpart of metamaterials, have caught great attention thanks to their powerful capabilities on manipulation of electromagnetic waves. Recent times have seen the emergence of a variety of metasurfaces exhibiting not only countless functionalities, but also a reconfigurable response. Additionally, digital or coding metasurfaces have revolutionized the field by describing the device as a matrix of discrete building block states, thus drawing clear parallelisms with information theory and opening new ways to model, compose, and (re)program advanced metasurfaces. This paper joins the reconfigurable and digital approaches, and presents a metasurface that leverages the tunability of graphene to perform beam steering at terahertz frequencies. A comprehensive design methodology is presented encompassing technological, unit cell design, digital metamaterial synthesis, and programmability aspects. By setting up and dynamically adjusting a phase gradient along the metasurface plane, the resulting device achieves beam steering at all practical directions. The proposed design is studied through analytical models and validated numerically, showing beam widths and steering errors well below 10° and 5% in most cases. Finally, design guidelines are extracted through a scalability analysis involving the metasurface size and number of unit cell states., This work was supported in part by the Iran’s National Elites Foundation (INEF), in part by the Spanish Ministry of Economía y Competitividad under Grant PCIN-2015-012, and in part by ICREA under the ICREA Academia programme., Peer Reviewed, Postprint (author's final draft)

Recent advances in Deep Reinforcement Learning (DRL) techniques are providing a dramatic improvement in decision-making and automated control problems. As a result, we are witnessing a growing number of research works that are proposing ways of applying DRL techniques to network-related problems such as routing. However, such proposals failed to achieve good results, often under-performing traditional routing techniques. We argue that successfully applying DRL-based techniques to networking requires finding good representations of the network parameters: feature engineering. DRL agents need to represent both the state (e.g., link utilization) and the action space (e.g., changes to the routing policy). In this paper, we show that existing approaches use straightforward representations that lead to poor performance. We propose a novel representation of the state and action that outperforms existing ones and that is flexible enough to be applied to many networking use-cases. We test our representation in two different scenarios: (i) routing in optical transport networks and (ii) QoS-aware routing in IP networks. Our results show that the DRL agent achieves significantly better performance compared to existing state/action representations., This work has been supported by the Spanish MINECO under contract TEC2017-90034-C2-1-R (ALLIANCE) and the Catalan Institution for Research and Advanced Studies (ICREA)., Peer Reviewed, Postprint (author's final draft)

Recently, a Graph Neural Network (GNN) model called RouteNet was proposed as an efficient method to estimate end-to-end network performance metrics such as delay or jitter, given the topology, routing, and traffic of the network. Despite its success in making accurate estimations and generalizing to unseen topologies, the model makes some simplifying assumptions about the network, and does not consider all the particularities of how real networks operate. In this work we extend the architecture of RouteNet to support different features on forwarding devices, specifically we focus on devices with variable queue sizes, and we experimentally evaluate the accuracy of the extended RouteNet architecture., This work was supported by the Spanish MINECO under contract TEC2017-90034-C2-1-R (ALLIANCE), the Catalan Institution for Research and Advanced Studies (ICREA), FI-AGAUR grant by the Catalan Government and the AGH University of Science and by the Polish Ministry of Science and Higher Education with the subvention funds of the Faculty of Computer Science, Electronics and Telecommunications of AGH University. The research was also supported in part by PL-Grid Infrastructure., Peer Reviewed, Postprint (author's final draft)

Today, network operators still lack functional network models able to make accurate predictions of end-to-end Key Performance Indicators (e.g., delay or jitter) at limited cost. Recently a novel Graph Neural Network (GNN) model called RouteNet was proposed as a cost-effective alternative to estimate the per-source/destination pair mean delay and jitter in networks. Thanks to its GNN architecture that operates over graph-structured data, RouteNet revealed an unprecedented ability to learn and model the complex relationships among topology, routing and input traffic in networks. As a result, it was able to make performance predictions with similar accuracy than resource-hungry packet-level simulators even in network scenarios unseen during training. In this demo, we will challenge the generalization capabilities of RouteNet with more complex scenarios, including larger topologies., This work was supported by the Spanish MINECO under contract TEC2017-90034-C2-1-R (ALLIANCE), the Catalan Institution for Research and Advanced Studies (ICREA) and the AGH University of Science and Technology grant, under contract no. 15.11.230.400. The research was also supported in part by PL-Grid Infrastructure., Peer Reviewed, Postprint (author's final draft)

© 2019 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes,creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works, Wireless Network-on-Chip (WNoC) has emerged as a promising alternative to conventional interconnect fabrics at the chip scale. Since WNoCs may imply the close integration of antennas, one of the salient challenges in this scenario is the management of coupling and interferences. This paper, instead of combating coupling, aims to take advantage of close integration to create arrays within a WNoC. The proposed solution is opportunistic as it attempts to exploit the existing infrastructure to build a simple reconfigurable beamforming scheme. Full-wave simulations show that, despite the effects of lossy silicon and nearby antennas, within-package arrays achieve moderate gains and beamwidths below 90°, a figure which is already relevant in the multiprocessor context., Peer Reviewed, Postprint (author's final draft)

Inter-domain routing security is of critical importance to the Internet since it prevents unwanted traffic redirections. The current system is based on a Public Key Infrastructure (PKI), a centralized repository of digital certificates. However, the inherent centralization of such design creates tensions between its participants and hinders its deployment. In addition, some technical drawbacks of PKIs delay widespread adoption. In this paper we present IPchain, a blockchain to store the allocations and delegations of IP addresses. IPchain leverages blockchains' properties to decentralize trust among its participants, with the final goal of providing flexible trust models that adapt better to the ever-changing geopolitical landscape. Moreover, we argue that Proof of Stake is a suitable consensus algorithm for IPchain due to the unique incentive structure of this use-case, and that blockchains offer relevant technical advantages when compared to existing systems, such as simplified management. In order to show its feasibility and suitability, we have implemented and evaluated IPchain's performance and scalability storing around 350k IP prefixes in a 2.5 GB chain., Peer Reviewed, Postprint (published version)

Software-defined metasurfaces are electromagnetically ultra-thin, artificial components thatcan provide engineered and externally controllable functionalities. The control over these functionalities isenabled by the metasurface tunability, which is implemented by embedded electronic circuits that modifylocally the surface resistance and reactance. Integrating controllers within the metasurface able them tointercommunicate and adaptively reconfigure, thus imparting a desired electromagnetic operation, opens thepath towards the creation of an artificially intelligent (AI) fabric where each unit cell can have its own sensing,programmable computing, and actuation facilities. In this work we take a crucial step towards bringing theAI metasurface technology to emerging applications, in particular exploring the wireless mm-wave intercellcommunication capabilities in a software-defined HyperSurface designed for operation in the microwaveregime. We examine three different wireless communication channels within the landscape of the reflectivemetasurface: Firstly, in the layer where the control electronics of the HyperSurface lie, secondly inside adedicated layer enclosed between two metallic plates, and, thirdly, inside the metasurface itself. For each casewe examine the physical implementation of the mm-wave transceiver nodes, we quantify communicationchannel metrics, and we identify complexity vs. performance trade-offs., Peer Reviewed, Postprint (published version)

Today, network operators still lack functional network models able to make accurate predictions of end-to-end Key Performance Indicators (e.g., delay).This thesis introduces the benchmark for computer network modeling using the RouteNet Graph Neural Network as well as a routing creation algorithm.

La seguretat de l'encaminament entre dominis és fonamental per al funcionament d'Internet, ja que impedeix redireccions de trànsit no desitjades. El protocol actualment utilitzat, el Border Gateway Protocol (BGP), té problemes de seguretat. En aquest projecte, provarem i avaluarem IPChain, una solució que usa blockchain proposada per resoldre aquests problemes de seguretat. Avaluarem la viabilitat del projecte per resoldre aquest problema. Per fer-ho hem dissenyat i analitzat un conjunt d'experiments que intenten emular les condicions reals. També trobarem colls d'ampolla i altres problemes que impedeixen que el prototip funcioni de manera eficient., Inter-domain routing security is of critical importance to the Internet since it prevents unwanted traffic redirections. The currently used protocol, the Border Gateway Protocol (BGP), is proven to have security issues. In this project, we will test and evaluate IPChain, a blockchain solution proposed to solve these security issues. In this thesis, we will evaluate the feasibility of the project for solving this issue. To do it we designed and analyzed a set of experiments that try to emulate real-life conditions. We will also find bottlenecks and other issues that prevent the solution from performing in an efficient way.

Aquest TFG consisteix en la implementació de dos optimitzadors de "Routing Matrix" disenyats per a minimitzar la làtencia d'una xarxa mitjançant la Graph Neural Network (GNN) de RouteNet, desenvolupada per un grup de recerca de la FIB., This Final degree project consists in the implementation of two Routing Matrix optimizers designed to minimize the delay in a network by using a new Graph Neural Network (GNN), RouteNet, developed by a FIB's research group.

This paper addresses the use of Deep Reinforcement Learning for automatic routing in Optical Transport Networks at the electrical-layer level. We propose a DRL-based solution that achieves both high performance and fast learning., Peer Reviewed, Postprint (published version)

Desarrollo de una aplicación Multiplataforma en Android e iOS para la Reserva de Salas dentro de un entorno de empresa. La metodología usada será Xamarin Forms que permitirá el desarrollo simultaneo en ambos sistemas., Development of a Multiplatform application in Android and iOS for Room Booking in a company environment. The methodology used will be Xamarin Forms that will allow the simultaneous development in both systems.

Metasurfaces are envisaged to play a key role in next-generation wireless systems due to their powerful control over electromagnetic waves. The last decade has witnessed huge advances in this regard, shifting from static to programmable metasurfaces. The HyperSurface (HSF) paradigm takes one step further by integrating a network of controllers within the device with the aim of adding intelligence, connectivity, and autonomy. However, little is known about the traffic that this network will have to support as the target electromagnetic function or boundary conditions change. In this paper, we lay down the foundations of a methodology to characterize the workload of programmable metasurfaces and then employ it to analyze the case of beam steering HSFs. We observe that traffic is bursty and highly dependent on the position of the target. These results will enable the early-stage evaluation of intra-HSF networks, as well as the estimation of the system performance and cost., This work was supported by the European Union’s Horizon 2020 research and innovation programme-Future Emerging Topics (FETOPEN) under grant agreement No 736876., Peer Reviewed, Postprint (author's final draft)

The specification and enforcement of network-wide policies in a single administrative domain is common in today's networks and considered as already resolved. However, this is not the case for multi-administrative domains, e.g. among different enterprises. In such situation, new problems arise that challenge classical solutions such as PKIs, which suffer from scalability and granularity concerns. In this paper, we present an extension to Group-Based Policy -a widely used network policy languagefor the aforementioned scenario. To do so, we take advantage of a permissioned blockchain implementation (Hyperledger Fabric) to distribute access control policies in a secure and auditable manner, preserving at the same time the independence of each organization. Network administrators specify polices that are rendered into blockchain transactions. A LISP control plane (RFC 6830) allows routers performing the access control to query the blockchain for authorizations. We have implemented an end-to-end experimental prototype and evaluated it in terms of scalability and network latency., This work has been supported by the Spanish MINECO under contract TEC2017-90034-C2-1-R (ALLIANCE) and the Catalan Institution for Research and Advanced Studies (ICREA)., Peer Reviewed, Postprint (published version)

Network modeling is a critical component for building self-driving Software-Defined Networks, particularly to find optimal routing schemes that meet the goals set by administrators. However, existing modeling techniques do not meet the requirements to provide accurate estimations of relevant performance metrics such as delay and jitter. In this paper we propose a novel Graph Neural Network (GNN) model able to understand the complex relationship between topology, routing and input traffic to produce accurate estimates of the per-source/destination pair mean delay and jitter. GNN are tailored to learn and model information structured as graphs and as a result, our model is able to generalize over arbitrary topologies, routing schemes and variable traffic intensity. In the paper we show that our model provides accurate estimates of delay and jitter (worst case R2 = 0.86) when testing against topologies, routing and traffic not seen during training. In addition, we present the potential of the model for network operation by presenting several use-cases that show its effective use in per-source/destination pair delay/jitter routing optimization and its generalization capabilities by reasoning in topologies and routing schemes not seen during training., This work was supported by AGH University of Science and Technology grant, under contract no. 15.11.230.400, the Spanish MINECO under contract TEC2017-90034-C2-1-R (ALLIANCE) and the Catalan Institution for Research and Advanced Studies (ICREA). The research was also supported in part by PL-Grid Infrastructure., Peer Reviewed, Postprint (author's final draft)

Deep reinforcement learning (DRL) has recently revolutionized the resolution of decision-making and automated control problems. In the context of networking, there is a growing trend in the research community to apply DRL algorithms to optimization problems such as routing. However, existing proposals fail to achieve good results, often under-performing traditional routing techniques. We argue that the reason behind this poor performance is that they use straightforward representations of networks. In this paper, we propose a DRL-based solution for routing in optical transport networks (OTNs). Contrary to previous works, we propose a more elaborate representation of the network state that reduces the level of knowledge abstraction required for DRL agents and easily captures the singularities of network topologies. Our evaluation results show that using our novel representation, DRL agents achieve better performance and learn how to route traffic in OTNs significantly faster compared to state-of-the-art representations. Additionally, we reverse engineered the routing strategy learned by our DRL agent, and as a result, we found a routing algorithm that outperforms well-known traditional routing heuristics., Peer Reviewed, Postprint (author's final draft)

Network modeling is a critical component for building self-driving Software-Defined Networks.Traditional modeling solutions,such as simulation,are insufficient as they need a long time to run the simulations.We study how GNN models can help to solve network optimization problems such as routing.

A consensus algorithm is the core of a blockchain, a technology that allows the development of flexible trust relationships in distributed systems. This project aims to design and develop a consensus algorithm for IPchain, a blockchain that will act as a security layer for the inter-domain routin.

This paper presents an efficient approach for exciting a dielectric resonator antenna (DRA) in the terahertz frequencies by means of a graphene plasmonic dipole. Design and analysis are performed in two steps. First, the propagation properties of hybrid plasmonic one-dimensional and two-dimensional structures are obtained by using transfer matrix theory and the finite-element method. The coupling amount between the plasmonic graphene mode and the dielectric wave mode is explored based on different parameters. These results, together with DRA and plasmonic antenna theory, are then used to design a DRA antenna that supports the TEy 112 mode at 2.4 THz and achieves a gain (IEEE) of up to 7 dBi and a radiation efficiency of up 70%. This gain is 6.5 dB higher than that of the graphene dipole alone and achieved with a moderate area overhead, demonstrating the value of the proposed structure., Peer Reviewed, Postprint (published version)

We present IPchain, a blockchain to store the allocations and delegations of IP addresses, with the aim of easing the deployment of secure interdomain routing systems. Interdomain routing security is of vital importance to the Internet since it prevents unwanted traffic redirections. IPchain makes use of blockchains' properties to provide flexible trust models and simplified management when compared to existing systems. In this paper we argue that Proof of Stake is a suitable consensus algorithm for IPchain due to the unique incentive structure of this use-case. We have implemented and evaluated IPchain's performance and scalability storing around 150k IP prefixes in a 1GB chain., Peer Reviewed, Postprint (published version)

Graphene offers a large potential to downscale antennas to the micrometer scale, due to its special dispersion relation and its ability to support plasmons in the THz frequency range. For an adequate performance of the antenna, graphene material quality is crucial. A high chemical potential, as well as a high relaxation time are needed. Fabrication and processing, as well as the material environment are very critical to achieve a high graphene quality and a good emissivity of the antenna. We demonstrate the simulation, fabrication and analysis of a graphene based plasmonic antenna structure acting as an active THz emission device., Peer Reviewed, Postprint (published version)

Wireless Network-on-Chip (WNoC) appears as a promising alternative to conventional interconnect fabrics for chip-scale communications. WNoC takes advantage of an overlaid network composed by a set of millimeter-wave antennas to reduce latency and increase throughput in the communication between cores. Similarly, wireless inter-chip communication has been also proposed to improve the information transfer between processors, memory, and accelerators in multi-chip settings. However, the wireless channel remains largely unknown in both scenarios, especially in the presence of realistic chip packages. This work addresses the issue by accurately modeling flip-chip packages and investigating the propagation both its interior and its surroundings. Through parametric studies, package configurations that minimize path loss are obtained and the trade-offs observed when applying such optimizations are discussed. Single-chip and multi-chip architectures are compared in terms of the path loss exponent, confirming that the amount of bulk silicon found in the pathway between transmitter and receiver is the main determinant of losses., Peer Reviewed, Postprint (author's final draft)

The final publication is available at ACM via http://dx.doi.org/10.1145/3229607.3229613, Recent trends in networking are proposing the use of Machine Learning (ML) techniques for the control and operation of the network. In this context, ML can be used as a computer network modeling technique to build models that estimate the network performance. Indeed, network modeling is a central technique to many networking functions, for instance in the field of optimization, in which the model is used to search a configuration that satisfies the target policy. In this paper, we aim to provide an answer to the following question: Can neural networks accurately model the delay of a computer network as a function of the input traffic? For this, we assume the network as a black-box that has as input a traffic matrix and as output delays. Then we train different neural networks models and evaluate its accuracy under different fundamental network characteristics: topology, size, traffic intensity and routing. With this, we aim to have a better understanding of computer network modeling with neural nets and ultimately provide practical guidelines on how such models need to be trained., Peer Reviewed, Postprint (author's final draft)

Recent trends in networking are proposing the use of Machine Learning (ML) techniques for the control and operation of the network. The application of ML to networking brings several use-cases as well as challenges. The objective of this paper is to explore the feasibility of applying different models and ML techniques to model complex networks elements, such as Virtual Network Functions (VNFs). In particular, we focus on the characterization of the CPU consumption of the VNF as a function of the characteristics of the input traffic. The traffic is represented by a set of features describing characteristics from the transport layer to the application layer in small time batches. The CPU consumption is observed from the hypervisor and corresponds to the average CPU consumption when the traffic batch is processed. We experimentally demonstrate that we can learn the behavior of different VNF in order to model its CPU consumption. We conclude that the behavior of different VNF can be modeled using ML techniques. © 2018 IEEE., Peer Reviewed, Postprint (published version)

Leaving the current 4th generation of mobile communications behind, 5G will represent a disruptive paradigm shift integrating access networks, ultra-high capacity access/metro/core optical networks and intra-datacentre network and computational resources into a single converged 5G network infrastructure. Thanks to an extensive deployment of network virtualization techniques leveraged by Software-Defined Networking (SDN) and Network Function Virtualization (NFV) technologies, such a 5G network infrastructure will have to be capable of inter-connecting anything anywhere and over a set of network services truly meeting their diverse communication requirements. In this paper, we overview the ALLIANCE project research activities. ALLIANCE ambitiously aims at architecting a converged 5G-enabled network infrastructure investigating several networking solutions such as SDN/NFV, OpenOverlayRouter (OOR) and the clean-slate Recursive Inter- Network Architecture (RINA) covering access, metro, core and datacentre segments. ALLIANCE relies on a Knowledge-Defined Networking (KDN) orchestrator which take advantage of state-of-the-art machine learning techniques to deploy, operate, monitor and troubleshoot networks automatically., Peer Reviewed, Postprint (author's final draft)

Persistence Optimization for MAC protocols in Wireless Networks on Chip., Optimización de la persistencia del protocolo MAC para redes inalámbricas en chips., Optimizació de la Persistencia del protocol MAC per a xarxes inalàmbriques dintre d'un chip.

En aquest projecte s'analitza la viabilitat d'utilitzar aprenentatge per reforç i "self- play" per entrenar un agent a jugar Batalles Pokémon. El joc és analitzat en detall i les seves propietats úniques són revelades. El projecte analitza diverses plataformes d'aprenentatge per reforç., In this project we analyze the feasibility of using reinforcement learning and self-play to train an agent playing Pokémon Battles. The game is analyzed in depth and it's unique properties and challenges revealed. The project surveys different reinforcement learning libraries.

© 2018 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes,creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works., Graphene is enabling a plethora of applications in a wide range of fields due to its unique electrical, mechanical, and optical properties. In the realm of wireless communications, graphene shows great promise for the implementation of miniaturized and tunable antennas in the terahertz band. These unique advantages open the door to new reconfigurable antenna structures which, in turn, enable novel communication protocols at different levels of the stack. This paper explores both aspects by, first, presenting a terahertz Yagi-Uda-like antenna concept that achieves reconfiguration both in frequency and beam direction simultaneously. Then, a programmable antenna controller design is proposed to expose the reconfigurability to the PHY and MAC layers, and several examples of its applicability are given. The performance and cost of the proposed scheme is evaluated through full-wave simulations and comparative analysis, demonstrating reconfigurability at nanosecond granularity with overheads below 0.02 mm2and 0.2 mW., Peer Reviewed, Postprint (published version)

© 2018 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes,creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works., Wireless on-chip communication is a promising candidate to address the performance and efficiency issues that arise when scaling current NoC techniques to manycore processors. A WNoC can serve global and broadcast traffic with ultra-low latency even in thousand-core chips, thus acting as a natural complement to conventional and throughput-oriented wireline NoCs. However, the development of MAC strategies needed to efficiently share the wireless medium among the increasing number of cores remains a considerable challenge given the singularities of the environment and the novelty of the research area. In this position article, we present a context analysis describing the physical constraints, performance objectives, and traffic characteristics of the on-chip communication paradigm. We summarize the main differences with respect to traditional wireless scenarios, and then discuss their implications on the design of MAC protocols for manycore WNoC, with the ultimate goal of kickstarting this arguably unexplored research area., Peer Reviewed, Postprint (author's final draft)

En aquest projecte s'escolleix i estableix un sistema software capaç d'assignar adreces IP amb una seguretat acceptable, comprovant quins problemes sorgeixen en la seguretat i quins són evitables partint d'eines actuals que desenvolupen la mateixa tasca. Per realitzar aquest treball utilitzarem IOTA., En este proyecto se escoge y establece un sistema software capaz de asignar direcciones IP con una seguridad aceptable, comprobando qué problemas surgen en la seguridad y cuales son evitables partiendo de las herramientas actuales que desarrollan la misma tarea. Para hacer este trabajo usaremos IOTA.

A dynamic subarray allocation for multi-user massive MIMO systems working in very high frequency bands (mmWave and THz) is proposed as a promising technique to unleash the capacity limits in future cellular networks capable of supporting high consuming bandwidth applications.

El objetivo principal del proyecto es construir un prototipo funcional de blockchain que asegure la información del enrutamiento de Internet con fines de investigación para el análisis de sus beneficios. En este TFG se trata la implementación de las transacciones y la red P2P.

El proyecto pretende eliminar la dependencia de las Autoridades Certificadoras en el uso de los DDT de LISP mediante el uso de una BlockChain., This project pretends to eliminate the dedendency from Certificate Authorities in the use of LISP's DDT using a BlockChain.

Aquest projecte es basa en dissenyar i implementar la funcionalitat de LISP-DDT per a la plataforma OpenOverlayRouter(OOR). OOR és una implementació de codi obert per a crear xarxes de superposició programables, escrita en C i disponible per a Linux, Android i OpenWRT. Amb aquest projecte, incorporarà també LISP-DDT, completant així les funcionalitats de LISP.

© 2018 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes,creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works., Wireless Network-on-Chip (WNoC) appears as a promising alternative to conventional interconnect fabrics for chip-scale communications. The WNoC paradigm has been extensively analyzed from the physical, network and architecture perspectives assuming mmWave band operation. However, there has not been a comprehensive study at this band for realistic chip packages and, thus, the characteristics of such wireless channel remain not fully understood. This work addresses this issue by accurately modeling a flip-chip package and investigating the wave propagation inside it. Through parametric studies, a locally optimal configuration for 60 GHz WNoC is obtained, showing that chip-wide attenuation below 32.6 dB could be achieved with standard processes. Finally, the applicability of the methodology is discussed for higher bands and other integrated environments such as a Software-Defined Metamaterial (SDM)., Peer Reviewed, Postprint (author's final draft)

This document analyzes how blockchain technology can be used to secure the allocation, delegation and binding to topological information of the IP address space. The main outcomes of the analysis are that blockchain is suitable in environments with multiple distrusting parties and that Proof of Stake is a potential candidate for a consensus algorithm., Preprint

The Wireless Network-on-Chip paradigm offers important advantages in the area of many-core processors: boardband communications, reconfigurable network topologies and flexibility. Further information about this paradigm can be found in: http://www.n3cat.upc.edu/papers/Evaluating_the_Feasibility_of_Wireless_Networks-on-Chip_Enabled_by_Graphene.pdf, This project involves a study of neural networks execution on different hardware architectures where they can be processed in, i.e. CPUs, GPUs and specialized AI accelerators. FPGAs are left out from this study. Different tests will be performed on the architectures, demonstrating its capacity, specially in terms of parallelization. The study includes a previous detailed DNN mathematical description to help the understanding of the underlying computation the hardware is performing. Finally, they are also evaluated on the feasibility of incorporating a Wireless Network on Chip (WNoC, intra-processor wireless communication) to the different processors to improve their global performance.

Graphene plasmonic antennas possess two significant features that render them appealing for short-range wireless communications, notably, inherent tunability and miniaturization due to the unique frequency dispersion of graphene and its support for surface plasmon waves in the terahertz band. In this letter, dipole-like antennas using few-layer graphene are proposed to achieve a better trade-off between miniaturization and radiation efficiency than current monolayer graphene antennas. The characteristics of few-layer graphene antennas are evaluated and then compared with those of antennas based on monolayer graphene and graphene stacks, which could also provide such improvements. To this end, first, the propagation properties of one-dimensional and two-dimensional plasmonic waveguides based on the aforementioned graphene structures are obtained by transfer matrix theory and finite-element simulation, respectively. Second, the antennas are investigated as three-dimensional structures using a full-wave solver. Results show that the highest radiation efficiency among the compared designs is achieved with the few-layer graphene, while the highest miniaturization is obtained with the even mode of the graphene stack antenna., Peer Reviewed, Postprint (published version)

Project made in a company that manufactures and designs 3D printers. The purpose of this project is to be able to offer a better experience to the customers of the company so that they can take advantage of all the functionalities of their printers., Projecte realitzat a una empresa que fabrica i dissenya impressores 3D. L'objectiu d'aquest projecte ha estat el de poder oferir una millor experiència als clients de l'empresa per a que puguin aprofitar totes les funcionalitats de les seves impressores.

This document analyzes how blockchain technology can be used to generate random- ness decentralized beacons, in a distributed way, to secure the allocation, delegation and binding to topological information of the IP address space.

La aparición de las tecnologías Blockchain/Distributed Ledger está significando una revolución en los paradigmas de Internet. En el presente proyecto, se ha aplicado HyperLedger Fabric, una tecnología de Distributed Ledger permisionado y privado, en un escenario entre varias empresas., The emergence of Blockchain and Distributed Ledger technologies is leading a revolution of digital paradigms. In this project, we applied HyperLedger Fabric, a permissioned and private Distributed Ledger technology, to a scenario with multiple companies.

Since its discovery in 2004, graphene has been a hot topic in virtually all engineering fields due to its outstanding properties. In wireless communications, this nanomaterial shows great promise for the implementation of smaller, faster and more efficient RF components. In its quest to innovate in wireless communications at all scales, the NaNoNetworking Center in Catalunya (N3Cat) is currently investigating the potential of graphene-based wireless communications., This work treats in depth the possibility and restrictions of making antennas in order to communicate the cores of a massive multicore processor. Since these must be commensurable with the processor, we will perform micrometer antennas that work at frequencies close to the Terahertz, trying not to exceed frequencies where it is impossible to work. With the help of graphene and fractal structures we will achieve smaller antennas at the same frequencies. From simulations of electromagnetic fields we will see how the properties of the fractals are affected by making them with graphene, such as the proportion that can be miniaturized, how they change the multi-band antennas and the restrictions that become the minimum and maximum width of a dipole ., Este trabajo trata en profundidad la posibilidad y restricciones de realizar antenas para comunicar los núcleos de un procesador multicore masivo. Dado que estas deben ser conmensurables los núcleos realizaremos antenas de pocos micrómetros que trabajen en frecuencias cercanas a los Terahertz procurando no sobrepasar frecuencias a las que sea imposible trabajar. Con la ayuda del grafeno y las estructuras fractales conseguiremos antenas más pequeñas a las mismas frecuencias. A partir de simulaciones de campos electromagnéticos veremos cómo se ven afectadas las propiedades de los fractales al hacerlos con grafeno como qué proporción se pueden miniaturizar, como cambian las antenas multibanda y las restricciones que se convierten de la anchura mínima y máxima de un dipolo ., Aquest treball tracta en profunditat la possibilitat i restriccions de realitzar antenes per tal de comunicar els nuclis d'un processador multicore massiu. Donat que aquestes han de ser commensurables als nuclis realitzarem antenes de pocs micròmetres que treballin a freqüències properes als Terahertz procurant no sobrepassar freqüències a les que sigui impossible treballar. Amb l'ajut del grafè i les estructures fractals aconseguirem antenes més petites a les mateixes freqüències. A partir de simulacions de camps electromagnètics veurem com es veuen afectades les propietats dels fractals al fer-los amb grafè com ara quina proporció es poden miniaturitzar, com canvien les antenes multibanda i les restriccions que esdevenen de l'amplada mínima i màxima de un dipol.

Open Overlay Router (OOR) is a tool to build Software defined networks based on Locator/ID Separation Protocol (LISP). There are some other tools to build overlay networks which use in Docker environments is widely extended. Among them, Open Virtual Switch (OVS) stands out. This report aims to describe the work performed in the scope of Docker with OOR.

Aquest document analitza i descriu la implementació d'un algorisme de consens que serà una part fonamental en un prototip de blockchain on el principal objec- tiu és el de assignar, delegar i vincular direccions IP de forma descentralitzada y segura., This document analyzes and describes a consensus algorithm implementation that will be a core part of a blockchain prototype whose main purpose is to allocate, delegate and bind IP addresses in a decentralized and secure way.

© 2018 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes,creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works., Metasurfaces, ultrathin and planar electromagnetic devices with sub-wavelength unit cells, have recently attracted enormous attention for their powerful control over electromagnetic waves, from microwave to visible range. With tunability added to the unit cells, the programmable metasurfaces enable us to benefit from multiple unique functionalities controlled by external stimuli. In this review paper, we will discuss the recent progress in the field of programmable metasurfaces and elaborate on different approaches to realize them, with the tunability from global aspects, to local aspects, and to software-defined metasurfaces., Peer Reviewed, Postprint (author's final draft)